ABSTRACT

MATTHEWS, KIMBERLY YANDORA. Functional Assessment for a Proposed Floodplain Stormwater Treatment Wetland. (Under the direction of Dr. James D. Gregory.)

Urbanization can dramatically alter the hydrologic cycle and water quality, causing adverse effects on urban streams and floodplain wetlands. A proposed regional stormwater treatment wetland on a forested floodplain of South Buffalo

Creek (SBC) is planned. The wetland should improve water quality and stream habitat in an urban watershed found in Greensboro, NC, USA. The objectives of this research were to (1) characterize in-stream stormwater concentrations of sediment and nutrients and species composition of macroinvertebrates within

South Buffalo Creek, (2) determine geomorphic properties of the stream channel upstream, within, and downstream of the proposed stormwater treatment wetland, (3) establish baseline water table hydrology on the floodplain of the proposed stormwater treatment wetland, and (4) determine the composition of the existing forest stand. The proposed wetland will remove from stormflow an estimated 1092 to 1639 g/m2/yr (3111 to 4666 tons/mi2/yr) total suspended sediment (TSS) per unit area of the wetland with an accumulation of 0.08 cm/yr

(0.20 in/yr). Total nitrogen and total phosphorus will be removed from floodwater in the wetland at a rate of 67% and 46% respectively. Reduction of peak flow and shear stress during storm flow should decrease channel erosion and lead to increased stream stability. Average depth to the local water table level on the floodplain should decrease, leading to an increased area of functioning wetland.

Forest vegetation should likely shift to more wetland species with changes occurring in the herbaceous and understory layers first. Overall, the proposed stormwater treatment wetland should improve water quality and increase stream stability in South Buffalo Creek.

DEDICATION

To my husband, Mark,

for your endless love and support.

I could not have done this without you.

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PERSONAL BIOGRAPHY

I grew up in southwestern Pennsylvania and attended college at Wittenberg

University in Springfield, OH. I received my Bachelor of Arts degree in Biology and minored in geology and environmental studies. I attended a semester at Duke

University Marine Laboratory in Beaufort, NC, where I pursued my interest in aquatic ecology. Upon completion of my studies, I went to work for the Storm Water

Services Department with the City of Greensboro, NC. Over the next fours years, I gained knowledge about urban water quality issues, stormwater best management practices, and water quality monitoring programs. A growing desire to learn more about stream restoration and wetlands led me to pursue graduate studies at North

Carolina State University.

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ACKNOWLEDGEMENT

I would like to acknowledge the endless support and encouragement I received from

the following people, without whom I would not have been able to complete this

research.

To my committee members, Dr. Jim Gregory and Dr. Doug Frederick, NCSU

Department of Forestry; Dr. Bob Holman, NC Department of Transportation; and Dr.

Greg Jennings, NCSU Department of Biological and Agricultural Engineering.

To James Martin, Janet Myers, Lynn Coryell, Lisa Terwilliger, Katie McDermott,

John Fisher, and Ayesha Peppers at the NCSU Center for Transportation and the

Environment for providing me a graduate fellowship to help fund this research and

the opportunity to learn more about the connection between transportation and the

environment.

To David Phlegar, Peter Schneider, Roy Graham, Rebecca Hall, and Ron Small of

the City of Greensboro Stormwater Management Division who all provided

assistance with field work, equipment installation, data collection and analysis, and

constant encouragement.

To Todd Hayes of the City of Greensboro GIS Division, who provided geographical

data.

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To Shastri Annambhotla, Stormwater Engineering Specialist, and Scott Bryant,

Stormwater Manager, both from the City of Greensboro, for creating this project and funding this research project that allowed me the opportunity to attend NCSU.

To my field assistants, Jed Weston and Melissa Donnelly.

To Dani Wise-Frederick from North Carolina State University Water Quality Group,

Doug Walters and Geoff Cartano from USGS, Lane Hall from NCDOT, and Dr. John

Parsons from NCSU Department of Biological and Agricultural Engineering.

To Steve Kroeger from NCDENR who helped to conduct vegetation surveys, provided assistance with data analysis, and helped save me from poison ivy.

To the Survey Crew at the City of Greensboro who spent over four months in the relentless heat and bugs to survey the site.

To fellow graduate students, Rebecca Vidra and Sarah Luginbuhl who also helped collect data and install wells.

To my parents for always encouraging me to follow my dreams and teaching me to believe in myself.

v

To my husband who made countless sacrifices and was my constant

encouragement.

Thank you.

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TABLE OF CONTENTS

LIST OF TABLES x

LIST OF FIGURES xii

INTRODUCTION 1

LITERATURE REVIEW 4

Water Quality Functions of Riparian Wetlands 4

Stream Geomorphology and Sediment Transport in Channel 9

Alteration of Floodplain Hydrology 12

Forest Stand on Riparian Wetlands 15

OBJECTIVES 18

METHODS 19

The Study Watershed 19

Study Site 27

Proposed Stormwater Treatment Structure 32

Experimental Design 36

Water Quality 36 Ambient Stream Conditions 36 Stormwater Stream Conditions 38 Flow Estimation and Pollutant Loading 42 Suspended Sediment 44 Macroinvertebrates 47

Stream Geomorphology 48

Water Table Hydroperiod 50

Vegetation 52

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RESULTS AND DISCUSSION 55

Water Quality 55 Ambient Stream Conditions 55 Stream Flow and Pollutant Yield Estimates 60 Suspended Sediment 65 Macroinvertebrates 69

Stream Geomorphology 74

Water Table Hydroperiod 83

Wetland Vegetation 91

CONCLUSIONS AND RECOMMENDATIONS 98

Water Quality 98 Conclusions 98 Recommendations 99

Stream Geomorphology 99 Conclusions 99 Recommendations 100

Wetland Hydrology 100 Conclusions 100 Recommendations 100

Wetland Vegetation 101 Conclusions 101 Recommendations 101

REFERENCES CITED 103

APPENDICES 112

Appendix A: Site Photographs 113

Appendix B: Water Quality Results and Pollutant Yield 116

Appendix C: Total Suspended Solids Results 122

Appendix D: Macroinvertebrate Results 133

Appendix E: Geomorphology and Survey Results 141

Appendix F: Water Table Hydrology 192

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Appendix G: Vegetation Results 201

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LIST OF TABLES

Table 1. Land use category descriptions for study watershed (City of Greensboro 1993) 25

Table 2: Ambient water quality sampling sites used to compare site data 37

Table 3: Stormwater monitoring sites used for comparison of project site data 42

Table 4: Description of vegetation components inventoried on riparian wetland 52

Table 5: Ambient stream results for total suspended solids and turbidity 56

Table 6: Median ambient stream results for nitrogen and phosphorus (mg/l) 56

Table 7: Median ambient stream concentration of fecal coliform bacteria 57

Table 8: Median total suspended sediment concentrations (mg/l) for South Buffalo Creek 58

Table 9: Median stormflow concentrations for nutrients for South Buffalo Creek and reference site (mg/l) 58

Table 10: Comparison of fecal coliform bacteria during storm flow from grab samples (CFU = coliform forming units) 59

Table 11: Annual stream flow for South Buffalo Creek at the proposed stormwater treatment wetland based on USGS Station 02094770 60

Table 12: Location of vegetation plots to charcterize existing vegetation wetland areas 61

Table 13: Nitrogen and Phosphorus loss rates as reported in literature for riparian wetlands 64

Table 14: Summary TSS concentrations (mg/l) for passive samplers 66

Table 15: Comparison of suspended sediment yields based on results from automatic sampler (fixed point, 12-hour flow weighted composite value) and passive samplers (4 stage levels average values) 67

Table 16: Total suspended sediment (mg/l) summary statistics for station-bottle effect and calculated discharge (Mannings’ Equation) 68

Table 17: Number and average length of pools, riffles, and runs 76

x

Table 18: Results of overstory species (>7-cm diameter) 92

Table 19: Results of understory species inventory 96

Table 20: Results for herbaceous layer, <0.5 m, inventory 97

xi

LIST OF FIGURES

Figure 1: Map of North Carolina, the Cape Fear River Basin and general location of South Buffalo Creek (NCDENR 2000) 20

Figure 2: Cape Fear River Subbasin 03-06-02 (NCDENR 2000) 21

Figure 3: Soils series of South Buffalo Creek 24

Figure 4: Land use map of watershed to proposed stormwater treatment wetland 26

Figure 5: Map of the city limits of Greensboro and the watershed to the proposed stormwater treatment wetland 28

Figure 6: Map of the study site including the proposed stormwater treatemnt wetland and the study reach, 2.4 km (1.5 mile) long, upstream of the proposed water level control structure 27

Figure 7: Soils of proposed stormwater treatment wetland on South Buffalo Creek 31

Figure 8: Diagram of proposed stormwater treatment wetland on South Buffalo Creek 33

Figure 9: Single-stage suspended sediment sampler (USGS U-59) 45

Figure 10: Map of passive sediment samplers upstream, within, and downstream of the project area 46

Figure 11: Location of water tables wells on the riparian floodplain of the proposed stormwater treatment wetland 51

Figure 12:Estimaed Annual Yield of Pollutants from the Watershed of South Buffalo Creek and estimates of pollutants loads to wetland treatment systems 53

Figure 13: Storm hydrograph and TSS concentrations on December 10, 2001 65

Figure 14: Summary of NC Bioclassification for South Buffalo Creek and a reference site 70

Figure 15: Composition of Functional Feeding Groups for 4 sites on South Buffalo Creek 73

Figure 16: Identification of Stream Reaches Upstream Main, Upstream Tributary, Project, and Downstream 74

xii

Figure 17: Proposed stormwater treatment wetland in 1959 and 2001 75

Figure 18: Comparison of channel slope from 1959 to 2000 for South Buffalo Creek showing loss of stream length and increase of slope 76

Figure 19: Cross-section of floodplain and channel of South Buffalo Creek in 1959 and 2001 78

Figure 20: Cross-section at bedrock riffle (station 5556) within the project area 79

Figure 21: Example of a typical cross-section at a stable riffle within the project area 80

Figure 22: Monthly median depth to water table 84

Figure 23: Monthly median precipitation (30-yr mean) and 2001 and 2002 86

Figure 24: Daily rainfall totals for the proposed stormwater treatment wetland for February 9, 2002 to August 8, 2002 87

Figure 25: Floodplain hydrology for February 9, 2002 to August 8, 2002 for the proposed stormawater treatment wetland. 87

Figure 26: Water table gradient from South Buffalo Creek across the proposed stormwater treatment wetland from July – December 2001 88

Figure 27: Water table gradient from South Buffalo Creek across the proposed stormwater treatment wetland from January – August 2002 89

Figure 28: Class distribution of green ash (Fraxinus pennsylvanica) in overstory 93

Figure 29: Size distribution of Celtis occidentalis (hackberry) based on DBH measurements 94

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INTRODUCTION

Riparian wetlands are ecotones between uplands and deepwater aquatic

systems (Mitsch 1995) and in the last thirty years, the important ecological functions

of these wetlands have been recognized. Specifically, riparian wetlands perform

valuable hydrologic functions such as water storage and moderation of groundwater

discharge, biogeochemical functions such as nutrient cycling and particulate

retention, and biological functions through distinct plant and animal communities

(Brinson et al. 1995; Mitsch and Gosselink 2000). Subsurface flows, precipitation,

overbank flows, and overland flows are the sources of water for most riverine

wetlands. Water is exported from these wetlands through subsurface and surface

flows to the channel, to groundwater recharge, or to evapotranspiration.

Urbanization dramatically alters the hydrologic cycle causing adverse effects

on urban streams and floodplain wetlands. In urban environments, the buildings,

roads, and other impervious areas replace naturally permeable grass and forested lands. Increased runoff due to urban development and impervious areas increases peak flows in streams and results in decreased water quality. As little as 10 percent impervious cover has been linked to stream degradation, with degradation becoming

more severe as the proportion of impervious cover in the watershed increases

(Schueler 1995). Many streams have become deeply incised and disconnected from

their adjacent floodplains as a result of increased stormflow from urbanization and

historical maintenance practices of dredging (Nelson and Booth 2002). The riparian

areas adjacent to such streams are not providing the maximum potential ecologic

benefits to the ecosystem.

1

Urban areas are increasing in size due to population growth, while agricultural land (especially newly developed agricultural land) is decreasing. This trend toward urbanization has shifted the principal cause of wetland loss from agriculture to urbanization (Syphard and Garcia 2001). Urbanization directly impacts wetlands through hydrologic alteration, topographic alteration, and reductions in wetland area.

Indirect impacts to wetlands include an increase in impervious areas, a decrease in upland storage, and the channelization of streams. In order to restore urban wetlands, manipulation is sometimes necessary, and regular maintenance is required (Lewis 1988). Unlike natural wetlands that are self-maintaining, restored urban wetlands will need to be periodically maintained to remain efficient and operating as wetlands.

One of the main hydrologic functions of wetlands, particularly riparian wetlands, is the ability to improve water quality through biochemical processes.

While these processes occur naturally, created wetlands are used for treatment of wastewater and stormwater runoff. Nitrogen (N) and phosphorus (P) found in these wastewaters are considered pollutants to streams and lakes. Under saturated soil conditions in wetlands, nitrate-nitrogen is reduced to molecular nitrogen, which is lost to the atmosphere. Most of the phosphorus is retained with the sedimentation of particulates. Plant uptake also contributes to retention of N and P in vigorous, aggrading plant communities. Both processes help to reduce nutrient and sediment concentrations in the water.

South Buffalo Creek in Greensboro, North Carolina, drains a densely urbanized area (71% developed land). The North Carolina Division of Water Quality

2

(NCDWQ) evaluated South Buffalo Creek in 1996 and determined it was Not

Supporting (NS) its designated uses; however, a re-evaluation in 1999 upstream of a

wastewater treatment plant (WWTP) reclassified the stream reach upstream of the

WWTP as Partially Supporting (PS) its uses (NCDENR 2000). Sediment, as a result

of non-point source pollution, was identified as a major pollutant in the creek. In

urban areas, non-point source pollution is often identified as the most widespread

water pollutant in North Carolina (NCDENR 2000).

In efforts to improve water quality in South Buffalo Creek, the City of

Greensboro proposed to construct a regional stormwater treatment wetland on the

forested floodplain of South Buffalo Creek. Historical maintenance of urban streams

resulted in the straightening, channelization, and dredging of the streams in the

1930s and 1940s. The goal of these practices was to convey stormwater flow quickly

and efficiently without causing flooding to adjacent property. At the project location,

baseflow of South Buffalo Creek is over 3 meters below the adjacent floodplain, and water rarely reaches the floodplain. North Carolina rural streams with this drainage area are typically 1-2 meters deep with water flowing over bank top on average every 1.5 years (Doll et al. 2002).

South Buffalo Creek rarely flows over the top of its banks within the area of

the proposed stormwater treatment wetland. Therefore, stormwater transporting

suspended sediment infrequently reaches the floodplain. The functional area of the

riparian wetland is reduced and opportunities for the riparian wetland to perform

water quality functions are limited. In order to reconnect the stream with its

floodplain, a water level control structure is proposed for the stream channel that will

3

be activated by stream stage increase. The control structure will temporarily detain

water in the channel and floodplain for 24 to 72 hours. It is estimated the floodplain

will be inundated approximately 40 times a year. Alteration of hydrologic conditions

should expand the wetland area in the floodplain and result in improved water quality

for the South Buffalo Creek (City of Greensboro 2000).

The purpose of this paper is to describe existing stream geomorphology,

water quality, the hydrology and vegetation of the riparian wetland, and to

hypothesize the effects of the proposed water control structure on the stream and floodplain through a review of current literature. Herein stream water quality and benthic marcoinvertebrate communities are characterized, geomorphic properties of the stream channel are determined, baseline water table hydrology within the floodplain are established, and the composition of the existing forest stand is described.

LITERATURE REVIEW

Water Quality Functions of Riparian Wetlands

Natural riparian wetlands have long been recognized for their ability to trap and store sediment and transform nitrogen, phosphorus, and carbon (Richardson

1988; Johnston 1991; Craft and Casey 2000). For this reason, riparian wetlands with overbank flow naturally improve stream water quality. However, several factors affect the effectiveness of nutrient cycling including: particle size, retention time, chemical processes, and velocity of flow. Urbanization increases instream nutrient

4 and sediment concentrations, increases flow quantity and velocity, and decreases the size, connectivity and retention time of wetlands.

