20021881 Ver 1_Complete File_20021218

Michael F. Easley
Governor
William G. Ross; Jr., Secretary
Department of Environment and Natural Resources
Alan Klimek, PE
Division of Water Quality
December 18, 2002
Mr. Ron Ferrell
Wetlands Restoration Program
1619 MSC
Raleigh, NC 27699-1619
Subject: Stream Restoration/Enhancement
Silas Creek Stream Restoration
Forsyth County, NC
DWQ# 021881
Dear Mr. Ferrell:
This Office is in receipt of the plans for the stream restoration projects of approximately 4633 feet of Silas
Creek and Buena Vista Branch in the Yadkin River Basin originally submitted to this Office on December 9,
2002. DWO Staff reviewed the plans and determined that stream restoration and/or enhancement would be
achieved.
The stream impacts associated with the project may proceed without written approval from the Division. Please
be advised that seven copies of a complete, formal application and a $475.00 fee is required for projects
intended for compensatory mitigation credit (see General Certification No. 3353, issued March 18, 2002). Any
request for mitigation credit shall be addressed under separate cover.
If you have any questions regarding this matter, please contact Mr. Todd St. John at [phone].
Sr?n?/geel,
John R. Dorney
Wetlands Unit Supervisor
cc: Mr. Todd St. John, Wetlands Unit
Jeff Jurek, WRP
Raleigh Regional Office
File
North Carolina Division of Water Quality, 401 Wetlands Certification Unit,
1650 Mail Service Center, Raleigh, NC 27699-1650 (Mailing Address)
2321 Crabtree Blvd., Raleigh, NC 27604-2260 (Location)
Silas Creek
Stream Restoration Project
Winston-Salem, North Carolina
North Carolina Department of Environment and Natural Resources
Wetlands Restoration Program
021881
Prepared By:
BUCK 8000 Regency Parkway
Suite 200
Cary, North Carolina 27511
Phone: [phone]
C; i X I I. I% NGTMA_ G Fax: [phone]
www.buckengineering.com
November 2002
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Silas Creek
Stream Restoration Project
Winston-Salem, North Carolina
Prepared For:
NC Department of Environment and Natural Resources,
Wetlands Restoration Program
November, 2002
Design Report Prepared By Buck Engineering PC
William A. Harman, PG
Principal In-Charge
Shawn Wilkerson
Project Manager
John Hutton
Project Scientist
Jessica Rohrbach
Project Biologist
Marco Hilhorst
CADD Analyst
Karen Missell
Project Scientist
Daniel Taylor
Project Engineer
Heath Wadsworth, El
Hydraulic Engineer
Kevin Varnell
Field Supervisor
Marshall Wight
Field Technician
_10

' Executive Summary
The North Carolina Wetlands Restoration Program (WRP) proposes to restore 4,633
linear feet of stream along two reaches of Silas Creek and one reach of Buena Vista
Branch in Winston-Salem, North Carolina. The reaches are located in Shaffner Park.
' The existing stream channels have low sinuosity and varying levels of incision due to
historic channelization. The proposed stream restoration design is based on natural
channel design principles and considers drainage area, watershed land uses, floodplain
land uses, urban constraints, and future development potential. The design addresses the
channel dimension, pattern, and profile based on reference reach parameters and
hydraulic geometry relationships. When considering design alternatives, every effort was
' made to create a stable meandering channel with an accessible floodplain at the bankfull
elevation. Development restrictions along Silas Creek do not allow for new channel
pattern to be established. The existing incised channels will be enhanced by excavating
' new floodplain benches at the bankfull stage and installing structures to improve bed
diversity and control channel grade.
' A summary of existing and design reach lengths with proposed restoration design
approaches is provided in the table below.

Existing Restored

Sub-Project Length Length
Restoration Approach
ft ft
Bankfull benches and in-stream
Silas Creek 1 &2 3,805 3,805 structures (Priority 3 restoration)
Buena Vista Creek 828 910 Priority 2 restoration
Total 4,633 4,715
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Table of Contents
1 Introduction .............................................................................................................. 1-1
1.1 Project Description ...........................................................................................1-1
1.2 Project Objectives .......................................................................................... .. 1-1
1.3 Watershed Characterization ........................................................................... ..1-2
2 Existing Condition Survey ..................................................................................... ..2-6
2.1 Channel Stability Assessment ........................................................................ .. 2-6
2.2 Benchmarks and Underground Utilities ......................................................... .. 2-9
2.3 Silas Creek ..................................................................................................... .. 2-9
2.4 Buena Vista Branch ....................................................................................... 2-12
2.5 Threatened and Endangered Species ............................................................. 2-14
3 Bankfull Stage Verification ................................................................................... 3-18
3.1 Bankfull Stage and Discharge ........................................................................ 3-18
3.2 Bankfull Hydraulic Geometry Relationships (Regional Curves) .................. 3-18
3.3 Bankfull Verification in the Silas Creek Watershed ...................................... 3-19
4 Reference Reach Analyses ..................................................................................... 4-22
5 Natural Channel Design ......................................................................................... 5-28
5.1 Design Summary ............................................................................................ 5-28
5.2 Silas Creek Natural Channel Design .............................................................. 5-28
5.3 Buena Vista Natural Channel Design ............................................................ 5-34
6 Sediment Transport Analysis ................................................................................. 6-36
6.1 Background .................................................................................................... 6-36
6.2 Silas Creek ..................................................................................................... 6-37
6.3 Buena Vista Branch ....................................................................................... 6-41
7 Flooding Analyses ................................................................................................. 7-46
8 Monitoring and Evaluation .................................................................................... 8-47
8.1 Cross-sections ................................................................................................ 8-47
8.2 Pattern ............................................................................................................ 8-47
8.3 Materials ........................................................................................................ 8-47
8.4 Longitudinal Profiles ..................................................................................... 8-48
8.5 Photo Reference Sites .................................................................................... 8-48
8.6 Survival Plots ................................................................................................. 8-49
9 References .............................................................................................................. 9-50
Appendix 1 Existing Condition Data ............................................................................. .. 9-1
Appendix 2 Reference Reach Data ................................................................................ .. 9-1
Appendix 3 Photographic Log ....................................................................................... ..9-2
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List of Figures
Figure 1.1 Project Location Map ...................................................... -
Figure 1.2 Project Watershed Map .................................................... 1-5
Figure 3.1 Rural and Urban Piedmont Regional Curves with Surveyed
Bankfull Cross-Section Areas for Project Reaches .................... 3-20
Figure 3.2 Rural and Urban Piedmont Regional Curves showing Bankfull
Discharge Versus Drainage Area ......................................... 3-21
Figure 4.1 Reference Reach Location Map - Silas Creek ........................ 4-25
Figure 4.2 Reference Reach Location Map - Unnamed Tributary to
Lake Jeanette ............................................................... 4-26
Figure 4.3 Rural and Urban Piedmont Regional Curves with Surveyed
Bankfull Cross-Section Areas for Project Reference Reaches...... 4-27
Figure 5.1 Parking Lot BMP Design .................................................... 5-32
Figure 6.1 Silas Creek Pavement/Subpavement Analysis ........................ 6-37
Figure 6.2 Modified Shields Curve for Grain Diameter of Transported
Particle in Relation to Critical Shear Stress ........................... 6-40
Figure 6.3 Buena Vista Branch Pavement/Subpavement Analysis............ 6-42
Figure 6.4 Modified Shields Curve for Grain Diameter of Transported
Particle in Relation to Critical Shear Stress ............................. 6-44
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List of Tables
Table 1.1 Existing Stream Lengths and Drainage Areas ................................................. 1-1
Table 2.1. Conversion of Bank Height Ratio (Degree of Incision) to Adjective Rankings
of Stability (Rosgen, 2001) ...................................................................................... 2-7
Table 2.2. Conversion of Width/Depth Ratios to Adjective Ranking of Stability from
Stability Conditions (Rosgen, 2001) ........................................................................ 2-8
Table 2.3. Existing Condition Parameters for Silas Creek (Reaches 1 and 2 are presented
by one survey dataset) ............................................................................................2-10
Table 2.4. Existing Condition Parameters for Buena Vista Branch . ........................... 2-13
Table 2.5 Federally Protected Species for Forsyth County .......................................... 2-15
Table 2.6 Federal Species of Concern for Forsyth County ............................................ 2-17
Table 3.1. Piedmont Rural and Urban Regional Curve Equations ............................... 3-19
Table 3.2. Bankfull discharge comparison of HEC-RAS and regional curve ............... 3-21
Table 4.1. Project Design Stream Types ........................................................................4-22
Table 4.2. Summary Reference Reach Data .................................................................. 4-24
Table 5.1. Natural Channel Design Parameters for Silas Creek (Reaches 1 &2 are
represented by the same dataset) ............................................................................ 5-29
Table 5.2. Natural channel design parameters for Buena Vista Branch ........................ 5-35
Table 6.1. Boundary shear stresses for existing and design riffle cross sections on Silas
Creek ...................................................................................................................... 6-41
Table 6.2 Boundary shear stresses for existing and design riffle cross sections .......... 6-45
t Winston-Salem Stream Restoration Projects v Buck Engineering
' 1 Introduction
t 1.1 Project Description
t The North Carolina Wetlands Restoration Program (WRP) proposes to restore 4,633
linear feet of stream along two reaches of Silas Creek and one reach of Buena Vista
Branch in Winston-Salem, North Carolina. The reaches are located in Shaffner Park
(Figure 1.1). These streams are tributaries to Muddy Creek (USGS Hydrologic Unit
03040102) and are in the Yadkin River basin.

Table 1.1 Existinj4 Stream Lengths and Drainage Areas.
Reach Name Existing Length (ft) Drainage Area (mil)
Silas Reach 1 1,127 5.4
Silas Reach 2 2,678 7.2
Buena Vista 828 1.4
1.2 Project Objectives
The Silas Creek stream restoration project is one component in the enhancement of the
Silas Creek watershed. The overall goal is to improve the water quality, habitat, and
stability within this urban watershed. As in many developed watershed, the increase of
peak flow events, loss of floodplains and adjacent wetlands, and conventional
engineering of streams has caused a substantial loss of the ecological value and has
resulted in degraded water quality. By stabilizing channels, preserving and installing
riparian buffers, enhancing habitat structure, allowing natural storage capacity for storm
flows, and constructing necessary storm water treatment BMPs, the overall watershed
health can be restored to Silas Creek.
The objectives of the Silas Creek stream restoration project are to enhance the Silas
Creek watershed by:
1. Restoring 4,715 LF of channel dimension, pattern, and profile to the extent
possible considering the project constraints, watershed characteristics, and data
from reference reaches in similar watersheds;
2. Improving floodplain functionality by matching floodplain elevation with
bankfull stage therefore increasing watershed attenuation and reducing peak
flows;
3. Establishment of native floodplain vegetation which will allow treatment of
diffuse storm flow and nutrient uptake from vadose zone flow while help to
establish part of a wildlife corridor in the watershed;
4. Improving the natural aesthetics of the stream corridor; and,
Winston-Salem Stream Restoration Projects 1-1 Buck Engineering
' 5. Improving the water quality in the Silas Creek watershed by reducing bank
erosion, increasing nutrient storage and uptake, and increasing the dissolved
' oxygen of the system.
1.3 Watershed Characterization
The project site is located in the city of Winston-Salem in the urban Piedmont
physiographic region. The topography is characterized by gently rolling hills and wide
alluvial valleys with a dendritic stream pattern.

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Over the last two decades, land use in the Winston-Salem area has undergone a rapid
conversion from rural and open space to urban. The City of Winston-Salem Planning
Department is responsible for the future growth and development of the city. Information
on land use planning in Winston-Salem can be found at:
http://www.cityofws.orWGIS/html/main.htm
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More detailed information for each project reach is presented in the sections below.
Characterizations were performed by gathering information on topography, soils, land
use, and percent impervious. The percent impervious of each watershed was estimated
using aerial photography and GIS analysis. Figure 1.2 shows the watershed delineations
for both Silas Creek and Buena Vista Branch on aerial photography.
1.3.1 Silas Creek
' The Silas Creek watershed area is approximately 7.2 square miles. Land use for the
watershed is highly diversified with land uses including: residential, commercial,
industrial, park, and recreational. Based on this information, the impervious land cover
' was determined to be approximately 39%.
Elevations within the Silas Creek watershed range from approximately 790 feet to 1,000
' feet with a relative relief of 210 feet. Based on the North Carolina Soil Survey for
Forsyth County (NRCS, 1976), soils at the project site are mapped primarily as Chewacla
loam (Ch). The Chewacla series consists of nearly level, somewhat poorly drained soils
' of stream floodplains. These soils formed in recent alluvium and are frequently flooded
for brief periods of time. The surface layer typically extends to a depth of 9 inches and is
dark brown. The subsoil is a dark brown or light olive brown color with grayish brown to
' yellowish brown mottles. The Chewacla soil series is listed as hydric by the National
Resource Conservation Service (1996). However, hydric conditions no longer exist
within the project area due to the incision of Silas Creek and Buena Vista Branch. This
incision has lowered the water table and decreased overbank flooding.
' 1.3.2 Buena Vista Branch
The Buena Vista Branch watershed area is approximately 1.4 square miles. The land use
' is composed largely of residential lots (0.25 acres) and a golf course; however
approximately 10% of the watershed area was delineated as commercial and industrial.
Overall, the watershed has approximately 27% impervious land cover.
' Elevations within the Buena Vista Branch watershed range from approximately 800 feet
to 960 feet with a relative relief of 160 feet. Similar to Silas Branch, soils at the project
t site are mapped as Chewacla loam (NRCS, 1976), which is described above.
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Silas Creek
Winston Salem, NC
Forsyth County
NorthCarolina
Wetlands Restoration Program

