20070168 Ver 1_More Info Received_20081001

Revised Proposed Impoundments Watershed Modeling and Adaptiv...
Subject: Revised Proposed Impoundments Watershed Modeling and Adaptive Management Plan
From: "Sam, Robert" <[e-mail]>
Date: Wed, 1 Oct 2008 16:53:44 -0400
To: "Ian McMillan" <[e-mail]>, <[e-mail]>, <kevin. bamett@ncmail. net>, "Jones, Amanda D SAW"
<Amanda. D. Jones@saw02. usace. army. mil>
CC: <[e-mail]>, "Conger, Allen" <[e-mail]>, "Shortelle, Ann" <[e-mail]>, "Jarvis, Brandon"
<BMJAR V I S @m actec. com>
Ian,
Per our conversations from earlier today MACTEC has, on the behalf of the Fall Creek Land Company, revised
the previously submitted Proposed Impoundments Watershed Modeling and Adaptive Management Plan.
The primary addition is highlighted in red to save time during your review process. We appreciate your timely
review.
Sincerely,
Robert Sain
Robert L. Sain, CFM
MACTEC Engineering and Consulting, Inc.
1308 Patton Avenue
Asheville, NC 28806
Office: 828-252-8130
Cell: 828-989-8899
Fax: [phone]
[e-mail]
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1 of 1 10/2/2008 9:44 AM
MACTEC
engineering and constructing a better tomorrow
October 1, 2008
Ms. Cyndi Karoly
N.C. Division of Water Quality
401 Oversight/ Express Review Permitting Unit
1650 Mail Service Center
Raleigh, North Carolina 27699
Subject: The Grandview Peaks Development
Revised On-site Impoundments Modeling and Adaptive Management Plan
USACE Action ID: 2007-200-359
DWQ Project # 07-0168
McDowell County, North Carolina
MACTEC Project No. 6229052914
Dear Ms. ICaroly:
MACTEC Engineering and Consulting, Inc. (MACTEC), on behalf of the applicant, the Fall
Creek Land Company (FCLC), would like to address Division of Water Quality (DWQ)'s request
for a watershed modeling plan; request made during a meeting at the DWQ, Raleigh office July
21, 2008 (see Attachment A). The purpose of this document is to present a scientifically valid
watershed modeling plan, to accomplish the goal of preserving water quality.
We would appreciate your timely review of this information and your written response regarding
the acceptability of this modified procedure for the required analyses.
cc: Todd Black, Fall Creek Land Company
Amanda Jones, Asheville Regulatory Field Office, USACE
]on McMillan, Raleigh Headquarters, DWQ
Kevin Barnett, Asheville Regional Office, DWQ
MACTEC Engineering and Consulting, Inc.
1308 Patton Avenue • Asheville, NC 28806 • Phone: 828,252.8 130 • Fax: [phone] www.mactec.com
4YMACTEC MACTEC Engineering and Consulting
PattonAvenue
Asshhevevilille, North Carolina
Phone: [phone] Fax: [phone]
LETTER OF TRANSMITTAL
TO: Ms. Cyndi Karoly DATE: 10/01/2008
Mr. Ian McMillan
Ms. Amanda Jones MACTEC PROJECT NO.: 6229-05-2914; Task 15
Mr. Kevin Barnett PROJECT NAME: Grandview Peaks
SUBJECT: Revised On-site Impoundments Modeling Mngt. Plan
WE TRANSMIT TO YOU: N HEREWITH
UNDER SEPARATE COVER
SUBJECT:
? DRA WING S
?SPECIFICATIONS
?CALCULATIONS
EREPORT
?COST ESTIMATE
?AS NOTED
ACTION: SENT BY:
?FOR YOUR INFORMATION ?MAIL
EFOR YOUR COMMENT OR APPROVAL ?CERTIFIED MAIL
?RETURNED FOR CORRECTION: RESUBMIT EEXPRESS FED
?APPROVED AS NOTED ?COURIER
?AS REQUESTED ?HAND DELIVERED
?FACSIMILE:
mcludme transmittal sheet
COPIES DATE DESCRIPTION
1 10/0108 Revised Impoundments Watershed Modeling and Adaptive Management
REMARKS: Please find attached one copy-Revised On-site, Impoundments Watershed Modeling and Adaptive Management
Plan. Should you have any questions, please contact Robert Sain at (828)-252-8130 or Allen Conger (803)-798-1200
CC: Todd Black; Fall Creek Land Company By: 12 Z_
Robert L. Sain
Direct Phone: [phone]
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Re: Revised Proposed Impoundments Watershed Modeling and Adap...