The effectiveness of wetlands in sediment deposition is a function of watershed size, land use, wetland connectivity, inflow rates, volume ratio, and flood duration and frequency (Asselman and Middelkoop 1995; Craft and Casey 2000;

Carleton et al. 2001). Flow velocity will determine the size of sediment particles carried by the flow. Urbanization causes higher flows that erode and transport larger sized particles. This is important as the flow fills the river channel and expands on the floodplain of the proposed stormwater treatment wetland of South Buffalo Creek.

A transfer of momentum and suspended sediment occurs as the water enters the floodplain. The larger sand particles will accumulate on levees (Heimann and Roell

2000), or in this case, the constructed berms of the proposed stormwater treatment wetland. Theoretically, sediment accumulation will decrease with distance from the channel and the particle sizes will also decrease (Pizzuto 1987; Asselman and

Middelkoop 1995). Oxbows or old river channels were found to have the least amount of sand, the highest amount of clay, and the greatest amount of fine organic matter (Asselman and Middelkoop 1995; Heimann and Roell 2000). Inflow rates will affect sediment retention by degree of bottom scouring and remobilization of sediment (Carleton et al. 2001). While sediment previously deposited on a floodplain wetland may remobilize during the next flood event, at least one study of ten different basins has shown that this does not reduce long-term sediment storage on the wetland (Phillips 1989).

5

Once the water quality benefits of wetlands were recognized, they have been

used for wastewater and stormwater treatment. These treatment wetlands have

been successful in removing 60-90% of suspended sediments (Richardson 1988;

Reed et al. 1980). The amount of sedimentation in the wetland will depend upon the

particle size of soil in the watershed (Boto and Patrick 1978). A study by Cooper et

al. (1987) in an agricultural basin in the North Carolina Coastal Plain found that 80%

of the sediment loss from a field was deposited in a riparian area and the remaining

20% in a floodplain swamp. In Georgia, natural riverine wetlands were found to

have a 30-year sediment deposition rate of 123 g/m2/yr (Craft and Casey 2000). A

study from a three-day flood in the Netherlands found sediment accumulation on

floodplains of 570 g/m2 for one site and 1000 g/m2 for another site (Asselman and

Middelkoop 1995). The annual rate of sediment deposition in a small riparian

wetland in northern Missouri was 1 cm/yr for the years 1995-1998 (Heimann and

Roell 2000).

Phosphorus (P) (as well as sediment-bound toxins) removed from the water column will be a function of detention time via particle settling. Smaller particles will take longer to deposit on the floodplain. Therefore, the retention rate for clay- dominated sediment may not be as high as that of sand dominated sediment.

Phosphorus retention for wetlands typically ranges from 16% to 90% for natural and created wetlands respectively (Niswander and Mitsch 1995). Niswander and Mitsch

(1995) estimated P retention in an urban constructed riparian wetland in central Ohio to be 2.9 g P/m2/yr. High hydrologic loading, low retention time, and immature vegetation affected this study. In another study of riparian, created wetlands in Ohio,

6

P retention was 5.4 g P/m2/yr (Nairn and Mitsch 2000). Mitsch and Gosselink (2000)

noted literature reports of P retention rates of 0.4 to 5.6 g P/m2/yr in freshwater

wetlands receiving non-point source pollution and an average of 1 to 2 g P/m2/yr for

P retention.

Wetlands are usually a sink for nitrogen (N). Detrification and plant uptake is

thought to be the most important processes for nitrate removal in riparian wetlands.

Nitrogen cycling is affected by the duration of the flooding time, presence of organic

matter, anaerobic conditions, and biological activity (Richardson and Vepraskas

2001). Sustained saturation of the floodplain enhances the denitrification process

(Burt et al. 2001). When the floodwaters recede and the floodplain dries, the redox potential in wetland sediment will increase, thus suppressing denitrification (Carleton et al. 2001). Therefore, long flooding and short dry periods are optimal for the removal of nitrogen. Nitrate removal is greatest in soil surface layers where the organic carbon content is higher than in subsurface layers (Williams et al. 1997).

High rates of subsurface water flow and low soil temperatures tend to reduce nitrate

removal below the potential for a particular soil. High subsurface flow rates limit

diffusion of nitrate to sites of denitrification and low soil temperatures inhibit

biological processes. Johnston (1991) found that nitrogen retention ranged from –28

to 100% in freshwater wetlands without direct anthropogenic inputs. The negative

value indicates that under certain conditions, more nitrate discharges from the

wetland than enters in the inflow due to nitrification of ammonium within the wetland

(Johnston 1991). This process often results when heavy rainfall occurs following

relatively long dry periods. Nitrate builds up in the soil due to organic matter

7

decomposition and nitrification of ammonium. Rapid subsurface flow in a large event

then flushes the nitrate from the soil (Hazel 1997). A restored riparian wetland was

found to retain 6.9 g N/m2/yr (Lowrance et al. 1985) and a floodplain wetland in

Georgia retained 1.4 g N/m2/yr (Craft and Casey 2000). Mitsch and Gosselink (2000)

determined that freshwater wetlands receiving non-point source pollution retain 3 to

69 g N/m2/yr. As a “rule of thumb” freshwater wetlands retain 10 to 20 g N/m2/yr

(Mitsch and Gosselink 2000).

The proposed stormwater treatment wetland project on South Buffalo Creek may be criticized for not creating a wetland adequately sized to treat the drainage basin. The wetland to drainage basin ratio is 0.36% whereas the recommended minimum area ratio is 2% (Carleton et al. 2001). However, overall hydrologic and water quality benefits can be achieved by cumulative restoration (Lewis 1988). This

proposed stormwater wetland treatment system is one element of the City of

Greensboro’s Stormwater Management Plan to improve water quality in South

Buffalo Creek. Urbanization causes a loss of wetland area. Restoration of a small

proportion of wetlands can have a proportionately larger water quality benefit than if

all of the lost wetlands were restored. Therefore, the restoration of a small area of

wetland, such as with this project, may restore a greater proportion of lost function

than restoring all the wetland area that was lost. For example, Oberts et al. (1989)

found that streams draining watersheds with wetland area varying from 10 to 20

percent had the same loading of suspended solids. However, watersheds with less

than 10 percent wetland area had loading rates 100 times greater than watersheds

with more than 10 percent wetland area.

8

Stream Geomorphology and Sediment Transport in Channel

Multiple flow regimes are needed to maintain the biology and geomorphology

of the stream and riparian ecosystem. There are four main stream processes that

control the stream and floodplain structure: (1) in-channel flows that preserve the

substrate properties (Reiser et al. 1989), (2) in-channel flows that form the stream bank and maintain the capacity of the channel to move water and sediment (bankfull flow), (3) overbank flows that maintain the riparian zone and floodplain water table, and (4) valley flows that affect the channel position (Hill et al. 1991; Whiting 1998).

Channelization and other man-made alterations reduce this natural flow regime.

Valley floors seldom flood and the local water table is not recharged as close to the

surface. Sediment deposition within the channel and tributary confluences aggrades

into the channel. Side channels become disconnected and the riffle-pool sequence

is altered (Hill et al. 1991).

Bankfull is a simple way to determine channel-forming flows. Typically,

bankfull flows occur every 1.5 years (Dury 1976; Rosgen 1996), but other studies

indicate bankfull flows are stream specific occurring every 1 to 32 years (Chorley et

al. 1984). Leopold (1994) found that the return period for urban streams could be

less than 1.05 years. Doll et al. (2002) found that the bankfull return interval for

urban Piedmont streams in North Carolina ranged from 1.2 to 1.7 years. The varying

definitions of bankfull height can also lead to a wide range of values. Bankfull can be

defined as the stage above which discharge flows over the floodplain (Riley 1972) or the stage at which the ratio of channel width to channel depth is minimum (Wolman

9 and Leopold 1955). Williams (1978) defined over 16 methods to determine the

magnitude of bankfull stage and discharge, but the methods proposed by Rosgen

(1996) natural stream classification will be used in this study.

Channelization increases stream gradients, channel erosion, sedimentation

on floodplains, and downstream flooding (Heimann and Roell 2000). In response to

urbanization, channels become wider and deeper. The process of channelization

shortens stream length, which results in increased channel slope gradient and

stream power (Nakamura et al. 1997). Generally, channel slope gradient decreases

in a downstream direction as channel discharge increases and sediment size

decreases (Rosgen 1996). Doll et al. (2002) found that bankfull area and discharge

both increased with the amount of urbanization in a watershed.

The most frequent stream discharges are low and do not transport much

sediment (baseflow conditions). The large, infrequent discharges from storm events

transport most of the sediment within a stream (Andrews 1980; Simmons 1993;

Trimble 1997). Richter et al. (1995) found that 71% of the annual sediment transport

was produced in 36 to 37 high-flow days per year in a watershed in the western

Piedmont of North Carolina based on 40 years of data. They also found that 26% of

the annual flow occurred in 3 to 4 days.

Simmons (1993) estimated that urban streams in the North Carolina

Piedmont transport on average 14 times more sediment annually than forested basins in the North Carolina Piedmont. In pristine forested basins, they found that

Piedmont and Mountain ecoregions [103.7 MT/km2 (44 tons/mi2)] transported considerably more sediment than the Coastal Plain [11.8 MT/km2 (5 tons/mi2)]. This

10 ecoregion difference of suspended sediment yield (SSY) was multiplied in urban basins where average annual SSY was 3535 MT/km2 (1500 tons/mi2) in the

Piedmont and only 37 MT/km2 (43 tons/mi2) in the Coastal Plain. In the Coastal

Plain, decrease in stream gradients and flow velocities, broader floodplains and increase in vegetated wetlands were reasons for decreased sediment discharge as sediment was deposited in the riparian zone. For example, 118,000 MT (130,000 tons) of sediment was deposited along 186 km (240 miles) of the Cape Fear River in the Coastal Plain area between 1970 and 1979 (Simmons 1993).

The main cause of sediment increase in urbanized watersheds is channel bank erosion. Nelson and Booth (2002) determined that a 20% increase of the sediment budget was caused by channel erosion in a rapidly urbanizing basin in

Washington State. Under pre-development conditions, only 8% of the sediment budget came from bank erosion.

Studies have shown that re-stabilization of altered stream channels generally occurs within 10 to 20 years of constant urban land use (Hession et al. 2000). They found that re-stabilized channels would typically be larger and less geomorphically complex than pre-urbanization channels. Stable streams neither aggrade nor degrade. A channel can have a stable width even though the stream is moving laterally (Rosgen 1996). The width to depth ratio will remain constant. Stream stability can be compared to reference or known stable streams of similar drainage area and region (Doll et al. 2002).

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Alteration of Floodplain Hydrology

Water level inputs to riparian floodplains include precipitation, overland flow, and subsurface flow. The effects of periodic flooding depend on the amount and timing of precipitation and overland flow. Natural floodplain wetlands are dry in the summer and fall and wetter in the winter and spring. This pulsing of water levels imports nutrients and exports waste and detritial matter leading to high productivity.

This fluctuation in water level is key to the hydrology of a riparian wetland. The constructed berms of the proposed stormwater treatment wetland at South Buffalo

Creek will act as natural levees and impede the flow of surface water back to the channel. The water table will be recharged during flood inundation as water returns to the channel not only by drainage channels but also from shallow groundwater discharge (Ward 1986).

The response of a riparian wetland to an overbank flooding event will depend

upon the antecedent moisture conditions. When floodplain soils are dry, water from

the flooding event will infiltrate the soil and raise water table levels. During the

growing season, evapotranspiration will also remove the ponded water. However,

when floodplain soils are saturated and a flooding event occurs, very little water can

infiltrate the soil. Most of this water will return to the channel from overland flow

routes. This will be especially true during the dormant season.

The principal hydrologic benefit from the inundation of the riparian floodplain

is water storage that results in floodpeak attenuation. Floodpeak attenuation is the

loss of river water during the rising limb of the hydrograph to bank storage, infiltration

of overbank flow into floodplain soils, and temporary surface storage. In urban areas,

12 peak storm flows occur very rapidly after the onset of rainfall with high erosive force.

The operation of the water level control structure proposed for South Buffalo Creek will reduce the force and power of the stream and slow the velocity. The wetland will hold the water for 24-72 hours and will slowly release during baseflow the same volume of water that without the structure, would have traveled down stream as part of the storm flow. This reduction in storm flow volume will reduce the height of peak flow, reduce erosive forces in the channel, and reduce the potential for downstream flood damage.

When the control structure in South Buffalo Creek is raised in response to a rise in stream stage, water from upstream will fill the stream channel before entering the floodplain. During small events the water may never reach the floodplain. This may affect the flow direction of shallow groundwater. When the control structure is raised, stream stage will rise much more quickly than would be the case with normal runoff and stream flow conditions. As the stream stage rises, the hydraulic gradient between the channel and floodplain soil may reverse. There may be a net flux of water from the channel to the floodplain, particularly during dry periods with deep water tables. A groundwater ridge may move across the floodplain away from the stream during the short period of time that the flood control structure is raised (Burt et al. 2001). This process also converts a portion of the storm flow to a more slowly released baseflow.

Another consideration in the attenuation of stream flow by the control structure is the hyporheic zone. The hyporheic zone is the ecotone where streams and groundwater intersect (Hancock 2002). This zone can have a filtering effect on

13 the water that moves through it. Physically, the sediment particles within the hyporheic zone will trap silt and particulate matter. Chemically, the zone will encourage the precipitation of dissolved minerals and metals. Human impacts that increase storm flows tend to impair the water exchange in the hyporheic zone that occurs mainly during base flow. The loss of the hyporheic zone due to channel scouring by high flows decreases bank storage and reduces the penetration of down-welling water into the sediments (Hancock 2002). The operation of the proposed control structure in South Buffalo Creek should increase the interaction of water in the stream and floodplain with the hyporheic zone. Higher water table elevations will make baseflow conditions higher, thus providing better aquatic habitat and a larger hyporheic zone.

Cole and Brooks (2000) found that created floodplain wetlands are wetter for longer periods than natural floodplain wetlands in Pennsylvania. Natural wetlands had saturated soils instead of ponded surfaces that were found in created wetlands.

Conversely, Kolka et al. (2000) found that disturbed sites have lower water table levels due to geomorphic alterations than do undisturbed sites. On disturbed sites, erosion, compaction, and loss of topsoil or organic soil occur during the disturbance.

In addition, disturbed sites with young vegetation communities also have higher

throughfall and lower evapotranspiration than undisturbed sites. Therefore, in the

proposed stormwater treatment wetland on South Buffalo Creek, more of the flood

water may infiltrate in subsequent years after construction as vegetation becomes

established, organic matter accumulates, and soil macroporosity and infiltration

capacity improve.

14

Forest Stand on Riparian Wetlands

Few studies have detailed the effects of dredging and channelization of streams in urban, riparian, forested wetlands. However, a large amount of literature exists on the effects of regulated streams on riparian zones. Sections of streams downstream from dams are similar to channelized streams. Downstream effects include reduced riparian flooding, modified sediment erosion and deposition, and modified patterns of water and nutrient availability on floodplains (Merritt and Cooper

2000). After urban streams have been channelized and dredged, riparian flooding

decreases and the riparian plant community shifts toward a typical upland

community rather than a wetland community. This community shift is similar to the

downstream riparian communities of regulated streams where flood tolerant species

are replaced with drought tolerant upland species (Merritt and Cooper 2000).

Riparian forests are often assumed to have high species diversity and relative

abundance. Flooding may increase biodiversity through transport of seeds and

nutrient rich waters on the floodplain. Seed transport by flood waters may also be a

source for competitive invasive species to enter the community (Deiller et al. 2001).

Riparian forests that undergo annual flooding from adjacent rivers usually contain a

large number of trees with greater canopy height and higher productivity than

forested wetlands not flooded by rivers (Ward 1986).

The flooding regime may actually be a limiting factor for many species.

Flooding causes anaerobic soil conditions that many plants cannot tolerate. In

addition, the seed bank may be carried away with receding waters. Flooding impacts

15 will be spatially distributed, with upland species existing on levees or higher elevations in floodplain ecosystems. In addition to topography, the structure and spatial distribution of plant communities will reflect species-specific differences in flood tolerance and water dependence (Ward 1986).

The proposed stormwater treatment wetland on South Buffalo Creek will increase the frequency, duration, and extent of flooding. It is expected that some plant species will die or experience stress with the increased flooding regime. The ecological response of the plant community will likely show similar behavior to that upstream of impoundments on regulated streams. Large trees should be more tolerant to flooding than smaller trees and understory vegetation. Changes in species composition will mostly likely be detected first with saplings, shrubs, and herbaceous species (Bedinger 1978). Increased frequency and duration of flooding increased the incidence of root hypoxia in a Southeast Florida swamp, resulting in canopy decline, tree mortality, and a shift in species composition (Ford and Brooks

2002). Riparian vegetation is controlled by stream hydrology, distance from the stream bank, and elevation. Because woody vegetation is more resistant to the deleterious affects of soil saturation when dormant, increased frequency and duration of flooding has the greatest impact in the growing season.

