20131016 Ver 1_Mitigation Plans_20131015

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�Sr�rc�oF PTI' •
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
151 PATTON AVENUE
ROOM 208
ASHEVILLE, NORTH CAROLINA 28801 -5006
October 2, 2013
Regulatory Division
Action ID. 2011 -01724
Mr. Jarrod Karl
Mitigation Administrator
City of Charlotte
Storm Water Services
600 East Fourth Street
Charlotte, NC 28202
Dear Mr. Karl:
13-106
OCi 1 5 2013 I
Please reference the Site Specific Mitigation Plan for the Monteith Park Watershed
Restoration Project dated July 11, 2012, a subsequent addendum dated August 1, 2013 and final
plans dated August 30, 2013. This plan proposes the restoration and enhancement of
approximately 4,015 linear feet of stream channels, restoration of 0.94 acres of wetlands, and
0.10 acres of wetland preservation to be included in the City of Charlotte's Umbrella Stream and
Wetland Mitigation Bank (Bank). This plan will generate approximately 6,948 stream mitigation
units (SMUs) and 0.96 wetland mitigation units (WMUs). The proposed plans and credit ratios
have been reviewed and approved as proposed for inclusion into the Bank. We have determined
that the proposed plan and credit releases are in accordance with guidelines set forth in the
Mitigation Banking Instrument (MBI) entitled, "Agreement to Establish the City of Charlotte,
Umbrella Stream and Wetland Mitigation Bank in Mecklenburg County ", the Interagency
Stream Mitigation Guidelines (April 2003) and the recently published federal rule entitled
Compensatory Mitigation for Losses of Aquatic Resources (33 CFR Part 332). Also, these
submittals included real estate reports for the project as required by the MBI. The report and
associated maps is acceptable and completes the requirements of the MBI to allow the initial
release of 15% of total anticipated credits (1, 1042.20 SMUs and 0.14 WMUs). If you have any
questions, please contact me at (828) 271 -7980 extension 231.
Sincerely,
FUEMMELER.
AMANDA.JO
NES.1242835
090
Digitally signed by
FUEMMELER.AMANDAJON ES.
1242835090
DN: c =US, o =U.S. Government,
ou =DOD, ou =PKI, ou =USA,
cn =FU EMM ELERAMANDAJO
NES.1242835090
Date: 2013.10.03 16:03:53
_1,00,

Amanda Fuemmeler
Project Manager
Asheville Regulatory
Field Office
Copies Furnished-
Mr Eric Kulz
NC Division of Water Quality
401 Oversight/Express Permitting
and Transportation Permitting Units
5'12 North'Salisbury Street
Raleigh, NC 27604
Mr Alan Johnson
North Carolina Dept of Environment & Natural Resources
Division of Water Quality
610 E. Center Ave, Suite 301
Mooresville, NC 28115
Mr Todd Bowers
Wetlands and Marine Regulatory Section
Water Protection Div - Region IV
U S Environmental Protection Agency,
61 Forsyth Street, SW
Atlanta, Georgia 30303
Mr Bryan Tompkins
U S Fish & Wildlife Service
160 Zillicoa Street
Asheville, North Carolina 28801
Ms Shari Bryant
N C Wildlife Resources Commission
P O Box 129
Sedalia, NC 27342 -0129

�3 - �W 4
Cardno
ENTRIX
Shaping the Future

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Document In
Prepared for
Project Name
Project Number
Project Manager
Date
formation
Charlotte - Mecklenberg Storm Water Services
Monteith Park Mitigation Site
03097001 00
Adam McIntyre
July 2013
Prepared for
Charlotte - Mecklenberg Storm Water Services
! 600 East Fourth Street, 14th Floor, Charlotte, NC, 28202
Prepared by
�� Cardnom
ENTR /X
Shaping the Future
Cardno ENTRIX
5400 Glenwood Ave, Suite G03, Raleigh, NC 27612
I

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table of Contents
1 Site Identification and Location ............... ............................... .. .. ..................... . 1-1
1 1
Project Description
1 -1
1 2
Project Goals
1 -1
1 3
Mitigation Credit Establishment and Mitigation Site Operation
1 -2
1 31 Mitigation Description By Type
1 -2
1 3 2 Mitigation Credit Summary
1 -3
14
USGS Hydrologic Unit Code and NCDWQ River Basin Designation
1 -4
1 5
Directions to Project Site
1 -4
i 2 Watershed Characterization ................................ ............................... .....................2
-6
21
McDowell Creek Watershed
2 -6
22
Physiography, Geology, and Soils
2 -8
23
Historic Land Use and Development Trends in Monteith Watershed
2 -11
24
Surface Water Classification/Water Quality
2 -11
25
Drainage Areas
2 -11
I 26
Jurisdictional Wetlands
2 -15
2 6 1 NC Wetland Assessment Method Results
2 -15
27
Climate Conditions
2 -16
' 28
Threatened and Endangered Species
2 -16
{ 29
Cultural /Historic Resources
2 -16
210
Potential Constraints
2 -17
2101 Utility Easements
2 -17
2 10 2 Property Ownership and Site Access
2 -17
3 Project Site Existing Conditions ...... ............................... .. ...............................
.3 -1
! 3 1
Existing Channel Geomorphic Characterization
3 -1
31 1 Cross Sectional and Longitudinal Profiles
3 -1
_
3 1 2 Parent Material & Soil Types
3 -1
31 3 Bed and Bank Material Properties
3 -1
3 1 4 Vegetation Type and Density
3 -1
_ 32
Topographic Survey
3 -1
33
Reach Designation and Channel Characterization
3 -1
3 3 1 Reach 1
3 -2
3 3 2 Reach 2
3 -2
3 3 3 Reach 3
3 -3
3 3 4 Reach 4
3 -3
3 3 5 Reach 5
3 -3
34
Bankfull Characterization
3 -7
35
Bed Material
3 -1
36
Bank Material (Soils)
3 -1
' 37
Bank Vegetation
3 -2
38
Existing Riparian Vegetation Characterization
3 -3
July 2013 Cardno ENTRIX

Site Specific Mitigation Plan
Monteith Park Mitigation Site
July 2013 Cardno ENTRIX
39 Benthic Macroinvertebrates
3 -4
3 10 Existing Conditions for Storm Water Facilities
3 -4
-
3 11 Summary of Existing Conditions
3 -4
4
Watershed Hydrograph (Storm Water) Restoration Plan
.......... ............................... 4 -6
5
.................. .......................... ...............................
Stream Restoration Plan ... ... 5 -1
51 Overview of Applied Restoration Approach
5 -1
52 Hydrologic Modeling
5 -2
5 2 2 Soil Moisture Accounting
5 -3
5 2 3 Hydrograph Generation (Transform)
5 -4
524 Reach Routing
5 -7
5 2 5 Precipitation
5 -7
5 2 6 Evapotranspiration and Canopy Loss
5 -11
53 Analytical Assessment
5 -11
5 3 2 Most Effective Discharge
5 -13
54 Geomorphology
5 -16
5 4 1 Active Channel Width
5 -16
542 Planform Dimensions
5 -18
55 River Mechanics
5 -19
55 1 Channel Geometry & Longitudinal Slope
5 -19
5 5 2 Final Stream Design Parameters
5 -20
5 5 3 Grade Control & Drop -Pool Structures
5 -22
'
56 Summary of Design
5 -24
6
Wetland Restoration Plan .............................. .............................................................. 6-1
7
Stream Buffer and Vegetation Restoration Plan.. .... . .................... 7 -1
t
71 Stream Buffer Vegetation
7 -1
8
Performance Criteria and Monitoring ......................... ..
.................... .. .. ..........8 -1
1 i
82 Stream Channel Stability
8 -2
8 2 1 Bankfull Events
8 -3
822 Cross Sections
8 -3
I
8 2 3 Longitudinal Profile
8 -3
824 Bed Material Analysis
8 -3
8 2 5 Photo Reference Sites
8 -4
83 Stream Water Quality and Macroinvertebrates
8 -4
84 Buffer and Wetland Vegetation Monitoring
8 -4
85 Wetland Hydrology Monitoring
8 -4
86 Visual Monitoring
8 -5
87 Storm Water BMP Monitoring
8 -5
88 Schedule and Reporting
8 -5
i
9
Environmental Education ......... .... .......................... ......................... .................9 -1
10
References .............. ............... ............................... ........................ ... . ............... 10-1
July 2013 Cardno ENTRIX

Site Specific Mitigation Plan
Monteith Paris Mitigation Site
Appendices
Vicinity Map and Directions to the Monteith Park Mitigation Site
Appendix A
Nutter and Associates Sod Evaluation
McDowell Creek Watershed and Monteith Creek
Appendix B
Historical Aerial Photographs
Monteith Creek Soils
Appendix C
Endangered Species Descriptions
Existing conditions for Monteith Creek
_ Appendix D
Stream Photos
Historical Catchment Locations
Appendix E
Existing Conditions Cross Sections
Current Monteith Creek Catchments
Appendix F
60% Design Plans
Conservation and Access Easements
Appendix G
BMP Calculations
i�
Appendix H
Vegetation Planting Plan
_ Appendix I
,s
Title Ownership Documents and Easments
Tables
Table 1 -1
Credit Calculations for Monteith Park Mitigation Site
1 -3
Table 2 -1
Summary of Soil Characteristics
2 -9
I ` Table 2 -2
Impervious surface calculations by Monteith Creek Catchment
2 -15
Table 2 -3
Federally Listed Species under the ESA within Mecklenburg County
2 -16
i Table 2 -4
Summary of Easements
2 -19
j Table 3 -1
Summary of Existing Channel Conditions
3 -8
' Table 3 -2
Critical Shear Stress Values for Consolidated Bank Material
3 -2
Table 4 -1
Summary of BMP Design
4 -1
Table 5 -1
Summary of Soil Moisture Accounting Parameters
5 -2
Table 5 -2
SCS Unit Hydrograph Time of Concentration Results for Undeveloped Conditions
5 -5
Table 5 -3
SCS Unit Hydrograph Time of Concentration Results for Future Conditions
5 -6
Table 5 -4
Muskingum -Cunge Reach Routing Parameters
5 -7
i Table 5 -5
Evapotranspiration Data
5 -11
Table 5 -6
Summary of Geomorphically Significant Flows for Design of the Active Channel
5 -16
Table 5 -7
Summary of Resulting Geomorphically Stable Channel Dimensions
5 -21
Table 5 -8
Summary of Estimate Drop -Pool Dimensions for Reaches Where These Features
Will be Applied
5 -23
Table 7 -1
Proposed Riparian and Wetland Vegetation
7 -3
Table 7 -2
Proposed Floodplain Buffer Vegetation for Reaches 1 and 2
7 -4
Table 7 -3
S
Proposed Permanent Herbacaous Seed Mixture
7 -4
i
Table 8 -1
Monitoring Schedule
8 -2
Figures
Figure 1 -1
Vicinity Map and Directions to the Monteith Park Mitigation Site
1 -5
Figure 2 -1
McDowell Creek Watershed and Monteith Creek
2 -7
Figure 2 -2
Monteith Creek Soils
2 -10
Figure 2 -3
Existing conditions for Monteith Creek
2 -12
Figure 2 -4
Historical Catchment Locations
2 -13
Figure 2 -5
Current Monteith Creek Catchments
2 -14
Figure 2 -6
Conservation and Access Easements
2 -18
July 2013 Cardno ENTRIX

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Figure 3 -1
Existing longitudinal profile of Monteith Creek
3 -5
' Figure 3 -2
Monteith Creek Reach Designations
3 -6
Figure 3 -3
Grain size distribution for Monteith Creek
3 -1
J Figure 4 -2
Mitigation Design Layout for Lower Reach of Monteith Creek
4 -3
Figure 5 -1
Illustration of the Rainfall -Runoff Hydrologic Module
5 -3
Figure 5 -2
Comparison of Annual Precipitation Volumes between Charlotte - Douglas (311690)
and Mooresville (315814)
5 -8
Figure 5 -3
Comparison of Precipitation Intensity Charlotte - Douglas (311690) and Mooresville
(315814)
5 -9
' Figure 5 -4
Comparison of Seasonal Precipitation Volumes Charlotte - Douglas (311690)
and Mooresville (315814)
5 -10
Figure 5 -5
Comparison of Peak Discharges at the Downstream Location of Monteith
5 -12
Figure 5 -6
Comparison of Pre- and Post - Development Distributions of Work Done
5 -15
Figure 5 -7
Predicted Bankfull Channel Widths from Hydraulic Geometry
5 -17
Figure 5 -8
Meander Pattern and Associated Variables of Interest
5 -18
Figure 5 -9
Example Design Cross Section for Reach 5
5 -19
Figure 5 -10
Chart of Pre and Post Development Work Done
5 -20
Figure 7 -1
Vegetation Zones for cross section of Monteith Creek
7 -2
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July 2013 Cardno ENTRIX v

Site Specific Mitigation Plan
Monteith Park Mitigation Site
1 Site Identification and Location
1.1 Project Description
Charlotte - Mecklenberg Storm Water Services (CMSWS) has teamed with Cardno ENTRIX to Implement
watershed restoration practices in an upper portion of the McDowell Creek (Torrence Creek) watershed
that has been highly Impacted by urbanization and agricultural land uses The Monteith Park Mitigation
Site (hereinafter referred to as MPMS) represents a unique opportunity to reestablish predevelopment
hydrologic conditions with the restoration of a first to second order stream, reestablish a native hardwood
+ buffer, restore /enhance a bottomland hardwood wetland community, and implement multiple Best
Management Practice's (BMP's) The proposed project will Include the restoration of approximately 3485
linear feet of a first to second order stream (hereinafter referred to as Monteith Creek) and enhance an
additional 530 feet of first order tributaries to Monteith Creek in Huntersville, North Carolina The
proposed project will also include the restoration of 0 94 acres of riparian wetland and the preservation of
an additional 0 10 acre of wetland In addition to the restoration of the Monteith Creek stream system and
associated wetlands, the proposed project will establish storm water quality and quantity detention
facilities to attenuate the storm event at five storm water outfalls for the Monteith Park residential
community This combination of natural stream /wetland restoration techniques coupled with stormwater
BMPs provides a rare opportunity to holistically Improve an ecosystem through a watershed based
approach And finally, Cardno ENTRIX along with CMSWS will take advantage of working so closely with
the residents of Monteith Park by offering public education workshops along the various stages of design,
construction, and monitoring so as to promote the industry and public awareness of ecosystem health
1.2 Project Goals
The Monteith Creek watershed has been Impacted historically by agricultural practices (cattle and farming
operations over the past century) and more recently by residential development within the last 15 years
As urban growth from the City of Charlotte spread north along the 1 -77 corridor, the historically rural and
agricultural community of Huntersville became a prime target for development and growth Monteith
Creek shows the classic signs of habitat degradation associated with the transition of a watershed from
an agricultural community to an urban development through hydromodification, severe channel incision,
and a loss of wetland habitat Our goal Is to reestablish long -term stability by rebalancing the watershed's
geomorphic and hydrologic processes with a two- pronged approach Through the restoration of the
Monteith Creek stream system and associated wetlands, the design will recondition the site to create
natural geomorphic processes leading to enhanced habitat quality and greater riparian function
Complementing the restoration effort, the design will incorporate BMPs to minimize the hydrologic effects
of urbanization This goal of long term stability will be achieved through the following objectives
• Size the active channel based on the anticipated urban hydrology and limited watershed sediment
yields
• Reestablish floodplain connectivity of the currently incised channel
• Rebalance imposed shear forces and sediment transport capacity with supply
• Reestablish dense native riparian vegetation
• Use current biotechnical engineering techniques where applicable
• Incorporate habitat features such as woody material, pools and backwaters to provide wildlife (fauna)
with shelter and food sources
• Construct storm water BMPs to manage runoff from residential areas and restore watershed hydrology
to natural conditions
> Maintain flood control
July 2013 Cardno ENTRIX 1 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
> Create an accessible public amenity while maintaining public safety and providing environmental
education opportunities
1.3 Mitigation Credit Establishment and Mitigation Site Operation
The proposed mitigation site will become a part of the existing Charlotte Umbrella Stream and Wetland
Mitigation Bank currently owned and operated by the City of Charlotte This existing umbrella mitigation
bank has been in operation since 2004 with the goal of providing restoration projects within the multiple
! watersheds that encompass Charlotte and Mecklenburg County The McDowell Creek watershed has
seen significant impacts to streams and wetlands due in large part to the development throughout
Mecklenburg County Watershed modifications associated with these changes include increasing
impervious surface, decreasing natural buffers, and concentrating flow through pipes prior to entering
stream channels which lead to significant degradation to stream networks through bank erosion and
habitat loss McDowell Creek is listed on the 303d list for sedimentation in large part because of the
urban development within the watershed (NCDWQ, 2011a)
The MPMS has been a target of the City of Charlotte umbrella bank for well over five years The Monteith
Creek watershed, a subwatershed of McDowell Creek, has undergone mayor development in recent years
leading to MPMS being identified as one of the preeminent candidates for restoration The contributing
factors for MPMS's selection are the same as those identified in the larger McDowell Creek watershed
increased impervious area, reduction of natural buffers, and introduction of storm drainage in the upper
portion of the watershed These contributing factors have created a degraded stream system visible
through the presence of eroded banks, head cuts, channel straightening and loss of wetlands
Restoration of this system offers a valuable opportunity to minimize the effects of development activities
in an upper portion of the McDowell Creek watershed providing a greater overall benefit to the system
downstream
As Important as the restoration of an urban ecosystem such as Monteith Creek, its' tributaries, and the
associated wetlands is, a significant benefit to this project is the rare opportunity to restore watershed
hydrology through the Implementation of storm water BMP's The Introduction of the storm water BMP's
allow for the attenuation of high energy, unnatural, peak flows from smaller storm events created by
watershed development The storm water BMP's redistribute the amount and rate of water being
Introduced Into the stream system in a manner resembling natural runoff This attenuation and
redistribution promote a healthier stream system by mimicking natural flows creating sustainable banks,
pool development, and natural habitat Therefore the Introduction of BMPs into an urban concept stream
restoration Is Integral In the success of the project
1.3.1 Mitigation Description By Type
North Carolina regulations for stream mitigation credit allowances follow guidance provided in the North
Carolina Stream Mitigation Guidelines (USAGE et al 2003) For stream restoration, a 1 1 credit ratio Is
allowed (generally corresponding with Priority 1 and 2 restoration Involving replacement of stream pattern,
dimension, and profile to historic or modified floodplain elevations) Ratios for stream enhancement vary
from 1 1 to 5 1 depending on activities undertaken for functional uplift Stream preservation ratios are
typically equal to or greater than 5 1 Monteith Creek will be restored for the full extent and to historical
location and conditions (1 1 credit ratio) Two Unnamed Tributaries (UT) to Monteith Creek will maintain
dimension, pattern, and profile but will receive buffer planting and some general earthwork improvements
within the floodplain to allow for a natural transition to Monteith Creek and floodplain access (3 1 credit
ratio)
North Carolina regulations for wetland mitigation (15A NCAC 02H3 0506 h (4)) define wetland restoration
as "the reestablishment of wetland hydrology and vegetation In an area where it previously existed"
Enhancement Is defined as "increasing one or more of the functions of an existing wetland by
manipulation of vegetation or hydrology" Therefore, to obtain restoration credit, a mitigation provider
July 2013 Cardno ENTRIX 1 -2

Site Specific Mitigation Plan
Monteith Park Mitigation Site
must show restoration of two primary wetland parameters (hydrology and vegetation) Restoration areas
within the MPMS Bank Site will be associated with the reestablishment of characteristic wetland
hydrology and vegetation per NCWAM wetland type as well as Improvements to existing soil conditions
(described later in this document) Enhancement areas within the MPMS Bank Site will be associated
with the reestablishment of characteristic vegetation per NCWAM wetland type (described later in this
document)
North Carolina does not currently have regulations defining and /or creating a "storm water credit"
Through collaboration with Charlotte - Mecklenburg Storm Water Services, the IRT has approved a
process to generate additional stream restoration credits where storm water BMP's treat incoming water
from the impacted watershed This method (referred to In this document as the Charlotte Storm Water
Credit method [CSC]) has been approved for use on a case -by -case basis by the IRT on projects within
the City of Charlotte umbrella bank The City of Charlotte and IRT members met In October 2011 to
approve the use of this method for MPMS and specifically to approve additional stream credits A follow
up with the City of Charlotte, Cardno ENTRIX and IRT members was held on July 15` to confirm the
project and resulting credit Based on this meeting and the approved use of CSC, the IRT agreed MPMS
would be able to generate additional stream credits All wetland, stream, and "storm water" credits are
depicted In Table 1 -1 below
1 3 2 Mitigation Credit Summary
The potential number of credits derived from the MPMS bank site is based on the relative condition of on-
site habitats, I e , their historic and current jurisdictional status An estimate of potential stream
restoration and enhancement credits was based on multiple variables Including the presence of the
existing stream, use of historical aerial photography, field Indicators, and the design of a stream
ecosystem to function within the current watershed An estimate of potential wetland restoration and
enhancement was based on Integrating multiple variables soil characteristics, depth, distribution, and
relationship of the effective drainage depth of Monteith Creek, current vegetation, and typical DRAINMOD
simulation results for this soil type Wetland restoration /enhancement areas were identified, mapped, and
defined by Nutter and Associates Areas effectively drained below wetland jurisdictional limits by the
deepened Monteith Creek were classified as "restoration" while areas where wetland hydrologic
conditions were predicted to be "outside the influence" of Monteith Creek were classified as
"enhancement" (Appendix A) As mentioned above, this project Is the Inaugural step In credit
determination for the Inclusion of storm water BMPs in the Charlotte Mecklenburg area Therefore
meetings were held with the IRT to approve the use of CSC In which It was determined storm water
credits would in effect double the stream credits Credit types Include warm water stream, "storm water ",
and riparian riverine wetland and are tallied In Table 1 -1 below
Table 1 -1 Credit Calculations for Monteith Park Mitigation Site
Credit Type
Warm Water
"Storm water"
Estimate Stream
Riparian Riverme
Stream
Credit Total
Wetland Total
3485 LF
0 94 acres
Restoration
3564 SMUs"
6861 SMUs
3297 SMUs
0 94 WMUs
530 LF
Enhancement
N/A
177 SMUs
N/A
177 SMUs
0 1 acre
Preservation
N/A
N/A
N/A
0 02 WMU
Total Credits
7038 SMUs
0 96 WMUs
July 2013 Cardno ENTRIX 1 -3

r ,
Site Specific Mitigation Plan
Monteith Park Mitigation Site
1.4 USGS Hydrologic Unit Code and NCDWQ River Basin Designation
The Monteith Park Mitigation Site is an upper watershed within the McDowell Creek watershed, which
drains to the Catawba River along the northern end of Mountain Island Lake This portion of the Catawba
River is located in USGS Hydrologic Unit 0305010114 and NCDWQ subbasin 03 -08 -33
1.5 Directions to Project Site
The Monteith Park Mitigation Site is located in Huntersville, NC, north of Stumptown Road and east of
Highway 21 (Statesville Road) The site is located near the south end of Lake Norman in Mecklenburg
County (Figure 1 -1) and can be accessed by using the following directions
• Interstate 77 North from Charlotte, NC
• Take Exit 23 for Gilead Road
• Turn right on Gilead Road
• Take the first left onto Highway 21 (Statesville Road)
• Turn right onto Bankside Drive
• Project site is on the left
July 2013 Cardno ENTRIX 1-4