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Figure 'll: Watershed Map
Buena Vista ;,reek ? Silas Creek
stop Watershed Boundary -- - Watershed Boundary
rat ,- Buena Vista Silas Creek
Restoration Reach Restoration Reach
Forsyth County 0 3,000 6,000 9,000
?? Feet
2 Existing Condition Survey

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The primary purposes of the existing condition survey are to determine the stability of the
project stream reach and its potential for restoration, if needed. This is accomplished
through a quantitative and qualitative investigation of the stream corridor, including
channel dimension, pattern, and profile. This analysis provides information that is used to
assess the potential for restoration. Data collected during the existing condition survey
are used to determine if the stream is moving towards stability or instability and if the
cause of instability is localized or system-wide. Examples of localized instability include
removal of riparian vegetation and/or trampling of the stream banks by livestock or
humans. System-wide instability is often caused by channel incision, which causes head-
ward erosion until stopped by a knick point.
2.1 Channel Stability Assessment
Buck Engineering used a modified stream channel stability assessment methodology
developed by Rosgen (2001). The Rosgen 2001 method is a field assessment of the
following variables:
1. Stream Channel Condition or "State" Categories,
2. Vertical Stability - Degradation/Aggradation,
3. Lateral Stability,
4. Channel Pattern,
5. River Profile and Bed Features,
6. Channel Dimension Relations,
7. Stream Channel Scour/Deposition Potential (Sediment Competence),
8. Channel Evolution.
A description of each variable is provided below.
2.1.1 Stream Channel Condition or "State" Categories
Seven categories are included in this analysis and include: a) riparian vegetation, b)
sediment depositional patterns, c) debris occurrence, d) meander patterns, e) stream
size/stream order, f) flow regime, and g) altered states due to direct disturbance. These
condition categories are determined from field inspection and measurement of stream
channel condition characteristics.
2.1.2 Vertical Stability - Degradation/Apmradation
The bank height and entrenchment ratios are measured in the field to determine vertical
stability. The bank height ratio is measured as the ratio of the lowest bank height divided
by a maximum bankfull depth. Table 2.1 shows the relationship between bank height
ratio and vertical stability developed by Rosgen (2001).
Winston-Salem Stream Restoration Projects 2-6 Buck Engineering
Table 2. 1. Conversion of Bank Height Ratio (Degree of Incision) to
Adjective Rankings of Stability Ros en, 2001).
StabiliRatin Bank Hei ght Ratio
Stable (low risk of degradation) 1.0- 1.05
Moderately unstable 1.06 -1.3
Unstable (hi risk of degradation) 1.3- 1.5
Highly unstable > 1.5
The entrenchment ratio is calculated by dividing the flood-prone width (width measured
' at twice the maximum bankfull depth) by the bankfull width. If the entrenchment ratio is
less than 1.4 (+/- 0.2), the stream is considered entrenched (Rosgen, 1996).
2.1.3 Lateral Stability

The degree of lateral containment (confinement) and potential lateral accretion are
determined in the field by measuring the meander width ratio and Bank Erosion Hazard
Index (BEHI). The meander width ratio is the meander belt width divided by the
bankfull channel width, and provides insight into channel adjustment processes
depending on stream type and degree of confinement. BEHI ratings can be used to
estimate the annual, lateral streambank erosion rate.
2.1.4 Channel Pattern
Channel pattern is assessed in the field by measuring the meander width ratio (described
above), ratio of radius of curvature to bankfull width, sinuosity, and meander wavelength
ratio (meander wavelength divided by bankfull width). These dimensionless ratios are
compared to reference reach data for the same valley and stream type to determine where
channel adjustment has occurred due to instability.
2.1.5 River Profile and Bed Features
A longitudinal profile is created by measuring elevations of the bed, water surface,
bankfull, and low bank height along the reach. This profile can be used to determine
changes in river slope compared to valley slope, which are sensitive to sediment
transport, competence, and the balance of energy. For example, the removal of large
woody debris may increase the step/pool spacing and result in excess energy and
subsequent channel degradation.
2.1.6 Channel Dimension Relations
The bankfull width/depth ratio (bankf ill width divided by mean bankfull depth) is
measured in the field. The ratio provides an indication of departure from the reference
reach and relates to channel instability. An increase in width/depth ratio indicates
accelerated streambank erosion, excessive sediment deposition, stream flow changes, and
alteration of channel shape (e.g., from channelization). Channel widening is also
Winston-Salem Stream Restoration Projects 2-7 Buck Engineering

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associated with an increase in width/depth ratio due to evolutionary shifts in stream type
(e.g., from G4 to F4 to C4). Table 2.2 shows the relationship between the degree of
width/depth ratio increases and channel stability developed by Rosgen (2001).
Table 2.2. Conversion of Width/Depth Ratios to Adjective Ranking of
Stability from Stability Conditions (Ros en, 2001).
Stability Rating Ratio of W/D Increase
Very stable 1.0
Stable 1.0-1.2
Moderately unstable 1.21-1.4
Unstable > 1.4
While an increase in width/depth ratio is associated with channel widening, a decrease in
width/depth ratio is associated with channel incision. Hence, for incised channels, the
ratio of channel width/depth ratio to reference reach width/depth ratio will be less than
1.0. The reduction in width/depth ratio indicates excess shear stress and an adjustment of
the channel toward an unstable condition.
2.1.7 Stream Channel Scour/Deposition Potential (Sediment Competence)
This methodology is discussed in detail in Chapter 6 of this report.
2.1.8 Channel Evolution
A common sequence of physical adjustments has been observed in many streams
following disturbance. This adjustment process is often referred to as channel evolution.
Disturbance can result from channelization, increase in runoff due to build-out in the
watershed, and removal of streamside vegetation, as well as other changes that negatively
affect stream stability. All of these disturbances are common in the urban environment.
Several models have been used to describe this process of physical adjustment for a
stream. Simon's channel evolution model (1989) characterizes evolution in six steps,
including 1) sinuous, pre-modified, 2) channelized, 3) degradation, 4) degradation and
widening, 5) aggradation and widening, and 6) quasi equilibrium.
The channel evolution process is initiated once a stable, well-vegetated stream that has
access to its floodplain is disturbed. Disturbance commonly results in an increase in
stream power which causes degradation, often referred to as channel incision. Incision
eventually leads to increased slopes of stream banks, and when critical bank heights are
exceeded, the banks begin to fail and mass wasting of soil and rock leads to channel
widening. Incision and widening continue migrating upstream, a process commonly
referred to as a head-cut. Eventually the mass wasting slows and the stream begins to
aggrade with a new low-flow channel forming in the sediment deposits. By the end of
the evolutionary process, a stable stream with dimension, pattern, and profile similar to
those of undisturbed channels forms in the deposited alluvium. The new channel is at a
lower elevation than its original form with a new floodplain constructed of alluvial
material and the old floodplain remains a dry terrace (FISRWG, 1998). Most urban
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streams are at some stage of this evolutionary process. The time required to reach a state
of quasi equilibrium is highly variable and has not yet been determined.
2.2 Benchmarks and Underground Utilities
Four control benchmarks were established on site by Arcadis G&M. Their locations and
coordinates are shown on the enclosed plan view. Topography, planimetric information
and aerial photographs were obtained from the City of Winston-Salem in GIS format.
The topographic mapping included one-foot contours. MA Engineering located all
underground utilities and Arcadis G&M provided the utility mapping to overlay with the
topographic and planimetric data in GIS. Buck Engineering supplemented the existing
mapping with a longitudinal profile and cross sectional survey of the existing channel.
Buck Engineering also collected additional topographic data in areas where intensive
grading may take place (e.g. a new channel or stormwater best management practice
(BMP)).
2.3 Silas Creek
Silas Creek flows through Shaffner Park within the project limits. The project is divided
into two project reaches with a drainage area of 7.2 square miles at the downstream end
of reach 2. The watershed was determined to be approximately 39% impervious. Reach
1 is from the point where Silas Creek enters Shaffner Park to Yorkshire Road. Reach 2 is
from Yorkshire Road down to the point where Silas Creek flows out of Shaffner Park
(Figure 1.1). Table 2.3 summarizes the existing condition data for Silas Creek reaches 1
& 2.
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Table 2.3. Existing Condition Parameters for Silas Creek (Reaches 1 and 2 are presented
by one survey dataset)
Parameters Existing
Rosgen Stream Type B4c*
Drainage Area (sq mi) 7.2
Reach Length (ft) 3805
Bankfull Width (ft) 40
Bankfull Mean Depth (ft) 3.5
Width/Depth Ratio 11.7
Bankfull Area (sq ft) 138
Bankfull Max Depth (ft) 4.5
Width of Floodprone Area (ft) 112
c
0 Entrenchment Ratio 2.71
U) Max Pool Depth (ft) 7.4
E
p Ratio of Max Pool Depth to
Bankfull Depth 2.1
Pool Width (ft) 35.3
Ratio of Pool Width to
Bankfull Width 0.9
Pool to Pool Spacing (ft) 82-189
Ratio of Pool to Pool Spacing
to Bankfull Width 2.0-4.75
Bank Height Ratio 1.3-1.7
Meander Length (ft) N/A**
Meander Length Ratio N/A**
E Radius of Curvature (ft) N/A**
Radius of Curvature Ratio N/A**
CU Meander Belt Width (ft) 40
Meander Width Ratio 1
Sinuosity 1.03
Valley Slope (ft/ft) 0.0029
WS Slope (ft/ft) 0.0025
m Riffle Slope (ft/ft) 0.0028
o
a Ratio of Riffle Slope to WS
Slope 1.12
Pool Slope (ft/ft) 0.0005
Ratio of Pool Slope to WS
Slope 0.19
* The entrenchment ratio is high for a Bc stream type. However, given other factors such
' as a low sinuosity and a moderate bank height ratio, we determined that Silas Creek
functioned more like a Bc / F than a C or E stream type. A more thorough discussion of
stability is presented below.
' ** Due to the extremely low sinuosity, pattern data cannot accurately be calculated. Any
data calculated would overestimate pattern.
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2.3.1 Stability Assessment
As part of the stability assessment, four cross sections were surveyed at stable riffles and
pools throughout both reaches. The survey data and cross sections are provided in
Appendix 1. Bankfull cross sectional area averaged 138 ft2 for the two riffles surveyed,

' while the pool bankfull area averaged 150 ft2. The bankfull width/depth ratio is variable,
ranging from 9.2 to 14.2 in the riffles and ranging from 7.4 to 9.5 in the pools. An
increase in bankfull width/depth ratio in comparison to reference ratios is indicative of a
' channel that is trying to widen through streambank erosion. Lateral bars and point bars
are located in areas with high bankfull width/depth ratios, evidence of channel deposition
and aggradation. This type of aggradation is indicative of a stage V in Simon's channel
' evolution model and indicates that the stream is evolving towards greater stability.
However, thousands of tons of sediment must be eroded from the streambank for the
stream to reach stage VI, quasi-equilibrium.
' Bank height ratios range from 1.5 to 1.7 and entrenchment ratios range from 1.7 to 6.7.
These values demonstrate that the stream is highly unstable; however, the stream is not
severely entrenched (no ER values below 1.4). Streambank erosion is extreme due to the
high bank height ratios. There is a wide flood prone area on the left bank of Reach 1 and
on the right side of Reach 2; however, this is only accessible to the stream at discharges
' 3.5 times the bankfull discharge or greater. Bankfull benches along the left side of the
Reach 2 below Silas Creek Parkway provide a small active floodplain.
The longitudinal profile, shown in Appendix 1, varies over the project length. The overall
average channel slope across both reaches is 0.25%. Reach 1 is extremely flat (slope =
0.04%) due to the backwater effect of the culvert at Yorkshire Parkway. There is very
little diversity in riffle-pool sequence in Reach 1. Large scour pools below each of the
' culverts on the project have decreased the effective slope of Reach 2 from 0.25% to
0.18% (culverts subtracted from slope calculation). However, this slope is still
' significantly greater than that of Reach 1, which is reflected in the increased bed form
diversity.
The modified Wolman pebble count was used to characterize the bankfull channel
bottom. Transects were sampled throughout the reach and were stratified by the
proportion of riffles and pools. Ten particles were sampled at ten different cross sections
' spread throughout each reach. The pebble count data show that the D50 is 23-mm and
the D84 is 32-mm indicating that coarse gravel is the dominant bed material in the stream
channel. The riffle D50 was only used for Rosgen stream classification purposes.
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The riparian area within the park consists of a combination of ma
forested areas. Woody species found along the banks and surrounding riparian areas
' include green ash (Fraxinus pennsylvanica), sycamore (Platanus occidentalis), river
birch (Betula nigra), sweetgum (Liquidambar styraciflua), tulip poplar (Liriodendron
tulipifera), american elm (Ulmus americana), black walnut (Juglans nigra), white pine

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(Pinus strobes), maple (Acer spp.), oak (Quercus spp), spicebush (Lindera benzoin),
silky dogwood (Cornus amomum), elderberry (Sambucus canadensis), box elder (Acer
negundo), black willow (Salix nigra), and tag alder (Alnus serrulata). These species
were most prevalent in Reach 1 where a small but nearly continuous buffer exists on both
sides of the stream.
The vegetative and vine layers are composed of christmas fern (Polystichum
acrostichoides), oriental ladysthumb (Polygonum caespitosum), jewelweed (Impatiens
capensis), False Stinging Nettle (Boehmaria cylindrica), virginia creeper (Parthenocissus
quinquefolia), american pokeweed (Phytolacca americana), trumpet creeper (Campsis
radicans), and poison ivy (Toxicodendron radicans).
2.3.2 Constraints
Constraints to achieving the highest level of stream restoration in Shaffner Park include
the following:
• A walking path along the left bank and recreation fields under construction along
the right bank of Reach 1 limit the potential for channel relocation and the extent
of bankfull benches.
' • A sanitary sewer line and recreation fields along the left bank of Reach 2 between
Yorkshire Road and Silas Creek Parkway limit the potential for channel
relocation and the extent of bankfull benches.