Vegetation may also be affected by an increase in the rate of sedimentation on the wetland soil surface. Higher rates of deposition of mineral sediments may change the character of the surface soil on the floodplain. In a Japanese marsh,

Nakuamua et al. (1997) found that existing wetland species of Alnus were replaced with Salix, traditionally a riparian species found on sandy levees. As sediment

16 deposition increased from urbanization, soil conditions suitable for Salix were created in the interior of the wetland.

The operation of the proposed control structure on South Buffalo Creek may also affect vegetation within the channel. Sediment deposition can cause islands or

point bars to develop within the channel which vegetation can colonize. Also, deeply

rooted woody vegetation along the bank provides soil stability and minimizes stream

bank erosion. The operation of the proposed control structure will cause the entire

stream channel to fill with water for 24-48 hours. In-stream marsh vegetation may

develop on newly deposited channel islands (Merritt and Cooper 2000), which could

increase the stability of the streambed. The effects of more frequent saturation of the

stream banks are unknown. Frequently, saturated soils may slump and erode from

around plant roots causing loss of bank vegetation or the vigor and density of the

vegetation may increase due to reduced friction (Friedman and Auble 1999).

After construction of the treatment system, several acres of wetland tree

species will be planted on floodplain areas disturbed during construction. Growth of

wetland tree seedlings is generally poor during the first growing season then

increases in the following years as they adjust to wetter conditions and establish root systems (Vann and Megonigal 2002). These results were found with Acer rubrum

and Taxodium distichum seedlings in Maryland and North Carolina. Success of tree

establishment will depend on proper selection of species, proper planting

techniques, and competition among species. Some maintenance of the vegetation

may be required.

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OBJECTIVES

The long-term objectives of the stormwater treatment wetland are to:

· Increase and expand the area of wetland in the floodplain in order to increase

the functional capacity for water quality amelioration;

· Improve in-stream water quality;

· Improve aquatic habitat in the project area and downstream;

· Improve terrestrial habitat in the project area.

The dual purpose of this research project was to determine the existing functionality of the stream and wetland system and to predict the consequences of altering the hydrology of the system. Specific objectives were to:

Objective 1: Characterize in-stream stormwater concentrations of sediment,

nutrients, and heavy metals in South Buffalo Creek and determine species

composition of macroinvertebrates upstream, within, and downstream of the

proposed stormwater treatment wetland;

Objective 2: Determine the geomorphic properties of the stream channel upstream,

within, and downstream of the proposed stormwater treatment wetland;

Objective 3: Establish the baseline water table regime within the proposed

stormwater treatment wetland; and

Objective 4: Determine the composition of the existing forest stand including

overstory, understory, and herbaceous layers on the floodplain of the proposed

stormwater treatment wetland.

18

METHODS

The Study Watershed

Geographic Location. The study area was located along a reach of South Buffalo

Creek, a third-order stream in Greensboro, North Carolina, USA (2002 census

230,000 people). The City of Greensboro is located in the upper portions of the

Cape Fear River Basin (Figure 1). All streams that flow through the City are

tributaries of the Haw River. South Buffalo Creek is located in the United States

Geological Survey (USGS) Accounting Unit Subbasin 03030002 (USGS 1975). The

creek is also located in the Cape Fear Subbasin 03-06-02 as designated by the

North Carolina Division of Water Quality (Figure 2) (NCDENR 2000).

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Location of Study Area

Not to Scale

Figure 1: Map of North Carolina, the Cape Fear River Basin and general location of South Buffalo Creek (NCDENR 2000)

20

21

Figure 2: Cape Fear River Subbasin 03-06-02 (NCDENR 2000) Subbasin 03-06-02 River Fear Cape Figure 2:

Topography. The study watershed is located in the Piedmont physiographic region

and is characterized by rolling hills and moderate steep slopes along its drainage

ways. Elevations within the watershed range from 225 to 286 meters (740 to 940

feet) above mean sea level (USGS 1997).

Climate. The site is located in a humid, temperate climate. Site conditions were based on 1971-2000 data from the Piedmont Triad International Airport, 7.5 km (12

mi) northwest of the study site. The normal annual precipitation is 109.6 cm (43.14

in) (NOAA 2002). The normal maximum and minimum monthly rainfall totals occur in

July with 11.3 cm (4.4 in) and November with 7.5 cm (2.96 in). The normal annual

daily temperature was 14.5 °C (58.1 °F), ranging from 8.7°C to 20.3°C (47.7 to

68.5°F). Normal maximum temperatures occur in July at 25.5°C (77.9°F) and

minimum temperatures occur in January at 3.2°C (37.7°F). The growing season was

defined by the period between the last date in the spring and the first date in the fall

when there was a 50% probability (5 of 10 years) that the daily minimum air

temperature would decline to –2.2°C (28°F) (USACOE 1987). The beginning and

ending dates and length of the growing season for use in wetland determinations are

provided by the Natural Resource Conservation Service (NRCS). The current

growing season data are based on 1961-1990 air temperature normals calculated

from temperature data also collected at the Piedmont Triad International Airport. For

Greensboro, NC, the growing season is March 27 through November 9 (or 227

days) (NRCS 2002).

22

Geology. The study watershed is predominately intrusive metamorphosed granitic

rocks (NCDNRCD 1985). South Buffalo Creek is located on the western edge of the

Carolina Slate Belt (NCDENR 2000).

Soils. The study watershed has soils that are mapped in two soil associations. Soils

of the Enon-Mecklenburg Association are located on broad interstream divides and

side slopes that are dissected by long, narrow drainage ways. This association is

49% Enon soils and 20% Mecklenburg soils both of which are well drained and have

subsoils of sandy clay loam, clay, or clay loam (Stephens 1977). Soils in drainage

ways or floodplains that formed from alluvium are in the Chewacla-Wehadkee-

Congaree Association (Figure 3). These soils are described as nearly level, well

drained to poorly drained, that have a sandy loam, loam, silt loam, clay loam, or silty

clay loam subsoil (Stephens 1977).

23

24

Figure 3: Soils series of South Buffalo Creek (Stephens 1977) (Stephens Creek South Buffalo series of Figure 3: Soils

Natural Vegetation. The natural vegetation within the study watershed is mixed

hardwoods or mixed pine and hardwood forests .

Land Use. Historically, the land use of the watershed was primarily agricultural

(pasture and cropland), but more recent land use is dominated by urban uses.

Based on a 1991 survey by Ogden Environmental, the most recent land use and

percentages for the study watershed are listed in Table 1 and Figure 4 (City of

Greensboro 1993).

Table 1. Land use category descriptions for study watershed (City of Greensboro 1993) Land Use Description Area (ha) Percent Percent Watershed Impervious Commercial Office parks and 1344 6 90-70 shopping centers Industrial Warehouses and 7757 37 75 terminal transfer Institutional Hospitals and 1433 7 60 schools Open Forested areas and 3386 16 4 parks High Apartments and 1692 8 50 Residential townhouses (<1/4 ac lots) Low-Medium Single family homes 4697 23 35-20 Residential (>1/4 ac lots) Right-of-Way Highways and roads 522 3 75

This watershed has undergone high rates of urban development in the last 10 years.

Much of the open space has been converted to residential and commercial

development. The drainage area also includes two major interstate highways,

several local highways, and two large commercial shopping areas.

25

26

1993) of Greensboro (City wetland treatment stormwater to proposed of watershed use map Figure 4: Land

Study Site

The location of the study site was selected by the City of Greensboro to treat stormwater runoff from a 34-km2 (13.5-mi2) urban watershed (Figure 5). The site is comprised of 2.4 linear kilometers (1.5 miles) of stream and 13.76 hectares (34 acres) of adjacent forested floodplain (Latitude: 36° 2’ N, Longitude: 79° 49’ W) upstream from the proposed stormwater control structure (Figure 6).

Figure 5: Map of the city limits of Greensboro and the watershed to the proposed stormwater treatment wetland

27

Figure 6: Map of the study site including the proposed stormwater treatment wetland and the study stream reach 2.4 km (1.5 mile) long upstream of the proposed water level control structure

The stream reach upstream from the proposed stormwater control structure

flows along I-40 in a park area and highway right-of-way before entering the area of the proposed stormwater treatment wetland. North of I-40 in the city park, the channel is straight and limited bank vegetation exists with a small strip of trees along the south bank and mowed grass to the top of bank on the north bank of the segment along Meadowview Avenue (Appendix A, Figures A1-A2). This stream segment is targeted for stream restoration. South Buffalo Creek flows in a closed box culvert under I-40 (Appendix A, Figure A3).

28

The next segment of stream channel between I-40 and US-220 was created in the early 1990s during construction of the I-40 highway access ramp. Much of the banks are lined with rip-rap and limited vegetation. The channel has few geomorphic stream features (Appendix A, Figure A4). An upstream tributary flows into South

Buffalo Creek at this point. This tributary has a drainage area of 7.8 square kilometers (3 square miles).

South Buffalo Creek continues to flow east through another closed box culvert under US-220 (Freeman Mill Road) and enters the site of the proposed stormwater treatment wetland (Appendix A, Figure A5-A6). The stream flows for a few hundred feet in the created channel until it is re-connected with the pre-existing stream channel. A makeshift bridge of various sized pipes and concrete crosses the stream

(Appendix A, Figures A7-A8). For the past two years (2001 and 2002) beavers have used this bridge crossing as a dam, causing water to pond upstream of this structure to the US-220 culvert. During storm events, water flows over top of the structure

(Appendix A, Figure A9). Immediately downstream of this bridge is the first of two sanitary sewer crossings. The pipes span the creek near bank top (Appendix A,

Figure A10). The channel continues downstream to the location of the proposed water level control structure, upstream of I-40.

Within the proposed stormwater wetland project, the majority of the stream banks are lined with hardwood trees, which maintains stable banks (Appendix A,

Figures A11-12). Exceptions to this stability include sanitary sewer crossings, the bridge crossing, and one area used for storage of commercial products (Appendix A,

Figures A13-A14). The floodplain of the proposed stormwater treatment wetland

29 north of the stream is forested except for a utilities access road, sanitary sewer lines, and billboards. The southern floodplain consists of a narrow band of trees and then mowed grasses at the edge of a trailer park community (Appendix A, Figures A15-

A16).

South Buffalo Creek flows under I-40 and Farragut Street in an armored, but

open stream channel (Appendix A, Figure A17). The study site includes South

Buffalo Creek downstream to where another tributary joins the creek. This stream

section also has one sanitary sewer crossing with active bank erosion. The

floodplain is well vegetated with trees, but the construction of a church is located on

the eastern floodplain (Appendix A, Figure A18).

Soils. The site is located in north central North Carolina in the Piedmont ecoregion.

Chewacla sandy loam (fine-loamy, mixed, active, thermic Fluvaquentic Dystrudept)

dominates the site with Enon fine sandy loam (fine, mixed, active, thermic Ultic

Hapludalf) on upland areas (Figure 7) (Stephens 1977).

The Chewacla soils are somewhat poorly drained with low organic content,

moderate permeability, and low shrink-swell capacity. Depth to the seasonal high water table is usually 0.5 ft to 1.5 ft in late winter and early spring. The land may have been used for water tolerant row crops, but flooding possibilities limit the soil for most crops and urban and recreational uses.

The Enon fine sandy loam located on the upland areas of the site is well

drained with low organic matter content, slow permeability, and high shrink-swell capacity. This soil is drier with the seasonal high water table at a depth of 1 to 2 feet.

30

A portion of these upland soils will be removed during the construction process to increase storage capacity.

Figure 7: Soils of proposed stormwater treatment wetland on South Buffalo Creek (City of Greensboro 2000; Stephens 1977)

The Enon-Urban land complex consists of Enon soils and Urban land that are

so mixed that is it not practical to map them separately. The complex consists of 30

to 60 percent Enon soils and 30 to 60 percent Urban land. The Enon soils are

previously described. “The Urban land consists of areas where the original soil has

been cut, filled, graded, paved, or otherwise changed to the extent that most soil

31 properties have been so altered that a soil series is not recognized” (Stephens 1977, p.15). Some Mecklenburg soils are included in this mapping unit.

Vegetation. Based on aerial photos and existing vegetation, it was determined that

the site has not been disturbed for at least 40 years (USACOE 1966; City of

Greensboro 2000). In July 2000, The Triangle Group, Inc. (Frederick 2000) was

hired to describe the existing vegetation on the site, which was classified as

bottomland hardwoods. The overstory species had an average basal area of 26.8

m2/ha (117 ft2/ac). The dominant species based on basal area were: green ash

(Fraxinus pennsylvanica), sycamore (Platanus occidentalis), sweetgum

(Liquidambar styraciflua), hackberry (Celtis occidentalis), and willow oak (Quercus

phellos). The dominant species based on frequency were green ash, box elder (Acer

negundo), American elm (Ulmus americana), and sweetgum. The most common

understory species found on the site by coverage and frequency were poison ivy

(Toxicodendron radicans), blackberry (Rhubus argutus), Virginia creeper

(Parthenocissus quinquefolia), box elder (Acer negundo), silky dogwood (Cornus

ammomum), jewelweed (Impatians capensis), elderberry (Sambucus canadensis),

greenbriar (Smilax spp.) and Japanese honeysuckle (Lonicera japonica).

Proposed Stormwater Treatment Structure

All information about the proposed stormwater treatment structure was

provided by the City of Greensboro (2000). The proposed stormwater treatment

wetland on South Buffalo Creek will inundate 8.5 hectares (21 acres) of the riparian

area with the possibility to increase the existing wetland area of 1.3 hectares (3.1

32 acres). A gate-type water level control structure, 12.2 m (40 ft) long and 3.7 m (12 ft) high, will be installed within the channel of South Buffalo Creek (Figure 8).

Proposed Control Structure

Figure 8: Diagram of proposed stormwater treatment wetland on South Buffalo Creek

The gate structure will have a hinged bottom attached to a concrete

foundation. A water level sensor mounted in the channel upstream of the gate will

control the structure. Raising and lowering of the gate will be actuated by an

inflatable rubber/Kevlar air bladder supplied by Obermeyer Hydro, Inc. of Fort

Collins, CO (Appendix A, Figures A19-A21). Typically, the gate will be set at the lowered position on the channel bottom to allow for normal stream flow.

To facilitate temporary flood stage in the riparian wetland, a berm approximately 0.3 m in height above bank top will be constructed along the stream

33 bank and across the downstream end of the wetland. A 1.5 cm stream level increase for 15 minutes will activate the control structure, which will retain storm flow in the stream channel and floodplain for 24 hours. The gate will then be deactivated and slowly lowered. If the desired elevation is reached before 24 hours duration, such as during high flow events, the gate will be lowered to restore full flow capacity of the channel. When the gate is lowered, water in the channel will discharge downstream.

Water on the wetland will drain through control pipes in the berm that will be designed to drain the floodplain in 48 hours. Flood analysis conducted by the City of

Greensboro has predicted that the control structure would raise flood stage 0.1 meters for a 10-year storm. There should be no increase of flood stage during larger storms to surrounding properties. Maximum floodplain water levels are planned at a depth of 0-1 meters (1-3 ft). The primary objective of the proposed stormwater treatment wetland is to treat the first flush of stormwater runoff (from a 2-year storm) carried by South Buffalo Creek.

The proposed stormwater treatment system is a regional, in-stream management practice that is the subject of some controversy regarding the pros and cons comparing on-site, upstream treatment facilities and online regional solutions.

The United States Environmental Protection Agency (EPA) was opposed to approval of the 404 dredge and fill permit for the project. The following reasons were given:

(1) the proposed treatment system was under-designed and will not improve downstream water quality; (2) there was inadequate analysis of alternatives such as using online ponds to treat runoff before reaching the main stream channel; (3) the

State 401 Certification did not consider cumulative water quality impacts or the

34 impacts of continued discharges upstream of the treatment system; (4) there was no mitigation for impacted stream and wetland; and (5) the project was not in the interest of the public (Welborn 2002).

The City of Greensboro’s Stormwater Manager disputes this analysis of the proposed treatment system. First, the alternative analysis concluded that 90 off-line

treatment systems would be needed to match the acres treated by the proposed

wetland with greater costs and logistical difficulties. Second, the proposed structure

was not the only solution to improve water quality in the watershed but was part of a

comprehensive management program. Third, the proposed wetland treatment

system will function as an off-line treatment system since the water quality treatment

will occur on the floodplain and the control structure will not change the natural

stream regime (Bryant 2001).