Site Specific Mitigation Plan
Monteith Park Mitigation Site
CNmo (errj Inc.
tin -9.S Triles hlontehh hlitiq .fial Project am. GI<n unoe a,., sat. cos p'(f19)2)9 -E900
0 0.1250.25 0.5 Niles hlecklenhmg County. North Cmoliva FaIvgh,NC2TC12 rr� "'�' "` °"
Figure 1 -1 Vicinity Map and Directions to the Monteith Park Mitigation Site
July 2013 Cardno ENTRIX 1 -5

Site Specific Mitigation Plan
Monteith Park Mitigation Site
2 Watershed Characterization
2.1 McDowell Creek Watershed
Monteith Creek is a first to second order tributary to an upper tributary of Torrence Creek (hereinafter
referred to as Torrence Tributary #1) in the headwaters of the McDowell Creek watershed McDowell
Creek is part of the Catawba River watershed and drains into Mountain Island Lake which is the primary
drinking water reservoir for Charlotte- Mecklenburg According to a recent Charlotte - Mecklenburg Storm
Water Services report (CMSWS 2008), the McDowell Creek watershed has seen significant growth in
population and change in land use from agriculture to residential development over the past decade
McDowell Creek is listed on the 2010 303(d) list for receiving poor bioclassiflcation scores for fish and
macroinvertebrates (NCDENR 2011 a) Land use changes, excessive storm water Inputs, and physical
changes to McDowell Creek and other surface waters in the watershed have caused degradation in water
quality through excess sedimentation When watersheds are converted from natural to agricultural and /or
urban landscapes, the ability of the watershed to retain rainfall is significantly reduced Therefore more
water is conveyed directly and Immediately to receiving streams via drainage Infrastructure An
imbalance is created from Increasing the amount and Intensity of runoff, which can Intensify erosion and
increase the stream's carrying capacity for sediment Channel straightening, significant channel incision
and excessive sedimentation from storm water runoff are evident throughout the entire McDowell Creek
watershed CMSWS has outlined a watershed plan (2008) highlighting current efforts to improve water
quality through stream and wetland restoration and storm water Improvements CMSWS has prioritized
parcels and streams for restoration in which Monteith Creek and Torrence Creek Tributary #1 are
included In addition, adjacent land located in the headwaters of Torrence Tributary #1 has received a
high priority ranking for improving water quality Because of the position of Monteith Creek in the upper
headwaters of the McDowell Creek system (Figure 2 -1), restoration of the Monteith Creek watershed can
produce significant Improvements in downstream water quality
July 2013 Cardno ENTRIX 2 -6

G�
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McDowell Creek }
watershed
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Site Specific Mitigation Plan
Monteith Park Mitigation Site
onneliiis E
e
�� 4 try /uPR $I
Hazard• Alle
S J •` <
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Elevation (ft) t ! 1
High 816
Low 643
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McDowell Creek Watershed and Monteith Creek
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*n . nro +•ser a we .rr ee
r w.
rw r w•r e•a• r•• +w•
+rx ■u�nrrw•rau Wmraar.•m
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rp Nl, r avow •mow Wa•1 aar r,r•M
� • .r -ra •.•rr•r .�wa ea:wr a...
Monteith Mitigation Project
Mecklenburg County, North Carolina
Figure 2 -1 McDowell Creek Watershed and Monteith Creek
July 2013 Cardno ENTRIX 2 -7

Site Specific Mitigation Plan
Monteith Park Mitigation Site
2.2 Physiography, Geology, and Soils
Monteith Creek Iles within the Piedmont physiographic region in northern Mecklenburg County, North
Carolina The Piedmont region consists of gently rolling hills that lie between the flat lands of the Inner
Coastal Plain region to the east and the Blue Ridge region to the west Piedmont physiography is
characterized by moderately hilly terrain with interstream divides intermixed with steeper slopes along
well - defined drainage ways The surface and bedrock materials consist primarily of granite, gneiss, mica
gneiss and mica schist Low to moderate gradient streams with mostly cobble, gravel and sandy
substrates are located in this region
Elevations at the Monteith Park mitigation site range from 722 feet to 778 feet within the boundaries of the
project area Physiographic characteristics are consistent with the features of the Piedmont region with
rolling hills of moderate relief
Soil evaluations were done by Nutter and Associates using the NRCS Web Soil Survey Soils in the
Monteith Creek watershed predominately consist of Cecil sandy clay foams (CeB, CeD) and Mecklenburg
fine sandy loams (MeB, MeD), with Enon sandy loam (EnB, EnD) and Monacan loam secondary (MO)
(Table 2 -1) Soils are well drained with a depth to water table and restrictive layer of more than 80
inches The soils in the upland areas surrounding Monteith Creek predominately consist of Mecklenburg
fine sandy loam (MeD) on slopes of 8 to 15 percent (Figure 2 -2) Mecklenburg fine sandy loam is a well -
drained soil type with a depth to water table and restrictive layer of more than 80 inches Mecklenburg
fine sandy loam soils have a hydrologic group classification of C
The soils on relatively flat slopes along the floodplain to Torrence Creek Tributary #1 are Monacan loam
(MO) Monacan foams are classified as having hydric Inclusions and typically occupy floodplains
Monacan loams are somewhat poorly drained with a depth to water table of 6 to 24 inches and a depth to
restrictive feature of more than 80 inches Monacan loams have a hydrologic group classification of C
Monacan loam soils are found in the floodplains adjacent to streams (NRCS, 1980) and thus likely to be
found extending up the channel bed of Monteith Creek However these were not mapped as they do not
appear on NRCS soils surveys at the scale and resolution of those surveys An on -site soil survey for
wetland restoration potential in areas with Monacan loams in the floodplain of the lower portion of
Monteith Creek was conducted by licensed soil scientists from Nutter and Associates, Inc The Nutter
and Associates report is provided in Appendix A
July 2013 Cardno ENTRIX 2 -8

Site Specific Mitigation Plan
Monteith Park Mdioation Site
Table 2 -1 Summary of Soil Characteristics
July 2013 Cardno ENTRIX 2 -9
Saturated
Hydro Sod
Water
Depth
Hydraulic
Classification
Content
Conductivity
(inches)
(in/hr)
(in /in)
CeB2 —Cecil sandy clay loam, 2
80
0 60 to 2 0
B
0 13 to 0 15
to 8 percent slopes, eroded
CeD2- -Cecil sandy clay loam, 8
80
0 60 to 2 0
B
0 13 to 0 15
to 15 percent slopes, eroded
MeB— Mecklenburg fine sandy
80
0 06 to 0 60
C
0 12 to 0 20
loam, 2 to 8 percent slopes
MeD— Mecklenburg fine sandy
80
0 06 to 0 60
C
0 12 to 0 20
loam, 8 to 15 percent slopes
EnB —Enon sandy loam, 2 to 8
80
0 06 to 0 60
C
0 12 to 0 18
percent slopes
EnD —Enon sandy loam, 8 to 15
80
0 06 to 0 60
C
0 12 to 0 18
percent slopes
MO— Monacan loam
80
0 60 to 2 0
B
0 14 to 0 20
July 2013 Cardno ENTRIX 2 -9

Site Specific Mitigation Plan
Monteith Park Mitigation Site
1 inch - 400 fed Winrueith 6litigation 1310ject cvw 1NC 110< ph [phone]
rvieckl ellil1111 Comity. NOIti1 f 110Illl.l 5N0GImW000 A." Snt<G49 tz(9I9)m4gIS
0 100 200 400 red ) t Raeign,uC:7stz
Figure 2 -2 Monteith Creek Soils
July 2013 Cardno ENTRIX 2 -10

Site Specific Mitigation Plan
Monteith Park Mitigation Site
2.3 Historic Land Use and Development Trends in Monteith Watershed
A historical aerial review from 1949 to the present (Appendix B) was used to assess landscape changes
in the Monteith Creek watershed Prior to the development of the Monteith Park community, the land was
utilized for cattle pasture and agriculture In the 1949 aerial, there was a substantial forested buffer that
surrounded Monteith Creek as well as the Torrence Creek Tributary #1 By 1965, most of the forested
buffer around Torrence Creek Tributary #1 and Monteith Creek had been removed A pond was
constructed on the upstream portion of Monteith Creek sometime between 1949 and 1965 The pond
was drained between 1999 and 2002 By 1993, low density residential neighborhoods had been
developed near the Monteith Creek watershed but the land within the watershed continued to be used for
agriculture In 2002, the Monteith Creek watershed remained dominated by agriculture but the
surrounding area contained low density residential development Construction began in 2002 for the
Monteith Park Community, a medium to high density residential development within the Monteith Creek
watershed In addition to the development, the watershed contains open space parks and unmaintained
herbaceous fields Development of Monteith Park is in the final stages with no plans to build additional
houses within the Monteith Creek watershed There are however, plans to build a school in the southern
portion of the watershed
2.4 Surface Water Class ification/Water Quality
Torrence Creek and McDowell Creek are classified as a Class WS -IV Class WS -IV denotes water supply
waters and water quality standards associated with Class C waters while incorporating more stringent
standards for water supply waters The project is located outside (upstream) of the water supply
watershed protection area, so the water quality classification at the proposed project location is likely C
McDowell Creek is listed on the 2010 303(d) list for receiving poor bioclassification scores for fish and
macroinvertebrates (NCDENR 2010) It is believed that habitat loss due to stream bank erosion and
excess sedimentation throughout the watershed are the primary stressors to the McDowell Creek
watershed (CMSWS 2010) which are also evident in Monteith Creek
2.5 Drainage Areas
The evolution of the land use within the Monteith Creek watershed from a historically forested watershed
to one consisting of predominately agricultural land and to the present day medium to high density
residential community have significantly altered the watershed characteristics Hydrology plays a critical
role in influencing the physical characteristics and ecological health of stream ecosystems Stream flow
magnitude, frequency, duration, and timing are mayor driving forces that control the physical and
j ecological conditions of stream corridors Figure 2 -3 shows the current development in the Monteith
fl i Creek watershed and illustrates the present configuration of Monteith Creek, its two tributaries, and the
locations of storm water outfalls Monteith Creek currently drains an area of 129 8 acres Figure 2 -4
illustrates the watershed delineation over natural topography, dividing the watershed into 12 catchment
I areas based on reach designation by slope and encompassing an historic area of 112 4 acres However,
due to development, the size and landscape of these catchments areas has been altered to their present
layout (Figure 2 -5) This development has altered the storm drainage network and severely altered the
flows and drainage patterns of the watershed Table 2 -2 shows total area of the catchments and total
` impervious area of the developed watershed Currently, the total impervious surface area within the
Monteith Creek watershed is approximately 41 percent Four catchment areas had little to no impervious
surface area while the other eight catchment areas contain dense residential development and
impervious areas ranging from 8 to 73 percent
July 2013 Cardno ENTRIX 2 -11

Site Specific Mitigation Plan
Monteith Park Mitigation Site
M %,
Figure 2-3 Existing conditions for Monteith Creek
July 2013 Cardno ENTRIX 2-12
Existing Conditions
Monteith Mitigation Project
Mecklenburg County, North Carolina
EArrJ:UX
Figure 2-3 Existing conditions for Monteith Creek
July 2013 Cardno ENTRIX 2-12

TGfME
ARFJ1. 4
d 1 Jtk
}
AREA.12 eAC �
01 +
f
0ACCT c� 9 J +
�
J
Site Specific Mitigation Plan
Monteith Park Mitigation Site
0
e
dUj
J
AREA, -103AC ��\ la CATCHMENT_ { 3 1: � � � ^.
3 '3t c OG tl C f Y
` CATCHMENTH
AREAS 1t3AC f o 1
AREA •9.3AC
GAImEkroo
L — GATGHMENTC8,f _
7" ` AREA 103AC + 4�� AREJ�C•ZOBAC
^ -••, `_ _: ,^ � .. ` � it <" `' ? _ C� -. t r r �
l
EASTiNGTNALWEG 0 300 000 •��••+�
mmra�vwe• s
Figure 2 -4 Historical Catchment Locations
July 2013 Cardno ENTRIX 2 -13

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Figure 2 -5 Current Monteith Creek Catchments
July 2013 Cardno ENTRIX 2 -14

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 2 -2 Impervious surface calculations by Monteith Creek Catchment
Catchment
Area
Undeveloped
Watershed
Total Area [ac]
From Figure 2 4
Developed
Watershed
Total Area [ac]
From Figure 2.5
Developed
Watershed
Impervious
Area facl
Developed
Watershed
Pervious
Area ac
Percent
Impervious
1
143
296
167
130
56%
2
93
108
00
108
0%
3
96
98
60
38
61%
4
34
15
00
15
0%
5
24
84
58
26
69%
6
203
232
01
231
1%
7
129
20
10
10
51%
8
103
118
66
52
56%
9
64
93
50
43
53%
10
163
43
04
40
8%
11
25
24
00
23
1%
12
47
167
121
46
73%
Total
112.4
129.8
537
761
41%
2.6 Jurisdictional Wetlands
Jurisdictional wetland limits were delineated using criteria in the Corps of Engineers Wetland Delineation
Manual (USACE 1987) and the Interim Regional Supplement for the Eastern Mountains and Piedmont
Region (USACE 2010) Delineation results show approximately 0 1 acres of wetlands associated within a
depositional area below storm water outlet 6 (Figure 2 -3) In the vicinity of storm water outlet 6, Monteith
Creek is not as Incised as other sections and floodplain connectivity is maintained, therefore wetland
habitat and structure remain intact However, current stream grades in this reach are maintained by a
relict culvert that is expected to fall and cause stream degradation and potential wetland loss In this
section This area is referred to as Assessment Area 1
Assessment Area 2 is located at the confluence of Monteith Creek and Torrence Tributary #1 soil types
are mapped as Monacan loam Based on field evaluations, this area historically contained jurisdictional
wetlands, as shown by soil evaluations done by Nutter and Associates However, due to changes in
drainage patterns, hydrology and the vegetative community, this area does not currently contain
functioning jurisdictional wetlands The area of Assessment Area 2 totaled approximately 1 63 acres A
detailed soils report describing conditions is attached in Appendix A
2 6 1 NC Wetland Assessment Method Results
The North Carolina Wetland Assessment Method (NCWAM) was applied to both the jurisdictional wetland
(Assessment Area 1) and the historic wetland (Assessment Area 2) to gauge current conditions of each
area Assessment Area 1 was determined to be a Headwater Forest type and received a rating of high
quality based on hydrological and water quality functions This area Is expected to be improved through
the long term protection of the ecosystem and planting of additional species for the project Based on
topography, soils and typical wetland characteristics for the Piedmont region, It was determined that the
natural, historic wetland type for Assessment Area 2 Bottomland Hardwood Forest Using current
July 2013 Cardno ENTRIX 2 -15

Site Specific Mitigation Plan
Monteith Park Mitigation Site
conditions, Assessment Area 2 received a rating of low quality based on hydrological and habitat loss
This area will be greatly improved though restoration activities
2.7 Climate Conditions
f Mecklenburg County has an average annual rainfall of around 44 Inches per year with over half of the
rainfall falling between April and September (USDA 1980) The average annual temperature is 607 with
an average daily maximum of 70 9 °F and average daily minimum of 49 5 °F (USDA 1980) The growing
season, calculated on a five out of ten year basis from data collected in years 1951 through 1977, is 233
days long and lasts from March 22 to November 11 (USDA 1980)
2.8 Threatened and Endangered Species
The United States Fish and Wildlife Service ( USFWS) maintain a list of species that qualify for protection
under the Endangered Species Act (ESA) According to the USFWS DENR Natural Heritage Inventory
Database (NHID), November 2007, there are four federally endangered or threatened species in
Mecklenburg County, North Carolina Federally listed endangered species Include Smooth coneflower
(Echmacea laevigata), Schweinitz's sunflower (Hebanthus schwemitzu), Michaux's sumac (Rhus
m►chauxu) and the Carolina heelsplitter (Lasmigona decorata) Based on numerous field visits to the site,
those species are not present and are not expected to be Impacted by restoration activities Descriptions
of these species and their current and historic ranges can be found in Appendix C Table 2- 3lllustrates
current and historic occurrences of rare and endangered species Included in the Natural Heritage
F Program's database None of the listed species are known to occur In the project area The Natural
Heritage Program's database Includes two non - federally listed species that have been historically found
within two miles of the project site, although these species have not been found in the area within the last
twenty years These species are the northern cup plant (Sllphium perfoliatum) and the Santee chub
(Cypnnel/a zanema)
Table 2 -3 Federally Listed Species under the ESA within Mecklenburg County
E = Endangered, T = Threatened, SC = Special Concern, SR =State Rare, NA =Not federally listed
2.9 Cultural /Historic Resources
There are no historic resources listed on the State Historic Preservation Office's list of properties and
sites at the proposed project location http //ais ncdcr gov /hpoweb/ The state list of historic sites was
accessed January 22, 2013 The closest historic properties are the Pink Graham House (MK2291 listed in
2002) which Is about a half mile from the proposed project Also nearby are the Rich Hatchett House
July 2013 Cardno ENTRIX 2 -16
State
Federal
Project
Major Group
Scientific Name
Common Name
Status
Status
Area
Invertebrate Animal
Lasmigona decorata
Carolina Heelsplltter
E
E
No
Record
Vascular Plant
Helianthus schweirntzn
Schwelnitz's
Sunflower
E
E
No
Record
Vascular Plant
Rhus michauxii
Michaux's Sumac
E -SC
E
No
Record
Vascular Plant
Echmacea laevigata
Smooth Coneflower
E -SC
E
No
Record
Vascular Plant
Sdphium perfoliatum
Northern cup plant
T
NA
Pre -1991
Vertebrate Animal (Fish)
Cyprnnella zanema
Santee chub
SR
NA
Pre -1970
E = Endangered, T = Threatened, SC = Special Concern, SR =State Rare, NA =Not federally listed
2.9 Cultural /Historic Resources
There are no historic resources listed on the State Historic Preservation Office's list of properties and
sites at the proposed project location http //ais ncdcr gov /hpoweb/ The state list of historic sites was
accessed January 22, 2013 The closest historic properties are the Pink Graham House (MK2291 listed in
2002) which Is about a half mile from the proposed project Also nearby are the Rich Hatchett House
July 2013 Cardno ENTRIX 2 -16

Site Specific Mitigation Plan
Monteith Park Mitigation Site
(MK2290 listed In 2002) and the MK2445 house (listed in 2002) which are both over a half mile from the
proposed project No other historic resources are located within a mile of the site Undisturbed historic
resources are not likely to be present at the proposed project site since it is adjacent to existing housing
developments along both sides of the creek
2.10 Potential Constraints
2101 Utility Easements
Duke Power maintains a 68 foot utility easement located in the upper reach of Monteith Creek below the
pond that Mr Monteith constructed during farming activities Cardno ENTRIX will restore this section of
Monteith Creek and maintain stream stability through this easement but will not maintain ownership of the
easement Energy United Electric Membership Corporation has a temporary 10 foot electric power
I easement dust upstream of the Bankside Drive road crossing This easement appears to have been
utilized during the development stages of Monteith Park and is not currently actively used In addition, a
15 foot sanitary sewer crosses the Monteith Creek conservation easement in the lower reach near the
'L confluence with Torrence Creek Tributary #1 Cardno ENTRIX will restore this section of Monteith Creek
and maintain stream stability through this easement but will not maintain ownership of this 15 foot section
I
of easement Credits within these easements were removed from the credit calculations
210.2 Property Ownership and Site Access
Cardno ENTRIX has entered into a legal agreement with the Monteith Park Homeowners Association in
order to gain access and to complete the restoration work at the Monteith Creek site Cardno ENTRIX
was given the option to purchase a total of four conservation easements which Include a minimum width
of 55 feet on each side of Monteith Creek The titles to these easements will be held under the entity
Monteith Holdings, LLC The conservation easements, detailed In Table 2 -4, total approximately 11 16
acres The conservation easements help assure the successful restoration, protection, and maintenance
consistent with this mitigation plan In addition, temporary construction easements and a total of five
permanent access easements were given to Monteith Holdings /Cardno ENTRIX to access the site for
restoration and future monitoring efforts 2- 18Flgure 2 -6 shows the easements listed in Table 2 -4
The conservation easement allows for the Monteith Park Homeowners Association to retain title and
possession of the land being restored while providing Monteith Holdings /Cardno ENTRIX easement rights
as stated In the signed legal agreements and as approved by regulatory agencies Upon closeout of
stream and wetland credits, the easement will be transferred to the City of Charlotte for long term
maintenance and monitoring
July 2013 Cardno ENTRIX 2 -17

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Figure 2 -6 Conservation and Access Easements
July 2013 Cardno ENTRIX 2 -18
q . P[n n• Miq <br qai¢! or g0.t^av
�r<r.. nu *•r•w PUS.•reorawwa
Easements
�+ qrf�
V f EAMAW
C• m•• t \ M i!\ fq«t0l9 > M uqr a
[ M qa P• to N• M.t b! u!•f!
'\w�>'\{�a ^.•;T!\0
T•�+PN1r�1+O lf:b Y 1rF:1:i.`:
.!tilt !l \ �0•. Mr
< a i .wn ,.�•
Monretth Mitigation Project
a!i^m•y a Pnn vapr •,rm •a Pmwe
•.a�w.,,�...�.. .n«..wm e, ..
Mecklenburg County, North Carolina
Figure 2 -6 Conservation and Access Easements
July 2013 Cardno ENTRIX 2 -18

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 2-4 Summary of Easements
Easements
Acreage
Conservation Easement # 1
1242+/-
Conservation Easement # 2
3188+/-
Conservation Easement # 3
6008+/-
Conservation Easement # 4
0722+/-
Conservation Easement Total
11 16+/-
Access Easement # 1
0014+/-
Access Easement # 2
0116+/-
Access Easement # 3
0 031 +/-
Access Easement # 4
0063+/-
Access Easement # 5
0 011 +/-
Access Easement Total
0235+/-
July 2013 Cardno ENTRIX 2 -19