Subject: Re: Revised Proposed Impoundments Watershed Modeling and Adaptive Management Plan
From: Kevin Barnett <Kevin. Barnett@ncmail. net>
Date: Thu, 02 Oct 2008 08:28:21 -0400
To: Ian McMillan <[e-mail]>
CC: [e-mail], "Jones, Amanda D SAW"
<[e-mail]>, Roger Edwards <[e-mail]>, Linda
Wiggs <Linda. Wiggs@ncmail. net>, Chuck Cranford <[e-mail]>, James Aaron
<Jame s. Aaron@ncmai l . net>
Ian:
I do not support this methodology.
The proposed is a modeling attempt in a disturbed watershed. Site logged over
(temp), construction in headwaters (pH, settable solids and turbidity) will give
artificially elevated background numbers.
Along with the submitted, they need to perform similar study in an undisturbed
watershed in same physiogeographic province and at same relative elevation.
Best regards,
Kevin
Sain, Robert wrote:
Ian,
Per our conversations from earlier today MACTEC has, on the behalf of the Fall
Creek Land Company, revised the previously submitted Proposed Impoundments
Watershed Modeling and Adaptive Management Plan.
The primary addition is highlighted in red to save time during your review
process. We appreciate your timely review.
Sincerely,
Robert Sain
Robert L. Sain, CFM
MACTEC Engineering and Consulting, Inc.
1308 Patton Avenue
Asheville, NC 28806
Office: 828-252-8130
Cell: 828-989-8899
Fax: [phone]
[e-mail] <mailto:[e-mail]>
1 of 2 10/2/2008 8:36 AM
Re: Revised Proposed Impoundments Watershed Modeling and Adap...
*CONFIDENTIALITY NOTICE: The information contained in this message is intended
only for the recipient and may contain information that is confidential. If you
are not the intended recipient or an employee or agent responsible for
delivering this message to the intended recipient; please be aware that any
dissemination, forwarding, printing, copying, disclosure or distribution of this
communication is strictly prohibited. If you have received this communication in
error, please immediately notify the sender by replying to the message and
deleting all copies, including attachments, from your system and deleting all
copies, including attachments, fxom your system.*
"The time is always right to do what is right"
Martin Luther King, Jr.
Kevin Barnett - [e-mail]
North Carolina Dept. of Environment and Natural Resources
Asheville Regional Office
Division of Water Quality - Water Quality Section
2090 U.S. 70 Highway
Swannanoa, NC 28778
Tel: [phone]
Fax: [phone]
Kevin Barnett <Kevin.Bamett a,ncmai1.net>
NC DENR - Asheville Regional Office
Division of Water Quality - Water Quality Section
2 of 2 10/2/2008 8:36 AM
Project Overview:
The Fall Creek Land Company's (FCLC) "Grandview Peaks (GP)" development contains 54,392
linear feet of jurisdictional, perennial, and intermittent stream channels. The north-western
portion of the property contains two networks of unnamed tributary streams that drain to
Hopper's Creek. The FCLC plans to impound these unnamed, tributary stream systems to create
small reservoir lakes (27.1 acre and a 6.8 acre). Both lakes are down gradient from existing
development activity and are the most feasible location on the property-having the right
combination of drainage area, perennial stream flow, constricted valleys (see Figure 1). Both
proposed impoundment(s) will be located in the upper Catawba River Basin (HUC 03050101;
sub basin 03-08-30) within the Northern Inner Piedmont Ecoregion.