1

• Walking paths on both sides of Reach 2 below Silas Creek Parkway limit the
potential for channel relocation and the extent of bankfull benches.
• There is a parking lot immediately adjacent to the left bank of Silas Creek and the
right bank of a storm-water ditch that discharges into Silas Creek.
• The stream crosses two sanitary sewer lines and one water line along Reach 2
below Silas Creek Parkway.
• Culverts at the two major road crossings set the grade of Silas Creek, limit the
potential for relocation and constrain the floodplain.
• There are a number of storm sewer outfalls located along the project.
2.4 Buena Vista Branch
The project reach of Buena Vista Branch flows through a golf course; however, it
originates in a residential area. The drainage area is 1.4 square miles and was determined
to be approximately 27% impervious. The summary data for this reach are shown in
Table 2.4.
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1 Table 2.4. Existing Condition Parameters for Buena Vista Branch.

Parameters Existing
Rosgen Stream Type E4
Drainage Area (sq mi) 1.4
Reach Length (ft) 828
Bankfull Width (ft) 14.5
Bankfull Mean Depth (ft) 2.11
Width/Depth Ratio 6.86
Bankfull Area (sq ft) 30.6
Bankfull Max Depth (ft) 3.21
Width of Floodprone Area (ft) 119
0
Entrenchment Ratio
8.2
Max Pool Depth (ft) 2.76
E
i5 Ratio of Max Pool Depth to
Bankfull Depth 1.3
Pool Width (ft) 15.8
Ratio of Pool Width to
Bankfull Width 1.08
Pool to Pool Spacing (ft) 45-157
Ratio of Pool to Pool Spacing
to Bankfull Width 3.1-10.8
Bank Height Ratio 1.8
Meander Length (ft) 72-105
Meander Length Ratio 5-7.2
E Radius of Curvature (ft) 25-100
o Radius of Curvature Ratio 1.7-6.9
Meander Belt Width (ft) 15.4-23.8
Meander Width Ratio 1.1-1.6
Sinuosity 1.09
Valley Slope (ft/ft) 0.0111
a) WS Slope (ft/ft) 0.0107
o Pool Slope (ft/ft) 0.0024
IL Ratio of Pool Slope to WS
Slope
0.227
2.4.1 Stream Stability Assessment
t Two cross sections were surveyed along Buena Vista Branch and are shown in Appendix
1. Riffle cross sectional area was determined to be 30.6 W. The width/depth ratio for the
riffle surveyed was 6.9. The bank height ratio varied from approximately 1.4 to 2.3
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across the site. Entrenchment ratios varied depending on the degree of incision from 1.4
up to 8.2. There are areas where the stream is incised and a bankfull bench is developing,
as shown in the cross-sectional survey data. This is indicative of stage IV of the Simon
stream evolution model.
The longitudinal profile shows a fair amount of diversity in bed form. However, the
riffles and pools do not necessarily correspond to the tangent and bend sections,
respectively. Many of the riffle sections are located at bends in the channel indicating
that bank erosion is occurring, eventually resulting in increased sinuosity. The bed
material is composed mostly of fine gravel, with a D50 of 5.7-mm. However, the D84 is
approximately 23-mm, which is course gravel.
The right bank is primarily maintained grass through the project reach. The predominant
vegetation on the left bank is consistent with the vegetation described for Silas Creek in
Section 2.3.1.
Overall, Buena Vista Branch is a moderately to highly incised stream with some access to
its floodplain. The Rosgen stream-type is an incised E4 with varying severity of incision
and entrenchment. The channel appears to be in stage III/IV of the Simon Channel
Evolution model, where downcutting is continuing with channel widening beginning to
occur. The stream will continue to widen in areas lacking good vegetation and develop
lateral bars (inner berm) as the channel develops a new floodplain at a lower elevation.
Left unchecked, this widening and aggradation process will continue until the stream
establishes a new floodplain with a sufficient belt width to create a stable dimension,
pattern, and profile at a lower elevation than the existing terrace / floodprone area.
2.4.2 Constraints
Constraints to achieving the highest level of stream restoration on Buena Vista Branch
include the following:
A sewer line crossing at the upstream end of the reach prevents channel relocation
in this section. The inability to relocate the channel and begin raising the bed
elevation results in an overall inability to achieve a priority I restoration.
Soccer fields along the right bank and a sewer line to the left of the channel set
the beltwidth limits for the priority II restoration.
Sewer line crossings at the downstream end prevent relocation in this area.
' 2.5 Threatened and Endangered Species
A search of the US Fish and Wildlife Service (USFWS) and NC Natural Heritage
' Program (NHP) databases, conducted on September 16, 2002, concluded that no habitat
or populations of federally protected species listed for Forsyth County exist in the project
area. The federally protected species for Forsyth County are listed in Table 2.5 below. A
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more detailed description of the characteristics and habitat requirements for the federally
protected species can be found below along with conclusions regarding potential project
impacts based on habitat requirements.
Table 2.5 Federally Protected Species for Forsyth County
Scientific Name Common Name Federal
Status State
Status Biological
Conclusion
Cardamine micranthera Small-anthered bittercress E E No Effect
Clemmys muhlenbergii Bog turtle T (S/A) T No Effect
Picoides borealis Red-cockaded woodpecker E E No Effect
Notes:
"E - Endangered" denotes a species in danger of extinction throughout all or a significant portion
of its range.
"T - Threatened" denotes a species likely to become endangered in the foreseeable future
throughout all or a significant portion of its range.
"S/A - Similarity of Appearance" denotes a species that closely resembles in appearance to an
endangered or threatened species that enforcement personnel would have substantial difficulty in
differentiating between the listed and unlisted species. The southern population of the bog turtle is
listed as T (S/A) due to Similarity of Appearance with the northern population of the bog turtle
(which is federally listed as Threatened and which does not occur in North Carolina).
' Cardamine micranthera (Small-anthered bittercress)
Plant Family: Brassicaceae
Federally Listed: September 21, 1989

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Endangered
Small-anthered bittercress is a slender, erect, perennial herb of the mustard family,
usually with one, but occasionally with multiple, stems, either simple or branched, 8 to 16
inches (20 to 41 centimeters) tall. Leaf edges have shallow, rounded teeth. Bottom
leaves are lobed, 0.4 to 0.8 inches (1 to 2 centimeters) long, and 0.2 to 0.24 inches (0.5 to
0.6 centimeters) wide. Upper leaves are alternate and usually unlobed, 0.4 to 0.6 inches
(1 to 1.5 centimeters) long, and wedge-shaped, with the narrow point at the stem.
Reduced leaves (bracts) occur at the base of the flowers, which have four small white
petals and six stamens with small round anthers. Flowering and fruiting occur in April
and May. This plant grows primarily in seeps and wet rock crevices of streambanks
adjoining sandbars, floodplain depressions, and moist woods near small streams fully to
partially shaded by trees and shrubs.
Small-anthered bittercress is endemic to the Dan River drainage in Stokes County.
Historically, it was also known to exist in Forsyth County.
Biological Conclusion:
No Effect
' No potential habitat such as substantial streamside shading or gravel/sandbars, exists
within the project area for the small-anthered bittercress. A search of the NHP database,
conducted on September 16, 2002, found no occurrence of the small-anthered bittercress
' Winston-Salem Stream Restoration Projects 2-15 Buck Engineering
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in the project area. It can be concluded that the project will not impact this endangered
species.
Clemmys muhlenbergii (Bog turtle)
Animal Family: Emydidae
Federally Listed: November 4, 1997
Threatened (Due to Similar Appearance)
Bog turtles are small [3 to 4.5 inches (7.6 to 11.4 centimeters)] turtles with a weakly
keeled carapace (upper shell) that ranges from light brown to ebony in color. The species
is readily distinguished from other turtles by a large, conspicuous bright orange to yellow
blotch on each side of its head. Bog turtles are semi-aquatic and are only infrequently
active above their muddy habitats during specific times of year and temperature ranges.
They can be found during the mating season from June to July and at other times from
April to October when the humidity is high, such as after a rain event, and temperatures
are in the seventies. Bog turtle habitat consists of bogs, swamps, marshy meadows, and
other wet environments, specifically those that have soft muddy bottoms. The southern
populations of bog turtles (in Virginia, Tennessee, North and South Carolina, and
Georgia) are listed as threatened due to similar appearance (T S/A) to northern bog turtles
that are listed as threatened. A Biological Conclusion is not required since T (S/A)
species are not afforded full protection under the ESA. However, the protected species
classification of the southern populations could be upgraded in the future.
Biological Conclusion: No Effect
No potential habitat for bog turtles exists in the project area. A search of the NHP
database, conducted on September 16, 2002, found no occurrence of the bog turtle in the
project area. It can be concluded that the project will not impact this species.
Picoides borealis (Red-cockaded woodpecker) Endangered
' Vertebrate Family: Picidae
Federally Listed: October 13, 1970
' The red-cockaded woodpecker once occurred from New Jersey to southern Florida and
west to eastern Texas. It occurred inland in Kentucky, Tennessee, Arkansas, Oklahoma,
and Missouri. The red-cockaded woodpecker is now found only in coastal states of its
' historic range and inland in southeastern Oklahoma and southern Arkansas. In North
Carolina, moderate populations occur in the sandhills and southern coastal plain. The
few populations found in the piedmont and northern coastal plain are believed to be relics
' of former populations.
This woodpecker is approximately 8 inches (20 centimeters) long with a wingspan of 14
' inches (36 centimeters). Plumage includes black and white horizontal stripes on its back,
and its cheeks and under parts are white. Its flanks are black streaked. The cap and stripe

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on the throat and side of neck are black, with males having a small red spot on each side
of the cap.
Eggs are laid from April through June. Maximum clutch size is seven eggs with an
average of three to five. Approximately 38 days are required from egg laying to
fledgling. Several more weeks pass before the young are completely independent.
Red-cockaded woodpeckers are found in open pine stands that are between 80 and 120
' years old. Longleaf pine stands are most commonly utilized. Dense stands are avoided.
The birds forage in pine and pine hardwood stands, with preference given to pine trees
' that are 10 inches (25 centimeters) or larger in diameter. The bird's diet consists of
primarily insects including ants, beetles, and wood-boring insects.

Biological Conclusion:
No Effect
No potential habitat such as pinewoods exists in the project area for the red-cockaded
woodpecker. A search of the NHP database, conducted on September 16, 2002, found no
occurrence of the red-cockaded woodpecker in the project vicinity. It can be concluded
that the project will not impact this endangered species.
Federal Species of Concern (FSC) are not legally protected under the Endangered Species
Act and are not subject to any of its provisions, including Section 7, until they are
formally proposed or listed as Threatened or Endangered. Only one FSC species is listed
for Forsyth County. Table 2.6 includes the FSC species listed for Forsyth County and its
state classification along with comment on whether habitat is present for this species.
Table 2.6 Federal Species of Concern for Forsyth County
State Available
Scientific Name Common Name Status Habitat
Alasmidonta varicosa Brook floater T (PE) No
Notes:
"T - Threatened" denotes a species likely to become endangered in the foreseeable future
throughout all or a significant portion of its range.
"PE - Proposed for Endangered status" denotes a species that has been proposed to be upgraded
from threatened to endangered status.
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3 Bankfull Stage Verification
3.1 Bankfull Stage and Discharge
Bankfull stage and its corresponding discharge are the primary variables used to develop
a natural channel design. However, the correct identification of the bankfull stage in the
field can be difficult and subjective (Williams, 1978; Knighton, 1984; and Johnson and
Heil, 1996). Numerous definitions exist of bankfull stage and methods for its
identification in the field (Wolman and Leopold, 1957; Nixon, 1959; Schumm, 1960;
Kilpatrick and Barnes, 1964; and Williams, 1978). The identification of bankfull stage in
the humid Southeast is especially difficult because of dense understory vegetation and a
long history of channel modification and subsequent adjustment in channel morphology.
It is generally accepted that bankfull stage corresponds with the discharge that fills a
channel to the elevation of the active floodplain. The bankfull discharge, known as the
channel forming discharge or the effective discharge, is thought to be the flow which
moves the most sediment over time. Field indicators include the back of point bars,
significant breaks in slope, changes in vegetation, the highest scour line, or the top of the
bank (Leopold, 1994). The most consistent bankfull indicators for streams in the
Piedmont of North Carolina are the highest scour line and the back of the point bar or
lateral bar. The indicator is rarely the top of the bank or the lowest scour or bar.
3.2 Bankfull Hydraulic Geometry Relationships (Regional Curves)

' Hydraulic geometry relationships are often used to predict channel morphology features
and their corresponding dimensions. The stream channel hydraulic geometry theory
developed by Leopold and Maddock (1953) describes the interrelations between
dependent variables such as width, depth, and area as functions of independent variables
' such as watershed area or discharge. These relationships can be developed at a single
cross-section or across many stations along a reach (Merigliano, 1997). Hydraulic
geometry relationships are empirically derived and can be developed for a specific river
' or extrapolated to a watershed in the same physiographic region with similar
rainfall/runoff relationships (FISRWG, 1998).