Site Specific Mitigation Plan
Monteith Park Mitigation Site
r
3 Project Site Existing Conditions
3.1 Existing Channel Geomorphic Characterization
Field crews conducted a rapid geomorphic assessment of the Monteith Creek watershed and stream
j channels focusing on channel erosion due to Increased urban runoff Field observations were taken for
sediment supply and transport, channel boundary material properties (bed and bank), vegetation
characteristics, evidence of excessive channel erosion, and overall channel stability Where excessive
erosion occurred, observations noted the mechanism of failure, whether the Instability was localized or
reach wide, and if the failure was recently active or historical The following paragraphs summarize the
i types and forms of information used
3.1.1 Cross Sectional and Longitudinal Profiles
i I
_ Profile and cross section station and elevation data were generated from the topographic data at twenty
stations located throughout the project length Cross section geometry and longitudinal slope was used
to compute channel hydraulics and applied boundary shear stress (force)
31.2 Parent Material & Soil Types
Parent material Is the main geologic material forming the structure of the earth surface and soil types
This material makes up the channel boundary, and helps explain the geomorphic features and erosion
I I character observed in the field The sods ability to resist the hydraulic forces is of interest to the design
process and for re- establishing stability
31 3 Bed and Bank Material Properties
Bed and bank material properties (as well as vegetation type and density) characterize the channels
( I susceptibility to the forces of flowing water For the bed, the geomorphic assessment data include
observed bed forms, bed mobility, material type and size, and if any armoring exists For the bank, the
geomorphic assessment data include material type and stratigraphy, an American Society of Civil
Engineers (ASCE) classification, observed mechanisms of failure (if any), and an overall stability rating
Notes were collected on whether any observed problems are localized or reach wide, recently active or
historical
3.1.4 Vegetation Type and Density
I _ Dense vegetation and large woody debris adds roughness, slows flow velocity and reduces apparent
shear stress on stream banks In addition vegetative root structure enables soil cohesion Vegetation
data include type and density of the plants, density and depth of rooting mass, and whether presence of
woody debris is adding stability and enhancing habitat
3.2 Topographic Survey
Monteith Creek is a perennial first to second order stream and is depicted on the USGS topographic map
Topographic surveys Including channel, floodplain, and cross sections were conducted by Professional
Licensed Surveyors from Mattern and Craig, Inc These surveys were used to characterize existing
morphometrics throughout the project site
3.3 Reach Designation and Channel Characterization
Five reaches were designated on the basis of slope, channel characteristics and mayor flow changes
along the main stem, starting from the top lust below the Duke Power easement Reaches were
July 2013 Cardno ENTRIX 3 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
separated according to the longitudinal slope and similar stream characteristics. Two tributary streams
entering the main stem originate from the southeast but were not given reach designations because these
stream sections maintain stability and will not involve restoration activities. Figure 3 -1 plots the
longitudinal profile of Monteith Creek with reaches 1 -5 designated by color. Figure 3 -2 maps the reach
designations for the existing stream channel. Table 3 -1 summarizes the existing channel dimensions by
cross section and boundary properties according to junctions. The junctions represent where additional
flows from storm water pipes (increased catchment area) and the two tributaries enter Monteith Creek.
Appendix D contains additional photographs of the existing stream and reaches.
3.3.1 Reach 1
Reach 1 (Figure 3 -1, in red) is designated as the upper
section of Monteith Creek beginning from the Duke
Power easement and flowing downstream to a shallow
slope depositional area. Reach 1 contains cross
sections 1 through 7 and has slope range from 0.016 ft/ft-
0.028 ft/ft. The average slope for Reach 1 is 0.020 ft/ft.
The headwaters of Reach 1 accept storm water flow from
the residential development via a temporary sediment ru'
basin constructed during. Reach 1 receives additional r
flow from a small intermittent tributary from the south
between cross sections 4 and 5 Junction 2), and from
additional storm water flows from the north (future school
site). Total catchment for this reach is —0.08 square mile, which is relatively small for most perennial
stream systems. However, based on consistent flows during all site visits over the past 4 years and
based on in- stream features consistent with perennial streams, Monteith Creek exhibits characteristics of
a spring fed perennial system. The spring is likely located where the relict farm pond was constructed by
Mr. Monteith (a common agricultural practice). Reach is dominated by a historic headcut moving up-
stream that has led to significant degradation of the entire Monteith Creek ecosystem. The channel
banks are highly incised with elevations of up to ten feet totally removing floodplain access. Bank
erosion and instability are highly evident. The loss of buffer due to instability has led to a loss of 3 -5 trees
annually. Aquatic habitat and water quality are significantly affected due to excessive channel slope and
erosion. This section of Monteith Creek is considered highly unstable.
3.3.2 Reach 2
Reach 2 (Figure 3 -1, in dark blue) is designated as a
depositional area that has received and settled a large
portion of the upstream erosion from Reach 1 and
resulted in an average slope of 0.0045 ft/ft . The
remnants of two culverts used during previous
agricultural activities have maintained the current channel
elevation reducing the headcut potential from
downstream. However, the lifespan of these culverts is
short by evidenced by 1 failure to date. Reach 2 contains
cross sections 8 and 9 and receives additional storm
water flow from residential development (Junction 3). In
stream bank erosion from Reach 1 settled in Reach 2
due to the presence of the two culverts, producing wide shallow flows with minor anabranching (multi
thread braiding). The banks outside of the braided portion are slightly incised limiting floodplain access
by the channel. Due to wider stream channel and shallower slope, aquatic habitat is of higher quality,
however habitat and water quality are affected due to upstream erosion. Current stream grades in Reach
July 2013 Cardno ENTRIX 3 -2

Site Specific Mitigation Plan
Monteith Park Mitigation Site
2 are maintained by one of the two relict culverts; however, based on field indicators, this relict culvert is
expected to fail and lead to significant headcutting and downstream migration of sediment (erosion).
Reach 2 contains a small jurisdictional wetland area (Assessment Area 1) that will be impacted when this
culvert lost.
3.3.3 Reach 3
Reach 3 (Figure 3 -1, in green) is designated as the
segment between two depositional areas with a slope
range between 0.012 -0.014 ft/ft. Reach 3 contains cross
sections 10 through 14. Reach 3 receives additional
flow from a tributary from the south (Junction 4) and from
storm water runoff from both the north and south. The
channel is moderately incised and bank erosion and
instability are evident throughout the length of Reach 3.
Future failure of culverts between Reaches 2 and 3 will
cause increased channel erosion and bank instability.
Water flow access to the floodplains is restricted and
aquatic habitat and water quality is impaired. There is
little riparian vegetation in Reach 3 due to regular maintenance
the large downstream culvert associated with Waterfront Drive.
3.3.4 Reach 4
Reach 4 (Figure 3 -1, in yellow) is a depositional area
through a large culvert associated with Waterfront Drive.
Reach 4 contains cross sections 15 and 16 and has an
average slope of 0.0053 ft/ft. The large size of the
culvert is preventing additional erosion from occurring in
this reach. In addition, there is a debris jam located in
the lower portion of Reach 4 that helps maintain the
shallow channel slope. Outside of the culvert, the
channel banks in this reach are moderately incised with
elevations of up to four feet. Bank erosion and instability
are highly evident. As mentioned above, future failure of
. Reach 3 is not highly incised because of
upstream culverts will increase water flow and bank
instability of this depositional area, causing erosion of built up sediment and stressing of the large culvert.
3.3.5 Reach 5
Reach 5 (Figure 3 -1, in purple) is a previously
straightened segment that connects the depositional area
in Reach 4 with Torrence Creek Tributary #1. Reach 5
contains cross sections 17 through 20 and has an
average slope of 0.0075 ft/ft. The upper portion of Reach
5 receives the most significant storm water flow from the
south (Junction 5) that has led to significant bank erosion
and degradation of Monteith Creek. The channel is
highly incised (with elevations up to five feet) and water
flow access to the floodplain is severely restricted
resulting in alterations to the hydrology and functionality
of the adjacent wetlands (Assessment Area 2).
July 2013 Cardno ENTRIX 3 -3

I'
' -I
i�
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Bank erosion and Instability are evident throughout the length of Reach 5 In stream habitat Is limited In
this highly Impacted reach Reach 5 represents a mayor source of sediment and nutrient loads to the
McDowell Creek watershed
July 2013
Cardno ENTRIX
3-4

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Monteith Creek Existing Longitudinal Profile
r
d
d AAA
O
cv
AAA W
Station (feet)
Figure 3 -1 Existing longitudinal profile of Monteith Creek
July 2013 Cardno ENTRIX 3 -5
y = - 0.078x
Depositional
Deposition thru
Reach
y = - 0.020x
Debri
jam (GC)
y = -0.00
5x
1
�
y = 0.0053
y = -0.14x
y = - 0.0075x
Figure 3 -1 Existing longitudinal profile of Monteith Creek
July 2013 Cardno ENTRIX 3 -5

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Emsing Wetlands
tn` O�TMA
m • •.n �Cnt.9AmV
^mo�w.4 br mxu... ar btq row
•�,::T• •�•�_� >�.�.ar•.a..a.
Reach Designations
ENrNr�x1°
t•� •w t � ♦a aw �.ma±watB > �. uwr m
m1anM l In. mt. an IY Tt. 'wa. In. rtR.
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y. •. -,y.
.. ner':.�v balth l5.lsly
•!NCIro•l snwa4•o
+mt
�''�wtem ssn.mwrany
Monteith Mitigation Project
e» rtnwe
ptiw•.a...rrar . =an wawa a, o:
D..a.ea•r
wan
T —
v
r• -0.olo.
aw ►m �
o..o.tbrr aiw �...a
r• -0.00as.
y 0.0053•
y -0A74
y -0A07s.
Emsing Wetlands
tn` O�TMA
m • •.n �Cnt.9AmV
^mo�w.4 br mxu... ar btq row
•�,::T• •�•�_� >�.�.ar•.a..a.
Reach Designations
ENrNr�x1°
t•� •w t � ♦a aw �.ma±watB > �. uwr m
m1anM l In. mt. an IY Tt. 'wa. In. rtR.
.... T,.wm •w nup.s ., atOt +ar
y. •. -,y.
.. ner':.�v balth l5.lsly
•!NCIro•l snwa4•o
+mt
�''�wtem ssn.mwrany
Monteith Mitigation Project
e» rtnwe
ptiw•.a...rrar . =an wawa a, o:
Mecklenburg County, North Carolina
Figure 3 -2 Monteith Creek Reach Designations
July 2013 Cardno ENTRIX 3 -6

Site Specific Mitigation Plan
Monteith Park Mitigation Site
3.4 Bankfull Characterization
The bankfull channel is defined as the primary channel that carries frequent flows up to an elevation
where flows spill out onto floodplalns The capacity of this channel Is referred to as bankfull discharge, or
most effective discharge Few bankfull Indicators were noticed along this degrading stream system,
however when backfull Indications were Identified, we found a consistent backfull area associated with
Monteith Creek Table 3 -1 contains data for the main channel of Monteith Creek and Its tributary
Twenty cross sections (Appendix E) were collected from the topographic survey data As seen In the
table under Discharge (cfs) and Flow Area (sq -ft), the flow regime and size of the channel generally
Increase in the downstream direction Areas where the trend is Inconsistent Include the two depositional
reaches where the slope decreased dramatically thus having an effect on the discharge estimation The
significant Increase in discharge and flow area along the lower portion of Monteith Creek Is a function of
' the location of storm water outfalls and the Increased runoff from the adjacent residential areas The
channel's Width (ft), Depth (ft), and W/D Ratio are listed, as well as the Floodprone Width and Ratio Also
` listed are the mean size of measured bed material, the sand fraction and the estimated critical shear
M stress of bank material
July 2013 Cardno ENTRIX 3 -7

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 3 -1 Summary of Existing Channel Conditions
July 2013 Cardno ENTRIX 3 -8
Observed Channel
Flood Prone Area
Disch
Flow
Width
Depth
W/D
Width
Entrench
Slope
D50
Sand
Shear
Area
(max)
ment
Fraction
Stress
(cfs)
(sq -ft)
(feet)
(feet)
ft)
(feet
�
ft ) s /sq-
XS-1
7
21
25
14
29
71
29
0 028
31
20
087
XS -2
17
42
60
09
85
104
17
0 028
31
20
1 12
XS -3
15
37
52
12
7 4
105
20
0 028
31
20
1 09
s
m
XS-4
NOT USED
XS -5
19
51
40
1 5
31
120
30
0 016
31
20
084
XS -6
22
57
42
19
31
135
32
0016
31
20
089
XS -7
18
63
90
19
130
254
28
0016
31
20
058
ci
XS -8
NOT USED
t
ea
IX
XS -9
15
70
69
16
68
500
73
00045
31
20
091
XS -10
29
73
42
24
24
589
141
0 014
31
20
089
M
XS -11
29
74
43
21
25
114
26
0014
31
20
088
m
XS -12
35
84
47
26
26
709
152
0014
31
20
095
XS -13
33
85
44
25
23
250
56
0012
31
20
097
XS -14
30
83
71
20
60
280
40
0012
31
20
085
a
XS -15
23
89
49
27
28
477
96
00053
31
20
037
t
m
XS -16
18
78
56
22
41
477
85
00053
31
20
032
XS -17
25
74
50
22
33
421
85
001
31
20
063
s
d
XS -18
NOT USED
W
XS -19
30
98
52
21
28
73
14
00075
31
20
050
July 2013 Cardno ENTRIX 3 -8

Site Specific Mitigation Plan
Monteith Park Mitigation Site
July 2013 Cardno ENTRIX 3 -9
Observed Channel
Flood Prone Area
Disch
Flow
Width
Depth
WID
Width
Entrench
Slope
D50
Sand
Shear
Area
(max)
ment
Fraction
Stress
(cfs)
(sq -ft)
(feet)
(feet)
(ft/ft)
(feet)
(ft/ft)
(ft/ft)
(mm)
(� /a)
(lbs /sq-
ft)
XS -20
30
97
63
27
40
182
29
00075
31
20
053
T1 -3
5
13
60
05
100
006
31
20
023
N
d
125
T2 -3
6
18
0 5
60
004
31
20
023
a
T2 -2
Swale like
005
31
20
023
T3 -5
Swale like
004
31
20
023
July 2013 Cardno ENTRIX 3 -9

Site Specific Mitigation Plan
Monteith Park Mitigation Site
3.5 Bed Material
The bed is primarily sand with some silt, overlain by an infrequent deposit of gravel. Underlying the bed
surface is the same parent material that formed the banks. Coarse material was found in a few isolated
deposits. Coarse material likely originates from the banks, where silt and sand has been flushed
downstream during storm flows, as opposed from being delivered from an upstream source.
Wolman pebble counts were performed on deposits of gravel. Figure 3 -3 plots the results using the
standard sizes and the Unified Soil Classification chart. Two curves are shown-, one with particles less
than 2 mm and one without. The median grain size of the collected data is 1.3mm. With sand removed
from the distribution, the median grain size is 3mm. The 84 percentile is 2.8mm and 7mm, respectively.
Such small grain sizes can be easily transported with flows around 1 cfs.
On the basis of the above information, the creek bed is primarily a firm loam overlain with periodic
deposits of medium to coarse sand and fine gravel. Channel material is highly erodible and easily
mobilized during small to medium storm events in an incised channel like Monteith Creek.
GRAVEL
SAND
SILT AN D C LAY
COARSE FNE
C0.4RSE MEDIUA1 FINE
U. S. STANDARD SIEVE SIZES
HYDROMETER
Adjusted w/o Fines
B
.}-. h_.__ �.__,.... i_..... i....._._ j ... ............i.{..i..l._t...i---
e
E
+--+—+--+---+---+---+-------+-- ----------- +- +-- +-- +--�-- + - - --+ ---' - --- - --+ -- --------+—} -+- -f-- +-- r--- +----- -r--- - - - - -r --------- -- -- r- +- r-- r-- +- --`---- r- - - - -', - - - - - -� ------------tt- i-- i--- r---{— i------ t�------ - +-------...----
.t._._�___ _.._____._______
s
3" 2" 1" 314"
318" 4 10
20 40 60 100
200
�� � � �
100
.j_.�..j...i...i....t..... _._...__... ___ }.i._t__i�...t_._.h__... +___ — F ............. .i.t_...1_..
.._.... i....._-_-___ t.+. i._ i... h_._ i. _i...__.........�.....__....._.
� � � I
90
80
F
70
W
3
60 >.
m
Z
50
to
U)
Q
a
40 r
Z
w
30 U
W
IL
20
10
100 50 20
10 5 2
1 0.5 0.2
0.1 0.05 0.02
0.01 0.005 0.002 0.001 D
GRAIN SIZE IN MILLIMETERS
GRAVEL
SAND
SILT AN D C LAY
COARSE FNE
C0.4RSE MEDIUA1 FINE
U. S. STANDARD SIEVE SIZES
HYDROMETER
Figure 3 -3 Grain size distribution for Monteith Creek
3.6 Bank Material (Soils)
Soils along the Monteith channel consist of Mecklenburg fine sandy loams (MeD) and Monacan loam
secondary (MO). Soils are well drained with a depth to water table and a restrictive layer of more than 80
inches. Occasional grey colored clay lens are exposed along the creek bank and bed indicating erosion
to subsurf
ace clay layer. Monacan loam is found along the floodplains of Monteith Creek and Torrence
July 2013 Cardno ENTRIX 3 -1
Wolman Pebble Count
• � �__. t_. _�._______i_______.._.._i_ +_i__ t__.i....h_...� ._
'----- �------ �----• -------•- --- ------- •-•-�- -• ---- T � � � ,
Adjusted w/o Fines
.}-. h_.__ �.__,.... i_..... i....._._ j ... ............i.{..i..l._t...i---
...__t.__.... }_....__ -_ -__
+--+—+--+---+---+---+-------+-- ----------- +- +-- +-- +--�-- + - - --+ ---' - --- - --+ -- --------+—} -+- -f-- +-- r--- +----- -r--- - - - - -r --------- -- -- r- +- r-- r-- +- --`---- r- - - - -', - - - - - -� ------------tt- i-- i--- r---{— i------ t�------ - +-------...----
.t._._�___ _.._____._______
1_—_ _._...._ ..._.________� �
_..___....__.
i_ —_ _____ i_______ 1.—
.... }_._.— ___.__
�� � � �
.j_.�..j...i...i....t..... _._...__... ___ }.i._t__i�...t_._.h__... +___ — F ............. .i.t_...1_..
.._.... i....._-_-___ t.+. i._ i... h_._ i. _i...__.........�.....__....._.
� � � I
Figure 3 -3 Grain size distribution for Monteith Creek
3.6 Bank Material (Soils)
Soils along the Monteith channel consist of Mecklenburg fine sandy loams (MeD) and Monacan loam
secondary (MO). Soils are well drained with a depth to water table and a restrictive layer of more than 80
inches. Occasional grey colored clay lens are exposed along the creek bank and bed indicating erosion
to subsurf
ace clay layer. Monacan loam is found along the floodplains of Monteith Creek and Torrence
July 2013 Cardno ENTRIX 3 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Creek Tributary #1 Monacan loams are less well drained and are classified hydric, they typically occupy
floodplains with frequent inundation
Bank material properties were qualitatively described by the field crews Field tests suggest the soils are
moderately soft when moist The soil can be rolled In your hand up to finger size ribbon, and breaks
apart easily Vertical creek banks in Reach 5 range from 3 5 to 4 5 feet tall At the toe of banks,
moderate effort is required to push a blunt object into the bank soils up to 1 Inch Solis along the top of
banks become harder as they become drier
For cohesive bank and bed material, critical shear stress values are estimated from the ASCE Manual of
Engineering Practice No 77 based on bank soil conditions, material type and degree of compaction
Table 3 -2 lists values for a range of bank materials types, with and without vegetation On the basis of
the above description, Monteith Creek banks and bed soil may be classified as a firm loam, fairly
compact A critical shear stress value of 0 23 Ibs /sq -ft was selected for modeling and analysis
Table 3 -2 Critical Shear Stress Values for Consolidated Bank Material
Bank Material Type
Critical Shear Stress
(Ibs /ft )
ASCE Manual No 77
Hardpans, Duripans
067
Compacted Clays
050
Graded Loams with Cobble
038
Stiff Clays
032
Alluvial Silts, compact
026
Firm Loam, compact
023
Silty Loam, fairly compact
017
Sandy Loam, fairly compact
0 12
Fine Gravel
0 075
Alluvial Silts, Silt Loam
0 048
Biotechnical Engineering Data USAE1
Banks with Woody 041 to 2 5
vegetation
Short native grass
0 7 to 0 95
Long native grass
1 2 to 1 7
Biotechnical Engineering
0 4 to 8
'Biotechnical engineering data obtained from "Stability Thresholds for Stream Material ", by Craig Fischenich, USAE Research and
Development Center, Environmental Laboratory, Vicksburg, MS
3.7 Bank Vegetation
Vegetation (grasses and shrubs) adds strength to the stability of bank material Present vegetation
alternates from grasses to vines to trees and shrubs Some stream segments have only grasses whereas
other segments have what appears to be a high density of vegetative cover However, because of
channel incision and bank failures, bank vegetation and root density is considered low to moderate with
bare soil now exposed below the root zone Exposed bank soil occurs throughout the project near the
stream bed and along the toe of bank A significant amount of exposed roots are present, both larger
aged roots as well as small fine roots indicating recent exposure Bank under cutting was also observed
July 2013 Cardno ENTRIX 3 -2

Site Specific Mitigation Plan
Monteith Park Mitigation Site
_ In some places, trees occupy the active channel creating debris dams and dissipating flow energy
Shrubs and other woody vegetation add roughness to slow the flow of water and reduce shear stress at
the channel boundary At the same time, this debris often deflects flow toward the banks causing bank
failure and channel widening as water tries to pass around the outer edges of the vegetation
3.8 Existing Riparian Vegetation Characterization
Riparian vegetative communities adjacent to Monteith Creek consist of sections of maintained turf
grasses, disturbed alluvial forests maintained by unstable channel conditions, and forest communities
along steep banks representative of disturbed mixed -mesic hardwood forests (Schafale and Weakley
1990) All riparian areas along Monteith Creek have been significantly disturbed by past and current land
uses Past disturbances Include activities associated with cattle grazing and agriculture Current
disturbances Include massive erosion and bank failure typical of urban streams, resulting in unstable
conditions for riparian tree species
Reach 1 of Monteith Creek consist of disturbed mixed -mesic hardwood forest with mature trees that are
along the steep banks of the Incised channel Mature tree species Include eastern red cedar (Juniperus
virgmiana), Virginia pine (Pmus virgrniana), and sweetgum (Liguidambarstyraciflua), with scattered
slippery elm (Ulmus rubra), green ash (Fraxinus pennsylvarnca), red maple (Acerrubrum), and Invasive
Japanese empress tree (Paulowrna tomentosa) Shrub species Include smaller woody tree species
mentioned above as well as an abundance of invasive Chinese privet (Ligustrum smense) Herbaceous
species include mostly turf grasses Vines include poison ivy (Toxicodendron radicans), catbriar (Smilax
rotundifoha), blackberry (Rubus sp ), Virginia creeper (Parthenocissus qumquefolia), grape vine (Vitus
sp) and Japanese honeysuckle (Lonicera japonica) The channel banks are largely devoid of woody and
herbaceous vegetation resulting in unstable bank conditions
Reach 2 consists of a braided alluvial type forest system that is dominated by stands of black willow (Salix
} j rngra) and thickets of blackberry Braided conditions along this section are the result of large masses of
sediment that have deposited In this reach due to upstream bank erosion and land disturbance, a
�l reduction In overall channel slope, and downstream culvert control features that prevent sediment from
transporting further downstream This has created habitat conditions suitable for black willow The
-! majority of black willows in this section are Immature with DBH's less than six inches Other species
include grasses, sedges and rushes common to wet areas along alluvial floodplains Herbaceous species
+ include mostly turf grasses along with invasive species such as Japanese stilt grass (Microstegium
vimineum) The channel banks are largely devoid of woody and herbaceous vegetation resulting in
unstable bank conditions
i Reach 3 consists of maintained vegetation up to the top of bank throughout the majority of the channel
Some portions are completely devoid of woody tree species along the bank resulting in extremely
unstable bank conditions Shrub species including smaller woody tree species and an abundance of
1 Chinese privet are present Woody species within maintained riparian areas predominately include
sweetgum, green ash, eastern red cedar, black walnut (Juglans nigra), black willow, and Virginia pine
The majority of Reach 4 lacks vegetation due to the large culvert and road crossing Upstream of the
culvert, the vegetation is maintained up to the top of the bank and no vegetation is present inside the
banks Below the culvert, shrub species including smaller woody tree species and an abundance of
Chinese privet are present Vines include poison ivy, Virginia creeper, grape vine, blackberry, and
Japanese honeysuckle
Reach 5 of Monteith Creek consists of maintained vegetation up to the top of bank Some portions of the
downstream section are completely devoid of woody tree species along the bank resulting in extremely
unstable bank conditions Other portions have scattered trees along the bank and within the Incised
channel Most trees In maintained riparian areas are Immature and under 10 Inches diameter at breast
height (DBH) Shrub species Include smaller woody tree species mentioned above and an abundance of
July 2013 Cardno ENTRIX 3 -3