The United States Army Corps of Engineers(USACOE) issued the 404

dredge and fill permit to fill 0.09 ha (0.23 acres) (including 46 linear meters of stream

channel) of the jurisdictional waters of South Buffalo Creek. Their findings

supported the City of Greensboro’s claim that the treatment system will enhance the

wetland functions of the site. The USACOE letter also stated that numerous

upstream structures would be a larger jurisdictional impact than the proposed project

and the alternatives have been adequately considered. Water quality impacts would

be positive as supported by the North Carolina Division of Water Quality (NCDWQ)

issuance of Certification under Section 401 of the Clean Water Act. Lastly, the

impact to existing jurisdictional water was allowed when other impacts are avoided

35 and impacts are minimized such as with this project. In addition, the project will increase the ecological function of the wetland (Jolly 2002).

Experimental Design

Originally, the experimental design of this study focused on before/after and

upstream/downstream comparisons of ecological, geomorphological, and chemical

responses to the treatment system. Data collected during the pre-construction period

were to be compared to repeated measurements after project implementation. In

addition, water quality, stream geomorphology, and aquatic macroinvertebrates were

evaluated upstream and downstream of the project area. The upstream station

would have been the control site for the project. Delays associated with permitting,

property acquisition, and budgeting have postponed the construction of the project

beyond the time period of this study. The purpose of this report is to provide an

analysis of current conditions within this riverine wetland system and offer

predictions on the ecological effects of the project and the proposed impact of the

treatment system.

Water Quality

Ambient Stream Conditions

The City of Greensboro collected ambient water quality data every two

months as part of their stormwater monitoring program. These data are used to

establish average, baseflow water quality conditions. Ambient baseflow conditions

are defined as the flow following at least three days without precipitation. Samples

36 were collected 7.7 km upstream of the project site, 1.3 km downstream of the project site, and 9.7 km downstream of the project site (but upstream of a wastewater treatment plant). These sites are labeled as “Upstream SBC,” “Project,” and

“Downstream SBC” in the data summary. Data were also gathered from the North

Carolina Division of Water Quality (NCDWQ) for comparison (Table 2, Figure 2).

One urban site was located downstream of a wastewater treatment plant (WWTP) on North Buffalo Creek labeled as “Downstream NBC.” Two rural sites were used as

“reference” sites that receive drainage from predominately agricultural watersheds.

Data used for comparison were gathered from the City of Greensboro for years 1999 to 2002 and from NCDWQ for years 2000 and 2001.

Table 2: Ambient water quality sampling sites used to compare site data NCDWQ Location USGS Use County Classification Station Station ** N/A Merrit Drive near I-40 02094659 PS Guilford Upstream SBC N/A Farragut Street 02094770 PS Guilford Project N/A McConnell Road (Upstream 02095000 PS Guilford Downstream SBC WWTP) B-14 North Buffalo Creek at SR 2832 02095500 NS Guilford Downstream NBC B-1* Haw River at SR 2109 near Oak 02093265 PS Guilford Reference Ridge B-20 Jordan Creek at SR 1754 near 02096230 FS Alamance Reference Union Ridge *Station B-1 is not pictured in Figure 2. **NCDWQ: PS = partially supporting designated uses; NS = not supporting designated uses; FS = fully supporting designated uses.

The NCDWQ assessed the Cape Fear River Basin in 2000 and classified

each stream based on meeting its designated use. The Haw River (45 km) was

classified as Partially Supporting (PS) its uses based on biological monitoring data.

North and South Buffalo Creeks were classified as Not Supporting (NS) designated

37 uses based on biological monitoring data. Both of the sampling sites were located downstream of two wastewater treatment plants (WWTP). South Buffalo Creek was re-classified as PS upstream of the WWTP due to habitat degradation and fecal coliform contaminants. The proposed stormwater treatment wetland is part of a solution to improve water quality on South Buffalo Creek (NCDENR 2000).

Water quality sampling methods for both the City of Greensboro and NCDWQ programs follow similar protocols. However, the City of Greensboro specifically targets baseflow conditions, whereas the NCDWQ collects samples on a monthly schedule regardless of flow conditions. It was assumed that both sets of results reflect baseflow conditions. Both protocols collect a grab sample from the greatest flow in the channel. Samples are collected in sanitized bottles and preserved until lab analysis. Physical parameters are measured directly in the field such as pH, temperature, dissolved oxygen, and specific conductance. More information about both programs can be gained by contacting the respective agencies.

Stormwater Stream Conditions

The American Sigma 900Max Portable Wastewater Sampler with 950

Submerged Depth Sensor was used to collect water samples and determine stage levels of the stream. The sampling unit was installed in South Buffalo Creek downstream of the discharge from the proposed water control structure at the

Farragut Street Bridge. The sampling unit was activated by a 15 cm (6 in) stage increase above base flow. The sampler collected 1000 ml of water every 30 minutes for 12 hours. The 12-hour duration represented the average storm hydrograph

38 duration based on data collected from 1999-2001 at other locations along South

Buffalo Creek. A flow-weighted composite sample was compiled manually from the time-weighted samples. Flow measurements were calculated using Manning’s

Equation and the recorded stream level. Grab samples for fecal coliform analysis were collected by hand near the beginning of the sampling period.

Analysis of water quality parameters included suspended sediment concentration (TSS); turbidity; metals [cadmium (Cd), copper (Cu), iron (Fe), nickel

(Ni), lead (Pb), and zinc (Zn)]; nutrients [total phosphorus (TP), ortho-phosphorus

(OP), total Kjeldahl nitrogen (TKN), nitrate plus nitrite-nitrogen (NO3 + NO2) and ammonia-nitrogen (NH4)]; and fecal coliform bacteria (FC). Suspended sediment concentrations (mg/l) were determined from discrete samples collected every 90 minutes. All sediment analyses were conducted at the North Carolina State

University Department of Forestry Hydrology laboratory (methodology described below). A commercial laboratory conducted the analyses on metals, nutrients, suspended sediment and turbidity from the flow-weighted composite samples and fecal coliform analysis from grab samples.

The automatic sampling unit was programmed during base flow conditions.

The sampler unit, pump, and bottles were located in a storage shelter above the stream channel. PVC pipe was buried in the side slope of the stream channel and metal conduit was installed in the bottom of the streambed below base flow. Plastic tubing from the sampling equipment and depth sensor were run through the PVC and attached to the conduit in the stream. The cone of the level sensor was installed parallel to stream flow approximately two meters from the bank and the intake tubing

39 was placed perpendicular to stream flow. An American Sigma Tipping Bucket Rain

Gauge, Model 2149, was located near the sampling shelter. Before a predicted storm event, the sampler was programmed to activate on 15 cm (6 in) stage rise and ice was placed in the base of the samplers for sample preservation. The sampler recorded rainfall quantity and intensity, stage level, temperature, and sampler history. Level and rainfall were continuously recorded. All data were logged on 10- minute intervals. Grab samples for fecal coliform analysis were collected by hand during the rising limb of the hydrograph when possible. The fecal coliform water sample was preserved on ice and delivered to the contract laboratory for analysis within 6 hours.

The stormwater samples were retrieved from the field within 48 hours from the initiation of the sampling program. Two hundred and fifty milliliters (250 ml) of each well-mixed discrete sample were retained for TSS analysis. A flow-weighted composite sample was compiled from the discrete samples based on the flow data recorded by the American Sigma sampling unit. Composite stormwater samples were poured into bottles provided by the contract laboratory, preserved on ice, and delivered to the laboratory.

The automatic sampler method is intended to collect representative samples from the entire water column passing by the sampling point. There are two main limitations. First, the intake tubing is attached to a fixed point within 0.3 m (1 ft) of the stream bottom. Water samples from this location will not have constituent concentrations that are representative of concentrations in the entire water column.

Second, some reduction of mineral and organic particulate matter in the water

40 sample compared to that in the water column is expected because the pump may not be able to adequately collect heavier particles. The flow of sediment may be stronger than the suction of the pump especially for larger sized particles. Therefore, the automatic samplers may underestimate the concentration of TSS.

Analysis of total suspended solids was based on methods from Standard

Methods for the Examination of Water and Wastewater (APHA 1995). Samples were brought to room temperature before analysis. A well-mixed sample was filtered through a standard glass fiber filter (Whatman 934-A4), and the residue retained on the filter was dried to a constant weight at 103 to 105 °C. The increase in weight of the filter represented the total suspended solids (TSS). A Metter mass balance

Model AE240 was used to weigh all samples.

Stormwater samples were collected in SBC by automatic sampler each quarter by the City of Greensboro at sites upstream and downstream of the project area and at a rural reference site from 1999 to 2002. The results from these three sites were based on 3-hour flow weighted composite samples collected every 15 minutes. The reference stream data are compared to stormwater data collected from the downstream end of the project site over a 12-hour flow weighted composite.

Stormwater samples from the 3-hour sampling period typically represent the rising limb of the hydrograph where concentrations are often higher than in the flow of the receding part of the hydrograph that were collected from the 12-hour period.

Therefore, the constituent concentration results from these sites are expected to be slightly higher on average than the results from the project site. Comparable stormwater samples are not collected in the NCDWQ Ambient Water Quality

41

Monitoring Program; therefore, no data were available for comparison from the

NCDENR reference sites. However, the City of Greensboro collects stormwater samples from the Reedy Fork Creek upstream of water supply reservoirs. This site is used as “reference” for storm data (Table 3).

Table 3: Stormwater monitoring sites used for comparison of project site data Water Body Location USGS Station County Classification South Buffalo Creek Merrit Drive near I-40 02094659 Guilford Upstream SBC South Buffalo Creek McConnell Rd 02095000 Guilford Downstream SBC Reedy Fork Creek Bunch Road/SR 2128 02093800 Guilford Reference

Flow Estimation and Pollutant Loading

In order to estimate the pollutant loading to the proposed wetland treatment

system, total flow and number of times the wetland will be flooded was determined.

Total stream flow was estimated from a USGS gaging station 02094770, South

Buffalo Creek at US 220 at Greensboro, NC located 1.7 km downstream from the

proposed water level control structure. The drainage area for this gaging station is

39.9 km2 (15.4 mi2) and it has been in operation since September 1998. Annual data from 1999 and 2000 were used. Data were collected at 15-minute intervals and were

summarized into daily median and annual median flow. During storm events only

estimated daily median flow was available. Total stream flow was determined by

summing 15-minute interval flow data and daily estimated flow. The start of a storm

event was determined as a 1.5 cm (0.05 ft) level increase from the previous 15-

minute interval and ended when flow returned to the pre-storm flow or 0.28 m3/s (10

ft3/s), whichever occurred first. Total flows from the gaged sites were reduced by

42

12.3% (35 km2 drainage area of project watershed divided by 40 km2 of the gaged watershed) to approximate the flow upstream at the project site.

The calculated storage volume of the proposed stormwater treatment wetland was 37,000 m3 or 3.6 ha-m (30 ac-ft). Estimated total annual water volume treated by the wetland was based on the average number of events per year determined from the historical flow data. A stormflow event was designated by a 1.5 cm stream level increase sustained for 15 minutes. Since the control structure will be operated for at least 24 hours, the 24-hour flow was calculated for each event and this volume was used for pollutant load estimates if less than the total storage volume of 37,000 m3. The percent of stormflow that will be diverted to the wetland was calculated.

Since pollutant loading was estimated for South Buffalo Creek, loading to the proposed wetland was estimated based on a percentage of the total flow that will enter the wetland. The average ratio used was 0.078, which is the volume of water treated by the wetland (1,591,369 m3 in 1999) divided by total stream flow

(20,891,344 m3 in 1999). Pollutant treatment percentages based on literature results

(Richardson 1988; Reed et al; 1980, Schueler 1996; Dortch 1996; Mitsch and

Gosselink 2000) were then used to estimate total pollutant removal by the proposed stormwater treatment wetland.

There are several limitations with this method. The flow data were only based on two years of flow data where a thirty-year average would be more appropriate.

This method assumed the volume of the stormwater treatment wetland and assumed the water level control structure will operate on an 1.5 cm (0.05 ft) increase. This method also assumed that the baseflow pollutant concentration was

43 negliable and was not considered a contributing factor to the pollutant load estimations. These load estimates were a gross estimation and inflow and outflow data should be collected to determine actually pollutant load and removal efficiencies for the treatment wetland.

The total stream pollutant load was calculated by taking the median pollutant concentration (mg/l) multiplied by the total annual stormflow in South Buffalo Creek.

The stream load was then multiplied by the percentage of the flow that is treated by the wetland to estimate pollutant yield to the proposed stormwater treatment wetland. This stream load is an estimate of the pollutants flowing in South Buffalo

Creek immediately downstream of the proposed water level control structure for the stormwater treatment wetland.

Suspended Sediment

Single stage sediment samplers were used to collect samples for total suspended sediment within the stream channel. These passive samplers collect water while the stream is rising and are installed before the storm event. Single stage sediment samplers were placed upstream, within, and downstream of the project area. Design of the sampler is based on USGS single stage-sediment sampler US U-59 (Wilde et al. 1998).

The bottles and stopper were attached to metal posts installed in the stream channel (Figure 9). Plastic ties secured the bottles and copper tubing to the post to create a vertical profile of sediment samples. As the stream rose during storm events, water and sediment entered in the lower tube and air exited the bottle

44 through the higher piece of tubing. The bottle was filled as the stream rose. Once the bottle was full, no more water could enter the bottle. Valid samples were retrieved before another storm event, as rising waters would invalidate the sample. The neck

of the bottle containing air, and the stopper intact in the bottle determined a good

sample. The bottles were capped and labeled with site number and position on the

pole. Analysis of TSS (mg/l) was as conducted as described earlier.

Level water enters the sample container.

Figure 9: Single-stage suspended sediment sampler (USGS U-59)

Six sampling sites were established: 1 upstream main, 1 upstream tributary, 3

within the project and 1 downstream of the project. See Figure 10 for the location of

each station.

45

Figure 10: Map of passive sediment samplers upstream, within, and downstream of the project area

The approximate discharge was calculated using Manning’s Equation, based on the

stage elevation of each collection bottle.

V = [1.49 * R2/3 * S1/2 ] / n [Eq. 1]

Where

V = Average velocity (m/s)

R = hydraulic radius (m)

S = slope of the water surface n = roughness coefficient, 0.025

46

And

R = A / P [Eq. 2]

Where

A = Cross-sectional area of flow (m2)

P = wetted perimeter (m)

Total suspended solids for each station and each bottle at each station were summarized. The following tests were conducted to determine if the sediment concentrations were statistically different between the stations and the station-bottle effect: single factor analysis of variance (ANOVA), the Fisher multiple comparison, and one sample t-tests. Correlation coefficients were determined for suspended sediment concentrations and discharge, rainfall, and days since the last rain event.

All statistical analyses were conducted using StatView and Microsoft Excel.

Macroinvertebrates

Macroinvertebrate surveys in the stream were conducted in July 2000 and

July 2001 at four locations: upstream of the project area at Hillsdale Park and Rolling

Roads Park, in the project area, and downstream of the project area at Randleman

Road. The City of Greensboro’s Water Quality Monitoring Technicians collected these samples following protocol developed by the North Carolina Division of Water

Quality (NCDENR 1997). Qualitative samples of 10 habitats were collected including

2 kick nets, 3 sweep samples, sand sample, log/rock wash, leaf pack, and a 10- minute visual inspection. Samples were sorted in the field and preserved in 70% ethanol. A certified biologist at a commercial laboratory identified the collected

47 organisms. Results were analyzed using the North Carolina Biotic Index (NCBI)

Value, Ephemeroptera, Plecoptera, Trichoptera (EPT) richness, EPT diversity, total taxa richness and total taxa diversity to determine overall bioclassifcation for the site

(NCDENR 1997).

The NCBI is based on a scale of zero (pollution intolerant species) to ten

(pollution tolerant species). Hilsenhoff Tolerance Values were used when North

Carolina Values were not available. The percent of each feeding group

(collectors/gathers, filtering/collectors, predators, omnivores, scrappers, and shredders) was determined for each site. Determination of functional feeding groups was conducted using an USEPA method (Barbour et al. 1999).