Background Information:
A list of project milestones has been provided in Appendix A. The DWQ recently (March 2008)
came out with an analytical monitoring protocol to predict how water quality will affect future
impoundment(s) (March 2008, Predictability Study Protocol for Sampling Reference
Impoundment(s) NCDWQ, 2008). These guidelines currently state that applicants wishing to
build new impoundment(s) conduct rigorous monitoring of two "similar, existing" lakes as
reference for what to expect. The Fall Creek Land Company (FCLC) provided an alternative to
the DWQ's guidelines on July 8, 2008; FCLC proposing a stand-a-lone procedure for predicting
water quality, on-site. The GP alternative procedure uses watershed loading analyses consistent
with the currently accepted and recommended DWQ lakes modeling procedures. The GP
alternative procedure will ensure that appropriate BMPs are in place to establish and maintain
impoundment(s) water quality.
Purpose:
During a meeting held on July 21, 2008 to discuss the project, MACTEC provided a modified
monitoring plan, and the DWQ requested to see a draft of the Fall Creek Land Company's,
proposed watershed modeling and adaptive management plan for the proposed reservoirs. The
plans initial step required on-site assessment of existing water quality prior to development of the
two proposed lakes. Pre-development existing water quality, can be used to set baseline
parameters which the Fall Creek Land Company (FCLC) may use to set target threshold
indicators for water quality for after the lakes have been created. The Draft Grandview Peaks
Lakes watershed modeling and adaptive management plan is outlined as follows.
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
2
I. Watershed Modeling
A detailed watershed model will be developed to quantify loading contributions from both
upstream portions of the watershed as well as changes to water quality loading parameters that
are anticipated (in the absence of appropriate BMPS) with the development of low-density
residential housing on site. Estimates of annual nutrient contributions entering via runoff from
the residential community will be determined by identifying sub-basin drainage areas within the
watershed. Watershed sub-basin delineation will be performed by incorporating aerial
photographs of the site, topographic contours, and proposed conveyance structures within the
community into a GIS platform for analysis. Calculation of annual runoff volumes and associated
loading from the identified sub-basins will incorporate the following information into the
watershed model:
A. Precipitation
Precipitation data will be collected from several local rain gauge stations near the proposed
development. Multiple years of daily rainfall data, up to a maximum of 10 years, will be
used in the model to most accurately reflect weather variations from drought, normal, and
significant storm event rainfall periods.
B. Watershed Characteristics
Determination of surface water runoff during an individual rain event requires a known
amount of precipitation falling on the project site as well as generated runoff curve
numbers (CN). To determine the CN for the project area, land use type and hydrologic soil
group values will be defined using Geographic Information Systems (GIS). Land use
within the project area will incorporate the proposed residential development and newly
constructed reservoirs to reflect future loading characteristics following the completion of
construction.
Interconnected Pond Routing Stormwater (ICPR) or similar modeling platform will be used to
incorporate existing and proposed conveyance systems within the watershed. Using the
predetermined curve numbers and regional precipitation data as inputs to the ICPR model, annual
runoff volumes will be calculated for each sub-basin area within the watershed. Results of the
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
3
ICPR model will provide accurate estimates of annual sub-basin runoff volumes based on
changing land use and conveyance systems anticipated with the proposed development.
Runoff volumes calculated within the watershed model will be used to estimate the annual
nutrient load entering the proposed reservoirs via the project site. Nutrient loads are estimated by
multiplying the annual runoff volume by the event mean concentration (EMC). EMCs are
established for specific parameters of interest (TSS, TN and TP for this analysis) and vary by land
use. Proposed BMPs developed during construction may also be incorporated into the annual
loading estimates by identifying the portion of stormwater runoff treated through a given BMP.