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Chinese privet. Vines include poison ivy, Virginia creeper, grape vine, blackberry, and Japanese
honeysuckle. The channel banks are largely devoid of woody and herbaceous vegetation resulting in
unstable bank conditions.
3.9 Benthic Macroinvertebrates
Benthic macroinvertebrates were sampled in August 2012 at locations within the project area,
downstream of the project area in Torrence Tributary #1 and at a nearby reference site. The purpose of
sampling for benthic macroinvertebrates is to assess pre- construction water quality conditions based on
insect community composition. This approach is useful in first and second order streams, such as
Monteith Creek. The following taxa (known as EPT taxa), Ephemeroptera (mayflies), Plecoptera
(stoneflies), and Trichoptera (caddisflies), are highly intolerant to stresses and higher abundances of EPT
taxa indicate a higher quality stream. Samples were collected according to the Qual -4 method (NC
DENR 2011 b). The August 2012 sampling returned no aquatic insects. These data will be used
qualitatively to assess the progress of the Monteith Creek restoration during post construction monitoring
as well as to compare water quality with a nearby reference reach. Benthic macroinvertebrate
decolonization is a goal of the stream restoration.
3.10 Existing Conditions for Storm Water Facilities
Monteith Park represents a residential development community typical of development projects in the
early 2000 time period. The community is characterized as a medium to high density "Charleston style"
development. This development type utilizes a series of "pods" that form higher density clusters of homes
with alleyway access, primary front door road frontage,
and smaller lot size. As is the case at Monteith Park, the
clusters of homes are often connected to larger open
space parks for use by the residents. These open space
parks are usually centered along low -lying floodplains,
wetlands, and /or streams and typically receive the storm
water outfalls from the surrounding community. At the
time Monteith Park was developed, the Town of
Huntersville was developing a rigorous set of storm
water regulations to help contain and treat water quantity
and water quality. However, as in the case of
Huntersville, many smaller communities on the
development fringe often see rapid growth before the necessary storm water regulations are in place.
Monteith Park is an example of a community that was designed and developed based on the weaker
storm water regulations leaving inadequate storm water infrastructure in place. The existing storm water
infrastructure was designed to move water from the residential homes, streets, and impervious areas,
quickly and efficiently to the open space with very minimal energy dissipation, flood attenuation, or
treatment for water quality. Therefore, as a result, in- stream bank erosion, failed storm water structures,
and active overland erosion is evident throughout the open space area.
3.11 Summary of Existing Conditions
The slope of the Monteith Creek channel is highly variable; shallower in small sections upstream of
culverts and steeper throughout the rest of the stream. Cross section data indicate a narrow, deeply
incised channel where bankfull events are contained inside the larger channel below top -of -bank,
modifying hydrology and sediment supply. Soils in the channel bed and banks are highly erodible and
very susceptible to degradation via the modified hydrology. Vegetation along the banks of Monteith
Creek is inadequate therefore minimizing any beneficial usefulness towards channel stability. The
riparian communities have been impaired by past disturbances and large portions of the channel bank are
July 2013 Cardno ENTRIX 3-4

r
1
1 '
f �
I_
r
f
Site Specific Mitigation Plan
Monteith Park Mitigation Site
maintained turf with larger trees being undercut due to channel incision With existing soil consistency,
depth of incision, current storm flows, and unstable vegetation conditions, Monteith Creek will continue to
degrade resulting in deeper channel Incision, excessive stream bank erosion, and greater loss of habitat
July 2013 Cardno ENTRIX 3 -5

Site Specific Mitigation Plan
Monteith Park Mitigation Site
4 Watershed Hydrograph (Storm Water) Restoration
Plan
As outlined In this plan, one of the most significant components of the restoration of the Monteith Creek
watershed Includes the restoration of the watershed hydrograph to predevelopment conditions A
challenge In all stream and wetland restoration projects is the ability to design a natural stream ecosystem
within a watershed that is far from Its natural state in terms of runoff regime, land use, and overall
hydrography For the MPMS, our restoration plan Includes the "restoration" of this predevelopment
hydrograph in a watershed that has no post construction storm water management Proposed storm
water Improvements at Monteith Park Include retrofit of a number of the existing storm drain outfalls with
best management practices (BMPs) A total of five (5) BMPs are proposed at all but one of the
stormwater outfalls, all designed as bioretention cells Additionally, an abandoned sediment basin at the
headwaters of Monteith Creek will be vegetated with riparian and wetland species and a swale out of the
final stormwater outfall will be stabilized with riparian vegetation The five (5) bioretention BMPs are
providing stormwater attenuation and water quality benefits through the removal of Total Suspended
Solids (TSS), thus providing additional stream credits for the project The two (2) additional stormwater
features are being addressed to provide stability for the stream system and thus have not been Included
for additional stream credits
The proposed BMPs are designed to control and manage stormwater currently entering Monteith Creek
from existing stormwater outflows The current outflow configurations offer no water quality treatment and
very little energy dissipation from "hungry" storm water flows during rain events The proposed design
Incorporates diversion structures coupled with bioretention cells to dissipate high energy flows while
diverting, capturing, and treating specific water quality volumes based on the one Inch of runoff or first
flush concept Each bioretention cell will utilize an under drain system since In situ soils do not have
adequate Infiltration rates to prevent the ponding of water This under drain system is specifically
designed not to impede the infiltration rate of the engineered soil media used within the bioretention cell
The media will be topped with sod layer to prevent significant erosion within the cell while minimizing
maintenance Finally, an overflow weir is established at specific elevations to allow for the bypassing of
large storm events while maintaining a proper ponding depth for treatment conditions These
configurations are presented in detail on the 60% design plans in Appendix F with supporting
documentation in Appendix G
Located at the top of the project site Is an existing sediment basin that was constructed during the
development stages of the community This location receives 24% of the total watershed area, including
the highest percentage of impervious coverage, and receives water through a series of 3 storm water
outlets This sediment basin represents the head of Monteith Creek and will be enhanced through
vegetated planting to aid in the stabilization of the redesigned stream channel The diverse wetland
vegetation and added micropool will provide for additional filtering and settlement of sediment in order to
improve water quality The vegetated swale is proposed in a location that doesn't accumulate enough
storm water flows to justify a separate bioretention basin but acquires enough runoff to begin the
development of concentrated flow The vegetated swale serves to provide energy dissipation and redirect
storm water flows parallel to the stream to maximize floodplain infiltration and increase stream stability
Constructing these BMPs is a critical component of mimicking, as close as possible, the pre - development
hydropenod The combination of these stormwater controls will allow for the attenuation of fast peaking
storm water flows resulting in increased bank stabilization, increased nutrient retention, and decreased
sedimentation thus achieving the goal of an overall watershed restoration Table 1 -1 summarizes the
BMPs that will be installed according to the engineering plans
July 2013 Cardno ENTRIX 4 -6

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 4 -1 Summary of BMP Design
BMP
BMP Size (acres)
Reach
Type
1
0 035
1
Bio- retention Basin
2
0 067
1
Bio- retention Basin
3
0 122
2
Bio- retention Basin
4
0 035
3
Bio- retention Basin
5
0 155
5
Bio- retention Basin
Additional Stormwater Features
Vegetated Sediment Basin
053
Headwaters
Vegetated Wetland
Swale
N/A
3
Swale
July 2013 Cardno ENTRIX 4 -1

l
MR
AA Bh1P J- �
> 1
r i P3
lY,.•�b �.. -fit. + '�' •r
i \: �
ft
e -
Site Specific Mitigation Plan
Monteith Paris Mitigation Site
a
•-. Fall . +e a u» •n a» a,u.a
a »�enw: area »a,. wobro»
ress
e��ernann »� am ea sna mer »rue+
npenwb a n. agar ro
Mitigation Design Layout- Upper Reach
ENMIX
bnr*na ant a »eon t1 *all *Ina tna.safa
'»wa Tw♦ w» n n urva�eaea nn
�';
;genre
•aO
ao•wq m aeon eno. rn.� an r»o;ne
Monteith Mitigation Project
-.
Proposed Channel
Wetland Preservation
Mecklenburg County, North Carolina
Enhancement Reaches
sups
-
-
UOIayEasement
50 h Butter
Dialing Sidewalk
i vegetated Area -
'` ti
.
° - ° -•-• Pro posed Sidewalk Rep tacement
Conservation E asement
Proposed Unpaved Greenway
= Welland Em ironmental Edu cation Area
-y
Fall,
•-. Fall . +e a u» •n a» a,u.a
a »�enw: area »a,. wobro»
ress
e��ernann »� am ea sna mer »rue+
npenwb a n. agar ro
Mitigation Design Layout- Upper Reach
ENMIX
bnr*na ant a »eon t1 *all *Ina tna.safa
'»wa Tw♦ w» n n urva�eaea nn
rn+c+n A1"u LaSda »i: isi�k
K:-a,> Ysn::reea.s
;genre
•aO
ao•wq m aeon eno. rn.� an r»o;ne
Monteith Mitigation Project
Mecklenburg County, North Carolina
Figure 4 -1 Mitigation Design Layout for Upper Reach of Monteith Creek
July 2013 Cardno ENTRIX 4 -2

Site Specific Mitigation Plan
Monteith Paris Mitigation Site
a =» .m wu wows
*!. *19N1.9 a1cm manor a +n In
D��9
amt . n9 .m+► n.*�x :.e N av
nn1m =mm ror uw,p1 e+ oen'nn
»�91+t...1!
Mitigation Design Layout- Lower Reach
Qvnanr
�;;;.n�.<<�9•�
awnnl im. as nrMe Tm�snl w.rro
q n1a me r10
y,,,,.y,. �'�.ya s. a35i
Aee Twn ♦ iw !N colts �+ Nm� at .
Monteith Mitigation Project
0109,g0q b 19On 9npl NMr 010 O�O1n0
t . w!rc..mra+.,we emwc 9r n
Mecklenburg County, NORh Carolina
Figure 4 -2 Mitigation Design Layout for Lower Reach of Monteith Creek
July 2013 Cardno ENTRIX 4 -3

Site Specific Mitigation Plan
Monteith Park Mitigation Site
5 Stream Restoration Plan
5.1 Overview of Applied Restoration Approach
Our recommended approach for evaluating long -term channel stability and developing restoration plans is
r the use of continuous hydrology and the analysis of all flows as opposed to selecting a few discrete
events (Bledsoe & Watson 2001 a, Geosyntec 2007, MacRae 1992 and 1993, Palhegyl 2009,
SCVURPPP 2005) Continuous hydrology Incorporates the full probability distribution of storm events
and uses flow time series as a basis for restoration design This approach captures all the Important
` geomorphically significant flows and allows one to examine the distribution of sediment transport and
Identify the most effective discharges at carving the landscapes erodible soils
Cardno ENTRIX uses a natural channel design procedure That method applies continuous hydrologic
modeling to generate frequency distributions of erosion and transport and Identify the active channel and
its channel forming discharge Once bankfull discharge is determined, hydraulic geometry is calculated to
determine active channel width (Soar & Thorne 2001) Given bankfull discharge and the estimated
bankfull widths, we then determine the slope and depth of flow that balances sediment supply and
transport, without aggradation or degradation (Copeland 1994) In sediment supply limited systems
where channel stability is controlled by cohesive bank and bed soils, we adjust channel dimension and
slope to rebalance the erosive forces of flowing water with the channel's ability to resist these forces,
incorporating sod and vegetation properties
Our process centers around the application of natural channel design procedures which Integrate
If hydrology, geomorphology, hydraulics, shear stress and sediment transport Natural channel design is
based on the principles of dynamic equilibrium, which requires a balance between a stream's flow energy,
incoming sediment load, and channel resilience In order for a stream to remain stable (Bledsoe & Watson
2001 a, MacRae 1992, Soar & Thorne 2001)
Long -term sustainablllty Is achieved given the expected future flow and sediment supply regimes These
conditions make It more difficult to determine a stable channel configuration Our design approach
combines a geomorphic determination of size and shape with an analytical assessment using hydraulic,
sediment transport, and cohesive soil erosion models Geomorphic relationships and models are the
tools we apply to evaluate site specific restoration concepts
The restoration design process generally Involves the following steps
> Hydrology Determine the design flow rates and frequencies of Interest Apply flow frequency curves
to predict the range of geomorphically significant flows and the most effective discharge
> Geomorphology Predict the expected future stable channel configuration using published hydraulic
geometry equations Supplement and verify hydraulic geometry equations with watershed and site
specific relationships derived from field surveys
> River Mechanics Evaluate long -term channel stability using hydraulic, sediment transport and shear
stress models Evaluate shear stress and erosion potential of beds and banks Predict bank erosion
and lateral migration tendencies Evaluate uncertainties by predicting the channels response to
changing hydrologic and sediment load characteristics
> Refinement Refine design concepts such that long -term stability Is achieved
July 2013 Cardno ENTRIX 5 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
5.2 Hydrologic Modeling
Hydrologic modeling consists of defining the watershed or catchment boundaries and physical properties
related to the hydrologic process The sections below describe the drainage area delineation and
characterization, the amount of rainfall available for runoff (i e , excess rainfall), hydrograph and reach
routing This section also describes the selection of rainfall and evapotranspiration data
Cardno ENTRIX delineated the drainage areas for both the pre - developed and post - developed (at build
out) conditions Figure 2 -4 presents the drainage area delineation of the undeveloped watershed and
Figure 2 -5 presents the delineation for the developed case
Cardno ENTRIX identified land cover characteristics and soil types based on GIS and AutoCAD project
files Cardno ENTRIX overlaid drainage area delineations on topography and soils layer to identify
parameters for each drainage area Site observation and aerial photography were used to identify
vegetation and urban land cover types Soil Conservation Service soils data were downloaded and
reviewed with drainage area boundaries to identify soil parameters Table 5 -1 summarizes the drainage
area parameters required for modeling undeveloped open space and for future development
Table 5 -1 Summary of Soil Moisture Accounting Parameters
Basin
Area
(sq mi)
Canopy
Storage
(in)
Surface
Storage
(in)
Max
Infiltration
(in /hr)
IMP
( %)
Soil
Storage
(in)
Tension
Storage
(in)
Sod
Perc
(in /hr)
GW1
Storage
(in)
GW1
Percolation
(in/hr)
Catch 1
00279
015
035
0 6
0
6
4 5
0 6
6
006
Catch 1 IMP
00188
0
0 2
0
0
6
4 5
0
6
006
Catch
00155
015
035
06
0
6
45
06
6
006
Catch 3
00084
015
035
0 6
0
6
4 5
0 6
6
006
Catch 3 IMP
00069
0
0 2
0
0
6
4 5
0
6
006
Catch 2 IMP
0 004
0
0 2
0
0
6
4 5
0
6
006
Catch 5
00075
015
035
0 6
0
6
4 5
0 6
6
006
Catch 5 IMP
00057
0
0 2
0
0
6
4 5
0
6
006
Catch 4
00038
0 15
035
0 6
0
6
4 5
0 6
6
006
Catch 6a
00138
015
035
0 6
0
6
4 5
0 6
6
006
Catch 8
00126
015
035
0 6
0
6
4 5
0 6
6
006
Catch 6a IMP
00099
0
0 2
0
0
6
4 5
0
6
006
Catch 8 IMP
00062
0
0 2
0
0
6
4 5
0
6
006
Catch 6b
00158
015
035
0 6
0
6
4 5
0 6
6
006
Catch 10 IMP
00036
0
0 2
0
0
6
45
0
6
006
Catch 10
00033
015
035
0 6
0
6
4 5
0 6
6
006
Catch 7
00021
015
035
0 6
0
6
4 5
0 6
6
0 06
Catch 7 IMP
0 001
0
0 2
0
0
6
4 5
0
6
006
Catch 9
00076
015
035
0 6
0
6
4 5
0 6
6
006
Catch 9 IMP
00052
0
0 2
0
0
6
4 5
0
6
006
Catch 12
00216
015
035
0 6
0
6
4 5
0 6
6
006
Catch 12 IMP
00083
0
0 2
0
0
6
4 5
0
6
006
July 2013 Cardno ENTRIX 5 -2

Site Specific Mitigation Plan
Monteith Park Mitigation Site
5.2.2 Sod Moisture Accountinq
The continuous hydrologic model Is designed to simulate the dynamic effect of soil moisture and other
losses on runoff over the course of a long -term rainfall record Parameters to compute these losses
Include climatic data, land use conditions, vegetation cover, and soils data The Hydrologic Engineering
Center — Hydrologic Modeling System (HEC -HMS, USACE 2000) uses soil Infiltration rate estimates and
other losses described below to calculate excess precipitation that contributes to runoff and stream flow
The applied continuous simulation routine uses the Soil Moisture Accounting (SMA, USACE 2000)
method The SMA method provides a more complete method for evaluating rainfall runoff processes In a
watershed In this approach, measured rainfall over an extended time period Is used as input to the
model Hydrologic parameters are computed on an hourly basis, and Include canopy and soil
evapotranspiration, surface depression storage, and Infiltration Table 5 -1 summarizes the SMA
parameters used In the model
Figure 5 -1 Illustrates the SMA model concepts for undeveloped land For each computational time step In
the model, HEC -HMS calculates storage In each of the categories shown in the schematic For
infiltration, when soils are dry water enters the soil at the maximum infiltration rate and when soils are fully
saturated water enters and leaves the soil column at the user specified saturated hydraulic conductivity
Canopy Storage W
Surface Storage
0
�0
Evapotranspiration
Sod Storage -infiltration
Deep percolation to
groundwater
Sod Column Properties
%rosity �—
IeiF d Capac
Overland
flow
Shallow sub-
surface flows
Flows to
Creek
The surface consists of a loose soil and organic matter (duff)
mixture in the top several feet
Saturation overland flow occurs as the sod moisture begins to
reach capacity Large percentage of runoff reaches the creek as
delayed sub -surface flows
Figure 5 -1 Illustration of the Rainfall -Runoff Hydrologic Module
July 2013 Cardno ENTRIX 5 -3
Canopy
Surface
Max
Soil
Tension
Soil
GW1
GW1
Basin
Area
Storage
Storage
Infiltration
IMP
Storage
Storage
Perc
Storage
Percolation
(sq mi)
(in)
(in)
(in /hr)
( %)
(in)
(in)
(in /hr)
(in)
(in /hr)
Catch 11
00038
015
035
0 6
0
6
4 5
0 6
6
006
5.2.2 Sod Moisture Accountinq
The continuous hydrologic model Is designed to simulate the dynamic effect of soil moisture and other
losses on runoff over the course of a long -term rainfall record Parameters to compute these losses
Include climatic data, land use conditions, vegetation cover, and soils data The Hydrologic Engineering
Center — Hydrologic Modeling System (HEC -HMS, USACE 2000) uses soil Infiltration rate estimates and
other losses described below to calculate excess precipitation that contributes to runoff and stream flow
The applied continuous simulation routine uses the Soil Moisture Accounting (SMA, USACE 2000)
method The SMA method provides a more complete method for evaluating rainfall runoff processes In a
watershed In this approach, measured rainfall over an extended time period Is used as input to the
model Hydrologic parameters are computed on an hourly basis, and Include canopy and soil
evapotranspiration, surface depression storage, and Infiltration Table 5 -1 summarizes the SMA
parameters used In the model
Figure 5 -1 Illustrates the SMA model concepts for undeveloped land For each computational time step In
the model, HEC -HMS calculates storage In each of the categories shown in the schematic For
infiltration, when soils are dry water enters the soil at the maximum infiltration rate and when soils are fully
saturated water enters and leaves the soil column at the user specified saturated hydraulic conductivity
Canopy Storage W
Surface Storage
0
�0
Evapotranspiration
Sod Storage -infiltration
Deep percolation to
groundwater
Sod Column Properties
%rosity �—
IeiF d Capac
Overland
flow
Shallow sub-
surface flows
Flows to
Creek
The surface consists of a loose soil and organic matter (duff)
mixture in the top several feet
Saturation overland flow occurs as the sod moisture begins to
reach capacity Large percentage of runoff reaches the creek as
delayed sub -surface flows
Figure 5 -1 Illustration of the Rainfall -Runoff Hydrologic Module
July 2013 Cardno ENTRIX 5 -3

Site Specific Mitigation Plan
Monteith Park Mitigation Site
5 2 3 Hydro-graph Generation (Transform)
Initially, the model determines how much incident rainfall is held in the watershed (losses), and how much
will appear as runoff That which appears as runoff is referred to as "excess precipitation " The model
then determines the time distribution of this excess precipitation as it flows across the land surface or as
` shallow sub - surface flow (interflow), eventually reaching small drainage channels, tributaries and the main
stem The resulting time distribution of runoff at a given location is referred to as the "hydrograph " HEC-
HMS offers a variety of methods for transforming excess precipitation from any given storm Into a runoff
(- hydrograph for each model drainage area
Cardno ENTRIX selected the Soil Conservation Service (SCS) Unit Hydrograph (UH) transform method
The SCS UH method requires one input time of concentration (T,) Tc values were calculated for each of
-- the sub - basins based on travel path, length and slope, over the various surfaces and channels used for
conveyance The SCS UH parameters applied in the modeling are listed in Table 5 -2 and Table 5 -3, for
Undeveloped and Future conditions
July 2013 Cardno ENTRIX 5-4

i
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 5 -2 SCS Unit Hydrograph Time of Concentration Results for Undeveloped Conditions
Catchment
ID
Total Flow
Length
(feet)
Channel
Length
(feet)
Channel
Slope
Travel
Time
,
(min)
Sheet Flow
Length
(feet)
Surface
S
Slope
Travel
Time
s
(min)
NC Travel
Time
e
(min)
SCS
Basin Lag
(min)
Total Travel
Time
(min)
1
1045
745
005
6
300
004
11
261
24
32
2
1100
800
007
7
300
005
10
244
23
31
3
1350
1,050
006
9
300
009
9
191
26
28
4
1050
750
007
6
300
007
9
206
22
27
5
620
320
Oil
3
300
007
9
207
15
23
6a
1000
700
005
6
300
003
12
302
23
36
6b
1050
750
008
6
300
003
12
302
21
36
7
1220
920
008
8
300
002
13
322
23
40
8
880
580
006
5
300
001
16
449
21
50
9
1360
1,060
005
9
300
001
17
489
28
58
10
1,555
1,255
003
10
300
003
12
285
34
39
11
1030
730
005
6
300
003
11
279
23
34
12
1130
830
005
7
300
001
15
409
25
48
'Velocity det from Manning's equation, roughness of 0 04, 2 foot bottom width, 1 1 side slopes
2Travel time det from Kinematic wave theory, with Manning roughness of 0 04 and 1" of rainfall
3USAGE Publication EM 1110 -2 -1417
"300 feet is considered the longest sheet flow before concentrated flow forms
5Charlotte Mecklenburg Storm Water Design Manual (Section 3 9 6 3 equation 3 21)
July 2013 Cardno ENTRIX 5 -5