Stream Geomorphology

The City of Greensboro’s survey crew conducted the initial survey of channel

cross-sections and longitudinal profile from June – October 2001. I collected cross-

sectional measurements in March 2002. A basic surveyor’s level or laser level was

used to measure vertical distances. The United States Forest Service (USFS)

provided instructions for operating equipment and collecting elevation

measurements (Harrelson and Potyondy 1994). All major features, slope changes,

and bankfull height were measured. Determination of bankfull height was based on a

variety of characteristics as listed by Rosgen (1996). Useful indicators include (1) the

height of depositional features, (2) vegetation changes, (3) undercut banks, and (4)

stain lines. Temporary benchmarks were established and channel cross sections

were measured to determine the cross-sectional area. A rebar monument was used

to mark cross sections. The cross sectional area profiles were standardized and

48 plotted on a time scale to illustrate alteration in stream geomorphology within the project area.

The longitudinal survey established the elevation of existing water surface, channel bottom, bankfull stage, floodplains and terraces as well as channel slope.

Elevations of thalweg, bankfull bench, water surface, and top of bank were collected at each feature (riffle, pool, glide, and run). The average length and slope of each stream feature and the average depth of the pools were calculated from the longitudinal survey. South Buffalo Creek was classified based on the Rosgen

Stream Classification system (1996). This classification system was selected because it emphasizes natural stream conditions and is a quantitative system based on measurements from over 450 stream reaches throughout the United States and

Canada (Rosgen 1994). The North Carolina Stream Restoration Institute (Doll et al.

2002), North Caroline Department of Transportation, and North Carolina Wetlands

Restoration Program implement stream restoration based on Rosgen’s methodology of natural channel design. The following geomorphic features were determined from the survey: bankfull area (Abkf), bankfull width (Wbkf), bankfull depth (Dbkf), width to depth ratio (W/D), width of floodprone area (Wfpa), entrenchment ratio (ER), slope of the water surface (Sws), channel sinuosity (K), average particle size of channel (D50), and bank height ratio (BHR). Wfpa and K were determined from topographic maps and aerial photos.

Aerial photographs and survey information in a USACOE (1966) flood report provide baseline data to compare the collected data. Channel size, shape and profile were compared to estimate geomorphic changes over the last 40 years. All data

49 calculations from 1966 were based on gross estimates as the precise data were not available.

Water Table Hydroperiod

Two transects of ten water table wells with six water level recorders were installed in the floodplain of the project area to determine the water table regime.

The wells were constructed of 5 cm ID; schedule 40 PVC well screens and casing with screen slots of 0.025 cm width. The wells were screened from about 15 cm to depth a depth of 3-4 meters with casing to a height of 1 meter above the surface.

The wells were installed in April and May 2001 by hand augering boreholes with a bucket auger. An envelope of #2 well sand was installed around each screen and a seal of bentonite clay was placed around the well casing at the soil surface. Solinst

Leveloggers, Model 3001 M5, with 4.5 m (15 ft) cords were used to record water level at six of the ten wells. The loggers were installed in February 2002. The dataloggers were downloaded monthly using Windows based software developed by

Solinst to a portable computer. The Mini 101 Water Level Meter (Solinst) was used to calibrate the Leveloggers and measure bi-weekly water table levels on the remaining wells. Leveloggers continuously logged data on a 30 to 60 minute interval.

To determine the impact of rainfall on the water table, rainfall data were obtained from the USGS monitoring station located 1.7 km downstream of the project site.

Wells 5, 7, and 10 were located in delineated wetland areas based on a 2000 survey conducted by Triangle Group Inc. for the City of Greensboro. All the wells were placed in two perpendicular transects (Figure 11). Manually measured water

50 level data were used to determine monthly mean depth to the water table and the water table gradient. Continuous logged data were used to determine if the wetland hydrology criterion was during in the growing season. The growing season is March

27 (day of year 86) through November 9 (day of year 313) or 227 days based on

1961-1990 normal data. The water table must be within 30 cm of the surface for 5% of the growing season or 11 days during this time period to meet the USACOE jurisdictional wetland hydrology criterion.

Figure 11: Location of water tables wells on the riparian floodplain of the proposed stormwater treatment wetland

51

Vegetation

Random sampling was not the goal of this procedure. Instead, the goal was to randomly sample within the designated wetland areas where the vegetation would likely respond quickest to an altered hydrologic regime. Seven plot centers were randomly located within the existing wetland area of the proposed stormwater treatment wetland. Three different sampling procedures were used to inventory the overstory, understory, and ground layer components of the forest vegetation (Table

4).

Table 4: Description of vegetation components inventoried on riparian wetland Vegetation Height DBH Plot Size Component Description Description Overstory None >7cm 62.8 m2 Understory None 2.54-7cm* 39.4 m2 Groundcover <0.5m and >0.5 m None 1 m2 *basal stem diameter

First, plot centers were randomly located off two transect lines utilizing a random

numbers table and were permanently marked with a 1.2 m piece of re-bar with the

last 0.3 m painted blue. These plots were used to sample all three canopy layers

(Figure 12).

52

Figure 12: Location of vegetation plots to characterize existing wetland areas

Circular plots with radius of 10 meters were selected for the inventory of the overstory trees. A wooden, graduated rod was used to locate diameter at breast height (DBH) at 1.3 meters. Galvanized 6.35 cm nails were used to mark the trees with aluminum numbered tags. Trees greater than 7 cm DBH were marked and measured. All tags faced the center of the plot. The diameter of each tree was measured 15 cm below the nail. Density, frequency, basal area, and Importance value were calculated for each species to describe the whole site (Brower and Zar

1977).

Relative frequency (RF) is the frequency of a given species (fi) as a proportion of the sum of the frequencies for all species (Sf):

53

Rfi = fi/Sf. [Eq. 3]

Relative species density (RD) is the number of individuals for species (ni) as a proportion of the total number of individuals of all species (Sn):

RD = ni/Sn. [Eq. 4]

The coverage of a species as determined by basal area is the basal area of the species (bai) expressed as a proportion of the total basal area of all species sampled

(ba):

BA = bai/Sba. [Eq. 5]

The importance value is an index used to summarize relative frequency, relative species density, and relative basal area:

Importance Value = (% RF + % RD + % RB)/3. [Eq. 6]

The understory layer was classified as woody species with basal stem diameter between 2.5 and 7.0 cm. The same plot centers were used as above with 5 m radii. Relative frequency, relative density, relative basal area, and importance values were calculated with each species.

Plots for inventorying ground layer vegetation were located within the circular overstory plots. The ground layer included all herbaceous plants plus woody plants that were less than 2.5 cm in diameter at the base. The plot was divided into four quadrants and a random numbers chart (0-360) was used to select the degree from north and another random numbers chart (2-9) was used to determine the distance from the center to locate the 1 m2 plot. Plots within one meter of the center were not included due to possible disturbance from sampling. Species were classified by height classes (<0.5 m and >0.5 m) and percent coverage. Bare area was also

54 estimated for the <0.5 m layer. Frequency and coverage were calculated for each height class.

RESULTS AND DISCUSSION

Water Quality

Ambient Stream Conditions

Data used for comparison were gathered for 2000 and 2001 from NCDWQ and for 1999 to 2002 from the City of Greensboro. Summary results for ambient stream conditions can be found in Appendix B (Tables B1-B2).

Sediment. Ambient suspended sediment concentrations in the project area were

lower than in the reference sites, and upstream and downstream South Buffalo

Creek locations (Table 5). The median value for the project area was 1.5 mg/l with a

maximum value of 22 mg/l. Ambient turbidity results had lower variance among

sites but there were no significant differences among the sites. There was no

statistically significant difference between stormwater concentrations of TSS and

turbidity upstream, downstream, within the site, and the reference sites. The

upstream has a high turbidity presumably associated with construction of I-40

widening and commercial and residential development. Water clarity improved and

sediment decreased downstream to the project sampling site. Low TSS and

turbidity at the project area may be attributed to stable stream banks and low

development activity in the surrounding area.

55

Table 5: Ambient stream results for total suspended solids and turbidity Site TSS (mg/l) Turbidity (NTU) Upstream SBC 6.5 21.3 Project 1.5 5.5 Downstream SBC 6.0 4.8 Reference 5.0 8.3 Reference 6.0 16.0

Nutrients. Total phosphorus concentrations were very low in the reference streams,

and at the upstream, downstream and project water sampling sites on South Buffalo

Creek (Table 6). Ambient phosphorus concentrations were always lower than 0.09

mg/l in South Buffalo Creek with median values of 0.05, 0.04, and 0.05 mg/L

upstream, within, and downstream of the project respectively. Nitrate plus nitrite-

nitrogen (NO3+NO2) and total Kjeldahl nitrogen (TKN) concentrations were also low for the project and reference sites. Median values for nitrate plus nitrite-nitrogen for

ambient conditions were 0.19, 0.26, and 0.19 mg/l at all three sites on South Buffalo

Creek. Median TKN concentrations for the South Buffalo Creek were <0.5 mg/l.

These results are less than 0.5 mg/l because the minimum quantification was 0.5

mg/l until March 2001 when the minimum detection level was decreased to 0.1 mg/l.

Median TKN concentration in the reference streams ranged from 0.39 to 0.45 mg/l.

Total nitrogen (TN), the sum of nitrate+nitrite-nitrogen and TKN, may also be overestimated.

Table 6: Median ambient stream results for nitrogen and phosphorus (mg/l) Site Nitrate+Nitrite TKN TN TP Upstream SBC 0.19 <0.50 0.69 0.05 Project 0.26 <0.50 0.76 0.04 Downstream SBC 0.19 <0.50 0.69 0.05 Reference* 0.10 0.45 0.55 0.04 Reference* 0.08 0.39 0.47 0.03 *Minimum detection levels for TKN were 0.10 mg/l for the NCDWQ reference sites.

56

Fecal Coliform Bacteria. Ambient fecal coliform pollution in SBC within the project

area was higher than upstream and downstream on SBC and in the reference

stream sites (Table 7). Median values in the project reach of SBC were 440 CFU/ml

with a maximum value of 2400 CFU/ml. The variance was lower than the two urban

sites possibly suggesting a continuous infiltration of bacteria rather than periodic

release such as overflowing sewer.

Table 7: Median ambient stream concentration of fecal coliform bacteria Site CFU/100 ml Upstream SBC 260 Project 440 Downstream SBC 240 Reference 84 Reference 125

Stormwater Conditions

Complete statistical summary data were available in Appendix B (Table B3-B4) for

the Project site, upstream and downstream of the project site on SBC and reference

site.

Sediment. Median stormwater TSS concentration for the project area was 111 mg/l

with a range of 19-362 mg/l (n=5). This was a 98% increase from ambient stream

conditions. Results were similar upstream, downstream, and at the reference site

(Table 8). Along South Buffalo Creek, TSS concentrations appear to increase

downstream but the results were not statistically significant. The higher TSS of 165

mg/L at the reference site is probably due to the land use being in agricultural

production. Higher velocities carrying higher amounts of sediment, re-suspension of

57 bedload sediments, bank erosion, and new sediment added to the stream from upland sources are the probable cause of increased sediment in storm events

(Simmons 1993, Water 1995).

Table 8: Median total suspended sediment concentrations (mg/l) for South Buffalo Creek Site Median Count Upstream SBC 104 12 Project 109 5 Downstream SBC 124 12 Reference 165 11

Nutrients. Median stormwater nitrate plus nitrite-nitrogen concentrations increased from ambient conditions to 0.42 mg/l (upstream), 0.36 mg/l (project), and 0.45 mg/l

(downstream). Stormwater median values for TKN were 1.3, 0.9, and 1.3 mg/l for the upstream, within, and downstream of the project respectively (Table 9). Little difference was seen between the sites. Although concentrations were nearly the same, loading of both nutrients was greater further downstream as the discharge of the stream increased.

Table 9: Median stormflow concentrations for nutrients for South Buffalo Creek and reference site (mg/l) Sites Nitrate+Nitrite TKN TN TP Upstream SBC 0.42 1.3 1.72 0.17 Project 0.36 0.9 1.26 0.20 Downstream SBC 0.45 1.3 1.75 0.17 Reference 0.47 0.7 1.17 0.10

Stormflow concentrations of phosphorus increased significantly above baseflow

conditions in South Buffalo Creek. TP median concentrations for storm conditions

were 0.2 mg/l (project) and 0.17 mg/l (upstream and downstream).

58

Fecal Coliform Bacteria. Median fecal coliform (FC) stormwater values were similar

among different sites on South Buffalo Creek with 4100 CFU/100ml at the project

site and 4250 and 3400 CFU/100ml upstream and downstream of the project (Table

10). Storm concentrations of fecal coliform were as high as 27,000 CFU/100 ml and

median concentrations were 7 times greater than baseflow conditions at the site of

the proposed stormwater treatment wetland on South Buffalo Creek.

Table 10: Comparison of fecal coliform bacteria during storm flow from grab samples (CFU = coliform forming units) Site CFU/100ml Upstream SBC 4250 Project 4150 Downstream SBC 3400 Reference 4600

Temporary storage of stream flow in the proposed stormwater treatment wetland will likely have little effect on fecal coliform concentrations. Some bacteria attached to suspended sediment will settle with the sediment but the retention period will not be long enough for bacteria die-off. In addition, immersion of the sanitary sewers lines that cross the stream and introduction of bacteria from the feces of warm-blooded mammals on the floodplain may actually increase FC loading.

Manhole elevations should be raised above the potential flood line and stream crossings should be stabilized. Ideally, removing the sanitary sewer line from this site would be advantageous and remove another possible FC contamination source.

59

Stream Flow and Pollutant Yield Estimates

Total stream flow and storm flow for South Buffalo Creek at the proposed stormwater treatment wetland and the estimated flow to the proposed wetland are listed in Table 11. Currently, water may reach the floodplain only once each year.

Based on recent flow data, it is estimated that the operation of the proposed stormwater treatment system should increase the flooding to 41 times annually. On average, flow to SBC averaged 0.66 m3/s (23 ft3/s) with over 86% of the total flow occurring as stormflow.

Table 11: Annual stream flow for South Buffalo Creek at the proposed stormwater treatment wetland based on USGS Station 02094770 1999 2000 Average Units Total Stream Flow SBC 20,891,344 20,627,759 20,759,552 m3 Total Storm Flow SBC 18,245,700 17,818,291 18,031,997 m3 Total Baseflow SBC 2,653,201 2,812,675 2,732,938 m3 Average Daily Stream Flow 0.66 0.65 0.66 m3/s

Number of Storm Events 43 40 41 Wetland Storage Volume 37,009 37,009 37,009 m3 Total Storage Volume 1,591,369 1,401,804* 1,496,587 m3 Treated Flow 7.6 7.9 7.75 %

Number of Storm Events GS 27 20 23.5 Total Stream flow GS 11,741,414 15,833,780 13787597 m3 Percent Stream flow in GS 56 77 66 % *Five events partially fill the wetland GS = Growing Season (April 11 – October 26)

On average, the proposed wetland will annually receive approximately 1,500,000 m3

of flow or 7.75% of the total stream flow in SBC. Approximately 57% of the loading

events will occur during the growing season.

Pollutant yield estimates were based on the median concentrations from the composite stormwater samples collected by the automatic sampler downstream of

60 the project area from September 2001 to June 2002. First, the loading to SBC was calculated (Table 12) by multiplying the event median concentration (EMC) by total stormflow (1.8 x 1010 L). Pollutant yield estimates for the watershed (Load) and estimated load to the wetland are listed in Table 12. Complete yield estimates for all parameters and the calculations are listed in Appendix B (Table B5-B9).

Table 12: Estimated annual yield of pollutants from the watershed of South Buffalo Creek and estimates of pollutant loads to the wetland treatment system Pollutant EMC* Total Yield Yield Total Load Load to (mg/l) SBC** SBC to Wetland Wetland*** (MT/yr) (g/m2/yr) (MT/yr) (g/m2/yr) Solids, Total Suspended 110.50 1,997 57.00 155.00 1821.00 Nitrogen, Ammonia 0.50 9 0.26 0.70 8.24 Nitrogen, Nitrate+nitrite 0.40 7 0.21 0.56 6.59 Nitrogen, Total Kjeldahl 0.95 17 0.49 1.33 15.65 Phosphorus, Ortho 0.06 1 0.10 0.08 0.99 Phosphorus, Total 0.20 4 0.03 0.28 3.30 Iron 3.70 67 1.91 5.00 60.97 *EMC = event mean concentration of storm events from September 2001-June 2002. **South Buffalo Creek ***In relation to the wetland area (8.5ha)

Sediment. Suspended sediment yield (SSY) from the watershed of South Buffalo

Creek was estimated at 1997 MT/yr or 57 g/m2/yr (163 tons/mi2/yr). Based on the

estimate that 7.75% of the pollutant load from the watershed would be treated by the

wetland, 155 MT/year (170 tons/yr) will flow into the proposed stormwater treatment

wetland for a potential surface loading of 1821 g/m2/yr (5185 tons/mi2/yr). Assuming

60-90% removal of TSS load (Richardson 1988; Reed et al. 1980), the proposed

wetland treatment system would remove sediment at the rate of 93-140 MT/yr or

1092-1639 g/m2/yr (3111-4666 tons/mi2/yr) of wetland area, which is 4.7-7% of the

61 total amount of sediment load in SBC. This sedimentation rate is higher than riparian wetlands in Georgia, USA at 123 g/m2/yr (Craft and Casey 2000) and comparable to

rates in the Netherlands at 560 and 1000 g/m2/yr (Asselman and Middelkoop 1995).