Characterization of existing water quality in several streams within the watershed was completed
to provide an assessment of baseline water quality conditions and upstream loading contributions.
Water quality monitoring was performed at six sampling stations in flowing portions of upstream
tributaries. Based on field observations, one of the possible locations entering proposed
impoundment(s) was found to be an intermittent stream, and did not have adequate flow for
sampling. Five stations were sampled on August 6, 2008 within "the hottest period of the year"
between the August 1st and August 30th. The five stations included sample locations in two sub-
watersheds; the proposed Lake#2 impoundment(s) and the proposed Lake#3 impoundment(s) (see
Figure 1).
• Station GP-L2-U1: Downstream of confluence at the dendriditic tributary split.
• Station GP-L2-U2: Located 105 stream meters up stream of gravel road (wet
crossing).
• Station GP-L2-U3: Located approx 80 meters up stream of culvert at gravel road.
• Station GP-L2-D1: Located in run section, just upstream of large bedrock pool.
30 meters up stream of waterfall section.
• Station GP-L3-U1: Located 30 meters north of gravel road.
• Station GP-L3-D1: Located 20 meters downstream of flag line for dam.
Water sampling protocols adhered to the requirements described in the Predictability Study
Protocol for Sampling Reference Impoundment(s) (NCDWQ, 2008). Water quality parameters
measured included water temperature, dissolved oxygen saturation, pH, turbidity, nutrients (total
phosphorus, total Kjeldahl nitrogen, ammonia [NH3], nitrate + nitrite [N02+NO31), chlorophyll-a
(corrected for pheophytin), and fecal coliform.
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
4
Water Quality results for August 6, 2008 monitoring data provided in Table 1.
Table 1: Draft On-site results; August 6, 2008.
Grandview Peaks / MACTEC Water Quality sampling
(August 6, 2008) prelim results.
On-Site Meter
A-hAi-I I oK
Proposed Lake #2 Proposed Lake #3
Stream Monitoring Parameters GP-L2-U1 GP-L2-U2 GP-L2-U3 GP-L2-D1 GP-L3-U1 GP-L3-D1
H 8.09 8.5 7.95 7.9 n/a 8.04
Conductivity mS 2.2 0.39 0.036 0.05 n/a 0.03
Dissolved Oxygen m /L 10.7 9.8 10.6 10.2 n/a 10.24
Tern rature (degrees C -,: 21.6 21.4 21.4 21.1 n/a 22.2
Salinity a ^.,` 0.00 0.00 0.00 0.00 n/a 0.00
Fecal Coliforms CFU/ 100mL SM 9222D 112 12 152 304 n/a 104
Turbidity (NTU EPA 180.1 16 2.6 4.2 13 n/a 5.7
Total Suspended Solid m /L SM 2540D 34 40.3 8 7.3 n/a 19.3
Ammonia m /L EPA 350.1 nd nd nd nd n/a nd
Nitrogen N02 plus N03 m /L EPA 353.2 0.02 0.09 0.08 0.17 n/a 0.04
TKN m /L EPA 351.2 0.54 0.36 0.57 0.55 n/a 0.41
Total Nitrogen (mg/L) EPA 353.2) 0.55 0.45 0.66 0.45
Total Phosphorus m /L EPA 365.1 0.028 0.015 0.006 0.012
Estimated Gradient % 1.8 3 to 6.8 4 t t 0.3
Wetted Width of stream (ft) 1.9 3.5 3.2 2.5
Max Depth of stream ft 0.9 0.3 0.28 0.14

Location GPS
see ma
see ma
see ma seemap seemap
see ma
Weather description sunny sunny sunny sunny Bunn sunny
Air Temperature (degrees C 32 32.6 31.6 32 33 33.5
Comments pink flagging ink flagging pink flagging pink flagging no water ink flagging
Created By: RLS, Sept, 2008
Checked By: ABS, Sept, 2008
This recent surface water monitoring data will be used to establish baseline water quality
conditions within local streams and upstream tributaries, and will serve as a target for future
stream water quality following construction. Existing water quality measurements recorded in
the streams will be incorporated into the watershed model to provide a benchmark for current
water quality conditions, which may then be compared to subsequent stream water quality
following residential construction.