Regional curves were first developed by Dunne and Leopold (1978) and relate bankfull
channel dimensions to drainage area. A primary purpose for developing regional curves
is to aid in identifying bankfull stage and dimension in un-gaged watersheds and to help
estimate the bankfull dimension and discharge for natural channel designs (Rosgen,
1994). Gage station analyses throughout the United States have shown that the bankfull
discharge has an average return interval of 1.5 years or 66.7% annual exceedence
probability on the maximum annual series (Dunne and Leopold, 1978; Leopold, 1994).
Regional curve equations developed from the North Carolina rural and urban Piedmont
study are provided by Harman et al. (1999) and Doll et al. (2002) and are shown in Table
3.1.
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Table 3. 1. Piedmont Rural and Urban Regional Curve Equations.
North Carolina Piedmont Rural Regional Curve Equations
bkf = 89.04 AW 0.71 R =0.95
Abkf = 21.43 AW 0.72 R2 =0.91
Wbkf = 13.69 AW ' R =0.92
dbkf = 1.57 AW 0.30 R' =0.88
North Carolina Piedmont Urban Regional Curve Equations
Qbkf = 340.66 AW 1-17 R2 =0.95
Abkf = 61.16 AW 0-64 R2 =0.97
Wbkf = 24.95 AW R2 =0.88
dbkf = 2.46 Aw77 R2 =0.85
' 3.3 Bankfull Verification in the Silas Creek Watershed
The bankfull indicators for the Silas Creek watershed included the back of a depositional
bench and an upper scour line. These indicators are consistent with other Piedmont
' streams that are at Stage V in Simon's Channel Evolution Model. Data for both project
sites are shown on Figure 3.1. The cross sectional areas for Silas Creek and Buena Vista
Branch fall between the urban and rural regional curve. Silas Creek is closer to the urban
' curve, which is indicative of the higher percent impervious cover (39% versus 27% for
Buena Vista Branch). The average percent impervious for the urban curve is 40% with a
' range from 20% to 80% (Doll et al. 2002). This relationship is also similar to the Buffalo
Creek watershed project in Greensboro, where the bankfull cross sectional areas fell
between the two curves. This may be a unique characteristic of the Triad or could relate
' to the similar types of urbanization in the two watersheds (refer to the WRP Buffalo
Creek Watershed: Stream Restoration Report for more information).

Bankfull discharge was determined for each reach using HEC-RAS and the field
surveyed indicators of bankfull stage. The HEC-RAS bankfull discharge was cross
referenced with the regional curve (Figure 3.2). Results are provided in Table 3.2 and
show that the values correspond well between the HEC-RAS analysis and the regional
curve.
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Rural and Urban Piedmont Regional Curves
Figure 3.1
1000

100

• y = 59.88xo.bs
RZ = 0.97
U 10 ?.

0.08
Y = 21.43x

R =0.95
Z
1

0.1 1.0 10.0 100.0 1000.0
Drainage Area (mi 2)
• Urban Data ? Rural Data )K Silas Creek • Buena Vista Branch - Power (Rural Data) - Urban Regression
Figure 3.1. Rural and Urban Piedmont Regional Curves with Surveyed Bankfull Cross-
Section Areas for Project Reaches. (Project data points were not used in determining the
regression line.)

1 Winston-Salem Stream Restoration Projects 3-20 Buck Engineering

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North Carolina Piedmont Regional Curve
Figure 3.2
10000

1000 •
w ¦
v
• _ y = 303.80x°-?'
u
o •
. ?
R`=0.94
100

y = 89.04x0.'_
W=0.91
10

0.1 1.0 10.0 100.0 1000.0
Drainage Area (sq mi)
F • Urban Data ? Rural Data ¦ Silas Creek • Buena Vista Branch - Power (Rural Data) -Urban Regression
' Figure 3.2 Rural and Urban Piedmont Regional Curves showing bankfull discharge
versus drainage area. The bankfull discharge predicted using HEC RAS is overlaid with
the regional curve for comparison.
Table 3.2. Bankfull discharge comparison of HEC-RAS and regional curve.
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HEC-RAS Q Regional Curve Regional Curve
Reach (cfs) Rural Q (cfs) Urban Q (cfs)
Silas Reach 1 460 300 879
Silas Reach 2 600 369 1054
Buena Vista 145 113 376
Branch
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4 Reference Reach Analyses
The reference reach provides the basis for a natural channel design. A reference reach is
a segment of river that has a stable dimension, pattern, and profile within an appropriate
valley type. A reference reach is selected after the determination of the potential for
restoration for the project reach and the selection of a design valley/stream type. The
parameters measured at the reference reach are converted into dimensionless ratios for
comparison and are used across stream reaches with varying drainage areas. Therefore,
the ratios, not the actual values, become the basis for the natural channel design.
The selection of reference reach information for this project included reference reach
surveys, evaluation of a reference reach database, and professional judgment based on
"lessons learned" from the evaluation of past projects. Two Rosgen stream types were
selected for the project and are shown in Table 4.1. These stream types were selected
based on the valley type, available belt width, constraints, and channel incision.
Table 4.1. Project Design Stream Types.
Reach Reference
Stream Type Rationale
Entrenchment ratios will be increased,
however the energy will be dissipated
Silas Creek (Reaches I & 2) 134c through step/pool morphology rather than
pattern.
Buena Vista Branch E4 Proper stream type for this valley.
The streams shown in Table 4.2 were taken from a reference reach database and represent
stable urban Piedmont streams. The Silas Creek reference site is located approximately
1.8 miles upstream from the project site (Figure 4.1). The reach was surveyed by the
NRCS in 2001. The unnamed tributary to Lake Jeanette was surveyed by North Carolina
State University (Figure 4.2). Data for these streams were overlaid with the North
Carolina Piedmont Regional Curves to show that they are part of the same hydro-
physiographic region (see Figure 4.3); however, the Lake Jeanette reference reach is
closer to the urban curve than Silas Creek. There is still a great deal of uncertainty in
enlargement processes related to urbanization. Much of the uncertainty is caused by the
fact that factors other than percent impervious can lead to enlargement. Other factors
include the location and density of stormwater outfalls, road density, direct channel
modification, and sediment supply / transport relationships (Hammer, 1973). Until the
interactions amongst all of these variables are known, the degree of uncertainty will
remain large. It has been observed however, that channels with well vegetated banks, low
bank height ratios, moderate sinuosity, large floodplains, and grade control can support
smaller bankfull channels than incised streams. As these stabilizing features will all be
present in the restored reach of Buena Vista Branch, we feel that the smaller cross
sectional area is justified.
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In order to verify the stability of the reference reaches, site visits were made to both the
Lake Jeanette tributary and the Silas Creek reference reach. A visual assessment and
limited quantitative measurements were taken at Silas Creek to confirm channel stability.
Considering the fact that the original survey was done in 2001 and the reach is controlled
by bedrock, no further surveys were deemed necessary.
We felt that resurveying the Lake Jeanette tributary was necessary to verify the stability
of this reach. The cross sections shown in Appendix 2 indicate that very little channel
adjustment has taken place since the original survey in 2000. Additionally, the pattern
measurements show that even the tightest bends on the reach have remained stable
through time.
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Table 4.2. Summary Reference Reach Data.
Parameters Reference Reference
Reach Name UT to Lake
Jeanette Silas Creek
Rosgen Stream Type E5 B4c/l
Drainage Area (sq mi) 0.2 3.3
Bankfull Width (ft) 12.8 25.6
Bankfull Mean Depth
(ft) 1.6 1.7
q Width/Depth Ratio (ft) 8.0 15.1
Bankfull Area (sq ft) 20.5 43.5
Meander Length (ft) 35 - 69 130 - 245
Meander Length Ratio 2.7-5.4 5.1-9.6
Radius of Curvature (ft) 18 - 23 19.5 - 54
Radius of Curvature
Ratio 1.4-1.8 0.8-2.1
Meander Belt Width 44 - 45 40 - 51
Meander Width Ratio 3.4-3.5 1.6-2.0
a Pool Depth (ft) 3.2 4-5
Pool Depth Ratio 2.0 1.4-1.7
Pool Width (ft) 20.5 22.6 - 28
Pool Width Ratio 1.6 0.9-1.1
Pool Spacing (ft) 18 - 35 27.2 - 126
Pool Spacing Ratio 1.4-2.7 1.1-4.9
Sinuosity 1.33 1.1
Valley Slope (ft/ft) 0.0044 0.0088
Channel Slope (ft/ft) 0.0033 0.0082
Riffle Slope (ft/ft) 0.0066-0.011 0.020
°
0. Riffle Slope Ratio 2.0-3.4 2.4
Pool Slope (ft/ft) 0.002 0.0
Pool Slope Ratio 0.64 0.0
D16 --- 0.28
D35 0.13 0.83
D50 0.50 19.1
D84 3.5 157.5
D95 7.8 300.2
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The final design ratios are shown in Section 5 and are based on bracketing the values
' from the reference reaches and applying professional judgment to ensure appropriate
values are used.

Rural and Urban Piedmont Regional Curves
Figure 4.3
0.1 1.0 10.0 100.0
Drainage Area (mi 2)
I • Urban Data ? Rural Data ¦ Silas Creek- Reference • lake Jeanette -Power (Rural Data) -Urban Regression
Figure 4.3. Rural and Urban Piedmont Regional Curves with Surveyed Bankfull Cross-
Section Areas for Project Reference Reaches. (Project data points were not
used in determining the regression line.)
The reference reaches compare fairly well in terms of ratios; however, some stream
geometry data are inappropriate for design. This is due to the fact that the reference
reaches have floodplains with mature bottomland forest, while the design reaches will
have a newly planted floodplain. For example, the radius of curvature ratios for the Type
E reference reaches are less than 2. The design reaches should have a larger ratio
because the banks will not initially have the necessary vegetation to prevent bank erosion.
In addition, riffle slope ratios greater than 1.5 were used to maximize riffle habitat value.
1000.0

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'
5 Natural Channel Design
'
5.1 Design Summary
' For each stream reach in the Silas Creek watershed project, the proposed natural channel
design is the highest level of restoration feasible given the valley type, stream type, land
use and urban constraints. For the incised reaches, selection of restoration type follows
' Rosgen's priority restoration approaches for incised streams (Rosgen, 1997) with the
overriding objective of re-establishing contact between the channel and a floodplain. For
the purposes of this discussion the four Rosgen restoration approaches have been defined
' below in order of decreasing priority:

' • Priority - Re-establish the channel on a previous floodplain (e.g., raise channel
elevation); meander new channel to achieve dimension, pattern, and profile
characteristic of a stable stream for the particular valley type; fill or isolate
' existing incised channel.
• Priority 2 - Establish a new floodplain for the existing bankfull elevation (e.g.
,
excavate a new floodplain); meander channel to achieve dimension, pattern, and
profile characteristic of a stable stream for the particular valley type; fill or isolate
' existing incised channel.
• Priority 3 - Establish a new floodplain at the existing bankfull elevation (e.g.,
using bankfull benches); leave existing channel in place; use in-stream structures
to dissipate energy through a step/pool channel type.
• Priority 4 - Stabilize the channel in place using in-stream structures and
' bioengineering to decrease streambed and streambank erosion.
' 5.2 Silas Creek Natural Channel Design
Refer to the plan sheets for the detailed design.
' Silas Creek is constrained throughout the project area by a combination of sewer lines,
walking paths, soccer fields, footbridges, and road crossings. As a result of these
' constraints, relocation of the Silas Creek channel is not feasible. The proposed natural
channel design for Silas Creek reaches 1 & 2 is based on a combination of a Rosgen
Priority 3 and Priority 4 techniques. This approach will allow for better bankfull-
floodplain connectivity, encourage positive changes to occur in the channel cross-section
' and will create diversity in bedform.
' Bankfull benches will be excavated intermittently along both sides of the channel to
create a new active floodplain or increase the size of existing active floodplains. This
will increase entrenchment ratios along the reach reducing near bank stresses during large
flows and will allow for sediment to be stored outside of the channel. In conjunction
with benching, cross vanes will be used throughout the existing channel to set and control
grade as well as encourage narrowing and steepening of the riffles. Below the culverts,
' step-pool structures will be used to raise the bed elevation thus increasing overall channel
' Winston-Salem Stream Restoration Projects 5-28 Buck Engineering

slope which will allow for better aeration and coarsening of riffle substrate. Double wing
deflectors will be constructed to narrow the low flow channel where it is over-wide as
well as stabilize the existing banks by reducing near bank stress. J-hook vanes and root
wads will be used to stabilize the banks on the outside of meander bends. All of these
structures will be spaced so as to mimic the pool to pool spacing ratio of the Silas Creek
reference reach. The spacing of these structures will allow Silas Creek to dissipate
energy through this series of steps thus decreasing shear stresses and bank erosion. The
streambank, bankfull bench, and terrace scarp will be seeded for temporary erosion
control (see Planting Design below). The streambank and terrace scarp will be covered
with erosion control matting.
A water line crosses Silas Creek at the downstream end of the project. The water line is
heavily protected with riprap and is set slightly above the existing bed elevation. Buck
Engineering will work with the City to relocate this water line beneath the channel
bottom and remove the riprap. This will be done according to the City's engineering
specifications. Removing this line from the active channel will allow for an increased
slope in the lower end of Reach 2, allowing for increased diversity in bedform.
By removing the water line, raising the bed at the culvert outlets and by installing cross-
vanes, wing deflectors, and j-hook vanes, Silas Creek's form will change with time. It is
expected that an overall increase in water surface slope will occur and that diversity in
bedform will allow for coarsening of riffles and deepening of pools thus improving
habitat and aeration. The various structures will encourage the bankfull channel to
narrow decreasing the width to depth ratio over time and increasing the efficiency of the
channel. So, although Table 5.1 below does not show direct change in many of the
design parameters, the design will set in place a change in channel dimensions and profile
over time while pattern will be held constant.
Table 5.1. Natural Channel Design Parameters for Silas Creek (Reaches
1 &2 are represented by the same dataset).