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 5 -3 SCS Unit Hydrograph Time of Concentration Results for Future Conditions
'Velocities Estimated Using USDA SCS Curves (shown below)
2Velocities Derived using FlowMaster
'Assumed 14" concrete pipe (n = 0 013)
bFlowing 50% full (normal depth is 0 5Diameter)
'Velocity = 2ft/s (previous calculation assumption)
July 2013 Cardno ENTRIX 5 -6
Roof Tops
Pavement'
Pipet
Natural
Total
Catchment
Number
Length
(feet)
Travel
Time
[min]
Length
(feet)
Slope
Velocity
I�sl
Travel
Time
[min]
Length
(feet)
Slope
Velocity
I�sl
Travel
Time
[min]
Length
(feet)
Slope
Velocity
I�sl s
Travel
Time
[min]
Travel
Time
[min]
1
112
3
10
10%
200
008
1363
13%
571
40
292
41%
2
24
950
2
0
0
0
N/A
N/A
N/A
0
N/A
N/A
N/A
1110
49%
2
93
3367
3
84
3
294
24%
3
163
657
41%
1014
1 1
78
90%
2
07
636
4
0
0
0
N/A
N/A
N/A
0
N/A
N/A
N/A
670
75%
2
56
2616
5
97
3
251
32%
35
120
860
45%
1062
13
41
73%
2
03
589
6
0
0
0
N/A
N/A
N/A
0
N/A
N/A
N/A
2348
29%
2
196
4979
7
97
3
114
53%
45
042
216
60%
1227
03
123
24%
2
10
474
8
70
3
117
09%
2
098
1065
30%
882
20
377
11%
2
31
913
9
0
0
227
22%
27
140
526
68%
95
09
583
09%
2
49
718
10
0
0
0
N/A
N/A
N/A
0
N/A
N/A
N/A
1213
33%
2
101
3863
11
0
0
0
N/A
N/A
N/A
0
N/A
N/A
N/A
1002
35%
2
84
3623
12
90
3
324
40%
39
138
1523
23%
759
33
447
13%
2
37
1145
'Velocities Estimated Using USDA SCS Curves (shown below)
2Velocities Derived using FlowMaster
'Assumed 14" concrete pipe (n = 0 013)
bFlowing 50% full (normal depth is 0 5Diameter)
'Velocity = 2ft/s (previous calculation assumption)
July 2013 Cardno ENTRIX 5 -6

Site Specific Mitigation Plan
Monteith Park Mitigation Site
524 Reach Routinq
HEC -HMS provides a variety of reach routing methods to translate the hydrograph from one drainage
area downstream to a point where it can be combined with another runoff hydrograph We selected the
Muskingum -Cunge method (USACE 2000), which uses basic channel dimensions and characteristics to
estimate hydrograph translation and attenuation over the routing reach For existing and future
conditions, surveyed cross - section data were used to characterize channel shape and characteristics for
reach routing Table 5 -4 summarizes the final reach routing parameters Each reach was defined by an
8 point channel shape
Table 5-4 Muskingum -Cunge Reach Routing Parameters
Reach
Length
(ft)
Slope
(ft/ft)
Roughness
Coefficients
Main stem
Reach -1
526
00200
004
Reach -2
406
00045
004
Reach -3
464
0 014
004
Reach -4
589
00053
004
Reach -5
633
00075
004
Tributary Channel
Reach -7
580
0 0600
004
5.2.5 Precipitation
The purpose for using the continuous rainfall record is to capture all the variability in rainfall patterns The
time series is important for tracking soil moisture over time and accounting for the seasonality variation in
rainfall and runoff The time series represents the full probability distribution of storms, and as such
allows the model to predict distributions of runoff and stream discharges for analysis Data from two
I
precipitation gage stations were considered for use in the modeling Charlotte- Douglas NCDC Gage
311690 and Mooresville NCDC Gage 315814 The project site is located in between these two gage
stations The 62 year record begins in June 1948 and ends in May of 2010
Figure 5 -2 presents the total annual precipitation volumes for each year in the record The variation from
year to year is similar, although the Charlotte - Douglas gage location receives greater precipitation
volumes The range in total annual rainfall volume for Charlotte - Douglas is 26 to 72 inches The range in
total annual rainfall volume for Mooresville is 18 to 62 inches The average total annual rainfall volume at
Charlotte- Douglas and Mooresville is 42 inches and 38 inches, respectively Figure 5 -3 presents a log -
probability plot comparing precipitation intensities (inches per hour) These results suggest that both
gages are similar in precipitation intensities As an example, the mean rainfall intensity is about 1 2
inches, and the 80th percentile is about 1 8 inches Lastly, Figure 5 -4 presents the average monthly
volumes for each gage, and illustrates the seasonal similarities Rainfall appears to be fairly uniform from
month to month, with March producing the most precipitation (3 9 to 4 4 inches) and Oct/Nov producing
the least (2 6 to 3 1 inches)
�I
July 2013 Cardno ENTRIX 5 -7

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Distribution of Total Annual Precipitation Volume
NC DC Gage 311690 ■ NCDC Gage 315814
80
70
60
a�
t
= 50
c
0
Z. 40 n
m
a
30
s
r
i
20 K
is
10
1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 2006 2010
Figure 5 -2 Comparison of Annual Precipitation Volumes between Charlotte - Douglas (311690) and Mooresville (315814)
July 2013 Cardno ENTRIX 5 -8

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Comparison of Charlotte and Mooresville Precipitation
Log Probability Plot
10
L '
O
rn
U
C
c 1
0
M
.Q
a�
L
a
0 Gage 311690 o Gage 315814
01
L N co d' C0 r` tp CA LO O
O O O O O O O O O O O O
O O O O
Probability of Occurrence
Figure 5 -3 Comparison of Precipitation Intensity Charlotte - Douglas (311690) and Mooresville (315814)
July 2013 Cardno ENTRIX 5 -9

5.0
4.5
4.0
N
t 3.5
(D 3.0
> 2.5
_
0
r 2.0
IL 1.5
1.0
0.5
0.0
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Seasonal Distribution in Average Monthly Precipitation Volume
aNCDC Gage 311690 ■NCDC Gage 315814
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 5 -4 Comparison of Seasonal Precipitation Volumes Charlotte - Douglas (311690) and Mooresville (315814)
July 2013 Cardno ENTRIX 5 -10
f'
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 5 -4 Comparison of Seasonal Precipitation Volumes Charlotte - Douglas (311690) and Mooresville (315814)
July 2013 Cardno ENTRIX 5 -10

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Both gage records could be used, however, we selected Charlotte - Douglas as the best representative
gage for Monteith The Charlotte - Douglas gage was selected because it was most complete, having the
longest record and the least amount of missing data
It Is recognized that measured rainfall from nearby gages is an approximation of rainfall that occurs
across the project site Actual rainfall rates vary spatially and in Intensity Thus, while measured rainfall
at the Charlotte - Douglas gage represents an Important estimate of rainfall for the project site, variations
during any Individual storm do occur
5.2.6 Evapotranspiration and Canopy Loss
Evapotranspiration data (Eto) was obtained for seven locations In the North Carolina region Four of the
closest gage data along with the associated crop coefficients are summarized in Table 5 -5 Due to the
proximity to the project site, the Charlotte WSO gage was used as Input to the model The sum total of
monthly measured evapotranspiration is 58 -in /yr with rates based on reference values for turf grass The
crop coefficients are required to adjust these values to the local prevailing land cover Monthly crop
coefficients (kc) listed in Table 5 -5 were selected for perennial pasture, and accounts for higher Eto rates
during the growing season and lower rates In the dormant season
Table 5 -5 Evapotranspiration Data
NOAA Technical Report NWS 34, Mean Monthly, Seasonal, and Annual Pan Evaporation for the US, R K Farnsworth and E S
Thompson, Dec 1982
5.3 Analytical Assessment
Figure 5 -5 presents the flood frequency curves for peak flows using multiple methods for comparison
Results from the hydrologic model (HEC -HMS) are presented for undeveloped, existing and future
development conditions Published regional curve results for bankfull flow (approximately the 2 -year
event) in North Carolina streams are included for rural and urban land uses The USGS Regional
Regression equation for North Carolina has also been added
The results show good agreement among the undeveloped HMS models, the NC Rural regional curve for
bankfull flow (Doll et al 2002), and the USGS Regional Regression equations for rural areas The NC
Urban regional curve estimates a 2 -year discharge greater than that being predicted by the HMS model
The existing and future flows produced from the HMS model are greater than the rural /no development
equations due to the Inclusion of impervious area The difference between the existing and future HMS
results is the addition of the planned school in the upper portion of the Monteith watershed
July 2013 Cardno ENTRIX 5 -11
Jan
Feb
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
Asheville
05
063
1 35
265
433
583
636
576
411
24
1 03
056
Charlotte
WSO
1 95
244
407
604
7 16
763
764
706
545
387
27
207
Raleigh
201
244
1 4
581
638
687
689
625
1 488
356
271
2 15
Wilmington
21
264
421
635
731
724
753
64
534
4
286
239
Crop Coef
040
075
1 05
1 05
1 05
1 05
1 05
1 05
1 05
096
000
000
NOAA Technical Report NWS 34, Mean Monthly, Seasonal, and Annual Pan Evaporation for the US, R K Farnsworth and E S
Thompson, Dec 1982
5.3 Analytical Assessment
Figure 5 -5 presents the flood frequency curves for peak flows using multiple methods for comparison
Results from the hydrologic model (HEC -HMS) are presented for undeveloped, existing and future
development conditions Published regional curve results for bankfull flow (approximately the 2 -year
event) in North Carolina streams are included for rural and urban land uses The USGS Regional
Regression equation for North Carolina has also been added
The results show good agreement among the undeveloped HMS models, the NC Rural regional curve for
bankfull flow (Doll et al 2002), and the USGS Regional Regression equations for rural areas The NC
Urban regional curve estimates a 2 -year discharge greater than that being predicted by the HMS model
The existing and future flows produced from the HMS model are greater than the rural /no development
equations due to the Inclusion of impervious area The difference between the existing and future HMS
results is the addition of the planned school in the upper portion of the Monteith watershed
July 2013 Cardno ENTRIX 5 -11

Peak Discharges at the Dov
t (HMS)
al Curve
'
1 i
;egression for Rural
i
iM5)
I
MS)
-ial Curve
i
i
♦ �
/-ice
1
i
1
I
j
i
i
1 I
i I
1
1(
Recurrance
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Figure 5 -5 Comparison of Peak Discharges at the Downstream Location of Monteith
July 2013 Cardno ENTRIX 5 -12

Site Specific Mitigation Plan
Monteith Park Mitigation Site
5 3 2 Most Effective Discharge
An Important flow rate for natural channel design Is the "most effective" discharge (I e , bankfull) The
most effective discharges are those flows that carve the active channel Into the landscape The active
channel Is the main creek channel that carries frequent flows up to an elevation referred to as bankfull or
the Incipient point of flooding The capacity of this channel is referred to as bankfull flow or the most
effective discharge
The Cardno ENTRIX approach applies analytical methods to directly compute the most effective
discharge given site specific conditions The most effective discharge is considered the most reliable
estimate of the channel forming discharge The most effective discharge is particularly Important to
estimate correctly when the hydrologic and sediment regimes are altered under agrarian and urban land
use because the design must balance the Imposed flow energy, sediment transport needs, and resistance
of the channel boundary based on the velocity and shear stress associated with the most effective
discharge Cardno ENTRIX geomorphologists Identified field Indicators of the most effective discharge
throughout the project site These Indicators Included the height of depositional landforms (such as Inset
floodplains), undercuts or scour Imes, vegetation Imes, and topographic breaks In bank slope This
geophysical Information coupled with modeling analytics were evaluated to determine the most effective
discharge for the purpose of design
The culmination of this effort is presented in Figure 5 -6 for Cross Section 17 in Reach 5 of the project
The Work Curve represented in Figure 5 -6 was conducted for all cross sections but for the purpose of this
section only Cross Section 17 is discussed Using geomorphic data collected from the existing conditions
survey, the existing channel geometry was input into HEC -HMS The precipitation data and other
watershed characteristics outlined above where input to describe a multitude of storm frequencies over
the undeveloped, developed, and future watershed conditions An output of the HEC -HMS model is the
amount of excess shear, or work, on the channel boundary as described by the input channel geometry
over varying discharge simulations This analysis provides insight into the range of discharges that create
conditions for excessive erosion potential The discharges that cause the most erosion potential are then
identified as the channel forming flows and can be estimated to be the most effective discharge Figure
5 -6 displays the excess shear as a percentage of total shear for comparison across the three watershed
conditions The excess shear Is represented as bars in the chart, while the Imes define the work curve for
the undeveloped, developed, and future watershed conditions
The conclusion drawn from Figure 5 -6 is twofold, for highly urbanized watersheds, the most effective
discharge occurs at smaller discharges over a narrower range of flow The existing developed and future
build out conditions Include high imperviousness and low evapotranspiration while Incorporating drainage
structures that are designed to move water out of the system quickly and efficiently through concentrated
flow These conditions create powerfully flashy systems that cause storm events to quickly rise in stage
Therefore for all storm events, the watershed provides more water in a shorter time to the stream channel
which increases velocity at lower stages within the channel boundary and thus creates more shear for
smaller discharges This can be seen in Figure 5 -6 when comparing the percentage of work occurring In
the 2cfs to 10cfs range For the undeveloped watershed, the amount of excess shear Is approximately
7% whereas the existing developed and future build out watersheds are approximately 25% Urbanized
systems also have inherent limitations as their design Is limited to a certain set of storm events These
events establish the sizing of pipes and routing patterns of drainage structures This drainage system
then has the ability to conform other storm events into the designed routing thus limiting the overall range
of discharges Figure 5 -6 Illustrates this phenomenon by the steep Increase In work around the 2 cfs
range and by the Insignificant amount of work performed In the larger discharges under the tall of the
work curve The system Increases velocities In the smaller events thus Increasing work while either
limiting or diverting flow In larger events thus conforming all events Into the designed discharge range
July 2013 Cardno ENTRIX 5 -13

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Therefore in developed watersheds, the amount of work performed within a stream channel is increased
at lower discharges and the range of discharges over which the work is performed is narrower
For the Monteith Park Mitigation Site, Cardno ENTRIX evaluated the undeveloped, existing and future
development work curves to identify the design discharge for the active channel For Cross Section 17,
Reach 5, the geomorphically significant flows are estimated to range from 6 cfs to 20 cfs under no
development, and 4 to 8 cfs under future development Table 5 -6 summarizes the range of
geomorphically significant flows for all cross sections and reaches Illustrated in Figure 2 -4
July 2013 Cardno ENTRIX 5 -14

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Distribution of Effective Work Done on the Channel Boundary
(Cross Section 17, Reach 5)
U) 30%
N ■ Undeveloped Watershed Runoff ■ Existing Development o Future Build -Out
-rL ^^
VJ
a>
25%
cr)
cn
q) 20%
X
w
_ !
a�
15%
Q 10%
76
O 5%
U
L
a_ 0%
04 O O O M M
Flows (cfs)
Figure 5 -6 Comparison of Pre- and Post - Development Distributions of Work Done
July 2013 Cardno ENTRIX 5 -15

E
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 5 -6 summarizes the range of geomorphically significant flows for all cross sections and reaches
Illustrated in Figure 2 4 The urban watershed increases the frequency of smaller flows more than the
frequency of higher flows, and concentrates the amount of work done Into a narrower range
Table 5 -6 Summary of Geomorphically Significant Flows for Design of the Active Channel
Cross Section
Slope
Flow
Junction
Most Effective Discharge (cfs)
Design Flow
for Active
Channel (cfs)
Undeveloped
At Build -Out
XS -1
0 028
J1
2 -3
1-25
2
XS -2
0 028
J1
4-6
2 -5
2
XS -3
0 028
J1
2 -6
15-25
2
XS -5
0 016
J2
3 -6
2 -5
4
XS -6
0 016
J2
3-6
2 -5
4
XS -7
0 016
J2
3-6
1-35
4
XS -8
00045
J2
8 -14
6 -8
4
XS -9
00045
J3
4 -7
2 -5
4
XS -10
0 014
J3
4 -10
2 -5
4
XS -11
0 014
J3
4 -10
2 -5
4
XS -12
0 014
J3
4 -10
2 -5
4
XS -13
0 012
J4
4 -13
2 -8
5
XS -14
0 012
J4
4 -13
4 -8
5
XS -15
00053
J4
6 -17
4 -8
5
XS -16
00053
J4
6 -17
4 -8
5
XS -17
001
J5
6 -20
4 -8
6
XS -18
00075
J5
6 -20
4 -8
6
XS -19
00075
J5
6 -20
4 -8
6
XS -20
00075
J5
6 -20
4 -8
6
5.4 Geomorphology
5 4 1 Active Channel Width
Determining the active channel width is the first step in developing the proposed channel geometry
Based on the channel forming discharge, the active channel width can be determined using a known
relationship According to Soar and Thorn (2001), the relationship between channel forming discharge
and channel width is the most reliable as it has the least statistical variability among the 270 data sets
evaluated Thus, using 6 cfs as the design discharge example, the average active channel width was
computed using published hydraulic geometry equations Results for eight equations, including published
equations for sand bedded systems, cohesive channel banks, and low or high vegetation density, are
_ shown in Figure 5 -7 (Knighton, 1998) and illustrate the range of possible results
July 2013 Cardno ENTRIX 5 -16

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Figure 5 -7 Predicted Bankfull Channel Widths from Hydraulic Geometry
July 2013 Cardno ENTRIX 5 -17
Published Hydraulic Geometry for Width
100
o
95/o Confidence Bounds
6.5 to 7.5 feet, mean =7 feet
Soar & Thorne (2001), <50% veg cover
�
—
I
I
_
- -.__ _....
- --
j
..
-�
.........
- ........... .. _..... -...
...._......
- -
-
-
- ...
- - -
-
,
-
_.._.
....... --
-
-
l
i
- -- a
---
- --
_,
...i
- - - --
- - ....-
-
�
1�
95% Confidence Bounds
4 to 5 feet, mean =4.5 feet
� I
Soar & Thorne (2001), >50% veg cover
{
1
0 1
6 10
100 1000
Bankfull Discharge (cfs)
* Lacey (1929), canals with sand
• Leopold et al. (1953), fine sediment
Mahmood et al. (1979), canals with sand
■ Church (1992), canals with sand
Simons and Albertson (1963), sandy banks
x Simons and Albertson (1963), cohesive banks
• Soar & Thorne, sand bed, cohesive banks, <50% veg cover
• Soar & Thorne, sand bed, cohesive banks, >50% veg cover
Figure 5 -7 Predicted Bankfull Channel Widths from Hydraulic Geometry
July 2013 Cardno ENTRIX 5 -17

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Another objective is to provide flow connectivity to floodplain surfaces at the proper frequency. Under
normal conditions, flood flows begin to spill out of the active channel at bankfull, with larger events
flooding more and more of the floodplain surfaces. The release of flood flows onto floodplains reduces
hydraulic forces on the active channel and promotes long -term stability. With incised systems, larger
flood flows are contained in the main channel intensifying erosive energy and impacts. Therefore the
proposed channel geometry will be developed to allow larger than bankfull flows to have access to the
floodplain.
Soar and Thorn (2001) developed a statistical relationship using 270 data sets to compute the range of
possible solutions with 95% confidence limits. Based on this statistical relationship the predicted channel
width ranges from 6.5 to 7.5 feet (95% confidence limits) for cohesive banks and low vegetation density.
With an increase in bank cohesiveness and vegetation density due to channel maturation over time, the
channel widths could be within four to five feet (95 percent confidence limits).
5.4.2 Planform Dimensions
Another reasonably reliable hydraulic geometry equation is the relationship between active channel width
and meander wave length (Soar & Thorn 2001). Planform is estimated from published hydraulic
geometry equations or reference information. Hydraulic geometry equations that estimate wavelength as
a function of flow or width are most accurate.
Figure 5 -8 illustrates the planform dimensions of interest; where:
L =meander wavelength
A = meander amplitude
W = active channel width
B = Belt Width = (A +W)" (1.2) Rm = radius of curvature
Figure 5 -8 Meander Pattern and Associated Variables of Interest
S
Meander wavelength averages about 11 times the channel width and is nearly always between 10 and 14
channel widths. Using this rule -of- thumb, wavelength ranges from 24 to 63 feet, depending on changes
in flows by reach. Using Soar & Thorn's statistical approach, the wavelength ranges from 27 to 56 feet,
depending on changes in flows by reach ( ±95% confidence limits).
Using Leopold and Wolman (1964) and a width of 4.5 feet; the average meander amplitude is estimated
to range from 6 to 17 feet. For Belt Width, we add an additional 20 percent to the floodway to allow room
for channel migration. The radius -of- curvature is commonly in the range of two to three times the active
channel width. Using this rule -of- thumb, the predicted radius -of- curvature is 5.2 to 14 feet. Using
Leopold and Wolman (1964) the predicted average radius -of- curvature could range from 5 to 14 feet.
July 2013 Cardno ENTRIX 5 -18

Site Specific Mitigation Plan
Monteith Park Mitigation Site
These various equations provide consistent results for design The range in design values provides
ample flexibility to fit sit conditions and constraints
5.5 River Mechanics
River mechanics involves a combination of modeling and analytical assessments to evaluate the
influence of watershed discharges (stream flows) on the creek channel's erodible boundary Part of river
mechanics is the determination of stable rock sizes in the design of engineered structures, such as grade
I control or riffles The analysis considers the bed separately from the banks, which consists of compacted
and /or cohesive soils and vegetation In sediment limited systems, cohesive channel boundary materials
control channel form more than sediment load and transport, and as such an excess shear stress model
was applied in our analysis This approach strives to rebalance the applied shear forces with the
resilience of bank material, including the influence of vegetation and other armoring materials (e g ,
biotechnical solutions) Transport capacity and excess shear are controlled by adjusting the active
_ channel longitudinal slope and depth relative to floodplain surfaces Slope is maintained by adding in-
stream structures, such as grade control or riffle structures
5 5 1 Channel Geometry & Longitudinal Slope
This section summarizes the active channel depth and slope requirements for the Monteith Creek
restoration Given the estimated bankfull discharge, estimated active channel width and floodway width,
the excess shear stress results were evaluated in terms of transport characteristics that re- balance the
relationship between flow, sediment load and channel resilience
Figure 5 -9 presents an example cross section evaluated for design purposes The design process
involves selecting a range of possible longitudinal slopes and depth combinations and computing total
effective shear and total sediment load over a period of record Combinations of slope and depth are
iteratively tested until the optimum combination achieves the design criteria of pre - development
conditions
Example Design Cross Section for Reach 5
40
E
15 35
- - - -- -� - - -- -
- -- -- - I — - -- -
-- -- - --
30
- - --- -- - - -- -
---- - - - -f- - - - - - -- -
- - -- -
25
- - -- -
- --
--
- - - --
I -— - - { -- - - - --
{
0 15
- - -- -- - - -
-
- - - -- - -� - -- - - -- - - - -I
- - -- I -- -
m
10
05
- --
- --- - --r --
--
I
00
0 10 20 30 40 50 60 70
Station (feet)
Figure 5 -9 Example Design Cross Section for Reach 5
Figure 5 -10 illustrates the results of performing this iterative step -wise procedure The chart plots the
total excess shear stress (work) done on the individual cross sections over the 62 year period of record
The figure depicts the difference in the magnitude of work under undeveloped watershed conditions
compared to developed watershed conditions As shown, the amount of erosive stream power is as
much as 10 times greater under developed conditions This is the cause of channel degradation, incision
and widening
July 2013 Cardno ENTRIX 5 -19