The sedimentation rate is based on the area of the wetland (8.5 ha); therefore,

increasing or decreasing the size of the wetland will affect the estimate of the

sedimentation rate.

A study of floodplain wetlands in Illinois created for stormwater treatment

found removal efficiencies of 77-100% for TSS (Schueler 1996). In this study, the

wetland is 5% of the size of its watershed in contrast to the proposed stormwater

treatment wetland on SBC that is only 0.4% of the SBC watershed. A more realistic

comparison by Dortch (1996) found 30% removal efficiencies for TSS in a riparian

wetland in Arkansas with a 5-day retention time. This study is comparable to this

proposed treatment with a retention time of 2-3 days. Based on 30% removal

efficiency, the proposed stormwater treatment wetland system on SBC would

remove sediment at a rate of 47 MT/yr or 546 g/m2/yr (1555 tons/mi2/yr) of wetland area. However assuming 60% removal efficiency and an average particle bulk density of 1.35 g/cm3, total annual accumulation of sediment will only be 0.08 cm in the proposed stormwater treatment wetland.

One of the shortcomings in this methodology for estimating the sediment yield was the method of sample collection. Median sediment concentrations were estimated with the automatic sampler with the intake set at a fixed point near the bottom of the stream bed. Depth integrated sampling would have provided a more accurate estimate of sediment transport for the entire water column. Stream velocity

62 increases away from the bottom and sides of the stream. The suspended sediment samples collected with the intake point located near the bottom of the channel likely underestimates the total sediment transport throughout the entire water column. In addition, the water is pumped out of the stream to the sampler 7.5 meters (25 ft) above the intake point. The force of the pump vs. the force of the stream water could result in an additional underestimate of sediment concentrations. Simmons (1993) used depth-integrated sampling and estimated 1600 mg/l as the mean suspended sediment concentration from storm flow in urban Piedmont streams from 1970 to

1979. True pollutant loading to the proposed stormwater treatment wetland on South

Buffalo Creek and removal efficiencies in the wetland can only be determined after

the project is implemented and actual sampling can take place.

While data is limited on the sediment removal efficiency of natural wetlands

stormwater treatment, sediment loads to North Carolina streams can be compared.

South Buffalo Creek at the proposed project location was estimated to have a

suspended sediment yield (SSY) of 57 g/m2/yr. This estimate is 3.5 times greater

than the mean SSY, 15.5 g/m2/yr, found in forested watersheds but almost 10 times

less than the mean SSY, 525 g/m2/yr, found in urban watersheds both in the North

Carolina Piedmont (Simmons 1993). Both the sediment yields for the South Buffalo

Creek and the proposed stormwater treatment wetland are probably underestimated

values.

Nutrients. Total nitrogen [TN = TKN + (NO3+NO2)] yield was estimated at 0.7g

N/m2/yr (1.99 tons/mi2/yr) for SBC. Based on the estimate that 7.75% of the pollutant

63 load from the watershed would be treated by the proposed wetland, 1.89 MT/year

(2.08 tons/yr) of TN will flow into the wetland with a potential surface loading of

22.24 g/m2/yr (64 tons/mi2/yr). Total yield of total phosphorus was estimated at 3.6

MT/yr (4.0 tons/yr) or 0.10 g P/m2/yr (0.29 tons/mi2/yr) for SBC. Total load of phosphorus to the proposed stormwater treatment wetland was 3.30 g P/m2/yr (9 tons/mi2/yr) per area of the wetland. Table 13 lists nutrient removal rates on similar riparian wetlands however the watershed area to wetland ratio was unknown.

Table 13: Nitrogen and Phosphorus loss rates as reported in literature for riparian wetlands Reference Location N P Units Craft and Casey (2000) Georgia 1.5 0.09 g/m2/yr Niswander and Mitsch (1995) Ohio *** 2.9 g/m2/yr Nairn and Mitsch (2000) Ohio *** 5.4 g/m2/yr Lowrance et al (1985) Georgia 6.9 0.17 g/m2/yr Peterjohn and Correll (1984) Maryland 4.5-6.0 0.29 g/m2/yr Dortch (1996) Arkansas 21.4% 3% -

Based on Mitch and Gosselink’s (2000) estimate that freshwater wetlands receiving

non-point source pollution retain 15 g N/m2/yr and 1.5 g P/m2/yr the proposed wetland will retain 67% of TN and 46% of TP that flow into the wetland with adequate assimilation conditions of 5.2% of TN and 3.5% TP that annually flows through SBC. The pollutant removal will occur during small storm events where the water quality improvement will be high. There will be little water quality improvement during large storm events with high pollutant loading. However, there will be a decrease in the frequency of polluted small storm events. Efficiency of the wetland to retain nitrogen and phosphorus will be directly related to time of retention, time of year, and volume of flow. The wetland will retain more nutrients in the growing

64 season, during longer retention times, and slower flow. Nutrients may actually flush from the proposed wetland during extremely large, high velocity events and in the winter months.

Suspended Sediment

Storm Hydrographs and TSS Concentrations. Sediment concentrations increased

with stream discharge and velocity (Figure 13 and Appendix C). TSS concentrations

increased during the rising limb of the hydrograph, were greatest at peak discharge,

and quickly decreased during the falling limb of the hydrograph. Simmons (1993)

found that the maximum suspended sediment concentration occurred just prior to

the maximum flow 80% of the time on streams in sampled in North Carolina.

400 2.0

1.8 350

TSS (mg/L) 1.6 300 Level (m) 1.4 250 1.2

200 1.0 Level (m) TSS mg/L 0.8 150 0.6 100 0.4 50 0.2

0 0.0 17:00 18:30 20:00 21:30 23:00 0:30 2:00 3:30 COMP Figure 13: Storm hydrograph and TSS concentrations on December 10, 2001

The operation of the proposed control structure will increase the duration of the

storm hydrograph but decrease peak flows. Bank erosion, a source of sediment,

65 occurs by direct shearing during storm events. The lower peak flow will help reduce bank erosion within and downstream portion of the project, helping to reduce sediment load in SBC (Baker 1998).

Passive Sediment Samplers. Passive sediment samplers were located in an

upstream tributary (station 1), upstream main channel (station 2), within the project

(stations 4-6) and downstream of the project area (station 7). Thirty storm events

were sampled between June 2001 and July 2002. Complete results are located in

Appendix C (Figures C1 through C10). Table 14 summarizes data for each station

location, combining the different stage levels.

Table 14: Summary TSS concentrations (mg/l) for passive samplers Station Mean Minimum Maximum Count 1 167 16 518 42 2 260 72 992 32 4 480 24 2604 65 5 416 20 2800 66 6 455 24 3124 69 7 316 2 1530 63

Single factor ANOVA indicates that mean TSS for each station was not equal

(Appendix C, Table C2). Fisher multiple comparison of total suspended sediment

concentration for station effect at 0.05 significance level indicated that station 1 had

significantly lower TSS than stations 4, 5, and 6 (p-values 0.0002, 0.0028, 0.005);

station 2 had significantly lower TSS than stations 4 and 6 (p-values 0.0159,

0.0306); and station 4 had significantly higher TSS than station 7 (p-value 0.0283).

Generally, sediment concentrations increased within the project area with no

statistically significant differences between upstream and downstream TSS

66 concentrations. However, mean and maximum concentrations were higher downstream as compared to upstream.

The passive sampler at station 7 is located in approximately the same location as the automatic sampler that collected water samples from one point at the bottom of the stream. Results from these two sampling techniques produced extremely different results. The concentration of suspended sediment from the fixed- point sampling was 111 mg/l compared to the mean of 316 mg/l from the passive samplers. Based on a mean sediment concentration of 316 mg/l, the SSY to the wetland would be 5207 g/m2/yr (Table 15). Assuming a 60% removal rate, the wetland would remove 3124 g/m2/yr or annual accumulation of 0.23 cm/yr. Based on the results from the passive samplers, the sedimentation on the proposed floodplain could be much higher than previously predicted.

Table 15: Comparison of suspended sediment yields based on results from automatic sampler (fixed point, 12-hour flow weighted composite value) and passive samplers (4 stage levels average values) Total Yield Yield Total Load Load to EMC* SBC** SBC to Wetland Wetland*** Pollutant (mg/l) (MT/yr) (g/m2/yr) (MT/yr) (g/m2/yr) TSS (automatic sampler) 111 1,997 57 155 1821 TSS (passive sampler) 316 5,711 163 443 5207

Mean values for each station-bottle are in Table 16 and the results for the

interaction analysis with bottle-station effect are in Appendix C. ANOVA for TSS for

station-bottle effect indicated that all the means were not equal at alpha 0.05. The

number of events sampled decreases with increase stage height of sample bottles

as listed by count.

67

Table 16: Total suspended sediment (mg/l) summary statistics for station-bottle effect and calculated discharge (Mannings’ Equation)

Count Mean Min. Max Median Q (m3/s) 1-1 23 166 16 518 120 1 1-2 12 164 64 295 150.5 4 1-3 5 188 138 232 198 9 1-4 2 150 138 162 150 13 2-1 22 180 72 448 147 47 2-2 8 387 172 644 370 81 2-3 2 631 270 992 631 117 4-1 28 393 24 2604 116 2 4-2 18 453 111 1414 256 9 4-3 15 622 134 1686 542 18 4-4 4 673 636 698 679 32 5-1 28 301 20 2800 140 6 5-2 18 442 102 2072 246 10 5-3 14 507 206 1010 558 22 5-4 6 670 536 841 685 26 6-1 30 247 24 1018 139 5 6-2 20 518 89 3124 266 16 6-3 12 745 252 1932 587 30 6-4 7 669 394 1016 636 37 7-1 29 144 18 1421 64 21 7-2 18 388 88 1490 208 43 7-3 9 605 201 1530 370 68 7-4 6 553 50 882 593 88

Bottles were located at similar heights above the baseflow surface level; however,

station 2 had several limitations that resulted in the bottles being located at higher

elevations and consequently sampled higher flow levels. During the sampling period,

only two sampling events were recorded at the 117 m3/s flow rate (station-bottle, 2-

3). Sediment concentrations at station 6 and 7 during high flow conditions were

significantly higher than during low flow conditions (alpha = 0.05). At station 6,

sediment concentrations at bottle 1 (5 m3/s) were lower than sediment

concentrations at 16, 30, and 37 m3/s. Similarly at station 7, sediment concentrations

at bottle 1 (21 m3/s) were lower than sediment concentrations at 43, 68, and 88 m3/s.

68

Complete results for Fishers Multiple Comparison of station-bottle effect are listed in

Appendix C (Table C3).

TSS Correlation with discharge, amount of precipitation, and antecedent moisture

conditions. There were no linear correlations between total sediment concentrations

and discharge, days since last rainfall, and amount of precipitation for the event

(Appendix C, Table C4). Correlation values were 0.0123, -0.118, and 0.110,

respectively. Regression analysis also indicated no affect on sediment

concentrations.

Caution needs to be exercised when using TSS concentrations to reflect the

total sediment transport. TSS concentrations do not necessarily reflect suspended

sediment concentrations as organic and mineral components may vary among

streams (Riedel and Vose, no date). Forested watersheds have more organic

sediments whereas impacted watersheds have more mineral sediments. Caution should be used in determining sediment TMDLs (total maximum daily loads) based on TSS concentrations since the stream may be impacted by bedload rather than suspended load.

Macroinvertebrates

Benthic macroinvertebrates, or aquatic insects, are effective indicators of in-

stream water quality and habitat. Generally, unpolluted streams support higher

diversity of species than polluted streams. Polluted streams lose species intolerant

to pollution in the families of Ephemeroptera, Plecoptera, and Trichoptera (EPT

species). These species are replaced by pollution tolerant species such as

69 tubificidae and chironomidae. High flows often increase the impacts due to nonpoint sources.

The North Carolina Biotic Index Value and the EPT richness are combined to determine a stream’s overall bioclassification. All sites on South Buffalo Creek had a final bioclassifcation of “Poor” compared to the reference reach of “Good” (Figure

14). A complete species list for each site is located in Appendix D. “Poor” bioclassification is similar to other urban sites in Greensboro (Yandora 1998). There were only 8 different EPT species found at the four sites on South Buffalo Creek:

Baetis flavistriga, Baetis intercalaris, Stenonema modestum, Caenis sp.,

Cheumatopsyche sp., Hydropschye sp., and Hydropschye betteni. No Plecoptera species were found at any of the sites. Zweig and Rabeni (2001) showed that low

EPT richness was correlated with high sediment deposition rates, a situation clearly present in South Buffalo Creek.

25 NCBI (using abundance value) GOOD EPT TAXA RICHNESS 20

15

10 POOR POOR POOR POOR

5

0 Upstream Upstream-Trib Project Downstream Reference

Figure 14: Summary of NC bioclassification for South Buffalo Creek and a reference site

70

Sedimentation has been identified as the main pollutant to South Buffalo

Creek and the macroinvertebrate community reflects excessive sedimentation.

Baetis, Cheumatopsyche, and Hydropsyche have been found to be associated with increased sediment levels (Penrose et al. 1980) in other North Carolina streams.

Penrose et al. (1980) also found the following genera associated with sediment which were all present in South Buffalo Creek: Nais sp., Lumbriculidae, Limnodrilus sp., Stenelmis sp., Cricotopus sp., Polypedilum illinoense, Rheotanytarsus sp.,

Thienemanniella sp., and Simulium sp.

Ideally, EPT species respond positively to gravel and cobble size substrate.

Excessive fine sediment fills the spaces between gravel and cobble particles, reducing available habitat. Habitat can be completely changed when gravel and cobble are no longer present and the stream is dominated by sand. EPT species are replaced with small, burrowing animals such as chironomids and oligochaetes

(Water 1995). Chironomidae actually use fine sediment in the construction of cases and tubes (Wood and Armitage 1997). In South Buffalo Creek, the domination of sand substrate was seen at the downstream site. The upstream area and project reaches were still dominated by gravel. The operation of the treatment system may help reduce downstream sedimentation and lead to habitat improvement.

Population numbers may fluctuate depending upon when the sample was collected. Numbers may be high during periods of low flow when the water is generally sediment free, but are eliminated during periods of high flow (Water 1995).

The overall result of excessive sediment in streams is that taxa richness is not affected, while abundance is reduced (Penrose et al.1980). Both taxa richness and

71 abundance in South Buffalo Creek were low. This suggested that sedimentation was not the only cause of degradation.

Functional feeding groups are another way to assess the health of a stream.

This method is based on the association between a limited set of feeding adaptations found in freshwater invertebrates and their basic nutritional resource categories (Merritt and Cummins 1996). The four main groups are shredders (SH) that feed on coarse particulate organic matter, collectors (CG/FC) that feed on fine particulate organic matter, scrapers (SC) that feed on periphyton or algae, and predators (P) that feed on other animals. Shredders typically dominate headwater

streams (1st to 3rd order). This shifts to scrapers in the midreaches and collectors in

the lower reaches (Vannote et al. 1980).

Collectors/gathers and predators dominated South Buffalo Creek (Figure 15).

The abundance of collector/gathers was related to the small particle size of the

substrate (Hachmoller et al. 1991). Collector/gathers are also more tolerant to other

pollution. Wiederholm (1984) found similar feeding groups in nutrient-enriched

streams because of the increase in algae and detritus caused by eutrophication.

72

Upstream Main Upstream trib 7% 10% 2% 9% 33%

25%

53% 2% 30% 15% 11% 3% Collector/Gatherer Filtering/Collector Omnivore PROJECT 9% Downstream Predator 5% 11% Scrapers Shredders 8%

46% 44% 22%

23% 5% 13% 3% 11%

Figure 15: Composition of functional feeding groups for South Buffalo Creek

An increase in shredders after project implementation would be a sign of water quality improvements. The effects of channelization, nutrient inputs, low stream velocity and small substrate size create a habitat similar to higher order streams.