Parameters Existing
Reaches
1&2 Design
Reaches
1&2
Rosgen Stream Type B4c B4c
Drainage Area (sq mi) 7.2 7.2
Reach Length (ft) 3805 3805
Bankfull Width (ft) 40 40
Bankfull Mean Depth (ft) 3.5 3.5
Width/Depth Ratio (ft) 11.7 11.7
Bankfull Area (sq ft) 138 138

q Bankfull Mean Velocity
(ft/sec) 4.35 4.35
Bankfull Discharge (cfs) 600 600
Bankfull Max Depth (ft) 4.5 4.5
Width of Floodprone Area (ft) 68-272 120-272
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Entrenchment Ratio 1.7-6.8 3.0-6.8
Max Pool Depth (ft) 6.8 6.8
Ratio of Max Pool Depth to
Bankfull Depth
1.2
1.2
Pool Width (ft) 35.25 35.25
Ratio of Pool Width to
Bankfull Width
0.9
0.9
Pool to Pool Spacing (ft) 82-189 72 - 144
Ratio of Pool to Pool Spacing
to Bankfull Width
2-4.8
2-4
Bank Height Ratio 1.6 1.0
Meander Length (ft) N/A* N/A*
Meander Length Ratio N/A* N/A*
Radius of Curvature (ft) N/A* N/A*
Radius of Curvature Ratio N/A* N/A*
Meander Belt Width (ft) N/A* N/A*
Meander Width Ratio N/A* N/A*
Sinuosity 1.03 1.03
Valley Slope (ft/ft) 0.0029 0.0029
WS Slope (ft/ft) 0.0025 0.0025
Pool Slope (ft/ft) 0.0005 0.0005
Ratio of pool slope to WS
slope 0.19 0.19
Riffle Slope 0.0028 0.0028
Riffle Slope Ratio 1.12 1.12
* Due to the extremely low sinuosity, pattern data cannot accurately be calculated. Any
data calculated would overestimate pattern.
Several storm-water ditches enter Silas Creek within the project area. These ditches
increase the sediment load in the Creek as headcuts move up the ditches from the lower
grade of Silas. The ditches will be stabilized using outlet protection structures or
step/pool designs. The step/pool design has been modified from earlier designs to
minimize the drop between steps (<= 0.5ft) and prevent piping. See the design drawings
for more detail.
5.2.1 Planting Design
A combination of native herbaceous and woody vegetation will be established in the
riparian buffer along Silas Creek. The buffer width will range between 15 and 25 feet
depending on space restrictions due to park boundaries. This buffer width will be in
accordance with the City of Winston-Salem's stream buffer recommendations (1999)
which include a variance stating that a stream buffer shall not exceed 25% of the
available land space on publicly owned property with a "cross sectional land space" less
then 400 feet. In addition, areas around utilities in the buffer zone will be left free of
woody vegetation to a minimum length of 10 feet and a maximum length of 30 feet.
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These clearings will also act as public access areas along with a path (10-15 feet wide)
leading to and from the footbridge. All access areas may need to be periodically
maintained by the City of Winston-Salem (Winston-Salem 1999).
Species used for seeding and woody vegetation will depend upon availability and cost at
the time of planting. Permanent seeding may include, but not be limited to, switch grass
(Panicum virgatum), Virginia wild rye (Elymus virginicus), soft rush (Juncus effusus),
fox sedge (Carex vulpinoidea), ironweed (Vemonia noveboracensis), joe-pye-weed
(Eupatorium fistulosum), and cardinal flower (Lobelia cardinalis). Trees and shrubs that
may be used include, but are not limited to, willow oak (Quercus phellos), river birch
(Betula nigra), red maple (Acer rubrum), green ash (Fraxinus pennsylvanica), red
chokeberry (Aronia arbutifolia), beautyberry (Callicarpa americana), witch-hazel
(Hamamelis virginiana), spicebush (Lindera benzoin), and winterberry (Ilex verticillata).
Species to be used for live staking include silky dogwood (Cornus amomum) and silky
willow (Salix sericea). Temporary vegetation for erosion control will consist of annual
rye (cool season) or millet (warm season) depending on the construction schedule.
5.2.2 Silas Creek Best Management Practice
Background
The objective of the storm-water BMP is to maximize pollutant removal considering site
constraints and costs. Storm water BMPs' removal efficiency is directly related to
detention time or treatment time and volume. Thus, as flows increase and volume fills,
treatment decreases. Although pollutant loading increases with flow, the total annual
contribution of pollutants from large (>2 inch) precipitation events is low due to their
infrequent nature. In fact most of the annual pollutant load is associated with the "first
flush." In the Southeast, designs are typically for the first inch of precipitation, thus
treating 90% of all precipitation events and eliminating the unnecessary expense of
building a large treatment facility.
The feasibility of constructing one or more best management practices (BMPs) at the
tributary entering Silas Creek just downstream of Silas Creek Parkway was examined to
both improve water quality and serve as a demonstration project. Due to the limited
' space to treat runoff from the tributary, areas adjacent to the parking lot were also
examined for the potential of treating parking lot runoff.
Four potential BMPs were identified based on site space restrictions and their potential to
' treat water quality impacts to Silas Creek. Alternatives were also identified that represent
a potential educational opportunity to demonstrate the applicability of BMPs within a
' maintained and landscaped area. Each alternative is described in more detail below.
Area A
' This area is shown in Figure 5.1 and allows for a small detention/infiltration basin (900
ft2) to be placed along the existing tributary to treat storm flows before entering Silas
' Creek. The treatment mechanisms would include particle settling, infiltration, and
' Winston-Salem Stream Restoration Projects 5-31 Buck Engineering
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nutrient uptake by vegetation. The drainage area to this site is +/-34 acres and drains part
of Silas Creek Parkway and single family residential neighborhoods. Nutrients and
suspended sediment are the constituents of concern. In order to treat the first flush, the
volume of this BMP would need to be approximately 30,000 cubic feet. The available
volume for a BMP in this area is about 3,000 cubic feet, about a tenth of the volume
needed. This area could be expanded but would involve moving the existing walking
path and removal of some landscaping, an expense that would increase the potential BMP
volume only slightly. This location would be a highly visible area for public education as
it is located at the beginning of the walking path.
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Area B
This area is shown in Figure 5.1 and allows for in channel improvements limited to
channel stabilization and vegetation enhancements. Existing invasive vegetation
(primarily Kudzu) would be replaced by native vegetation along the banks and the
channel would be regraded to allow for the construction of a step-pool system. This
alternative directly effects water quality by limiting erosion and by encouraging aeration
through a series of steps pools. Energy dissipation from the step pools would also
discourage erosion in Silas Creek on the opposite channel bank. This location would be
highly visible for public education as it is located adjacent to the bridge crossing to the
park.
Area C
This area is shown in Figure 5.1 and could be enhanced by creating a 5 foot wide filter
strip along the Northern boundary of the parking lot. The filter strip would allow settling
of particulates from the parking lot, catch trash, and encourage infiltration. The strip
would also act as a level spreader, so concentrated runoff from the parking lot would not
affect bank stability as it runs into Silas Creek. This area could be constructed in
conjunction with the bank construction of Silas Creek. Vegetation would be selected to
aesthetically fit within the park setting and still provide a native vegetated buffer to Silas
Creek. This area is not as visible a location as Areas A and B but could still provide an
educational opportunity.
Area D
This area is shown in Figure 5.1 and would be used to create a small infiltration basin
(800 SF) to treat parking lot runoff before entering Silas Creek. This area could be graded
to receive water from area C, allowing additional settlement, infiltration, and nutrient
removal before flows enter Silas Creek. The outflow from this area could be controlled so
as not to disturb the Silas Creek streambank. Area D's size is limited by the location of a
large water line. This area is not a visible location for public education because it is
located between the parking lot and Silas Creek Parkway.
Recommended BMP Design
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Considering the site constraints, treatment potential, costs, and educational benefits, Buck
Engineering recommends the improvements discussed above for areas B and C. The
Area B BMP is consistent with the water quality goals of the Silas Creek restoration and
also would be an aesthetic enhancement to the entrance of Shaffner Park. This is a key
public viewing and awareness area. Area C is a cost effective location since it is part of
the regrading efforts of Silas Creek and offers an opportunity to treat parking lot runoff
before it enters Silas Creek. Area C also demonstrates how an existing parking lot can be
retrofitted to improve water quality and still be an attractive amenity to a landscaped area,
which is a valuable public awareness goal.
Areas A and D were rejected for cost/benefit reasons. Area A would offer an excellent
opportunity but with its limited space, a significant water quality benefit could not be
accomplished with construction of a BMP in this area. Area D has limited space and
could only treat a limited part of the parking lot area.
5.3 Buena Vista Natural Channel Design
Refer to the plan sheets for the detailed design.
The proposed natural channel design for Buena Vista Branch is based on a combination
of a Rosgen Priority 2 and Priority 3 approach. A new meandering E4 channel will be
constructed from Station 11+80 to 17+81 at a lower elevation than the existing terrace. A
floodplain will be excavated along both sides of the channel. Cross vanes, rock vanes and
root wads will be used to stabilize the new channel and areas of the existing channel that
will be left in place. The streambank, bankfull bench, and terrace scarp will be seeded
for temporary erosion control (see Planting Design below). The streambank and terrace
scarp will be covered with erosion control matting. The rest of Buena Vista Branch will
be left at its existing location because of the presence of sewer lines, adjacent soccer
fields, and pedestrian footbridge crossings.
At the downstream end of the project, Buena Vista Branch is highly incised as a result of
a head-cut moving up from Silas Creek. This section will be stepped down to the bed
elevation of Silas Creek using a step/pool structure. The step/pool design has been
modified from earlier designs to minimize the drop between steps (<= 0.5 ft) and prevent
piping. See the design drawings for more detail.
Winston-Salem Stream Restoration Projects 5-34 Buck Engineering
Table 5.2. Natural channel design parameters for Buena Vista Branch.
Parameters Existing Design
Rosgen Stream Type E4 E4
Drainage Area (sq mi) 1.4 1.4
Reach Length (ft) 828 910
Bankfull Width (ft) 14.5 17.6
Bankfull Mean Depth (ft) 2.11 1.8
Width/Depth Ratio 6.86 10
Bankfull Area (sq ft) 30.6 32.2
Bankfull Max Depth (ft) 3.21 2.6
Width of Floodprone Area (ft) 20-119 60-160
o Entrenchment Ratio 1.4-8.2 3.4-9.1
Max Pool Depth (ft) 2.76 3.4
E
p Ratio of Max Pool Depth to
Bankfull Depth 1.3 1.9
Pool Width (ft) 15.8 22.9
Ratio of Pool Width to
Bankfull Width 1.09 1.3
Pool to Pool Spacing (ft) 45 - 160 60 -100
Ratio of Pool to Pool Spacing
to Bankfull Width 3.1 -11 3.5 - 6
Bank Height Ratio 1.8 1.0
Meander Length (ft) 72-105 120 - 200
Meander Length Ratio 5-7.2 7-11
E Radius of Curvature (ft) 25-100 32 - 53
Radius of Curvature Ratio 1.7-6.9 2.0-3.0
o- Meander Belt Width (ft) 15.4-23.8 53 - 88
Meander Width Ratio 1.1-1.6 3-5
Sinuosity 1.09 1.22
Valley Slope (ft/ft) 0.0111 0.011
9 WS Slope (ft/ft) 0.0107 0.009
o Pool Slope (ft/ft) 0.0025 0.0034
a Ratio of Pool Slope to WS

Slope
0.23
0.3

8
5.3.1 Planting Design
Plantings for Buena Vista Branch will be similar to the proposed plantings for Silas
Creek.
Winston-Salem Stream Restoration Projects 5-35 Buck Engineering
'
6 Sediment Transport Analysis

6.1 Background
A stable stream has the ability to move its sediment load without aggrading or degrading
over long periods of time. The total volume of sediment transported through a cross
section consists of bedload and suspended load fractions. Suspended load is normally
' composed of fine sand, silt, and clay particles transported in the water column. Bedload
is generally composed of larger particles, such as course sand, gravels, and cobbles,
' transported by rolling, sliding, or hopping (saltating) along the bed.
The ability of the stream to transport its total sediment load is quantified through two
measures: sediment transport competency and sediment transport capacity. Competency
' is a stream's ability to move particles of a given size and is a measurement of force, often
expressed as units of lbs/ft2. Sediment transport capacity is a stream's ability to move a
' quantity of sediment and is a measurement of stream power, often expressed as units of
lbs/ (ft-sec). Sediment transport capacity is also calculated as a sediment transport rating
curve, which provides an estimate of the quantity of total sediment load transported
' through a cross section per unit time. The curve is provided as a sediment transport rate
in lbs/sec versus discharge or stream power.
' 6.1.1 Competency Analysis
Median substrate size has an important influence on the mobility of particles in
' streambeds. Critical dimensionless shear stress (ti*,i) is the measure of force required to
initiate general movement of particles in a bed of a given composition. At shear stresses
exceeding this critical value, essentially all grain sizes are transported at rates in
proportion to their presence in the bed (Wohl, 2000). ti*,i can be calculated for gravel-
bed stream reaches using surface and subsurface particle samples from a stable,
representative riffle in the reach (Andrews, 1983). Critical dimensionless shear stress is
' calculated as follows (Jessup, pers. comm., 2002):
1. Using the following equations, determine the critical dimensionless shear
stress required to mobilize and transport the largest particle from the bar
sample (or subpavement sample).
' a) Calculate the ratio D50/D^50
Where: D50 = median diameter of the riffle bed (from 100 count
in the riffle or pavement sample)
' D^50 = median diameter of the bar sample (or subpavement)