Site Specific Mitigation Plan
Monteith Park Mitigation Site
The goal of our channel design process is to adjust the longitudinal slope until we reduce Work done on
the channel to undeveloped conditions. As shown in Figure 5 -10, the design channel geometry with
predicted equilibrium slopes reduces the erosive potential of flows to a narrow range well within the
undeveloped watershed condition. The design maintains more natural rates of erosion and transport.
The estimated bed slope for stable cross - sections ranges from 0.0062 in Reach 5 to 0.0103 in Reach 1.
The analysis of slope using the excess shear stress determined that slopes of 0.012 ft/ft up to 0.048 ft/ft
would be shallow enough for maintaining long -term stability.
Figure 5 -10 Chart of Pre and Post Development Work Done
5.5.2 Final Stream Design Parameters
Table 5 -7 summarizes the final geomorphically stable design parameters for each designated cross -
section of the project. Design parameters vary by cross - section, and by a change in flow from additional
storm water runoff. The first four columns list cross - section specific data. The remaining columns
summarize the results of the design process. Bankfull width and planform have acceptable ranges with a
±95 percent confidence level and their mean value provided. Estimates of planform dimensions are
based on the mean width value. Adjustments in the field can be made to fit site conditions as long as the
parameters stay within this acceptable range.
July 2013 Cardno ENTRIX 5 -20
Total Work Done on
Channel Boundary
10000
�
o
�C)
C
O
o X
o $ 1000
Trib 1
}design
100
Undeveloped
Developed
Designated
Condition
Figure 5 -10 Chart of Pre and Post Development Work Done
5.5.2 Final Stream Design Parameters
Table 5 -7 summarizes the final geomorphically stable design parameters for each designated cross -
section of the project. Design parameters vary by cross - section, and by a change in flow from additional
storm water runoff. The first four columns list cross - section specific data. The remaining columns
summarize the results of the design process. Bankfull width and planform have acceptable ranges with a
±95 percent confidence level and their mean value provided. Estimates of planform dimensions are
based on the mean width value. Adjustments in the field can be made to fit site conditions as long as the
parameters stay within this acceptable range.
July 2013 Cardno ENTRIX 5 -20
�
■ Trib 2
Figure 5 -10 Chart of Pre and Post Development Work Done
5.5.2 Final Stream Design Parameters
Table 5 -7 summarizes the final geomorphically stable design parameters for each designated cross -
section of the project. Design parameters vary by cross - section, and by a change in flow from additional
storm water runoff. The first four columns list cross - section specific data. The remaining columns
summarize the results of the design process. Bankfull width and planform have acceptable ranges with a
±95 percent confidence level and their mean value provided. Estimates of planform dimensions are
based on the mean width value. Adjustments in the field can be made to fit site conditions as long as the
parameters stay within this acceptable range.
July 2013 Cardno ENTRIX 5 -20

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 5 -7 Summary of Resulting Geomorphically Stable Channel Dimensions
Source
'Computed work curves, balanced energy for 60 years of record
2Soar & Thorne, 2001, >50% vegetation density
'Assumes 1 5 1 side slopes
July 2013 Cardno ENTRIX 5 -21
Bankfull Dimension
Planform (S)
Tau
Design
Width
Mean
Egwl
WID
Wave
Length
Belt
Crosssection
Critical
Disch'
Ra2ge
Width
Slope4
Depths
Ratio
low high
Radius
Amplitude
Width
(lbslsq
(cfs)
(ft)
(ft)
(fuft)
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
.ft)
1;
XS -1
C
023
2
28to
26
3010
605
27
32
5to8
6to9
14
2
043
XS -2
3
M
XS -3
M
XS -5
c
3
2 9 to
32
0 008
052
615
33
40
6 to
9 to 12
18
XS -6
XS -7
c023
3 4
3
10
XS -8
XS -9
XS-
M
10
0
0 23
4
3 4 to
3 7
0 008
057
649
38
46
7 to
10 to 14
21
XS-
4
0
11
�
11
rXS-
12
XS-
13
LO
XS-
0
14
023
5
3 8 to
41
0 007
063
651
42
51
8 to
12 to 16
24
XS-
44
2
12
15
XS-
16
XS-
17
XS-
LO
0
18
023
6
4 1 to
45
0 006
070
643
46
56
9 to
14 to 17
26
XS-
49
2
14
=3
19
XS-
20
Source
'Computed work curves, balanced energy for 60 years of record
2Soar & Thorne, 2001, >50% vegetation density
'Assumes 1 5 1 side slopes
July 2013 Cardno ENTRIX 5 -21

Site Specific Mitigation Plan
Monteith Park Mitigation Site
°Computed by balancing work done on the channel boundary
5Resulting depth of flow during bankfull discharge, given mean width and estimated slope
6Soar & Thorne, 200, Leopold & Wolman, 1960, Williams, 1984
5 5 3 Grade Control & Drop -Pool Structures
-- In- stream structures are required to re- establish long -term vertical stabilization of the stream bed and
provide channel habitat features The Monteith Creek restoration design Incorporates approximately 20
grade control structures, Including drop -pool structures and riffle structures made of rock and wood
These structures are designed to provide passage for aquatic animals and be stable during storm Other
structural elements Include bank stabilization measures using bioengineering techniques These may
Include vegetation planting, erosion control fabrics, brush mattresses, and soil layering
Drop -pool or step -pool structures are being used to provide vertical stabilization during high flow and In-
stream habitat during low -flow Drop -pool structures are designed to be stable during storm flows The
arrangement and size of the boulders contribute to the structures stability Stability Is provided by boulder
mass, and by Interlocking the weir and anchor boulders together during placement The alternating
sequence of supercritical flow over the steps and subcrltical flow In the pools provides the ability to
overcome steep slopes by energy dissipation mainly through the formation of roller eddies and
turbulence Natural step -pool formation requires near - critical to supercritical flow conditions The addition
of the drop structures helps maintain a low stream slope within the other reaches
' Pool dimensions are based on the paper 'A Design Procedure for Sizing Step -Pool Structures" published
by Thomas, D B , Abt, S R, Mussetter, R A, Harvey, M D Thomas, et al (2004) studied coarse - grained
streams to Identify the geomorphic and hydraulic characteristics of natural step -pool structures From this
study, they develop a design procedure for sizing and spacing step -pool structures Regression
equations were developed to determine pool length, scour depth, maximum pool width, and the amount of
contraction required to provide downstream tall water control Independent variables Included step
height, channel slope, discharge, and active channel width Other requirements Included confinement of
flow over the weir, a low -flow notch, adequate tall water control and bank protection In the downstream
pool The design centers around the placement of a few key boulders termed anchor boulders (footer
boulders) that are the largest rock and are 36 Inches In diameter
The computation of pool dimensions requires certain project specific Information, Including drop height,
average channel width, average channel slope and 100 -year discharge (cfs) Table 5 -8 summarizes the
Input values and the resulting size requirements Applying the above methodology, the resulting pool
length ranges from 5 8 to 7 4 feet and pool width ranges from 3 0 to 6 0 feet The pool rock size Is
estimated to be 1 5 to 3 5 Inches and the maximum pool depth should be 1 4 feet
July 2013 Cardno ENTRIX 5 -22
Bankfull Dimension
Planform (6)
Tau
Design
Width
Mean
Equll
WID
Wave
Length
Belt
Crosssection
Critical
Dischl
Ra2ge
Width
Slope"
Depths
Ratio
low high
Radius
Amplitude
Width
(lbslsq
(cfs)
(ft)
(ft)
(ftlft)
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
-ft)
°Computed by balancing work done on the channel boundary
5Resulting depth of flow during bankfull discharge, given mean width and estimated slope
6Soar & Thorne, 200, Leopold & Wolman, 1960, Williams, 1984
5 5 3 Grade Control & Drop -Pool Structures
-- In- stream structures are required to re- establish long -term vertical stabilization of the stream bed and
provide channel habitat features The Monteith Creek restoration design Incorporates approximately 20
grade control structures, Including drop -pool structures and riffle structures made of rock and wood
These structures are designed to provide passage for aquatic animals and be stable during storm Other
structural elements Include bank stabilization measures using bioengineering techniques These may
Include vegetation planting, erosion control fabrics, brush mattresses, and soil layering
Drop -pool or step -pool structures are being used to provide vertical stabilization during high flow and In-
stream habitat during low -flow Drop -pool structures are designed to be stable during storm flows The
arrangement and size of the boulders contribute to the structures stability Stability Is provided by boulder
mass, and by Interlocking the weir and anchor boulders together during placement The alternating
sequence of supercritical flow over the steps and subcrltical flow In the pools provides the ability to
overcome steep slopes by energy dissipation mainly through the formation of roller eddies and
turbulence Natural step -pool formation requires near - critical to supercritical flow conditions The addition
of the drop structures helps maintain a low stream slope within the other reaches
' Pool dimensions are based on the paper 'A Design Procedure for Sizing Step -Pool Structures" published
by Thomas, D B , Abt, S R, Mussetter, R A, Harvey, M D Thomas, et al (2004) studied coarse - grained
streams to Identify the geomorphic and hydraulic characteristics of natural step -pool structures From this
study, they develop a design procedure for sizing and spacing step -pool structures Regression
equations were developed to determine pool length, scour depth, maximum pool width, and the amount of
contraction required to provide downstream tall water control Independent variables Included step
height, channel slope, discharge, and active channel width Other requirements Included confinement of
flow over the weir, a low -flow notch, adequate tall water control and bank protection In the downstream
pool The design centers around the placement of a few key boulders termed anchor boulders (footer
boulders) that are the largest rock and are 36 Inches In diameter
The computation of pool dimensions requires certain project specific Information, Including drop height,
average channel width, average channel slope and 100 -year discharge (cfs) Table 5 -8 summarizes the
Input values and the resulting size requirements Applying the above methodology, the resulting pool
length ranges from 5 8 to 7 4 feet and pool width ranges from 3 0 to 6 0 feet The pool rock size Is
estimated to be 1 5 to 3 5 Inches and the maximum pool depth should be 1 4 feet
July 2013 Cardno ENTRIX 5 -22

i
I
i
C,
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 5 -8 Summary of Estimate Drop -Pool Dimensions for Reaches Where These Features Will
be Applied
July 2013
Cardno ENTRIX
5 -23
25 -Year
Discharge
Bankfull
Width
(ft)
Weir
Width
(ft)
Drop
Height
(ft)
Pool
Length
(ft)
Max Pool
Width
(ft)
Pool
Depth
(ft)
D30
(inches)
XS -1
40
26
25
10
58
30
14
15
XS -2
XS -3
XS -5
68
32
30
10
63
40
14
22
XS -6
XS -7
XS -8
XS -9
80
37
35
10
65
50
14
25
XS -10
XS -11
XS -12
XS -13
115
41
39
10
70
50
14
31
XS -14
XS -15
XS -16
July 2013
Cardno ENTRIX
5 -23

Site Specific Mitigation Plan
Monteith Park Mitigation Site
5.6 Summary of Design
Based on field data, assessment of current conditions, hydrologic modeling calculated from current
drainage and specific channel parameters summarized above, Cardno ENTRIX has developed a detailed
restoration design plan for the Monteith Creek Watershed Appendix F contains the detailed engineering
plans The general design for the watershed is shown for both the upper reach (Figure 5 -24 -1) and lower
reach (Figure 5 -24 -2) of the completed restoration The design details the specifics of reach routing,
channel morphology, drop structure and pool placement, and relocation or replacement of existing
sidewalks and footbridges Also shown In the plans and figures are the new Best Management Practice
(BMP) designs
July 2013 Cardno ENTRIX 5 -24

Site Specific Mitigation Plan
Monteith Park Mitigation Site
6 Wetland Restoration Plan
The restoration of Monteith Creek watershed allows for the potential for restoration enhancement and
preservation of associated wetlands within the project site An independent sod review was conducted by
Nutter and Associates to determine the presence of any areas suitable for the restoration and /or
enhancement of historic wetlands Criteria for determining wetland restoration potential include the
presence of hydric soils and groundwater depth within the soils as well as the potential for those soils to
develop or retain the necessary properties after the completion of the restoration The scope of this
review was focused on the land adjacent to Reach 5 (assessment area 2) of the restoration plan
Based on the findings of the Nutter and Associates review, soil characteristics show a potential for
wetland restoration after channel modifications occur As stated previously, the wetland type according to
NCWAM results should be a floodplain Bottomland Hardwood Forest and therefore the current on -site
conditions receive a quality rating of LOW Due to the Incision and oversized nature of Monteith Creek,
Assessment Area 2 has been actively drained and should demonstrate wetland hydrology
Using the Lateral Effect Model (Ver 2 6 3 0, Skaggs et al , 2013), Cardno ENTRIX calculated the effect of
the ditched portion of Monteith Creek (Reach 5) on the adjacent historic wetlands The Lateral Effect
Model accounts for soil properties and uses drainage theory to determine the distance of hydrological
influence By restoring Monteith Creek and utilizing a shallow channel depth and more natural design, the
proposed wetland restoration area is expected to maintain adequate hydrology during periods of the
growing season and allow for increased flooding onto the adjacent floodplain Currently, Lateral Effect
predicts that Monteith Creek and Torrence Tributary #1 influence soils approximately 100 feet away for
the stream channel This number is based on inputs of current channel depth and soil type (Monacan
Loam) Channel restoration and soil modifications (ripping) should result in an elevated water depth at
this portion of the project site Increased overbank flooding adjacent to Reach 5 and an overall increase
in sustained groundwater table due to a shallower channel depth should result in significant wetland
restoration Torrence Tributary #1 Creek will still be an incised channel and will influence drainage of that
side of the restoration area, however, we expect significant hydrological improvements from restoring
Monteith Creek Ground water modeling and long term monitoring of the water table depths will determine
the success of the restoration effort
Figure 6 -1 Wetland Restorationdetads the expected wetland restoration area adjacent to Reach 5
Shown are the existing channel alignments of Monteith Creek and Torrence Tributary #1 and the
remaining lateral effect Torrence Tributary #1 will have on the adjacent lands Based on changes to the
hydrological conditions in this area, Cardno ENTRIX expects to restore approximately 0 94 acres of
Bottomland Hardwood wetlands (discussed in section 2 6 1) Overbank flooding from the restored
Monteith Creek, as well as altered groundwater runoff and surface storage will be important sources of
water for this wetland area Groundwater monitoring wells were installed in May 2013 to measure
conditions prior to and post construction
An additional wetland (assessment area 1) was delineated located within Reach 2 As previously stated,
this wetland type is classified ( NCWAM) as a Headwater Forest with a quality rating of HIGH The
proposed restoration project should result in the preservation of the 0 1 acre wetland at this location
July 2013 Cardno ENTRIX 6 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
Figure 6 -1 Wetland Restoration
July 2013 Cardno ENTRIX 6 -2
Wetland Restoration
V
�w•..na .vn ro,••e. o.
NbnlNtn 1ti09atlan Proffcl
N►etiYnOUryC WMy, N91T Cfralln�
Figure 6 -1 Wetland Restoration
July 2013 Cardno ENTRIX 6 -2

Site Specific Mitigation Plan
Monteith Park Mitigation Site
7 Stream Buffer and Vegetation Restoration Plan
Native riparian buffer and wetland vegetation will be established along the restored stream buffer and
wetland restoration areas following guidance outlined in the NC EEP Guidelines for R>panan Buffer
Restoration (2004) Non - native invasive species such as privet, mimosa and Japanese princess tree will
be removed prior to native plantings Mature tree species currently on the project site will be preserved
as much as feasibly possible during construction
7.1 Stream Buffer Vegetation
A minimum 50 foot buffer will be established along the restored stream corridor throughout the full extent
of the project Three planting zones will be established along the stream corridor and targeted species for
each zone will be planted Zone 1 includes the area from toe of slope within the channel to the outside
edge of the channel Zone 2 includes the area from this outside edge effect of the channel and all along
the lower flood plain bench Zone 3 includes the area from the floodplain bench to the upper slopes of the
remaining buffer zone that are not anticipated to see frequent flooding Figure 6 1 depicts the potential
Zone locations
Native tree and shrub species recommended for planting in all zones will be tolerant of moderate to high
moisture levels and partial to full sun exposure Planted tree species will include 90 percent bare root
seedlings and, 10 percent container stock canopy trees for Zones 2 and 3 with the intent on providing
some age diversity as well as species diversity Zone 1 will consist primarily of live stakes and shrub
species plantings In general, the target plant communities are Piedmont Alluvial Forests grading to
Mesic Mixed Hardwood Forest as described by Schafale and Weakley (1990) Figure 7 -1 shows a cross
section view of the zones and lists the recommended tree species to be planted A list of plants by zone
is also given in Table 7 -1 and a detailed planting plan is provided in Appendix H
July 2013 Cardno ENTRIX 7 -1

a
Elevation Above Stream Level
Figure 7 -1 Vegetation Zones for cross section of Monteith Creek
July 2013 Cardno ENTRIX 7 -2
Site Specific Mitigation Plan
Monteith Park Mitigation Site
Vegetation Zones
Zone 3a & 3b
Zone
2
Zone 1
Pignut hickory
Qya giabra
River birch
Betula nigra
Painted buckeye
Aesculus sylvatsca
Sdky dogwood Comus amormin
Mockemut hickory
Carya tomentosa
Shagbark hickory
Carya ovate
River birch
Betula nigra
Silky willow Sal. sericea
Redbud
Flowxnng dogwood
CerchC..ckniais
3a Corpus Ronda
Flowering dogwood
American holy
Cornusflorda
3b 11. opaca
American hornbeam
Silky dogwood
CarpiruicamBniana
Comus amorrum
Elderberry Samb.. canadensis
Vegetation
White Ash
Fracinus americana
Black walnut
hrglansnigra
Green ash
Frowns pennsylvan[a
gBlack
walnut
Aglans nigra
Tulip poplar
Urodendion tulipdera
Blackwatnut
luglam nigra
Tulip poplar
Uriodendmn tulipdera
Hophombeam
Owp vhrginrarw
Tulip poplar
Urkdendron tulrpifera
Hophombeam
Os"vugmwna
Sycamore
Platanus occrdentalis
Sycamore
Platanmoccdentahs
White Oak,
Qirercusalba
Southern Red Oak
Quercus falcata
Swamp Chesnut Oak
Quercusmkhauail
Red oak6°
%a-4?—r,3
Winged Elm
Ulmusalata
Swampwdbw
Salixarohnlana
B
+ t
y
Elderberry
Arrow wood
Sambucus canadensis
Viburnum dentatum
4
e
firm"
1�
aJr ...
a
Elevation Above Stream Level
Figure 7 -1 Vegetation Zones for cross section of Monteith Creek
July 2013 Cardno ENTRIX 7 -2

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Site Specific Mitigation Plan
Monteith Park Mitigation Site
Table 7 -1 Proposed Riparian and Wetland Vegetation
Common Name
Scientific Name
Percent Planted
Type
Zone 1 Stream Side Assemblage
Silky dogwood
Corpus amomum
35%
Live stake
Silky willow
Sala sencea
35%
Live stake
Elderberry
Sambucus canadensis
30%
Live stake
Zone 2 Floodplain and Wetland Restoration Areas
Silky dogwood
Corpus amomum
10%
Bare Root
Amencan hornbeam
Carpinus carolmiana
10%
Bare Root
Tulip poplar
Lmodendron tulipifera
10%
Bare Root
Elderberry
Sambucus canadensis
5%
Bare Root
Arrowwood
Vibumum dentatum
5%
Bare Root
Painted buckeye
Aesculus sylvahca
5%
Bare Root
Green ash
Fraxinus pennsylvanica
11%
Bare Root
Sycamore
Platanus occidentahs
15%
Bare Root
Swamp Chesnut Oak
Quercus michauxu
4%
Bare Root
Black walnut
Juglans nigra
5%
Bare Root
River birch
Betula nigra
15%
Bare Root
Zone 3a Floodplain Buffer
Southern Red Oak
Quercus falcate
15%
Bare Root
Tulip poplar
Linodendron tulipifera
10%
Bare Root
Flowering dogwood
Corpus flonda
10%
Bare Root
Sycamore
Platanus occidentahs
10%
Bare Root
Shagbark hickory
Carya ovate
10%
Bare Root
American holly
Ilex opaca
10%
Bare Root
Hophornbeam
Ostrya virgmiana
10%
Bare Root
Black walnut
Juglans nigra
10%
Bare Root
River birch
Betula nigra
10%
Bare Root
Winged elm
Ulmus alata
5%
Bare Root
Trees will be planted within two days upon arrival to the project site If constraints exists that prevent
planting within two days, provisions will be made for temporarily storing trees in shallow ditches with
abundant moisture Bare root and container trees will be planted by hand using planting tools and will
generally be planted at a target density of 680 stems per acres or on an eight by eight foot grid Live
stakes will be installed randomly two to three feet apart along the stream bank or at a density 150 to 350
stakes per 1,000 square feet along the stream bank
The buffer zone in the upper portions of Monteith Creek in Reach 1 and the upstream portions of Reach 2
are on the steepest portions of the project site Zones 1 and 2 of Reaches 1 and 2 will be planted with the
same tree species as is recommended for downstream reaches However, Zone 3 (referred to as 3b) will
July 2013 Cardno ENTRIX 7 -3

I i
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it
Site Specific Mitigation Plan
Monteith Park Mitigation Site
be planted with species common to Basic Oak - Hickory Forests as described by Shafale and Weakley
(1990) Recommended tree species to be planted in Zone 3 of these reaches are detailed in Table 7 -2
Table 7 -2 Proposed Floodplain Buffer Vegetation for Reaches 1 and 2
Common Name
Scientific Name
Percent Planted
Type
Zone 3b Floodplain Buffer
White Oak
Quercus alba
15%
Bare Root
Red oak
Quercus rubra
10%
Bare Root
Mockernut hickory
Carya tomentosa
10%
Bare Root
Pignut hickory
Carya glabra
10%
Bare Root
White Ash
Fraxmus amencana
10%
Bare Root
Tulip poplar
Linodendron tulipifera
10%
Bare Root
Flowering dogwood
Corpus Honda
10%
Bare Root
Redbud
Cercis Canadensis
5%
Bare Root
Hophornbeam
Ostrya virginiana
10%
Bare Root
Black walnut
Juglans nigra
10%
Bare Root
The seed mix has been selected to incorporate site stability and native species Seeding /planting should
be conducted during the spring and /or fall seasons to ensure success Table 7 -3 lists the species,
mixtures, and application rates that are recommended The species provided are deep- rooted and have
been shown to proliferate along natural stream channels, providing long -term stability This herbaceous
seed mixture should be applied to all channel banks and disturbed areas adjacent to the channel
Table 7 -3 Proposed Permanent Herbacaous Seed Mixture
Botanical Name
Common name
Rate (Ibs /acre)
Tolerance
Agrostis alba
Redtop
075
FAC
Agrostis stolonifera
Creeping bentgrass
075
FAC
Andropogon gerardii
Big blue stem
075
FAC
Andropogon glomeratus
Bushy blue stem
075
FACW+
Aristida stricta
Wiregrass
1 0
FAC
Carex lupulina
Hop sedge
1 0
OBL
Carex vulpinoidea
Fox sedge
1 0
OBL
Eleochans obtusa
Blunt Spike Rush
1 0
FAC
Elymus virginicus
Virginia wild rye
1 0
FAC
Juncus effusus
Soft rush
1 5
FACW+
Panicum virgatum
Switchgrass
075
FAC+
Schizachyrium scopanum
Little blue stem
075
FACU
Sorghastrum nutans
Indiangrass
05
FACU
10 -15 Ibs /ac
July 2013
Cardno ENTRIX
7-4