Long-term sampling after the treatment system is constructed will determine if a shift in community composition will improve water quality and habitat.

In addition to altering substrate, sedimentation can affect respiration and increase drift of species. One concern was that the operation of the control structure and subsequent sediment deposition in the channel may negatively impact benthic macroinvertebrates. The natural variability of river flows results in the variability of deposition of sediments (Wood and Armitage 1997). Therefore, benthic communities should not be adversely impacted by elevated sedimentation during small storm

73 events. Most of the sediment will frequently be re-suspended in the channel during larger, more infrequent events.

Stream Geomorphology

The study area was summarized into four stream reaches for the purpose of this discussion: upstream main, upstream tributary, project, and downstream (Figure

16). All geomorphic classifications and conclusions were based on the average conditions over the entire reach. Complete survey data were listed in Appendix E.

Values from regional curves developed for urban streams in the piedmont of North

Carolina were used for comparison (Doll et al. 2002).

Figure 16: Identification of stream reaches Upstream Main, Upstream Tributary, Project, and Downstream

74

In the last 40 years, South Buffalo Creek and its watershed have undergone realignment and development respectively. Data from a floodplain report conducted by the United States Army Corps of Engineers (USACE) for the City of Greensboro in 1966 provided the baseline data. Aerial photography has shown that the stream was straightened (Figure 17). The upstream segment between I-40 and US-220 and the first 125 linear meters (400 feet) of the project reach were channelized in the early 1990’s by the North Carolina Department of Transportation. At this time US-

220 was elevated, the exit ramps were constructed, and I-40 was widened to eight lanes and realigned further south. The culverts under I-40 downstream were replaced with bridges. Four box culverts carry the stream under I-40 and US-220 upstream of the project. The old stream channel is still visible in the upper reach of the project area.

Figure 17: Proposed stormwater treatment wetland in 1959 and 2001

During these highway improvements, the upstream reach lost over 30 meters

(100 feet) of stream channel and the project reach lost over 45 meters (150 feet)

(Figure 18). As a result of these highway improvements, channel sinuosity decreased. The decrease in sinuosity caused an increase in channel slope from

75

0.001 to 0.002 within the project area. A higher channel slope can lead to more erosion and downcutting as the channel attempts to adjust.

Upstream Access Ramp Project Area 229 1960

228 I -40 2001 227 US-220 I -40 (2001) I -40 (1960) 226 225 224 223 Meters above sea level 1960 m = -0.2 % 1960 m = -0.3% 1960 m = -0.1 % 222 2001 m = -0.2% 2001 m = -0.3% 2001 m = -0.2% 221 0 500 1000 1500 2000 2500 Linear stream distance (m)

Figure 18: Comparison of channel slope from 1959 to 2000 for South Buffalo Creek showing loss of stream length and increase of slope

The existing channel slope and bed features were measured during the longitudinal profile. Slope of the water surface, bankfull height and top of bank were calculated for each of the four stream reaches. In addition, the length and slope of each riffle, pool and run were calculated. There were 18 pools, 23 riffles, and 15 runs over the entire study area with average length of 50 m (165 ft), 23 m (74 ft), and 45 (147 ft) respectively (Table 17).

Table 17: Number and average length of pools, riffles, and runs Total No. Avg. No. Avg. No. Avg. length Pools Length Riffles Length Runs Length Upstream Main 1250 12 40 13 26 8 39 Project 945 4 51 8 19 7 44 Downstream 305 1 67 2 18 0 ***

76

The project reach had only 4 pools with an average length of 50.6 meters

(166 ft) compared to the upstream reach that had 12 pools with an average length of

40 meters (131 ft) (Table 17). The upstream reach was characterized by longer riffles and frequent pools. A large scour hole and long run have formed downstream from the confluence of the upstream tributary. The riffles in the upstream reach were dominated by cobble and boulder sized substrate whereas the project reach was more gravel and sand sized substrate. The variability of the bed features decreased in the project reach. The 4 pools were located at bends in the channel. Average pool depth was 0.69 and 0.70 meters for the upstream and project reaches respectively.

The lower portion of the project reach was dominated by sand-sized particles and the beginning of a braided stream with a vegetated island beginning to form in the center of the channel.

The average pool depth upstream was 0.70 meters (2.3 feet) and was 0.77 meters (2.54) feet within the project area. The deeper pools in the project area were found on the outside of meanders where the bank was stabilized from massive tree roots. The roots provided the bank stability from eroding and the water formed a scour pool. Some sediment will deposit in the pool during small storm events when the control structure holds water in the channel and the velocity decreases and particles fall out of suspension. However, storms greater than a 2-year occurrence will overtop the structure and it will de-activate. This will restore the capacity of the stream and allowing the scour pool to maintain its depth.

Figure 18 illustrated change in channel slope gradient over the last 40 years.

Figure 19 illustrates that South Buffalo Creek has down cut 1.2 (4 feet) and widened

77 over 3 meters (10 feet). In 1960, South Buffalo Creek had a bank height of 1.8 meters (6 feet) and channel width of 12.2 meters (40 feet). In 2001, South Buffalo

Creek had a bank height of 3 meters (10 feet) and channel width of 12.25 meters (50 feet). As impervious surface from development increased, infiltration and subsurface flow decreased, and storm flow velocity and quantity increased. In urban areas, smaller storms, which produced no runoff before development, now generate substantial flow (Booth 1990). In order to transport more water in a shorter amount of time, the stream channel eroded a deeper, wider channel to accommodate the flow. Assuming an average particle density of 1.35 g/cm3, over 29,000 kg of sediment per stream meter (200,000 lbs/ft) eroded in the last forty years.

235 1960 2001

230

225 meters above sea level

220 0 100 200 300 400 500 Linear stream distance (m)

Figure 19: Cross-section of floodplain and channel of South Buffalo Creek in 1959 and 2001

The upstream reaches have eroded down to bedrock at several riffles. Within

the project reach, Station 5556 is also located at a bedrock outcrop (Figure 20). The

78 channel is actively eroding the outside bank as the channel tries to widen since it cannot down cut through the bedrock. The bankfull width is 19.2 m (66 ft) and bankfull area is 37.7 m2 (406 ft2) compared to the other riffles within the project reach that range from 11 to 15.5 meters (37 to 51 feet) and 19 to 32.5 m2 (250 to

350 ft2) for bankfull width and bankfull area respectively (Figure 21). Channel incision depends on the amount of sediment that the stream can transport relative to the sediment load (Booth 1990). The increased flow yields downcutting, streambank steepening, and eventually more sediment from bank erosion.

Station 5556 at Bedrock

October 2001 March 2002

227.0

226.0

225.0 Lt. BKF DA = 35 km2 A(bkf) = 37.7 m2 224.0 W(bkf) = 19.2 m D (bkf) = 2.4 m meters above sea level 223.0 W/D = 8.2 ER = 20.3 Thalweg Bedrock BHR = 1.19 222.0 0 5 10 15 20 25 30 meters

Figure 20: Cross-section at bedrock riffle (Station 5556) within the project area

79

Riffle at Station 5772 October 2001 March 2002

227.00

226.00

Lt. BKF Rt. BKF 225.00 DA = 35 km2 A(bkf) = 32.4 m2 224.00 W (bkf) = 15.5 m D (bkf) = 2.7 m

Meters above s ea level W/D = 5.8 m 223.00 ER = 23.5 BHR = 1.18 Lt. EOW Rt. EOW 222.00 0 5 10 15 20 25 30 Meters

Figure 21: Example of a typical cross-section at a stable riffle within the project area

The proposed stormwater treatment wetland should help reduce storm flow velocities and the erosive force of water. Some water will be stored on the floodplain and infiltrate through the soil. The stored water will slowly drain from the wetland to the stream channel over several days as compared to several hours without the structure. This will reduce stream erosion and downcutting of the channel within and downstream of the project area. The reduction in stream velocity may cause sediment deposition in pool areas and cause riffles to become clogged with sediment. The longitudinal survey determined long-term changes in channel morphology and aquatic habitat.

The results from the cross-section survey were used to determine stream type based on Rosgen’s (1996) natural channel methods. The upstream reach was

80 an E5 channel while the project reach was an E4 channel. The data are listed in

Appendix E (Table E36). The upstream reach had a drainage area of 23 km2 (9 mi2)

with a cross-sectional area of 23 m2 (246 ft2) and width to depth ratio of 5.8. The area is comparable to the North Carolina regional curves for urban Piedmont streams but the width to depth ratio was lower than the curve. The channel had a

higher bankfull depth than the regional curve. The entrenchment ratio averaged

11.7. This stream reach was slightly entrenched but more so than the project reach.

Sinuosity was a straight channel. The difference in substrate from the project area

led to the average classification of gravel substrate due to the dominance of

bedrock. The bank height ratio was moderately unstable but close to the stable

rating.

The project reach had a drainage area of 35 km2 (13.5 mi2). The width to

depth ratio was lower than the regional curve and suggests a greater bankfull depth

and narrower bankfull width. The large flat floodplain allows a wide floodprone area

between 330 and 440 meters (1075 and 1450 ft) and extremely high entrenchment

ratios. Sinuosity was high within the project reach despite straightening in the 1990s.

Bank stability rating was moderately unstable. The instability may be due to bank

erosion below the rooting depth of riparian vegetation (Rosgen 2001).

According to Rosgen (1994), characteristics of an E4 channel indicate that these reaches are rate “very high” in sensitivity to disturbance and with “good” recovery potential once the cause of instability is correct. There is typically a

“moderate” supply of sediment and “high” stream bank erosion potential in E4

channels. Vegetation is was rated “very high” as controlling the width to depth ration

81 of stability (Rosgen 1994), indicating the importance of maintaining existing vegetation and replacing vegetation through the construction of the wetland treatment system. All these characteristics indicate a stable stream reach in South

Buffalo Creek is possible.

Cross-section measurements collected in October 2001 and March 2002 indicated the upstream and project reaches were stable with instability toward the downstream reach and lower portions of the project reach. Cross-section data for all the stations are listed in Appendix E. There were no bankfull events during the study period. The project and upstream reaches appear to be generally stable with areas of instability created by sewer crossings and stormwater inlet channels. Results show that urban streams can re-stabilize within 10 to 20 years (Henshaw and Booth

2000). The project reach may have stabilized from alterations but the downstream reach is still in the process of stabilizing.

The stream stability and classification were based on the determination of bankfull height. Some uncertainty is related to determining bankfull height.

Difficulties occur when the two bank tops are not at the same elevation, the stream reach is not stable, there are no obvious breaks in floodplain and stream bank, or benches and terraces exist. In addition, there are over 16 definitions for “bankfull.”

These factors contribute to uncertainty of bankfull depth (Johnson and Heil 1996).

This is the reason why several cross sections were measured to characterize each reach.

At the time of this report, the upstream reach is scheduled for priority IV stream stabilization. The proposed stormwater treatment wetland should have no

82 impact to the upstream reach. Water will back up on the upstream segment between US-220 and I-40; however, the channel is stabilized with rip-rap on the banks and should have little impact to the geomorphology. The restoration should complement the treatment efforts by restoring channel sinuosity and increase stream stability.

It is unknown what effect the proposed treatment system will have on the channel stability of the project area. Low-order urban streams do not normally possess a water-filled channel for a 24-hour period. The water filled banks could become more vulnerable to erosive forces. The channel is most unstable where exposure exists at the road crossing, utility crossings, and non-vegetated banks.

Bank stabilizing structures such as root wads, J-hooks, and cross vanes could be used to stabilize the pattern and shape of the stream. The downstream reach will benefit from the effects of lowered peak flows and likely decreased bank erosion.

However, changes will be subtle since the channel forming bankfull events will not be affected by the structure.

Water Table Hydroperiod

Wetland hydrology criterion is met if “an area … is inundated or periodically saturated at mean depth <6.6 ft, or the soil is saturated to the surface at some time during the growing season of the prevalent vegetation” (USACOE 1987). Saturation to the surface is equivalent to water within 30 cm (12 in) of the soil surface. This depth is the typical range of rooting depths for plants (Cole et al. 1997). As previously stated, the growing season in Greensboro is March 27 through November

83

9 (227 days). To meet wetland hydrology, this site must be saturated for at least 5% of the growing season, which is equivalent to 11 consecutive days.

Wells 5, 7, and 10 were placed in areas delineated as wetland. Wells 2, 3, and 4 were located on a gradient from the stream to the wetland area. Wells 6, 8, 9, and 11 were located between the wetland areas and higher slopes. The median depths to water table for the growing season and non-growing season are listed in

Figure 22. Wells 5, 6, and 10 are located in the wettest areas of the floodplain and wells 2, 3, and 4 are the driest locations. In general the floodplain is drier in the growing season and wetter in the winter.

Median Depth to Water Table

Wells 2 3 4 5 6 7 8 9 10 11 0.00 -0.50 -1.00 -1.50 -2.00 -2.50 Mean depth GS

Meters below surface -3.00 -3.50 mean depth non-GS GS = Growing Season

Figure 22: Monthly Median Depth to Water Table

Wells 5 and 7 met the wetland hydrology criterion for 2002 based on logged

data while wells 7 and 10 met the criterion for 2002 based on manual bi-weekly

measurements. Based on manual measurements well 5 could only be considered

84 wet for 9 consecutive days. This illustrates the importance of hourly measurements to accurately determine the hydrology of a site. The data for all well sites are graphed in Appendix F.

The main sources of water into a riparian wetland are precipitation, upslope overland flow, interflow, and groundwater. Upland overland flow and near surface interflow are assumed to be negligible since the site is confined by Interstate-40 on the north and US Highway 220 on the east. Both highways have steep embankments with trenches at the base of each slope. All runoff is managed through the ditch system, which directs the flow to the stream downstream of the project area. Therefore, precipitation and groundwater are the two sources of water input to be considered.

Years 2001 and 2002 both had below normal rainfall for the North Carolina

Piedmont. Rainfall was 13.9 cm (5.5 in) below normal for 2001 and 26.6 cm (10.48 in) below normal for January to July for 2002 (NOAA 2002). Figure 23 illustrates the drought conditions. For this reason, long-term monitoring data were needed to accurately characterize the hydrology of the floodplain.

85

Average Rainfall compared to Rainfall total 2001 and 2002

30-yr Average (1971-2000) 16.00 2001 14.00 2002 12.00

10.00

8.00 cm 6.00

4.00

2.00

0.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Figure 23: Monthly median precipitation (30-yr mean) and 2001 and 2002

Figures 24-25 show the logged water level data and daily rain totals from

February to July 2002. Wells 2, 3 and 4 showed little to no response to precipitation.

Wells 5-11 respond directly to precipitation especially during the fall and winter.

Response in the growing season depends on existing moisture conditions.

86

3

2

1 RAIN (cm)

0 38 43 48 53 58 64 69 74 79 84 90 95 100 105 111 116 121 131 141 152 162 173 183 193 204 214 Day of the Year

Figure 24: Daily rainfall totals for the proposed stormwater treatment wetland for February 9, 2002 to August 8, 2002

38 43 48 53 58 64 69 74 79 84 90 95 100 105 111 116 121 131 141 152 162 173 183 193 204 214 50

0 30-cm below surface

-50

-100

-150

-200

cm below surface cm -250

-300

-350 Well 2 well 3 Well 4 Well 5 Well 6 Well 7

Figure 25: Floodplain hydrology for February 9, 2002 to August 8, 2002 for the proposed stormwater treatment wetland.

87

The water table of the floodplain is controlled by stream level. As expected the driest wells were located closest to the stream, wells 2, 3, and 4. These wells are located 15, 30, and 81 meters from the stream edge respectively. These wells respond to the long-term water table gradient and stream height. The water table gradient was higher in the upland and lowest at the stream causing shallow groundwater to flow toward the stream (Figures 26-27). The topography of the

floodplain dictated whether or not the water table was closer to the surface to cause

wetland conditions. The slope of the water table gradient was highest the closest to

the stream. The gradient was greatest during the winter months and lowest during

the growing season.