' If the ratio D50/D^50 is between the values of 3.0 and 7.0, then calculate
the critical dimensionless shear stress using Equation 1
.
c*,i = 0.0834 (D5o/D^50)-0.872 (Equation 1)
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b) If the ratio D50/D^50 is not between the values of 3.0 and 7.0, then
calculate the ratio of Di/Dso
Where: Di = Largest particle from the bar sample (or subpavement)
D50 = median diameter of the riffle bed (from 100 count in the
riffle or the pavement sample)
If the ratio Di/D50 is between the values of 1.3 and 3.0, then calculate the
critical dimensionless shear stress using Equation 2.
ti%i = 0.0384 (Di/D50)1.887 (Equation 2)
Entrainment analyses were conducted for the Silas Creek and Buena Vista reaches to
ensure that the design streambed neither aggrades nor degrades during bankfull flows.
6.2 Silas Creek
Because the designs for both reaches are similar, they were grouped for the purposes of
calculating sediment transport competency. The critical dimensionless shear stress for
Silas Creek was calculated using bed material samples from a stable riffle. The
cumulative frequency curves of the samples are shown on Figure 6.1.
Data presented in Figure 6.1 were used to determine particle sizes for the various
calculations. The D50/D^50 ratio is 4. 1, so Equation 1 is valid. Critical dimensionless
shear stress was calculated using Equation 1 as ti*,i = 0.024. This value of dimensionless
shear stress is used in the aggradation analysis presented below.
Silas Creek
Pavement -Subpavement
-
100

90

80
'e

c 70
- Pavement
60

Z
Subpaoement
a
m 50-

a 40

E 30
U
20

10-

0
0??, O^ry5 Ory? O? ^p ^b ?O p0 6!h ^ryh ^60 ry,L6 ,5`L ph ^?0 ^?O ??6 `l. y,?`L ^?ryb ?0?0 ryOaO
Particle Size -Finer Than (mm)
Figure 6.1. Silas Creek Pavement / Subpavement Analysis
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6.2.1 Auradation Analysis Through Critical Depth and Slope Calculation
An aggradation analysis was performed to predict whether the channel depth and slope
proposed in the design will cause the stream to aggrade. The aggradation analysis is
based on calculations of the required depth and slope needed to transport large sediment
particles, in this case defined as the largest particle of the riffle subpavement sample.
Required depth can be compared with the design mean riffle depth and required slope can
be compared to the design slope to verify that the stream has sufficient competency to
move large particles and thus prevent thalweg aggradation. The required depth and slope
are calculated by:
dr = 1.65ti*e;D;
Se
Sr =1.65ti:e
de
(Equation 3)
(Equation 4)
Where: dr (ft) = Required bankfull mean depth
de (ft)= Design bankfull mean depth
1.65 = Sediment density (submerged specific weight)
= density of sediment (2.65) - density of water (1.0)
,r%i = Critical dimensionless shear stress
Di (ft) = Largest particle from bar sample (or subpavement)
Sr (ft/ft) = Required bankfull water surface slope
se (ft/ft) = Design bankfull water surface slope
Using a design slope of 0.0023 ft/ft and the largest subpavement particle diameter of 45
mm, Equation 3 indicates a required depth of 2.6 feet. The current design would create
benches at the bankfull elevation but would not change the bankfull channel dimensions.
Therefore the mean design bankfull riffle depth is equal to the existing mean depth along
Silas Creek at 3.5 ft (Table 6.1). This is greater than the required depth and thus
sufficient to transport the larger materials and prevent aggradation. Using the design
depth, Equation 4 indicates a required slope of 0.00 15, which is less than the design
slope. Urban channels often have a design depth and slope that is greater than the
required values. There are several reasons for this, including:
1. Equations 1 and 2 are empirical relationships that were developed on large rural
rivers in Colorado and are very different from the project reach,
2. Since some enlargement has occurred, the increase in cross sectional area causes
the mean depth to increase.
During urbanization, the grain size distribution of the bed material often decreases.
Therefore, while existing depth and shear stress are increasing, the particle sizes are
decreasing.
Winston-Salem Stream Restoration Projects 6-3$ Buck Engineering
' 6.2.2 Competency Analysis Through Boundary Shear Stress and Shield's Curve
Comparison
' As a compliment to the required depth and slope calculations, we calculated boundary
shear stresses for design riffle cross sections and compared these with a modified
' Shield's Curve to predict sediment transport competency. The shear stress placed on the
sediment particles is the force that entrains and moves the particles, given by:
' z = yRs (Equation 5)
' Where, ti = shear stress (lb/ft2)
y = specific gravity of water (62.4 lb/ft)
R = hydraulic radius (ft)
' s = average channel slope (ft/ft)
The boundary shear stress estimated for the design cross-section is 0.46 lb/ft2. The
' measured Di of the subpavement was 45 mm. As shown on the Modified Shield's Curve
(Figure 6.2), this value of shear stress and Di are just slightly below the range of values
used to calculate the regression equation. The Shield's Curve analysis supports the
' critical depth based conclusion that the design-cross sections can move sediment
competently and prevent aggradation.
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500
200
100
50
20
d
to
a
y 5
A 2
1
0.5
0.2
0.1
0.001 0.002 0.005 0.01 0.02 0.05 0.1 02 0.5 1.0
T,, critical shear stress, lbsfsq ft

.
- a
• SIIAS CREEK DATA

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2 5 10

(Data from. Leopoldo Wokwn, and I iffer IO Rosgen, personal com uln.; and
Harman, personal cornnurn.)
Figure 6.2. Modified Shield's Curve for Grain Diameter of Transported
Particle in Relation to Critical Shear Stress.
6.2.3 Degradation Analysis
Degradation analysis was performed in order to assess whether the design cross sections
would result in scour and bed downcutting. We evaluated the potential for degradation
by examining the upper competency limits for design cross sections and by reviewing
existing and design grade control at the site.
The calculated shear stress discussed in Section 6.2.2 can be used to describe the upper
competency limits for the design channel. The estimated boundary shear stress was 0.46
lbs/ft2. Based on the Modified Shield's Curve (Figure 6.2), shear stress in this range will
move particles up to about 105 mm in size, which corresponds roughly to the largest
particle size of the reach-wide pebble count sample. Preferably, this stress would
correspond to the D84, but the concern for degradation is addressed through existing and
Winston-Salem Stream Restoration Projects 6-40
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design grade control. Reach wide confidence in vertical stability of the streambed comes
from a review of grade control at the project site. The existing culverts and the large
riprap apron at the downstream end of the project reach control the overall slope and will
prevent reach-wide degradation. Rock cross vanes throughout the projects will help
control grade locally.
Table 6.1. Boundary shear stresses for existing and design riffle cross sections on Silas
Creek.
Shear Stress Analysis Existing & Design
Design
Bankfull Area (sq ft) 138
Bankfull Width, W (ft) 40
Bankfull Mean Depth, 3.5
D (ft)
Wetted Perimeter 25
Hydraulic Radius, R 3.2
(ft)
Slope (ft/ft) 0.0023
Bankfull Discharge, Q
600
(ft3/sec)
Flow velocity, v 4.35
(ft/sec)
Boundary Shear 0.46
Stress, i (lbs/sq ft)
6.3 Buena Vista Branch
The critical dimensionless shear stress for Buena Vista Branch was calculated using bed
material samples from a stable riffle. The cumulative frequency curves of the samples
are shown on Figure 6.3.
Data presented in Figure 6.3 was used to determine particle sizes for the various
' calculations. The D50/D^50 ratio is 3.4, so Equation 1 is valid. Critical dimensionless
shear stress was calculated using Equation 1 as i*,i = 0.0285. This value of
dimensionless shear stress is used in the aggradation analysis presented below.

Winston-Salem Stream Restoration Projects 6-41 Buck Engineering

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Buena Vista Branch
Pavement - Subpavement
-
100 - - --- - --

90

80

70
m
60 - Pavement

m - Subpavement
a
50

40

S 30
v 2
0

10

0
doti 0y oryy oyo
0 0• ° ° ?° ae y? ^?`' ^yo ry?? 4 ay 'J, 4, yy ?yo yy`° yyti yti ?otib ?°ay ryoay
Particle Size - Finer Than (mm)
Figure 6.3. Buena Vista Branch Pavement / Subpavement Analysis.
6.3.1 Aggradation Analysis Through Critical Depth and Slope Calculation
An aggradation analysis was performed to predict whether the channel depth and slope
proposed in the design will cause the stream to aggrade. The aggradation analysis is
based on calculations of the required depth and slope needed to transport large sediment
particles, in this case defined as the largest particle of the riffle subpavement sample.
Required depth can be compared with the design mean riffle depth and required slope can
be compared to the design slope to verify that the stream has sufficient competency to
move large particles and thus prevent thalweg aggradation. The required depth and slope
are calculated by:
dr = 1.65ti eD-
SQ
Sr = 1.65ti*,iDi
de
(Equation 3)
(Equation 4)
Where: dr (ft) = Required bankfull mean depth
de (ft)= Design bankfull mean depth
1.65 = Sediment density (submerged specific weight)
= density of sediment (2.65) - density of water (1.0)
,r%i = Critical dimensionless shear stress
Di (ft) = Largest particle from bar sample (or subpavement)
sr (ft/ft) = Required bankfull water surface slope
se (ft/ft) = Design bankfull water surface slope
Winston-Salem Stream Restoration Projects 6-42
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As discussed previously, urban streams often show decreased subpavement particle size
distributions due to aggradation of fine sediments. This situation was evident in the first
subpavement sample taken in Buena Vista Branch which resulted in extremely low
critical depth and slope calculations. In order to obtain more representative samples, two
different methods were utilized for analyzing the subpavement particle size distribution.
One subpavement sample was taken from a point bar and compared to an additional
subpavement sample from a representative riffle. The results of both methodologies are
presented below.

Using a design slope of 0.0054 ft/ft and the largest subpavement (bar sample) particle
diameter of 55 mm, Equation 3 indicates a required depth of 1.6 feet. Using a design
slope of 0.0054 ft/ft and the largest subpavement (riffle sample) particle diameter of 36
mm, Equation 3 indicates a required depth of 1.0 feet. The mean design bankfull riffle
depth along Buena Vista Branch is 1.8 ft (Table 6.2). This is greater than the required
depth calculated using both samples and thus sufficient to transport the larger materials
and prevent aggradation. Using the design depth and point bar subpavement sample, the
slope check indicates a required slope of 0.0044. Using the design depth and riffle
subpavement sample, the slope check indicates a required slope of 0.0030. Both are less
than the design slope.
6.3.2 Competency Analysis Through Boundary Shear Stress and Shield's Curve
Comparison
As a compliment to the required depth and slope calculations, we calculated boundary
shear stresses for design riffle cross sections and compared with a modified Shield's
Curve to predict sediment transport competency. The shear stress placed on the sediment
particles is the force that entrains and moves the particles, given by:
z = yRs (Equation 5)
Where, r = shear stress (lb/ft2)
y = specific gravity of water (62.4 lb/ft)
R = hydraulic radius (ft)
s = average channel slope (ft/ft)
The boundary shear stress estimated for the design cross-section on Buena Vista Branch
is 0.51 lb/ft2. The measured Di of the subpavement was 55 mm from the bar sample and
36 mm from the riffle sample. As shown on the Modified Shield's Curve (Figure 6.4),
this value of shear stress and both Di values fall below the range of values used to
calculate the regression equation. The Shield's Curve analysis supports the critical depth
based conclusion that the design-cross sections can move sediment competently and
prevent aggradation. The issue of potential degradation is discussed below.
Winston-Salem Stream Restoration Projects 6-43 Buck Engineering
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500
200
100
50
20
d
10
5
2
1
0.5

0.2
0.1
0.001 0.002 0.005 0.01 0.02 0.05 0.1 02 0.5 1.0
T,, critical shear stress, lbs/sq ft
/
/
J

i t
? +
OL A 6

/ /

/
/

• ?

'

i Point Bar Sam
le
p

' Ride Sample
/' '• i
/ - Leopold, et al.

+?'
. 1 - - Rosgen &I arman
?
?
2 5 10
(Data from., teopola Woltnan, and Mflor 1964; Rosgen, personal commun.; and
Harman, personal com uln.)
Figure 6.4. Modified Shield's Curve for Grain Diameter of Transported Particle in
Relation to Critical Shear Stress.
6.3.3 Degradation Analysis
' Degradation analysis was performed in order to assess whether the design cross sections
would result in scour and bed downcutting. We evaluated the potential for degradation
by examining the upper competency limits for design cross sections and by reviewing
' existing and design grade control at the site.
The calculated shear stress discussed in Section 6.3.2 can be used to describe the upper
' competency limits for the design channel. The estimated boundary shear stress was 0.51
lbs/ft2. Based on the Modified Shield's Curve (Figure 6.4), shear stress in this range will
move particles up to about 125 mm in size, which is significantly larger than any particles
' encountered in the reach-wide pebble count sample. Preferably, this stress would
correspond to the D84, but the concern for degradation is addressed through existing and
design grade control. Reach wide confidence in vertical stability of the streambed comes
' Winston-Salem Stream Restoration Projects 6-44 Buck Engineering
' from a review of grade control at the project site. The existing at-grade sewer line
crossings at the start and end of the project length as well as the culvert set at the existing
' thalweg grade control the overall slope and will prevent reach-wide degradation. Rock
cross vanes throughout the project will help control grade locally.
' Table 6.2 Boundary shear stresses for existing and design riffle cross sections
on Buena Vista Branch (excludes priority IV restoration reach below culvert).