Site Specific Mitigation Plan
Monteith Park Mitigation Site
The planting plan includes the application of temporary seeding (rye grain, German millet and /or browntop
millet depending on time of year) for ground stabilization to meet new standards for the NPDES permit
All areas must be seeded and stabilized within seven days after work has ceased in a given area If
temporary seeding is applied from November through April, rye grain should be applied at a rate of 130
pounds per acre If applied from May through October, browntop millet should be used and applied at a
rate of 40 pounds per acre
A rolled erosion control product (RECP) should be utilized to provide stability and structure to recently
disturbed sods and along proposed channel slopes The matting should be applied from the top of bank,
across the flood bench and down to and keyed -in at the toe of the pilot channel Additionally, where
matting is applied, the recommended fertilizer, temporary seed mix, and permanent seed mix described
below along with landscaping straw should be applied underneath the RECP This will help to insure that
the seed mix does not wash away during storm events The recommended RECP for stream banks is
100 percent coconut fiber twine woven into high strength matrix (Rolanka BloD 70 or 700g Coir Fiber
Matting)
After seeding, a straw mulch layer should be applied on top of the seed layer A mixed fertilizer of 10
percent nitrogen, 10 percent potash, and 10 percent phosphate should then be applied at a rate of 750 to
1000 pounds per acre Fertilizer should be hand broadcast or distributed using a level spreader as evenly
as possible
July 2013 Cardno ENTRIX 7 -5

Site Specific Mitigation Plan
Monteith Park Mitigation Site
8 Performance Criteria and Monitoring
I Success criteria and a post - construction monitoring plan will be established by Cardno ENTRIX which will
i be available upon completion to the Interagency Review Team (IRT) Beginning in the first growing
season post - construction, the project site will be monitored for a period of five years The monitoring plan
! will incorporate the following aspects
1 Stream Channel Stability
2 Stream Water Quality and Macroinvertebrates
I 3 Planted Vegetation in Buffer and Wetland
4 Wetland Hydrology
5 Visual Monitoring
A schedule for monitoring events is shown in Table 8 -1 Monitoring reports will be prepared at the end of
each monitoring year and made available to the IRT by December 31st Detailed descriptions of
t monitoring activities are included below
July 2013 Cardno ENTRIX 8 -1

Site Specific Mitigation Plan
Monteith Park Mitioation Site
Table 8 -1 Monitoring Schedule
Year
Stream
Wetland
Pre - construction
Water Quality Monitoring
Delineation /Soil Survey
Macrobenthos monitoring
Year 0
As -Built Survey
As -Built Survey
Year 1
Vegetation Plot Monitoring
Vegetation Plot Monitoring
Stream Channel Stability
Wetland Hydrology Monitoring
Water Quality Monitoring (Twice)
Visual Monitoring (Twice)
Visual Monitoring (Twice)
Year 2
Vegetation Plot Monitoring
Vegetation Plot Monitoring
Stream Channel Stability
Wetland Hydrology Monitoring
Water Quality Monitoring (Twice)
Visual Monitoring (Twice)
Visual Monitoring (Twice)
Year 3
Vegetation Plot Monitoring
Vegetation Plot Monitoring
Stream Channel Stability
Wetland Hydrology Monitoring
Water Quality Monitoring (Twice)
Visual Monitoring (Twice)
Macrobenthos Monitoring
Visual Monitoring (Twice)
Year 4
Vegetation Plot Monitoring
Vegetation Plot Monitoring
Stream Channel Stability
Wetland Hydrology Monitoring
Water Quality Monitoring (Twice)
Visual Monitoring (Twice)
Visual Monitoring (Twice)
Year 5
Vegetation Plot Monitoring
Vegetation Plot Monitoring
Stream Channel Stability
Wetland Hydrology Monitoring
Water Quality Monitoring (Twice)
Visual Monitoring (Twice)
Macrobenthos Monitoring
Visual Monitoring (Twice)
8.2 Stream Channel Stability
Stream hydrology, channel stability, and bed substrate will be monitored In the restored Monteith Creek
channel for five years post - construction to document the success of channel restoration As -built surveys
July 2013 Cardno ENTRIX 8 -2

Site Specific Mitigation Plan
Monteith Park Mitigation Site
will be conducted Immediately following completion of channel construction and will include dimension,
pattern, plan and profile of the restored channel The as -built drawings will also Include the location of
photo documentation points, monitoring cross sections, vegetation plots, and crest gages Reference
stakes will be Installed in the riparian buffer near the stream bank every 100 feet and locations will be
Included in the as -built drawings Data collected from monitoring will be evaluated to determine whether
significant deviation from the as -built conditions has occurred and to record the frequency of bankfull
events post - construction
8.21 Bankfull Events
The occurrence of bankfull events will be documented by the use of a crest gage and photo
documentation of floodplain flow evidence One crest gage will be Installed on the floodplain within ten
feet of the restored channel The crest gage will record the highest watermark between site visits and will
be checked and re- calibrated during each site visit During each site visit photographs will be taken to
document evidence of bankfull flows such as debris lines and sediment in the floodplain Two bankfull
events in separate years must be documented within the five year monitoring period
8 2 2 Cross Sections
Permanent paired cross - sections will be established In approximately every 1,000 feet along the restored
channel for a total of eight cross sections Each section of the restored channel will have one cross -
section in a pool and one cross - section in a riffle Cross - sections will be established during as -built
surveys and monitored on an annual basis for five years Each cross - section will be marked with
permanent monuments on both banks to ensure year -to -year cross - section monitoring accuracy A
common permanent benchmark will be used for all cross - sections to establish consistent elevations and
comparisons of year -to -year data Cross - section surveys will Include points measured at all breaks in
slope, top of bank, bankfull, edge of water, thalweg, and any constructed features that are present
Measurements of W/D ratio, entrenchment ratio, bank height ration, cross sectional area and bankfull
width and depth will be measured and reported yearly Riffle cross - sections will be classified using the
Rosgen Stream Classification System
There should be little change in as -built cross - sections and morphometrics over the course of the five
year monitoring period If changes do take place, they will be evaluated to determine if they represent a
movement towards unstable conditions Examples would include aggradations, erosion, down - cutting, or
Impacts to stream bank vegetation
8 2 3 Longitudinal Profile
At least 2,000 feet of longitudinal profile will be surveyed during as -built surveys and during years three
and five of the five year monitoring period Measurements will include the thalweg, water surface,
bankfull along each bank, and any constructed features The survey will be tied to a permanent
benchmark to facilitate comparison of year to year data
The longitudinal profiles are intended to show that the bedform features remain stable and significant
aggrading or degrading is not occurring The pools should remain deep with flat water surface slopes,
while the riffles remain steeper and shallower A graphical presentation showing as -built and year -to -year
profile monitoring will be presented in each monitoring report Planform morphology such as beltwidth,
radius of curvature, wavelength, meander width ration, riffle length /slope, and pool length /slope should
remain stable Planform morphology will be presented in table format in each monitoring report
82.4 Bed Material Analysis
Wolman pebble counts will be conducted at each cross section during as -built surveys and during year
three and year five of the monitoring period Pebble count data will be plotted on semi -log and compared
with data from previous years Bed material analyses should indicate a reduction in fine sediments
July 2013 Cardno ENTRIX 8 -3

Site Specific Mitigation Plan
Monteith Park Mitigation Site
8 2 5 Photo Reference Sites
Photographs will be taken annually and will be used to document restoration success Reference stations
will be photographed before construction and continue annually for at least five years following
_ construction Permanent markers will be established to ensure that the same locations and view
directions are monitored each year Additional photo documentation of any problem areas will be taken
and evaluated
Photographs will be taken at each cross - section Photos will be taken of both banks, and upstream and
downstream standing in the thalweg looking towards the cross - section The survey tape will be centered
in the photographs of each bank with the water line located on the lower edge of the photo frame
Upstream and downstream cross - section photos will be taken approximately 25 feet from the cross
section looking towards the survey tape
Photographs will be used to evaluate channel aggradation or degradation, bank erosion, success of
riparian vegetation, and effectiveness of bank stability features A series of photos over time should
indicate successive maturation of riparian vegetation
8.3 Stream Water Quality and Macroinvertebrates
Both water quality and benthic macroinvertebrates will be monitored pre- and post - construction to aid in
determining the overall success of the stream and wetland restoration Water quality monitoring will be
conducted twice a year during normal flow conditions Data will be collected at two set sampling locations
within the restored channel Water quality data will be collected for pH, temperature, conductivity and
dissolved oxygen using handheld meters Benthic macroinvertebrates will be sampled using the Qual 4
sampling protocol (NCDWQ, 2011 b) Benthic macroinvertebrates will be sampled once a year in years 3
and 5 at stations used for water quality monitoring Pre - construction benthic macroinvertebrate results
are presented in Section 3 9
8.4 Buffer and Wetland Vegetation Monitoring
In order to determine if the vegetation success criteria are achieved, vegetation monitoring quadrats will
be installed across the restoration site Vegetation monitoring plots will encompass a minimum of 2% of
the approximate 11 acre planting area Twelve vegetation monitoring plots will be installed consisting of
ten plots for stream restoration buffer and two wetland plots installed at assessment area 2 for the
wetland restoration Vegetation monitoring plots will measure 100 m2 in either 10 x 10 m or 5 x 20 m
plots depending on site specific constraints Vegetation baseline data collection will occur upon
completion of the planting plan Vegetation monitoring will occur in spring, after leaf -out has occurred
Vegetation monitoring will generally follow Carolina Vegetation Survey Level 1 monitoring protocols
Individual seedlings will be marked to ensure that they can be found in succeeding monitoring years
Mortality will be determined from the difference between the previous year's living, planted seedlings and
the current year's living, planted seedlings
At the end of the first growing season, species composition and survival will be evaluated For each
subsequent year, until the final success criteria are achieved, the restored site will be evaluated between
July and November The interim measure of vegetative success for the site will be the survival of at least
320, 3 -year old, planted trees per acre at the end of year three of the monitoring period The final
vegetative success criteria will be the survival of 260, 5 -year old, planted trees per acre at the end of year
five of the monitoring period
8.5 Wetland Hydrology Monitoring
Groundwater monitoring stations will be installed in the wetland restoration area (Assessment Area 2 near
Reach 5) to document hydrologic conditions of the restored site Five automated groundwater monitoring
July 2013 Cardno ENTRIX 8-4

Site Specific Mitigation Plan
Monteith Park Mitioation Site
stations will be installed Groundwater monitoring stations will follow the USACE standard methods found
in ERDC TN- WRAP -05 -02 (June 2005) and ERDC -TN- WRAP -06 -02 (January 2006) In order to
determine if the rainfall is normal for the given year, rainfall amounts will be tallied using data obtained
from the Charlotte Douglas International Airport National Weather Service ASOS weather station
CoCoRaHS weather station Huntersville 0 6 ESE will also be monitored to assess precipitation closer to
the site The growing season in Mecklenburg County runs March 22 to November 11 for a total of 233
days The monitoring data should show that the site has been saturated within 12 inches of the soil
surface for at least 12 percent or 28 consecutive days of the growing season Groundwater data will be
reported in each year's monitoring report
8.6 Visual Monitoring
Visual monitoring of the entire restoration site will be conducted twice a year, typically to coincide with
water quality measurements Visual monitoring will cover stream, vegetation and wetland conditions and
any areas of concern will be documented and photographed Potential concerns could include bank
migration, bank failure, excessive sedimentation, poor plant growth or loss of vegetation, headcuts,
beaver activity, or invasive species recruitment A summary of the visual monitoring will be included in
each year's monitoring report
8.7 Storm Water BMP Monitoring
Stormwater BMP's will be surveyed and photographed during the as -built survey and then visually
inspected each year during the monitoring period Each BMP will be inspected and evaluated for integrity
during field visits with any deficiencies being noted in the annual report BMP's should remain in a stable
and maintained condition throughout the monitoring period
8.8 Schedule and Reporting
Annual monitoring reports will be submitted to the IRT by December 31 of each monitoring year Project
success criteria must be met by the fifth monitoring year or monitoring will continue until success criteria
are met
July 2013 Cardno ENTRIX 8 -5

Site Specific Mitigation Plan
Monteith Park Mitigation Site
9 Environmental Education
One stated goal of this project is to create a safe, accessible public amenity while providing the public
with environmental education opportunities Project Involvement from the Monteith Park Homeowners
Association and other public entitles has been Important from the beginning One way to ensure the
overall success of the project Is to provide continued education and awareness of why and how the
restoration process Is done
To aid in the success of the restoration project, two sections of Impervious sidewalk that currently exist
within the proposed 50 foot riparian buffer will be relocated To protect these buffers, the two sections will
rebuilt outside of the conservation easements to still allow public access near the restoration site In
addition, sections of natural surface trail (unpaved) greenway will be Incorporated in the lower portion of
the site These greenways will contain approximately 2400 linear feet of natural surface, pervious, all
weather walking trails The trails will be approximately three feet wide and follow the area adjacent to the
restored Monteith Creek Trails will be constructed to ensure long term stability taking Into account high
visitor use and rainfall events, while requiring low needs for long term maintenance In addition to walking
trails, greenways, and open spaces, a gazebo with multiple environmental education signs will be
constructed to allow views of the restored project site
Post construction, strategically placed permanent signage will be used to provide educational information
on the restoration efforts throughout the project site The signs will be designed to not only educate the
greater public on how and why the restoration was accomplished, but to elicit future involvement in
conservation efforts and promote community ownership of the restoration area Cardno ENTRIX will gain
approval from the Monteith Park Homeowners Association on content and placement of the interpretive
signs In addition, Environmental Education Days (EED) will be scheduled, allowing for a more formal
event to provide public education and encourage community involvement The initial EED will allow
Monteith Park Homeowners Association representatives and local residents the opportunity to review the
final construction plans Subsequent EED will include the presentation of project deliverables as well as
seminars that will provide education on the biological community, water quality and engineered solutions
to common problems associated with urban stream systems
July 2013 Cardno ENTRIX 9 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
10 References
American Society of Civil Engineers (ASCE) 1992 Design and Construction of Urban Stormwater
Management Systems Manuals and Reports of Engineering Practice No 77
Bledsoe, B 2001 Relationships of Stream Responses to Hydrologic Changes Linking Stormwater
BMP Designs and Performance to Receiving Water Impact Mitigation, Proceedings Engineering
Foundation Conference, 2001, Snowmass Village, CO 127 -144
Bledsoe, B and Watson, C 2001 Effects of Urbanization on Channel Instability Journal of the
American Water Resources Association, vol 37 (2) 255 -270
Booth, D and Jackson, R 1997 Urbanization of Aquatic Systems Degradation Thresholds,
Stormwater Detection, and Limits of Mitigation JAWRA, vol 33 (5), 1077 -1090
Booth, D 1990 Stream Channel Incision Following Drainage Basin Urbanization Water Resources
Bulletin, vol 26, 407 -417
Charlotte - Mecklenburg Storm Water Services 2008 McDowell Creek Watershed Management Plan,
Version 4 Charlotte, NC
Daniels, R B , S W Buol, H J Kleiss and C A Ditzler 1999 Soil Systems in North Carolina Technical
Bulletin 314 N C State Univeristy, Soil Science Dept Raleigh, NC
Geosyntec Consultants 2002 Hydromodification Management Plan Literature Review Prepared for the
Santa Clara Valley Urban Runoff Pollution Prevention Program
Geosyntec Consultants 2007 A Technical Study of Hydrology, Geomorphology and Water Quality in
the Laguna Creek Watershed Upper Laguna Creek Council Sacramento, CA
Griffith, G E, Omernik, J M, Comstock, J A, Schafale, M P, McNab, W H, Lenat, D R, MacPherson,
T F , Glover, J B , and Shelburne, V B 2002 Ecoregions of North Carolina and South Carolina,
(color poster with map, descriptive text, summary tables, and photographs) U S Geological
Survey, Reston, Va
Knighton, David, Ph D 1998 Fluvial Forms & Processes, A New Perspective Oxford University Press
Inc
MacRae, C 1992 The Role of Moderate Flow Events and Bank Structure in the Determination of
Channel Response to Urbanization Proceedings of the 45th Annual Conference of the Canadian
Water Resources Association Shrubsole, 2 1 -12 21
MacRae, C 1993 An Alternate Design Approach for the control of Instream Erosion Potential in
Urbanizing Watersheds Proceedings of the Sixth International Conference on Urban Storm
Drainage, Sept 12 -17 Torno, Harry C , vol 2, 1086 -1098
MacRae, C 1996 Experience from Morphological Research on Canadian Streams Is Control of the
Two -Year Frequency Runoff Event the Best Basis for Stream Channel Protection Effects of
Watershed Development and Management on Aquatic Ecosystems, ASCE Engineering
Foundation Conference, Snowbird, Utah, pg 144 -162
North Carolina Department of Environment and Natural Resources, Division of Water Quality 2011 a
Final 2010 303(d) List Accessed November 2011 at
httg / /portal ncdenr org /c /document library /get file?uuid=8ff0bb29-62c2-4b33-810c-
2eee5afa75e9 &groupld =38364
July 2013 Cardno ENTRIX 10 -1

Site Specific Mitigation Plan
Monteith Park Mitigation Site
North Carolina Department of Environment and Natural Resources, Division of Water Quality 2011 b
Standard Operating Procedures for Collection and Analysis of Benthic Macroinvertebrates Ver
3 0 http //portal ncdenr org/ c/ document_ library/get_file ?uuid= c2fdf380 -aa8a -481 a -8388-
a6e6596c6a96 &groupld =38364
Palhegyi, G 2009 Designing Stormwater Controls to Promote Sustainable Ecosystems, Science and
Application Journal of Hydraulic Engineering ASCE Low Impact Development, Sustainability
Science, and Hydrologic Cycle
Radford, A E , H E Ahles, and C R Bell 1968 Manual of the Vascular Flora of the Carolinas The
University of North Carolina Press, Chapel Hill, NC
Rohde, F C , R G Arndt, D G Lindquist, and J F Parnell 1994 Freshwater fishes of the
Carolinas, Virciinia, Maryland, and Delaware University of North Carolina Press, Chapel HIII &
London
Schafale, M P and Weakley, A S 1990 Classification of the Natural Communities of North Carolina
Third Approximation North Carolina Natural Heritage Program NCDENR Raleigh, NC
Soar, P J , and Thorne, C R 2001 Channel Restoration Design for Meandering Rivers US Army Corps
of Engineers, Final Report, ERDC /CHL CR -01 -1, September
Thomas, D B , Abt, S R, Mussetter, RA, Harvey, M D A Design Procedure for Sizing Step -Pool
Structures" (2004) (http / /www crwcd aov /news /reports /steopoolpaper doc)
Report Y -81 -1 Wetlands Research Program Environmental Laboratory Vicksburg, MS
U S Army Corps of Engineers (USACE) 1987 Corps of Engineers Wetland Delineation Manual
Technical
U S Army Corps of Engineers (USACE) 2000 Hydrologic Modeling System HEC -HMS Technical
Reference
U S Army Corps of Engineers (USACE), Hydrologic Engineering Center Manual Davis California
U S Army Corps of Engineers (USACE) 2000 Interim Regional Supplement to the Corps of Engineers
U S Department of Agriculture (USDA) 1980 Soil Survey of Mecklenburg County, North Carolina USDA
Soil Conservation Service
Wetland Delineation Manual Eastern Mountains and Piedmont Region ERDC /EL TR -10 -9
Wetlands Regulatory Program US Army Engineer Research and Development Center Vicksburg, MS
July 2013 Cardno ENTRIX 10 -2

Q`77) Car ino®
ENTR/X
Shaping the Future

G� Cardno°
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Shaping the Future

i
360 Hawthorne Lane
Nutter & Associates P (7 Athens, (7 30606 -06) 354 -7925 7925
environmental consultants F(706354 -7928
www NutterInc corn
TECHNICAL MEMORANDUM NO. 11- 020.01
PREPARED FOR: Alan Moore, Cardno Entrix
PREPARED BY: Lane Rivenbark, L S S No 1302
DATE- April 4, 2011
SUBJECT: Soils Evaluation, Monteith Mitigation Project, Mecklenburg
County, North Carolina
10
20
30
40
50
AT-
INTRODUCTION
BACKGROUND
METHODOLOGY
RESULTS AND DISCUSSION
REFERENCES
FACHMENT A Soil Boring Logs
CONTENTS
TABLES
Table 1 Seasonal and Normal Water Table Depths, Monteith Project Site
Table 2 Wetland Restoration Areas
FIGURES
Figure 1 Monteith project location, Mecklenburg County, North Carolina
Figure 2 Published soil map, Monteith project site, Mecklenburg County, North
Carolina
Figure 3 Soil boring locations, Monteith project site investigation, Mecklenburg County,
North Carolina