Baseline water quality data provided in Table 1 will be used in the watershed model to develop
loading estimates from contributing (upstream) portions of the watersheds. Results of the loading
estimates from the surrounding watershed will then be combined with the measured nitrogen,
phosphorus, and TSS load from these tributaries to determine a total annual load for the
impoundment(s). Estimates of the annual nutrient load within each reservoir may then be used to
determine appropriate Best Management Practices (BMPs) to eliminate the incremental loading
difference associated with the construction of the residential community.
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
5
Water quality conditions within the impoundment \611 be modeled using the inputs generated
from the watershed modeling, input parameters (as noted above) and inflowino tributary Water
quality (see "fable i ). fhe Water Quality Analysis Simulation Program (WASP) will be used for
this modeling, to predict future conditions for temperature and dissol\-ed owgen, as indicators of
water quality once the impoundment is tilled.
Best Management Practices (BMPs) will be selected to account for loading entering through
additional residential development, as determined in the watershed model. If the results of the
watershed model determine that additional BMPs are needed, BMP selection and design criteria
will be guided using the North Carolina Division of Water Quality Stormwater Best Management
Practices Manual (NCDWQ, 2007). A number of BMP design options may be chosen to capture
excess runoff prior to entering local streams or the proposed impoundment(s), including, but not
limited to:
a. Dry retention basins;
b. Wet detention basins;
c. Stormwater wetlands;
d. Bio-retention;
e. Infiltration devices; and
f. Grassed swales (etc.)
Emphasis will be given to BMPs that are considered Low Impact Development (LID) . and
sustainable for preservation of water quality and quantity. A number of LID alternatives for
stormwater management are available, including, but not limited to:
a. Minimizing impervious area;
b. Rainwater harvesting;
c. Incorporating permeable surfaces;
d. Depression storage; and
e. Soil filtration
To ensure that portions of each tributary below the impoundments are not negatively impacted by
the construction of the proposed impoundment(s), out flowing water quality may also be
preserved through best management practices within each impoundment(s). These practices are
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
6
likely to focus on temperature, dissolved oxygen and related constituents, and may include
conditions of management of water withdrawal from the impoundment(s), among other factors.
BMP design and implementation will utilize watershed loading estimates, upstream and
downstream surface water monitoring, and examples from similar impoundment(s) within the
regional area as guidance for managing water quality exiting the impoundment(s). BMPs within
the impoundment(s) will be designed and implemented, if necessary, to ensure that water quality
flowing downstream of the impoundment(s) is similar to the water quality of upstream tributaries.
II. Adaptive Management Plan
The purpose of an adaptive management plan is to provide for flexible management of the
proposed reservoirs, based upon a feedback loop so that management strategies are adjusted to
address changing field conditions, to maintain downstream water quality. Watershed BMPs are
anticipated to be sufficient to maintain nutrient loading at current levels. Impoundment of the
water will, however, potentially cause changes in surficial water temperature during summer
months. Primary water quality indicator of the physical affects of impoundment may be captured
by measuring temperature and dissolved oxygen at the surface and at depth during summer. It is
anticipated that during seasons where water temperatures in the stream are similar to surficial
impoundment temperatures (spring, winter, and fall), surficial water may be gravity fed over a
spillway or other conveyance, to the stream. When the need arises (e.g. when the temperature
and/or DO differential from upstream and impoundment require action), water for downstream
replenishment will be pulled from cooler, deeper waters of the impoundment, and oxygenated, if
necessary. These parameters (temperature and DO) provide a quick and reliable method of
assessing water quality within the reservoir. Reports of impoundment(s) water quality may be
provided to the NC DWQ 401 Oversight Unit as requested.