Shear Stress Analysis
Existing Design
Bankfull Area (sq ft) 30.6 31.7
Bankfull Width, W (ft) 14.5 17.6
Bankfull Mean Depth, 2.1 1.8
D (ft)
Wetted Perimeter 18.8 21.1
Hydraulic Radius, R 1.7 1.5
(ft)
Slope (ft/ft) 0.0063 0.0054
Bankfull Discharge, Q
145
145
(ft /sec)
Flow velocity, v 4.7 4.6
(ft/sec)
Boundary Shear
0.65
0.51
Stress, ti (lbs/s ft)
Winston-Salem Stream Restoration Projects 6-45 Buck Engineering
7 - Flooding Analyses
Silas Creek and Buena Vista Branch were located on the Federal Emergency
Management Agency's (FEMA) Flood Insurance Rate Maps. Both streams are located in
FEMA detailed flood study areas (designated Zone AE).
The Silas Creek existing condition stream model will be developed in HEC-RAS from a
combination of available topography and the data provided from the existing FEMA
generated HEC-2 model. The 10-year, 50-year, 100-year, and 500-year discharges
estimated in the Flood Insurance Study produced by FEMA will be used. The proposed
stream restoration condition will be compared to the existing stream condition to verify
that an increase has not occurred to the 100-year floodplain elevations.
Since the existing FEMA generated HEC-2 model was not available for Buena Vista
Branch, the existing and proposed models will be developed from available topography.
' Discharges for the 10-year, 50-year, 100-year, and 500-year storm events will be
obtained from the Flood Insurance Study produced by FEMA. In order to verify that the
' proposed stream restoration does not adversely impact the existing floodplain elevations,
a comparison will be made between the existing and proposed conditions using HEC-
RAS.
' A separate report will be prepared showing the results of the flood study.
' Winston-Salem Stream Restoration Projects 7-46 Buck Engineering
8 Monitoring and Evaluation
Environmental components monitored in this project will be those that allow an
evaluation of channel stability and riparian survivability. Specifically, the success of
channel modification, erosion control, seeding, and woody vegetation plantings will be
evaluated. This will be accomplished through the following activities for 5 years after
the project is built.
8.1 Cross-sections
Permanent cross-sections (either surveyed or located using a GPS) will be established at a
spacing of one per 20 bankfull-width lengths, with an effort made to include both riffles
and pools. These cross-sections may be the same as ones taken to develop construction
plans or they may be new. Each cross-section will be marked on both banks with
permanent pins to establish the exact transect used. A common benchmark will be used
for cross-sections and consistently used to facilitate easy comparison of year-to-year data.
The annual cross-section survey will include points measured at all breaks in slope,
including top of bank, bankfull, inner berm, edge of water, and thalweg. Calculations
will be made of width/depth ratio, entrenchment ratio, and low bank height ratio. Riffle
cross-sections will be classified using the Rosgen stream classification system.
Success Criteria: There should be little or no change in as-built cross-sections. If changes
do take place they should be evaluated to determine if they represent a movement toward
a more unstable condition (down-cutting, erosion) or are minor changes that represent an
increase in stability (settling, vegetative changes, deposition along the banks, decrease in
width/depth ratio and/or cross sectional area).
¦ 8.2 Pattern
' Annual measurements taken for the plan view of the restoration site will include
sinuosity, meander width ratio, and radius of curvature (on newly constructed meanders
only for the first year of monitoring).
¦
8.3 Materials
' Annual pebble counts will be performed on all gravel-bed project reaches based on the
percent of pools and riffles.
' Success Criteria: Established D50 and D85 should increase in coarseness in riffles, and
increase fineness in pools.
¦
Winston-Salem Stream Restoration Projects 8-47 Buck Engineering

'
8.4 Longitudinal Profiles
' A complete longitudinal profile will be completed once the first year and then every two
years for a total of five years (for a total of 3 times). Measurements will include slope
(average, pool, riffle) and pool-to-pool spacing. Survey points will include thalweg,
' water surface, inner berm, bankfull, and top of low bank. Each of these points will be
taken at the head of each feature, e.g. riffle, run, pool, and glide, and the max pool depth.

' The survey will be tied to a permanent benchmark.
Success Criteria: The as-built longitudinal profiles should show that the bedform features

' are remaining stable, e.g. they are not aggrading or degrading. The pools should remain
deep with flat water surface slopes and the riffles should remain steeper and shallower.
' 8.5 Photo Reference Sites
Photographs used to evaluate restored sites will be made with a 35-mm camera using
' slide film or a digital camera. There will be one photo reference site per cross-section
showing both banks and the stream channel. Several of the in-stream structures (e.g.,
rock vanes, cross vanes, and root wads) will also be photographed. Reference sites will
' be photographed before construction and continued once per year for at least 5 years
following construction. After construction has taken place, reference sites will be marked
with wooden stakes.

0
I

Longitudinal reference photos: The stream will be photographed longitudinally beginning
at the downstream end of the mitigation site and moving upstream to the end of the site.
Photographs will be taken looking upstream at delineated locations. Reference photo
locations will be marked and described for future reference. Points will be close enough
together to get an overall view of the reach. The angle of the shot will depend on what
angle provides the best view and will be noted and continued in future shots. When
modifications of stream position have to be made due to obstructions or other reasons, the
position will be noted along with any landmarks and the same position used in the future.
Lateral reference photos: Reference photo transects will be taken at each permanent
cross-section. Photographs will be taken of both banks at each cross-section. The survey
tape will be centered in the photographs of the bank. The water line will be located in the
lower edge of the frame and as much of the bank as possible included in each photo.
Photographers should make an effort to consistently maintain the same area in each photo
over time. Photos of areas that have been treated differently should also be included; for
example, two different types of erosion control material used. This will allow for future
comparisons.
Success Criteria: Photographs will be used to subjectively evaluate channel aggradation
or degradation, bank erosion, success of riparian vegetation, and effectiveness of erosion
control measures. Longitudinal photos should indicate the absences of developing bars
within the channel or an excessive increase in channel depth. Lateral photos should not
indicate excessive erosion or continuing degradation of the bank over time. A series of
Winston-Salem Stream Restoration Projects 8-48 Buck Engineering

' photos over time should indicate successional maturation of riparian vegetation.
Vegetative succession should include initial herbaceous growth, followed by increasing
' densities of woody vegetation, and then ultimately a mature overstory with herbaceous
understory.
1 8.6 Survival Plots
' Survival of planted vegetation will be evaluated using survival plots or counts. Survival
of live stakes will be evaluated using enough plots or a size plot that allows evaluating at
least 100 live stakes. Evaluations of live stake survival will continue for at least 5 years.
' When stakes do not survive a determination will be made as to the need for replacement;
in general, if greater than 25% die, replacement will be done.
' All rooted vegetation will be flagged and evaluated for at least 5 years to determine
survival. At least 2 staked survival plots will be evaluated. Plots will be 25 ft by 100 ft
and all flagged stems will be counted in those plots. Success will be defined as 320 stems
per acre after 5 years. When rooted vegetation does not survive, a determination will be
made as to the need for replacement; in general, if greater than 25% die, replacement will
be done.
1

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Winston-Salem Stream Restoration Projects 8-49 Buck Engineering
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9 References
Ackers, P. and W.R. White. 1973. Sediment transport: new approach and analysis.
Journal of the Hydraulics Division, ASCE, Vol. 99, No. HY11, pp. 2041-2060.
Andrews, E. D., Entrainment of gravel from naturally sorted river bed material,
Geological Society of America Bulletin, 94, 1225-1231, 1983.
Bunte, Kristin. 1994. Draft of "Modeling Bedload Sediment Transport in Sand-bed
Streams using the Ackers and White (1973) Sediment Transport Formula."
Prepared for the Stream Technology Center, Rocky Mountain Forest and Range
Experiment Station, U.S. Forest Service, Fort Collins, Colorado
Clinton, D. R. (2001). Stream morphology relationships from reference streams in North
Carolina. Thesis, North Carolina State University, Raleigh, North Carolina.
Doll, Barbara A., Dani E. Wise-Frederick, Carolyn M. Buckner, Shawn D. Wilkerson,
William A. Harman and Rachel E. Smith. 2000. Hydraulic Geometry Relationships
for Urban Streams Throughout the Piedmont of North Carolina. Riparian Ecology
and Management in Multi-Land Use Watersheds. American Water Resources
Association Summer Symposium. Portland, Oregon. Dates: September 28-31,
2000. Pp: 299-304.
Doll, B. A., D.E. Wise-Frederick, C.M. Buckner, S.D. Wilkerson, W.A. Harman, R.E.
Smith, and J. Spooner, 2002. Hydraulic Geometry Relationships for Urban
Streams throughout the Piedmont of North Carolina. In Press.
Dunne, T. and L. B. Leopold, 1978. Water in Environmental Planning. New York: W. H.
Freeman and Company.
Federal Interagency Stream Restoration Working Group (FISRWG). 1998. Stream
Corridor Restoration: Principles, Processes and Practices. National Technical
Information Service, Springfield, VA.
' City of Winston-Salem, NC, Stormwater Management Division. 1999. Why are our
Stream Banks "growing up" in Winston-Salem? Available from World Wide Web:
(http://www.ci.Winston-Salem.nc.us/stormwater/why are stream banks.htm)
' Hammer, T.R., 1973. Impact of Urbanization on Peak Streamflow. Regional Science
Research Institute Discussion Paper Series: No. 63. Philadelphia, Pennsylvania. 76
' PP
' Winston-Salem Stream Restoration Projects 9-50 Buck Engineering

'
Harman, W.A., G.D. Jennings, J.M. Patterson, D.R. Clinton, L.O. Slate, A.G. Jessup, J.R.
Everhart, and R.E. Smith, 1999. Bankfull Hydraulic Geometry Relationships for
' North Carolina Streams. Wildland Hydrology. AWRA Symposium Proceedings.
Edited by: D.S. Olsen and J.P. Potyondy. American Water Resources Association.
' June 30-July 2, 1999. Bozeman, MT.
Harmel, R. D., C. T. Haan, and R. C. Dutnell. 1999. Evaluation of Rosgen's streambank
erosion potential assessment in Northeastern Oklahoma. Journal AWRA 35(1):113-
' 121.
' Harrelson, C. C., C. L. Rawlins, and J. P. Potyondy. 1994. Stream Channel Reference
Sites: An Illustrated Guide to Field Technique. General Technical Report RM-245.
USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort
' Collins, CO.
Jennings, G. D., and W. A. Harman. 2000. Stream corridor restoration experiences in
North Carolina. ASAE Paper 002012, ASAE Annual International Meeting,
' Milwaukee, WI. Am. Soc. Agr. Eng., St. Joseph, MI.
Johnson, P.A., and T.M. Heil, 1996. Uncertainty in Estimating Bankfull Conditions.
' Water Resources Bulletin. Journal of the American Water Resources Association
32(6):1283-1292.
' Kilpatrick, F.A., and H.H. Barnes Jr. 1964, Channel Geometry of Piedmont Streams as
Related to Frequency of Floods. Professional Paper 422-E. US Geological Survey,
' Washington, DC.
Knighton, David. 1984. Fluvial Forms and Processes. Rutledge, Chapman, and Hall,
' Inc. New York, NY.
Leopold, L. B., M. G. Wolman and J. P. Miller. 1992. Fluvial Processes in
t Geomorphology. Dover Publications, Inc. New York, NY.
Leopold, L.B., 1994. A View of the River. Harvard University Press, Cambridge, Mass.
' l
h
anne
s
Leopold, L.B., and T. Maddock Jr., 1953. The Hydraulic Geometry of Stream C
and Some Physiographic Implications. U.S. Geological Survey Professional Paper
' 252, 57 pp.
Merigliano, M.F. 1997. Hydraulic Geometry and Stream Channel Behavior: An
' Uncertain Link. Journal of the American Water Resources Association 33(6):1327-
1336.
' Nixon, M., 1959. A Study of Bankfull Discharges of Rivers in England and Wales. In
Proceedings of the Institution of Civil Engineers, vol. 12, pp. 157-175.
' Winston-Salem Stream Restoration Projects 9-51 Buck Engineering