1.0 INTRODUCTION
On March 8, 2011, Nutter & Associates conducted a soil evaluation pursuant to wetland
restoration activities associated with the Monteith Mitigation Project, Mecklenburg
County, North Carolina The objective of the field evaluation was to identify areas of
contemporary and /or relic hydric soils to aid in the determination of areas suitable for
wetland restoration or creation
The project site is part of the Catawba River Basin centrally located in Huntersville,
North Carolina Specifically, the project area is located within the valley associated with
the confluence of a second and first order tributary to Torrence Creek (Figure 1) The
surrounding upland area consists of a residential community and its associated roads,
utilities, etc Prior to development, the site was managed as a pasture for livestock
The second and first order tributaries, hereunto referred to as S2 and S1, have been
channelized and straightened for agricultural purposes, and both exhibit evidence of
degradation The associated valleys have likely been leveled for agricultural use Most
of the area remains grassed with the exception of small groves of bottomland hardwood
species such as Black Willow (Salix n►gra) and Sweetgum (L►qu►dambarstyrac►flua)
along the stream channels
2.0 BACKGROUND
A soil is defined as hydric if it saturated long enough during the growing season (frost -
free days) to produce anaerobic conditions that support predominantly hydrophytic
vegetation Saturated conditions exist if the normal water table is within a foot of the soil
surface (saturation extends up to the surface due to capillary fringe) Certain features of
the soil indicate the presence of water during the growing season, most of which are
associated with the movement, presence, or absence of reduced iron In general the
soil matrix color is predominately grey (chroma < 2) at a depth where the soil is regularly
saturated due to iron reduction and movement The seasonal high water table (SHWT)
is typically noted where there is evidence that some iron has reduced and been
depleted from the soil profile Iron can also occur in varying shades of yellow in soils
that are saturated for brief periods of the year, but not long enough to become
predominately grey
The regional guidance document assembled by the U S Army Corps of Engineers
(USAGE) lists a number of soil indicators that can be used to identify hydric soils in the
field (USACE, 2010) Indicators common to the project area include the depleted matrix —'
(F3), iron /manganese masses (F12), floodplain soils (F19), and red parent material
(TF2) Detailed descriptions of each indicator can be found in the regional guidance
document This document also lists a number of common features of relic hydric soils
such as the presence of iron concentrations with duller, darker more red coloration
within the upper portion of the soil profile (USACE, 2010)
Based on published soil mapping, soils found in and adjacent to the project area include
the Mecklenburg, Wilkes and Monacan series (Figure 2) Both the Mecklenburg and
Wilkes soils are well drained, and formed in residuum weathered from mafic material in
Piedmont uplands They are classified as Alfisols, meaning that they are older,
moderately weathered soils that have an alluvial clay enriched subsurface horizon and a
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relatively high base saturation in the lower profile of the solum Monacan soils are
moderately well and somewhat poorly drained and are formed in recent alluvial
sediments of the Piedmont They are classified as Inceptisols, which are younger soils
that have developed structure and color but do not show evidence of alluvial clay
None of the soils listed as occurring within the project area would be considered hydnc
based on their official series descriptions However, published mapping maintains an
insufficient resolution to provide the level of detail necessary to evaluate the site for
wetland restoration purposes A more detailed soil evaluation was necessary to
account for site specific soils, landscape position and microtopography
3.0 METHODOLOGY
Nutter & Associates advanced over 15 hand auger borings along general transect lines
within the valleys associated with S1 and S2 (Figure 3) Soil profile descriptions were
recorded at 11 of the boring locations, and include soil horizonation, texture, color,
redoximorphic features, structure, and other pertinent characteristics (Attachment A)
The honzonation, texture, and structure provide an indication of the age, origin and
internal drainage capacity of the soil Color and redoximorphic features show the
presence, absence and movement of iron, thus indicating the depth and duration of the
water table under ordinary and seasonal conditions
Based on the location specific soil properties listed above along with landscape position
and microtopography, the following determinations were made
• whether or not hydric soil conditions currently exist at the boring location,
• the depth of the seasonal (depletions) and normal high water table (depleted
matrix), and
• the potential of the soils to develop or maintain hydnc properties following
restoration
4.0 RESULTS AND DISCUSSION
The boring logs confirm that the project area soils are not consistent with those on
published maps (Attachment A), however, the soils are similar in age and origin The
soils on site are considered poorly and somewhat poorly drained rather than moderately
well drained as suggested by published mapping Throughout the site, the upper
portions of the soil profile were underlain by a clay enriched impermeable layer of soil,
that occurred at the depth of the normal water table (Table 1) Water likely perches on
this layer and drains laterally towards the stream channels Due to degradation and
channelization of the streams, flood duration times are likely artificially shortened
While the soils throughout the project area were similar, four definable soil areas were
identified within the site as described below (Figure 3)
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Area 1. Confluence of S1 (right valley) and S2 (left valley) - Pit 1 through Pit 6
Soils within this area are reddish brown in hue in the upper portions of the soil profile
The SHWT varies between 0 6 to 1 6 feet (Table 1) The normal water table was noted
at depths ranging from 1 0 to 2 0 feet The area within the left valley floodplain of S2
represented by Pit 1 and Pit 2 actively receives sediment, but would not be considered
hydric per the F12 conditions At the toe of the adjacent upland knoll, lateral flow enters
a small depression that is considered hydric (Pit 3 and Pit 4) per the F3 indicator
Further investigation of the vegetation and hydrology is needed to confirm whether or
not this area is jurisdictional The normal water table (Pit 5 and Pit 6) adjacent to S1 is
deeper than that of a hydric soil likely due to the zone of influence associated with the
stream (USACE, 2010)
Relic hydric features could not be distinguished given the dark coloration of the soil,
which mask evidence of iron depletions Considering the landscape position,
microtopography and redoximorphic features of the soil, this area could have met hydric
soil criteria prior to stream channel modification And given the significant evidence of
iron transport (concentrations) throughout the soil profile and the presence of the
impermeable clay layer at the normal water table depth, it is likely that the area
frequently floods to the soil surface, and remains saturated much of the dormant
season But, it is likely that the duration in the growing season is insufficient to consider
the soils hydric, with the exception of the area represented by Pit 3 and Pit 4
Area 2. F/oodp/ain of S1 (left valley) and S2 (downstream left valley) - Pit 7
Soils within this area have a more bright red hue in the upper portions of the soil profile
The seasonal water table is at or below 1 5 feet, while the normal water table is typically
noted at depths of 2 0 feet or greater (Table 1) The normal water table is likely
lowered due to the zone of influence from the adjacent stream (USACE, 2010) There is
evidence of frequent flooding and /or saturation up to the depth of the SHWT, and the
restrictive clay enriched horizon is at or near the normal water table However, there is
little or no iron movement noted above the SHWT suggesting that flooding and /or
saturated conditions up to the soil surface occur less frequently than in Area 1
Area 3. Outer floodplain associated with S1 and S2 -Pit 9 and Pit 11
Soils within this area also have a more bright red hue in the upper portions of the soil
profile The seasonal water table is at or below 1 5 feet, while the normal water table is
typically noted at depths of 1 5 feet or greater (Table 1) This area is similar to the
floodplain described in Area 2 in that it shows evidence of flooding and /or saturation up
to the SHWT, and an underlying restrictive clay horizon at or near the depth of the
normal water table, but is not affected by the zone of influence of the stream But given
the landscape position and lack of evidence of iron movement above the SHWT, it is
unlikely that flooding and /or saturated conditions often occur up to the soil surface
Nutter & Associates, Inc

Historic S1 1S2 stream channel - Pit 8 and Pit 10
Coarse material and rock were noted that are consistent with that of stream bottoms in
the area In addition, the rocks present were characterized with rounded edges
suggesting historic fluvial tumbling These areas were saturated at shallower depths
that the adjacent soils, which suggests that they now serve as conduits to the stream
through shallow subsurface flow
Wetland Restoration Potential
Within Areas 1, 2 and 3 the normal high water table must be raised on average,
approximately one foot to meet hydric soil criteria Soil properties in Area 1 indicate that
flooding events with saturation to the soil surface occur frequently With improved, more
stable channel conditions and sinuosity, drainage would occur more slowly so that the
flood duration could be extended to support hydric soil restoration or development
Hydnc soil criteria would most likely be met during the early portion of the growing
season, and could include up to 0 64 acres of creation /restoration and 0 23 acres of
enhancement in soils that currently meet hydric criteria (Figure 3)
There is no evidence of relic hydric soils in Areas 2 and 3 However, the shallow normal
water table depth and restrictive clayey layer are conducive to holding water
Depending on the path of the stream and duration of flooding, much of these two areas
could develop hydric soil properties Up to 0 76 acres of hydric soils could be created
depending on the stream path (Figure 3) The historic channel, which meanders
through Areas 2 and 3, will likely remain a conduit for shallow subsurface flow Without
the restrictive layer to hold water, it is unlikely that the duration of flooding would be
sufficient to develop hydric soil properties
The overall effect of channelization and land leveling is evident throughout the project
site Degradation of the stream channel has extended the zone of influence on the water
table along the floodplains of both streams and shortened the duration of flooding and
saturated conditions at or near the soil surface A number of ground water models
could be used to support the projected flood duration throughout the project area Long
- term monitoring of water table levels would serve to verify model results It is
recommended that the soils be periodically reviewed by a qualified soil scientist to
ensure that hydric conditions are present
5.0 REFERENCES
U S Army Corps of Engineers (USACE) 2010 Interim Regional Supplement to the
Corps of Engineers Wetland Delineation Manual Eastern Mountains
and Piedmont Region, ed J S Wakeley, R W Lichvar, C V Noble, and
J F Berkowitz ERDC /EL TR -10 -9 Vicksburg, MS US Army Engineer
Research and Development Center
Nutter & Associates, Inc

Table 1 Seasonal and Normal Water Table Depths, Monteith Project Site
Boring
Water Table
Seasonal
I Normal
feet
Pit 1
1 6
20
Pit
06
1 1
Pit
09
1 6
Pit 4
07
1 0
Pit
08
20
Pit
15
18
Pit?
1 8
22
Pit
1 5
1 22
Pit 11
15
15
Table 2 Wetland Restoration Areas
Area
Type
Acres
1
Restoration
064
Enhancement
023
2
Restoration
038
3
Restoration
038
Total
1.63
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Data source ESRI Si atmap North Pmerca
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0 500 1,000 2,000 31000 4,000 5,000
Feet
Figure 1. Monteith project location,
Mecklenburg County,
North Carolina.
Nutter & Associates
0 n v I r c 11 m 0 n t A I e 0 n e U I t] n t t

Streams
Area of Investigation
NRCS Soil Codes and Descriptions
CeB2:Cecil sandy clay loam, 2 to 8 percent slopes, eroded
CeD2:Cecil sandy clay loam, 8 to 15 percent slopes, eroded s
EnD:Enon sandy loam, 8 to 15 percent slopes
MO:Monacan loam
- McB:Mecklenburg fine sandy loam, 2 to 8 percent slopes
McD:Mecklenburg fine sandy loam, 8 to 15 percent slopes
WkE.Wilkes loam, 15 to 25 percent slopes
t.
Data source: NCRS
0 50 100 200 300 400 500
Feet
Figure 2. Published soil map, Monteith project site, Mecklenburg County, North Carolina.
F:tprojects \11_020_Monteth \rres soi.mxd
Nutter & Associates
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Aerial photograph: USDA 2011
0 50 100 200 300 400 500 NuttejoiLmx_020_MOnteith\
Nuttersoil.mxd
Feet
Figure 3. Soil boring locations, Monteith project site investigation, Mecklenburg County,
North Carolina. Nutter & associates
on i Iron n e n, a l c o n e u l t a r t a

ATTACHMENT A
Soil Boring Logs
Nutter & Associates, Inc

Monteith Soil Evaluation, Profile Descriptions
Boring
De th ft
Texture
Structure
Matrix Color
IRedoximorphic Features
Remarks
Pit 1
0 0 -0 3
L
GR
7 5 YR 5/4
None
F, Mica
03-1 6
L
WSAB
7 5 YR 4/3
F, 7 5 YR 4/6
F, Mica
1 6 -2 0
CL
WSAB
10YR 5/3
M, 10 YR 5/2
SHWT
20-25+
C
MASS
10 YR 5/1
None
Few coarse sand grains
Pit 2
0 0 -0 4
L
GR
7 5 YR 5/4
None
Mixed
0 4 -0 6
CL
WSAB
7 5 YR 4/3
None
06-1 1
CL
WSAB
10YR 5/3
F, 10 YR 5/2
SHWT
1 1-25+
C
MASS
10 YR 6/1
None
Few coarse sand grains
Pit 3
0 0 -0 3
L
GR
7 5 YR 5/4
F, 7 5 YR 6/6
Pockets of Clay
0 3 -0 9
L
WSAB
10 YR 5/3
C, 7 5 YR 6/6
09-1 6
CL
WSAB
10YR 5/2
C, 7 5 YR 5/4
SHWT
1 6-25+
C
MASS
10 YR 611
C, 7 5 YR 5/4
Few coarse sand grains
Pit 4
0 0 -0 7
L
WSAB
10 YR 5/3
F, 7 5 YR 4/6
07-1 0
L
WSAB
10 YR 5/3
F, 7 5 YR 4/6 & F, 10 YR 6/2
SHWT
10-25+
C
MASS
10 YR 6/2 & 5/1
M, 10 YR 6/6
Pit 5
0 0 -0 8
SIL
WSAB
7 5 YR 5/3
F, 7 5 YR 4/6
0 8 -2 0
SIL
WSAB
7 5 YR 5/3
C, 10 YR 5/2
SHWT
120-25+
C
MASS
10 YR 5/1
F, 7 5 YR 4/4 & 5 YR 5/4
Pit 6
0 0 -0 3
L
WSAB
7 5 YR 4/3
F, 7 5 YR 4/6
F, Mica
03-1 5
L
WSAB
7 5 YR 4/3
C, 7 5 YR 4/6
F, Mica
1 5 -1 8
CL
WSAB
7 5 YR 4/3
F, 7 5 YR 4/6 & C, 10 YR 5/2
SHWT
1 8-25+
CL
WSAB
10 YR 5/1
F, 7 5 YR 4/6
F, Mica
Pit 7
0 0 -1 8
SCL
WSAB
5 YR 4/6
None
1 8-22
SCL
WSAB
7 5 YR 5/3
F, 5 YR 4/6 & F, 10 YR 6/2
SHWT
122-25+
SCL
MASS
10 YR 5/1
F, 5 YR 4/6
Pit 8
0 0 -0 2
CL
MASS
5 YR 5/6
None
Sediment Deposition
0 2 -2 0
SCUSL
MASS
Multi - Colored
None
Mixed, FIII
20-30+
SL
MASS
None
Mixed, Rock from historic stream bottom
Pit 9
0 0 -0 3
L
GR
5 YR 4/4
None
03-1 0
SL
GR
5 YR 4/6
None
C, Mica
1 0 -1 5
C
MASS
5 YR 5/3
F, 5 YR 5/6
1 5-22
C
MASS
5 YR 5/3
F, 10 YR 6/2 & F, 5 YR 5/6
SHWT
22-25+
C
MASS
10 YR 5/1
C, 7 5 YR 4/6
Pit 10
25-40+
None
Alluvial Sand, under fill material
Pit 11
00-1 2
SCL
GR
5 YR 4/6
F, 5 YR 6/6
C, Mica
12-1 5
SCL
WSAB
7 5 YR 4/4
F, 5 YR 4/6
1 5-20
SC
MASS
10YR 5/2
IF, 7 5 YR 4/4
SHWT & F, Rock
20-25+
SCL
MASS
10 YR 6/2
IF, 7 5 YR 4/6 & F, 2 5 YR 5/6
jMn Nodules
Notes' Texture L - Loam CL - Clay Loam, C - Clay, SiL - Silt Loam, SCL - Sandy Clay Loam, SL - Sandy Loam, SC - Sandy Clay
' Structure G - Granular MASS - Massive WSAB - Weak Sub - Angular Blocky
3 Redoximorphic Features / Remarks F - Few C - Common M - Many

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Monteith Park Mitigation Site
Site Specific Mitigation Plan
Plate 1. Aerial Photo from 1949
July 2013 Cardno ENTRIX B -1

Monteith Park Mitigation Site
Site Specific Mitigation Plan
Plate 2. Aerial Photo from 1965
July 2013 Cardno ENTRIX B -2

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Site Specific Mitigation Plan
Plate 5. Aerial Photo from 2002
July 2013 Cardno ENTRIX B -5

Monteith Park Mitigation Site
Site Specific Mitigation Plan
Plate 6. Aerial Photo from 2010
July 2013 Cardno ENTRIX B -6

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Site Specific Mitigation Plan
Carolina Heelsplitter (Lasmigona decorata)
The Carolina heelsplitter is a freshwater mussel species that was listed as federally endangered m 1993 The
shell shape is ovate trapezoid with a straight dorsal margin that sometimes ends with a slight wing The shell
color is green or brown and may have green or black rays The inner shell is white to mottled pale orange
Average shell length is around 78 mm
Hustoncally, Carolina heelsplitters were found in the Catawba River drainage around Mecklenburg County, in
the Pee Dee River drainage in Union and Cabarivs Counties, and in the Saluda and Savannah River systems of
South Carolma. According to the USFWS, there are currently only three extant populations known to exist m
North Carolina. One population on Goose Creek m the Pee Dee River drainage, a population m Waxhaw
Creek and Six Mile Creek in the Catawba River drainage, all in Union County There are four extant
populations known to exist in South Carolina. According to the NHIP, Carolina heelsplitter is thought to be
extirpated from Gaston and Mecklenburg Counties
The Carolina heelsplitter could historically be found m small to large streams and in small mill ponds They
are typically found m mud, muddy sand, or muddy gravel in well shaded streams It is thought however that
degradation of preferred more stable gravel habitats has restricted the species to these less desirable habitats
The decline ofthe species has been attributed to stream bank destabilization due to agriculture and
development practices, impoundments, channelization, dredging and declining water quality The presence of
the Carolma heelsplitter mussel in the project area is based on "historic occurrence ", but the species is believed
to be extirpated from the area
Schweimtz's Sunflower (Hei►anthus schwe►n►tz►►)
The Schweimtz's sunflower was listed as a federally endangered species in 1991 Schweinitz's sunflowei is a
rhizomatous perennial herb in the aster family that grows from 3 to 6 ft (1 to 2 m) tall from a cluster of carrot-
like tuberous roots Stems are usually solitary, branchmg only at or above mud -stem The stem is usually
pubescent but can be nearly glabrous, it is often purple The lanceolate leaves are opposite on the lower stem,
changing to alternate above They are variable m size, being generally larger on the lower stem and gradually
reduced upwards The pubescence of the underside of the leaves is distinctive and is one of the best characters
to distinguish Schweinitz's sunflower from its relatives The upper surface of the leaves is rough, with the
broad -based spmose hairs directed toward the tip ofthe leaf From September to frost, Schwenutz's sunflower
J blooms with comparatively small heads of yellow flowers
The species occurs m clearings and edges of upland woods on moist to dryish clays, clay - loams, or sandy clay -
loams that often have high gravel content and are moderately podzoli zed Schweimtz's sunflower usually
grows in open habitats not typical of the current general landscape in the piedmont of the Carolinas Some of
the associated species, many of which are also rare, have affiruties to glade and praine habitats of the Midwest
Other species are associated with fire - maintained sandhills and savannas of the Atlantic Coastal Plain and
piedmont The habitat of this sunflower tends to be dominated by members of the aster, pea, and grass
families, an association emphasizing affinities of the habitat to both longleaf pme- dommated sandhills and
savannas ofthe southeastern coastal plain and to glades, barrens, and prairies of the Midwest and Plains
(USFWS 2005)
July 2013 Cardno ENTRD( C -1

Monteith Park Mitigation Site
Site Specific Mitigation Plan
Michaux's Sumac (Rhus m►chauxi►)
The Michaux's sumac was listed as a federally endangered species in 1989 Michaux's sumac is a rhizomatous
shrub in the cashew family (Anacardiaceae), with erect stems that grow 1 to 3 feet high This sumac can be
distmguished by compound leaves with evenly serrated, oblong to lanceolate acuminate leaflets Typically,
most plants are unisexual but some have been found with both male and female flowers Flowers are in
terminal clusters, small, and colored greemsh yellow to white Flowering occurs from June to July A red
drupe fruit is produced in August through October
The sumac is thought to be endemic to the coastal plain and piedmont of North and South Carolina, Georgia,
and Florida. According to USFWS, thirty one extant populations are known to occur in North Carolina
According to the NM, three counties in North Carolina are known to have extant population while three
other counties have historically had population that may now be extirpated This species grows in sandy or
rocky open woods with basic soils It survives best in disturbed areas such as highway right of ways, -
roadsides, or maintained areas
Smooth Conef lower (Echinacea laev►gata)
The smooth coneflower was listed as a federally endangered species in 1992 Smooth coneflower is an
herbaceous perennial species in the aster farrnly (Asteraceae) that typically grows to a height of 15 meters
Flower heads are large, solitary and distinguished by long lanceolate basal leaves that can reach 20 cm m
length Rays are typically light pink to purple and 5 to 8 cm long Flowering occurs m late May through mid
July Fruiting occurs in June through September and fruits usually persist throughout the fall
Smooth coneflower is usually found in habitats that have a high level of disturbance and abundant sunlight
Historically, this species depended on fire and large herbivores for necessary habitat maintenance that reduced
competition and shading. Populations of smooth coneflower can be found in open woods, cedar barrens, dry
limestone bluffs, and power line right of ways m magnesium and calcium rich soils
Santee Chub (Cyprinella zanema)
The Santee chub was last recorded within 2 miles of the project area in 1970 The Santee chub is a
member of the family Cyprrmdae and genus Cyprinella The genus is distinguished by its larger, vertical
diamond shaped scales and black notch m the dorsal fin The Santee Chub has a maximum length of 3
inches This chub has a slender, fusiform body, along snout, and exhibits dark cross - hatching on the
back and sides
The Santee chub is restricted to the Santee River (Catawba) drainage within South Carolina, primarily in
the piedmont and Blue Ridge foothills The Santee Chub is a fish that inhabits sandy to rocky runs and
pools in creeks and in small to moderate rivers (Rohde et al 1994) There is little fish habitat within
Monteith Creek and habitat suitable for the Santee Chub is not currently present
Northern Cup Plant (Silph►um perfoliatum)
The northern cup plant was last recorded within 2 miles of the project site in 1991 The northern cup plant is
an herbaceous perennial flowering plant in the aster family (Asteraceae) that typically grows to a height of 1-
2 5 meters The flowers are yellow and typically measure 2 5 cm in diameter Flowering occurs from July
through September and fruiting follows into October
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July 2013 Cardno ENTRIX C -2

Monteith Park Mitigation Site
Site Specific Mitigation Plan
The northern cup plant is a facultative wetland plant that is more often found in wetlands than to uplands in the
southeast (USDA 2011, http //plants usda .gov /java/profile ?symbol= SIPEP) Accordmg to Radford eta]
(1968), the plant can be found m wetlands, low meadows and alluvial woods Potential habitat for the northern
cup plant is minimal along Monteith Creek due to the massive incision that has occurred resulting to
disconnected floodplam and few riparian wetlands
July 2013 Cardno ENTRIX C -3

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ENTR/X
IShapmg Ile Future
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Plate 1. Reach 1 Photo

Plate 2. Reach 1 Photo

Plate 3. Reach 2 Photo

Plate 4. Reach 2 Photo

Plate 5. Reach 3 Photo

Plate 6. Reach 4 Photo

Plate 7. Reach 5 Photo

Plate 8. Storm water Photo

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Shaping the Future
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Monteith Park Mitigation Site
Site Specific Mitigation Plan ±LLI
759
756
756 -
- -
---
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1
753 -
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Cross Section 1
Cross Section 2
756
749
748
754
747
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748
743
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-
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746
742
744
10 15 20 25 30 35 40 45
741
0 5 10 15 20 25 30
Cross Section 3
Cross Section 5
759
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756 -
- -
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July 2013 Cardno ENTRIX E -1
July 2013 Cardno ENTRIX E -1

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Monteith Park Mitigation Site
Site Specific Mitigation Plan
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10 15 20 25 30 35
Cross Section 6
0 10 20 30 40 50 60 70
Cross Section 8
7410
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T
1
1+
M 0
+
731
1#
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Cross Section
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July 2013 Cardno ENTRIX E-2
731
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July 2013 Cardno ENTRIX E-2

7370
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Site Specific Mitigation Plan
Cross Section 10
I
736
735
734
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0 10 20 30 40 50 60 70 80 10 I 0 20 40 60 60 100 120
L Cross Section 12 Cross Section 13
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July 2013 Cardno ENTRIX E -3
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July 2013 Cardno ENTRIX E -3

Monteith Park Mitigation Site
Site Specific Mitigation Plan
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Cross Section 16 Cross Section 17
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Cross Section 18 Cross Section 19
July 2013 Cardno ENTRIX E-4

Monteith Park Mitigation Site
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July 2013 Cardno ENTRIX E-5

Monteith Park Mitigation Site
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Cross Section T2 -2
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July 2013 Cardno ENTRIX E-6
11
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July 2013 Cardno ENTRIX E-6

G� Camino"
ENTRIX
Shaping the Future
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