This adaptive management plan focuses on the preservation of water quality both within the
constructed impoundment(s) and in downstream creeks. This management follows existing
recommendations from USEPA and the North American Lake Management Society. Existing
water quality conditions as sampled prior to construction may be used as baseline standards for
the preservation of water quality within downstream creeks. Select BMPs as described in Section
I also are anticipated to be utilized to ensure preservation of baseline and state water quality
standards.
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
7
References:
EPA, 2000. Ambient Water Quality Criteria Recommendations. Lakes and reservoirs in Nutrient
Ecoregion IX. United States Environmental Protection Agency. EPA 822-13-00-011. December
2000
NC DENR - Division of Water Quality "Redbook" Surface Waters and Wetlands Standards NC
Administrative Code 15A NCAC 02B .0 100, .0200 & .0300 Amended Effective: May 1, 2007;
Raleigh, North Carolina:
httR:Hh2o.enr.state.nc.us/admin/rules/documents/redbook 1may07 full with cover.pdf
Closing
The Fall Creek Land Company appreciates your timely review of our response to your request to
see a Watershed Modeling and Adaptive Management Plan for the Grandview Peaks
Development.
Sincerely,
MACTEC ENGINEERING AND CONSULTING, INC.
/2 Z. 57 - for Mn 6. &%Qrw6- ! _-sn wOlrt?
Robert L. Sain, CFM with permission Arai B. Sh elle, PHD
Project Scientist Limnologist/ Chief Scientist
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
8
Recent Project Milestones:
January 16, 2007: The FCLC submitted a combined "Individual 404/401 Permit application" to
the USACE and DWQ.
September 25, 2007: The USACE, DWQ, commenting agencies, and public came back with
public notice comments to be addressed. FCLC's "Response to Pubic Notice Comments" was
submitted to the USACE and NC DWQ.
September 2007 through January 2008: consistent efforts were made by the Fall Creek Land
Company to contact regulators while the waiting for responses.
January 4, 2008: The USACE responded, informally with an email dated.
January 10, 2008: A site meeting occurred with Ms. Amanda Jones, Asheville field office of the
USACE.
January 23, 2008: The DWQ responded formally to the "Response to Public Notice Comments"
with a letter stating that the application was "incomplete" pending analytical monitoring
(Attachment A).
February 6, 2008: a follow-up office meeting took place with the USACE-the USACE
informally requested additional information. This additional information was submitted to the
USACE, Asheville Field Office on June 24, 2008.
February 2008 through June 2008: various correspondences took place between the Fall Creek
Land Company and regulators while drafting additional response documents to address concerns
and new protocols.
June 23, 2008: a brief follow-up meeting took place with the USACE to discuss the draft
Additional Comments Response document.
June 24, 2008: The FCLC Draft - USACE Additional Comments Response document was
submitted to the USACE and copied to the DWQ.
July 8, 2008: the FCLC, On-Site Impoundment(s)s Sampling Protocol document was submitted
to the DWQ and copied to the USACE
July 21 2008: A meeting took place in Raleigh at the DWQ headquarters to discuss the FCLC
sampling protocol document and the project status. Action to the FCLC to capture, on-site,
August water quality and to carryon with the FCLC proposed sampling protocol.
August 6, 2008: Per the DWQ meeting, the FCLC conducted in-situ and analytical on-site
sampling at five locations adjacent to the proposed lakes.
August 29, 2008: On-Site Grandview Peaks, analytical sampling data results back from labs.
September 23, 2008: Impoundments Modeling and Adaptive Management Plan submitted to the
DWQ and copied to the USACE.
Grandview Lakes Monitoring Plan October 1, 2008
McDowell Lakes Development Site, McDowell County, North Carolina MACTEC Project No. 6229052914
2