' North Carolina Division of Water Quality. 1997. Standard Operating Procedures
Biological Monitoring. North Carolina Department of Environment and Natural
' Resources, Raleigh, NC.
North Carolina Division of Water Quality. 2000. Benthic Macroinvertebrate Monitoring
' Protocols for Compensatory Stream Restoration Projects. North Carolina
Department of Environment and Natural Resources, Raleigh, NC.
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Patterson, J. M., D. R. Clinton, W. A. Harman, G. D. Jennings, and L. O. Slate. 1999.
Development of streambank erodibility relationships for North Carolina stream. In:
Olson, D. S., and J. P. Potyondy (Eds.). Wildland Hydrology, Proc. AWRA
Specialty Conf., Bozeman, MT. pp. 117-123.
Rinaldi, M. and P.A. Johnson, 1997. Stream Meander Restoration. Journal of the
American Water Resources Association 33:855-866.
Rosgen, D. L. 1994. A classification of natural rivers. Catena 22:169-199.
Rosgen, D.L., 1996. Applied River Morphology. Wildland Hydrology Books, Pagosa
Springs, Colo.
Rosgen, D.L., 1997. A geomorphological approach to restoration of incised rivers. In:
Wang, S.S.Y, E.J. Langendoen, and F.D. Shields, Jr. (Eds.). Proceedings of the
Conference on Management of Landscapes Disturbed by Channel Incision. pp. 12-
22.
Rosgen, D.L., 1998. The Reference Reach - a Blueprint for Natural Channel Design.
Draft Presented at ASCE Conference on River Restoration in Denver Colorado -
March, 1998. ASCE. Reston, VA.
Rosgen, D.L. 2001. A stream channel stability assessment methodology. Proceedings of
the Federal Interagency Sediment Conference, Reno, NV, March, 2001.
Schafale, M.P. and A.S. Weakley, 1990. Classification of the Natural Communities of
North Carolina. Third Approximation. NCDEHNR Natural Heritage Program,
Raleigh, NC.
Schumm, S.A., 1960. The Shape of Alluvial Channels in Relation to Sediment Type. U.S.
Geological Survey Professional Paper 352-B. U.S. Geological Survey, Washigton,
DC.
Simon, A. 1989. A model of channel response in disturbed alluvial channels. Earth
Surface Processes and Landforms 14(1):11-26.
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Wilkerson, S.D., Karl G. Linden, James D. Bowen, Craig J. Allan. 1998. Development
and Analysis of Hydraulic Geometry Relationships for the Urban Piedmont of
North Carolina. University of North Carolina at Charlotte.
Williams, G.P., 1978. Bankfull Discharge of Rivers. Water Resources Research
14(6):1141-1154.
Williams, G.P., 1986. River Meander and Channel Size. Journal of Hydrology 88:147-
164.
Wilson, M.P. 1983. Erosion of Banks Along Piedmont Urban Streams. Water Resources
Research Institute of the University of North Carolina.
Wohl, E.E. 2000. Mountain rivers. Am. Geophys. Union Press, 320 pp.
Wolman, M.G., 1954. A Method of Sampling Course River-Bed Material. Transactions
of American Geophysical Union 35: 951-956.
Wolman, M.G. and L.B. Leopold., 1957. River Floodplains: Some Observations on their
Formation. USGS Professional Paper 282-C. U.S. Geological Survey, Washington, DC.
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Appendix 2 Reference Reach Data

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Piedmont Reference Reach Summary Table
Stream Name LAKE JEANETTE TRI BUTARY
Location GREENSBORO, NC
Stream Type: E
Watershed Area: 0.15 sq. miles
MEAN MEDIAN MIN MAX

Channel Dimensions
Riffle Width/Mean Bankfull Depth Wr/dbkf 8.45 8.45 7.20 9.70
Max. Pool Depth/Max. Riffle Depth dpmax/drmax : 1.28 1.28 1.28 1.28
Pool Width/Riffle Width Wp/Wr : 1.64 1.64 1.54 1.73
Pool Area/Riffle Area Ap/Ar : 1.38 1.38 1.33 1.43
Max. Pool De th/Mean Bankfull Depth dpmax/dbkf : 1.93 1.93 1.74 2.11
Lowest Bank Height/Max. Bankfull Depth Bhlow/dmbkf : 1.15 1.15 1.10 1.20
Channel Pattern
Meander Width Ratio(MWR=Wblt/Wbkf : 3.49 3.49 3.49 3.49
Ratio:
Radius of Curvature/Bankfull Width Rc/Wbkf : 0.91 0.71 0.48 1.97
Meander Wavelen th/Bankfull Width Lm/Wbkf): 3.51 3.45 1.63 5.75
Channel Profile
Riffle Slope/ Water Surface Slope: 1.41 1.02 0.23 3.41
Pool Slope/Water Surface Slope: 1.20 0.64 0.00 8.72
Run Slope/Water Surface Slope: 1.28 1.28 1.28 1.28
Glide Slope/ Water Surface Slope: - - - -
Max. Riffle Depth/Mean Bankfull Depth: 1.52 1.51 1.38 1.67
Max.Pool Depth/Mean Bankfull Depth: 1.93 1.94 1.76 2.13
Max. Run Depth/Mean Bankfull Depth: - - - -
Max. Glide De th/Mean Bankfull Depth: - - - -
Riffle Len th/Bankfull Width: 1.43 1.18 0.44 2.75
Pool Len th/Bankfull Width: 1.39 1.41 0.59 2.08
Run Len th/Bankfull Width: 1.41 1.41 1.33 1.50
Glide Len th/Bankfull Width: - - - -
Riffle to Riffle Spacing/Bankfull Width: 2.82 2.59 1.26 5.25
Pool to Pool Spacing/Bankfull Width: 2.94 2.67 1.92 4.92
Riffle to Pool Spacin /Bankfull Width: 1.63 1.49 0.59 3.50

Bed Material
D84: 3.50 mm
dmbkf: - mm
dmbkf/D84: -
u/u* : -
Mannings 'n': -

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Piedmont Reference Reach Summa Table
Stream Name LAKE JEANETTE TRI BUTARY
Location GREENSBORO, NC
Stream Type: E
Watershed Area: .15 sq miles
MEAN MEDIAN MIN MAX
Channel Dimensions
Riffle Width/Mean Bankfull Depth Wr/dbkf - - - -
Max. Pool Depth/Max. Riffle Depth dpmax/drmax : 1.28 1.28 1.28 1.28
Pool Width/Riffle Width Wp/Wr : - - - -
Pool Area/Riffle Area A /Ar : - - -
Max. Pool De th/Mean Bankfull De th dpmax/dbkf : 1.93 1.93 1.74 2.11
Lowest Bank Height/Max. Bankfull Depth Bhlow/dmbkf : 0.70 0.70 0.70 0.70
Channel Pattern
Meander Width Ratio MWR=WbIt/Wbkf : 3.49 3.49 3.49 3.49
Ratio:
Radius of Curvature/Bankfull Width Rc/Wbkf : 0.91 0.71 0.48 1.97
Meander Wavelength/Bankfull Width(Lm/Wbkf): 3.51 3.45 1.63 5.75
Channel Profile
Riffle Slope/ Water Surface Slope: 1.41 1.02 0.23 3.41
Pool Slope/Water Surface Slope: 1.20 0.64 0.00 8.72
Run Slope/Water Surface Slope: 1.28 1.28 1.28 1.28
Glide Slope/ Water Surface Slope: - - - -
Max. Riffle De th/Mean Bankfull Depth: 1.52 1.51 1.38 1.67
Max.Pool De th/Mean Bankfull Depth: 1.93 1.94 1.76 2.13
Max. Run Depth/Mean Bankfull Depth: - - - -
Max. Glide Depth/Mean Bankfull Depth: - - - -
Riffle Len th/Bankfull Width: 1.43 1.18 0.44 2.75
Pool Len th/Bankfull Width: 1.39 1.41 0.59 2.08
Run Len th/Bankfull Width: 1.41 1.41 1.33 1.50
Glide Len th/Bankfull Width: - - -
Riffle to Riffle Spacin /Bankfull Width: 2.82 2.59 1.26 5.25
Pool to Pool Spacin /Bankfull Width: 2.94 2.67 1.92 4.92
Riffle to Pool Spacing/Bankfull Width: 1.63 1.49 0.59 3,50

Bed Material
D84: 3.50 mm
dmbkf: - mm
dmbkf/D84: -
u/u* : -
Mannin s W: -

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Stream:
Silas Creek
Watershed:
Upper Yadkin River
Location
Winston-Salem, NC
Latitude:
Longitude:
County:
Forsyth
Date:
10/23-24/01
Observers Daph
Angela Jessup,
d J
M
h ne

Channel Type: an
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Drainage Area (sq mi): 3.3

Notes: Suburban watershed with
watershed. high percenta ge of forest in
Dimension
typical min max
Size: x-area bankfull 43.5 38.5 48.9
width bankfull 25.6 23.1 28.0
mean depth 1.7 1.5 1.9
Ratios: Width/Depth Ratio 15.1 12.4 17.2
Entrenchment Ratio 1.3 1.2 1.4
Riffle Max Depth Ratio 1.6 1.4 1.7
Pool Area Ratio 1.6 1.4 1.8
Pool Width Ratio 1.0 0.9 1.1
Pool Max Depth Ratio 2.6
_ 2.4 2.9
Bank Height Ratio _
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0
Run Area Ratio 1.4 1.4
Run Width Ratio 1.0 0.9 1.1
Run Max Depth Ratio 1.9 1.9 1.9
Glide Area Ratio 1.1 1.1 1.2
Glide Width Ratio 1.0 0.9 1.0
Glide Max Depth Ratio 1.9 1.7 2.1
Hydraulics: riffle pool run
discharge rate, Q (cfs) 199.0 199.0 199.0
velocity (ft/sec) 4.6 2.8 3.2
shear stress @ max depth (lbs/ft sq) 1.38 2.30 1.69
shear stress (lbs/ft sq) 0.77 1.23 1.10
shear velocity (ft/sec) 0.63 0.80 0.75
unit stream power (lbs/ft(sec) 3.973 3.973 3.97
relative roughness 3.3 5.2 4.520502
friction factor u/u* 7.3 3.6 4.3
threshold grain size @ max depth (mm) 135.8 367.8 200.9
threshold rain size mm 49 108 87
Pattern
typical min max
Sinuosity 1.1
Meander Width Ratio 1.7 1.6 2.0
Amplitude Ratio ---
Meander Length Ratio 6.6 5.1 9.6
Straight Length Ratio --- --- ---
Radius Ratio 1.6 0.8 2.1
arc angle (drees --- --- ---
Proflle
typical min max
channel slope (%) 0.819 --- ---
measured valley slope (%) --- --- ---
valley slope (%) 0.877
Riffle Slope Ratio 2.4 0.1 8.6
Pool Slope Ratio 0.0 -0.2 0.1
Run Slope Ratio 0.6 0.0 1.6
Glide Slope Ratio 0.6 --- 1.7
Pool Spacing Ratio 2.4 1.1 4.9
Channel Materials
total riffle ; pool run glide bar sample
D16 0.283 0.301 0.271 0.0 0.0 1.8
D35 0.83 2.46 0.46 0 0 15
D50 19.1 26.5 7.4 0 0 32
D84 157.5 167 134 0 0 96
D95 300.2 326 237 0 0 117
Largest Bar 0
%Silt/Clay 1% 0% 3%
% Sand 34% 33% 36% --- 17%
% Gravel 25% 25% 26% --- 63%
% Cobble 25% 28% 22% 20%
% Boulder 7% 10% 3%
% Bedrock 6% 5% 9%

100
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88
Silas Creek Upper Yadkin River Winston-Salem, NC
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150 200
Channel Distance (ft)
250 300 350 400
°bed water srf x Terrace + LEW 9 BKF - REW 0 x-section
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Appendix 3 Photographic Log
Winston-Salem Stream Restoration Projects 9-2 Buck Engineering

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Photo Log 1-Silas
A. Construction Access from Yorkshire Rd.
C Construction Access from Yorkshire Rd.

D. Construction Access from Yorkshire Rd.

Photo Log 2-Silas Reach 1
A. House on Reach 1
A. Reach 1 Upstream of Yorkshire Rd.
C. Upstream on Reach 1
D. Reach 1 at Pool Cross Section 1
F. Reach 1 at Riffle Cross Section 2
E. Reach 1 at Yorkshire Rd. Culvert

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H. Greenway Upstream of Yorkshire Rd.
G. Greenway Upstream of Yorkshire Rd.
1. Greenway Upstream of Yorkshire Rd.
Photo Log 3-Silas Reach 2 Downstream of Yorkshire Road
A. Culvert Downstream of Yorkshire Rd.

C. Reach 2 Downstream of Yorks hirc Rd.

li. Parkin(Lot at Yorkshire 1W.
I
E. Reach 2 Downstream of Yorkshirc Rd
D. Soccer Fields on Reach 2
F. Walking Path on Reach 2
Photo Log 3-Silas Reach 2 Downstream of Yorkshire Road

J. Bank Erosion on Silas Creek
G. Confluence of Silas and Buena Vista
H. Sewer Lines on Lett Bank of Reach 2
L. Bank Erosion on Silas Creek
1. Bank Erosion on Silas Creek
K. Bank Erosion on Silas Creek
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Photo Log 3-Silas Reach 2 Downstream of Yorkshire Road
M. Funk I?rosion on Silas Creek
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N. Culvert Upstream of Silas Parkway
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Photo Log 4 - Silas Reach 2 Downstream of Silas Creek
Parkway
A. Bench on Reach 3

B. Confluence on Reach 3
Silas Creek DWQ 021881
Subject: Silas Creek DWQ 021881
Date: Fri, 13 Dec 2002 15:30:11 -0500
From: "Todd St. John" <todd.st.john @ ncmail.net>
Organization: DWQ Wetlands Unit
To: [e-mail]
CC: "Todd St. John" <[e-mail]>
Jeff, I only have one question on this one... The cross section, etc.,
of the design stream is well above the Piedmont Rural Curve whereas the
upstream reference stream is right on the curve... I did not find an
explanation of this in the desgn manual.
Todd St. John, P.E.
Environmental Engineer II
DWQ
Wetlands Unit
1 of 1 12/13/02 3:30 Piv
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North Carolina
Department of Environment and Natural Resources F J
ALT ••
Michael F. Easley, Governor
William G. Ross Jr., Secretary NCDENR
MEMORANDUM:
TO: John Dorney
FROM: Ron Ferrell P 4.
SUBJECT: Permit Application-Silas Creek 9 off)'
DATE: 12-9-02
Attached for your review are 2 restoration plans (1 sent to Winston-Salem Regional) for
the Silas Creek Stream Restoration project in Forsyth County. Please feel free to call the
project manager (Jeff Jurek) with any questions regarding this plan (733-5316).
Thank you very much for your assistance.
attachment: Restoration Plan (2 originals)
PROD. REFERENCE N0. SHEET N0.
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