Stream = 0 0.5 meters 0 50 100 150 200 250 300 350 Road 0.0

-0.5

-1.0

-1.5 meters -2.0

-2.5 7/3/2001 8/1/2001 9/5/2001 10/1/2001 -3.0 10/29/2001 12/1/2001 12/26/2001 30 cm Line -3.5

Figure 26: Water table gradient from South Buffalo Creek across the proposed stormwater treatment wetland from July – December 2001

88

Stream = 0 meters 0.5 0 50 100 150 Road 200 250 300 350 0.0

-0.5

-1.0

-1.5 meters -2.0

-2.5 1/2/2002 2/4/2002 3/5/2002 4/2/2002 -3.0 5/1/2002 5/31/2002 7/1/2002 8/1/2002 30-cm Line -3.5

Figure 27: Water table gradient from South Buffalo Creek across the proposed stormwater treatment wetland from January – August 2002

Water exits the wetland via evapotranspiration, shallow groundwater

discharge to the stream, and overland flow. Evapotranspiration output dominates

the growing season, while discharge to the stream dominates the winter, but still occurs in the growing season. The evapotranspiration output is demonstrated in

Figure 23, which show the decrease in depth from the surface where the water table is within the root zone. Conversely, wells 2, 3, and 4 showed little change in the growing season, indicating these sites were not influenced by water loss through evapotranspiration.

The City of Greensboro estimated the structure would operate 25-30 times a year (Annambhotla, personal communication). Currently, the stream does not

89 regularly flow over the top of the banks. Bankfull flow is estimated to occur every 1 to

2 years. Since bankfull is below the top of bank, the frequency is even less. The new hydrology will significantly increase the overbank flow to the floodplain. In addition, the structure could be manually triggered during the growing season drought in order to meet wetland hydrology and to develop vegetation. However, this should be unnecessary since riparian wetlands are naturally drier in the summer. Hydrophytic vegetation and hydric soil conditions should be able to form without additional flooding.

The increased flooding and subsequent increases in the water table will elevate base flow conditions. The stream level controls the water table in the floodplain. Typically the hydraulic gradient will have water flowing from the floodplain into the stream. It is possible that during high intensity storm events, the channel will fill quickly and temporarily cause a higher gradient of flow into the floodplain. This could create a small hydraulic gradient wedge upslope until the infiltrating water is greater than the water moving out of the channel (Burt et al.

2000). Infiltration of water during the flooding events will increase the water table.

This water will exit the floodplain as shallow groundwater discharge to the stream at a slow rate. Currently, the water is transported downstream only during the storm event only. Storage and slow release of water from the floodplain will elevate base flow conditions. This is important for fish and other aquatic organisms that need higher flow levels in the channel and provide adequate habitat and food.

The stream hydrology will also be affected. Upstream of the project, water will back up in the channel to the confluence of the upstream tributary. The filling of the

90 channel and overflow onto the floodplain will decrease the velocity and erosive forces of the stream. This will decrease the flood peak down stream of the project area thereby decreasing bank erosion and flooding. Typically storms are extremely

“flashy” within this urban basin. Peak flow is reached within 5-9 hours and return to baseflow in 24-72 hours, depending upon the storm’s intensity, antecedent moisture conditions, and runoff volume. The control structure will increase the time to peak flow, will lower the level of peak flow, and extend the falling limb or return to base flow. This will decrease the erosion and stress to the stream channel and aquatic organisms. There will be less bank erosion and sediment transport of large particles.

Wetland Vegetation

Natural floodplain wetlands are inundated in spring floods and quickly drain.

The water remains in the root zone for days to weeks. Natural wetlands go dry in the summer and fall allowing for aerobic conditions to dominate and create a mixed plant community. When flooded too long, anaerobic pathways define the soil chemistry, which hastens the establishment of wetland vegetation. Vegetation in riparian ecosystems occurs along a gradient and is based on elevation relative to the water level on the floodplain. The different elevations on the floodplain create a diverse plant community. Currently, the riparian ecosystem in the floodplain of the project area is adapted to relatively dry conditions with only 10% of the floodplain in wetland area. As the hydrologic input increases toward wetland conditions, it is expected that the vegetation species will change in response to the wetter conditions.

91

Overstory Canopy. Seven plots were sampled with area of 314 m2 and total area

sampled of 0.2198 ha. Seven plant species were identified and listed in order of

density (trees/ha): Fraxinus pennsylvanica (green ash, 874), Celtis occidentalis

(hackberry, 68), Acer negundo (box elder, 34), Ulmus americana (American elm,

32), Platanus occidentalis (sycamore, 9), Acer rubrum (red maple, 5), and Salix

nigra (black willow, 5). Table 18 lists the statistics for the canopy species. The

hydrophytic classifications of the overstory trees were all Facultative (FAC) or wetter,

with two FAC, three facultative wetland (FACW), and one obligate wetland (OBL) (S. nigra) (Reed 1988). Fraxinus pennsylvanica was the most abundant species, occurring in all plots and having relative frequency, density, and basal area of 84%,

85%, and 89% respectively. The importance value of green ash was 87.0 with hackberry having the next highest importance value of 4.1. A complete list of species and DBH is located in Appendix G.

Table 18: Results of overstory species (>7-cm diameter) Relative Relative Relative No. of Frequency Density Basal Importance Overstory Species Common Name Status plots (%) (%) Area (%) Value Acer negundo Box elder FACW 4 3.3 3.3 1.9 2.6 Acre rubrum Red maple FAC 1 0.4 0.4 0.1 0.3 Celtis occidentalis Hackberry UPL 4 6.6 6.7 1.5 4.1 Fraxinus pennsylvanica Green ash FACW 7 84.2 85.1 88.8 87.0 Platanus occidentalis Sycamore FACW- 1 0.9 0.9 2.8 1.8 Salix nigra Black willow OBL 1 0.4 0.4 1.8 1.1 Ulmus americana American elm FAC 7 3.1 3.1 3.1 3.1 FACW = Facultative wetland plants (67-99% probability of occurring in wetlands) FAC = Facultative plants (37-67% probability of occurring in wetlands) FACU = Facultative upland plants (1-33% probability of occurring in wetlands) UPL = Obligate upland plants (<1% probability of occurring in wetlands) Status (Reed 1988)

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Total basal area of the overstory was 30.09 m2/ha and higher than 26.76 m2/ha as determined by the 2000 study (City of Greensboro 2000). The difference may be a result of sampling methods in this study where only vegetation in the wetland areas was sampled. The 2000 study characterized the entire floodplain forest.

Figures 28-29 illustrate the class size distribution for F. pennsylvanica and C. occidentalis. The class size with the greatest number of green ash trees was 16-20

cm DBH with fewer younger trees to replace the older trees, 24 trees at 7-10 cm

DBH, and 40 trees at 11-15 cm DBH. Green ash commonly occurs on moist

bottomlands or stream banks but, once established, can persist on dry soils. Under

forest competition, it is intolerant to moderately tolerant (Harlow et al. 1991). C.

occidentails was the next most important tree species with all individuals being less

than 15-cm DBH. If present hydrologic conditions persist, Hackberry (associated

with upland areas) may become a more dominant species on the site over time.

60

50

40

30

20

10

0 7-10 cm 11-15 cm 16-20 cm 21-25 cm 26-30 cm 31-35 cm

Figure 28: Class distribution of Fraxinus pennsylvanica (green ash) in overstory

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6

5

4

3

2

1

0 <8 cm <9 cm <10 cm <11 cm <12 cm <13 cm <14 cm <15 cm

Figure 29: Size distribution of Celtis occidentalis (hackberry) based on DBH measurements

The flooded riparian area will be an advantage for some species. Based on a greenhouse study by Hosner and Boyce (1962), F. pennsylvanica seedlings are tolerant of saturated soil conditions whereas A. negundo, P. occidentalis, and A. rubrum have intermediate tolerance and U. americana and C. occidentalis are intolerant. F. pennsylvanica actually grew taller in saturated soil compared to well- aerated soil. F. pennsylvanica is able to survive up to a year in standing water

(Hammer 1992). Plants have certain adaptations to survive and grow better in saturated conditions such as the ability to establish roots and continue to grow, to form adventitous roots, and also have drought resistant stems and leaves (Hosner and Boyce 1962). F. pennsylvanica was found to have improved growth (80% greater) in flood year compared to non-flood years (Broadfoot and Williston 1973).

Based on these and other studies, F. pennsylvanica will probably continue to be a dominant species in this ecosystem and will probably expand its range slightly as upland areas become saturated more frequently and for a longer duration

(Niswander and Mitsch 1995).

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The water level in the growing season will most directly affect the vegetation.

Great care should be taken when deciding to manually flood the wetland during the growing season for the establishment of hydrophytic vegetation. Riparian wetland systems naturally are drier in the summer months when evapotranspiration export rates are high. Additional flooding outside of the growing season is unnecessary. A fluctuating water table typical of most natural riparian ecosystems should help promote a plant community characteristic of floodplains. Prolonged flooding, greater than one year, will adversely affect the hardwood vegetation. Typical symptoms include decreased shoot growth, leaf chlorosis, curling of leaves, absence of fruiting, increased susceptibility to predation, and branch dieback (Broadfoot and Williston

1973). Ulmus americana would be most likely to show signs of stress first since it is classified as FACU.

Understory Canopy. The understory canopy consisted of young tree species less

than 7 cm dbh. Surprisingly, there were no Fraxinus pennsylvanica in this category.

Instead, Acer negundo and Celtis occidentalis dominated this layer with importance values of 59 and 27 respectively. Table 19 lists the results for the understory canopy layer inventory. Other species present in order of importance value included:

Quercus phellos (willow oak), Liquidambar styriciflua (sweetgum), Carya tomentosa

(mockernut hickory), Juniperus virginiana (eastern red cedar), Cornus amomum

(silky dogwood), Ligustrum sinense (Chinese privet) and Ulmus americana

(American elm). The wetter conditions, under the operation of the proposed stormwater treatment system, will likely cause an increase in the importance of F.

95 pennsylvanica in the understory. A. negundo and C. occidentalis will also likely continue as important species.

Table 19: Results of understory species inventory

Relative Relative Relative No of Frequency Basal Area Density Importance Understory Species Common Name Status Plots Stems (%) (%) (%) Value Acer negundo box elder FACW 7 33 60 56.3 61.1 58.7 Carya tomentosa mockernut hickory UPL 1 1 1.8 3.1 1.9 2.5 Celtis occidentalis hackberry FACU 4 13 23.6 30.1 24.1 27.1 Cornus amomum silky dogwood FAW+ 1 1 1.8 0.6 1.9 1.2 Juniper virginiana juniper FACU- 1 1 1.8 0.7 1.9 1.3 Liquidambar styriciflua sweetgum FAC+ 2 2 3.6 2.4 3.7 3.0 Quercus phellos willow oak FACW- 1 1 1.8 4.4 1.9 3.1 Ligustrum sinense Chinese privet FAC 2 2 3.6 1.3 3.7 2.5 Ulmus americana American elm FACW 1 1 1.8 1.1 0.1 0.6 Unknown #2 2 2 3.6 0.1 0.1 0.1 FACW = Facultative wetland plants (67-99% probability of occurring in wetlands) FAC = Facultative plants (37-67% probability of occurring in wetlands) FACU = Facultative upland plants (1-33% probability of occurring in wetlands) UPL = Obligate upland plants (<1% probability of occurring in wetlands) Status (Reed 1988)

Broadfoot and Williston (1973) found that Carya tomentosa was intolerant to

flooding and may suffer death in less than one month of inundation. Celtis

occidentalis, Acer negundo, and Ulmus americana can survive up to one year of

inundation. However, species grown in drier conditions may not survive as long

when flooding is introduced. The short flooding duration of the proposed stormwater

treatment wetland on South Buffalo Creek should not significantly impact the

overstory and understory layer of vegetation.

Ground Cover. Ground cover consisted of species less than 2.54 cm (1 inch)

diameter and were divided into two class heights, greater than or less than 0.5 m.

96

The results for height class less than 0.5 m are listed in Table 20. For the lower height class, Lonicera japonica (Japanese honeysuckle) and Toxicodendron radicans (poison ivy) were the dominant species with absolute frequencies of 89% and 54% and relative cover of 19% and 13% respectively. Exposed soil comprised

53% of the relative cover and was present in all the plots. For the greater than 0.5 m height class, Rhubus argutus (blackberry) was present in the most number of plots sampled with an absolute frequency of 14% but only accounted for 8% of the relative coverage. Rosa spp. and Unknown #1 were present in only 7% and 4% of the plots but accounted for 27% and 17% of the relative coverage for the species greater than

0.5 m.

Table 20: Results for herbaceous layer, <0.5 m, inventory Number Absolute Relative Relative Importance Herbaceous Species (<0.5 m) Status of Plots Frequency Frequency Cover Value Bare Area N/A 28 100 21 53.5 58 Lonicera japonica FAC 25 89 19 18.9 42 Toxicodendron radicans FAC 15 54 11 13.4 26 Parthenocissus quinquefolia FAC 17 61 13 3.5 26 Rhubus spp. Varies 6 21 5 1.1 9 Cornus spp. Varies 6 21 5 1.0 9 Carex spp. Varies 4 14 3 1.2 6 Sambucus canadensis FACW- 3 11 2 0.6 5 Fragaria spp. FAC- 3 11 2 0.1 4 Vitus spp. Varies 3 11 2 0.1 4 Lactura spp. Varies 2 7 2 0.4 3 Smilax spp. Varies 2 7 2 0.4 3 Celtis occidentalis FACU 1 4 1 0.2 2 FACW = Facultative wetland plants (67-99% probability of occurring in wetlands) FAC = Facultative plants (37-67% probability of occurring in wetlands) FACU = Facultative upland plants (1-33% probability of occurring in wetlands) UPL = Obligate upland plants (<1% probability of occurring in wetlands) Status (Reed 1988)

It is expected that herbaceous plants will establish relatively quickly after construction and be the first species to respond to the new hydrologic regime

97

(Niswander and Mitsch 1995). T. radicans and L. japonica may be negatively impacted by the increased flooding regime. However a decrease in these two species may be beneficial to the ecosystem by increasing biodiversity and allowing typical wetland plants on the site. These species could supply higher quality food for wildlife.

CONCLUSIONS AND RECOMMENDATIONS

Water Quality

Conclusions

· The proposed stormwater treatment wetland will flood approximately 41 times

a year with 7.75 % or 1,500,000 m3 of total storm flow from South Buffalo

Creek. Fifty-seven percent of the flooding is estimated to occur during the

growing season.

· The proposed stormwater treatment wetland will remove approximately 1092-

1639 g/m2/yr TSS, 15.0 g/m2/yr nitrogen, and 1.5 g/m2/yr phosphorus. This is

5-7% of the total suspended sediment to SBC, 5.2 % of the total nitrogen, and

3.5% of the total phosphorus in South Buffalo Creek.

· Pollutant yields are probably conservative estimates due to the limitations of

the sampling methodology. Higher pollutant yields would be expect.

· There are significantly higher TSS concentrations within the project area

compared to upstream and downstream. Reduction of peak flow will help

reduce TSS within the project area.

· TSS concentrations are positively correlated with discharge. Reduction of

high peak flows will help reduce TSS transport.

98

· Macroinvertebrate survey indicates “poor” water quality. Collectors and

gatherers dominate the entire length of South Buffalo Creek.

Recommendations

· Reduction of sediment at the source through best management practices on

upstream development to control both quality and quantity of runoff.

· Limit development and the destruction of open space, especially along

ephemeral and intermittent stream channels.

· Elimination of sanitary sewer pipes that cross South Buffalo Creek within the

project area because of increased vulnerability to floating debris and

increased chance for failure. If it is not possible to eliminate pipe crossings,

the pipes should be slip lined and re-enforced as well as increase the

elevation of manhole openings.

· Post-construction monitoring will be necessary to determine actual loading

and pollutant removal of the proposed stormwater treatment wetland.

Stream Geomorphology

Conclusions

· In the last 40 years, South Buffalo Creek has down-cut 1.2 meters and

widened 3.0 meters producing 29,000 kg of sediment per meter of stream.

· In the last 40 years, the stream reach has lost 76 linear meters of channel

and the channel slope has increased from 0.1 to 0.2 %.

· Based on Rosgen’s stream classification, South Buffalo Creek within the

project area is an E4 channel. While this classification is indicative of a stable

reach, bank height ratio indicates the stream is moderately unstable.

99

· The proposed wetland structure will decrease shear stress within the channel,

but decrease stability by saturation of banks and loss of vegetation during

construction. Sediment deposited during operation of the structure will be re-

suspended during high flow events.

Recommendations

· Bank stabilization in vulnerable areas would reduce bank erosion and

potential bank failure as a result of the altered flow regime.

· Upstream restoration and bank stabilization would decrease sediment input to

the proposed stormwater treatment wetland.

· Install in-stream structures to restore channel features of the riffle-pool

sequence and aid in habitat improvement.

Wetland Hydrology

Conclusions

· Wetland hydrology criteria were met at two of the three wells within the

delineated wetland.

· The stream levels control the water table on the wetland. Inundation of the

floodplain should increase baseflow and increase the water table level on the

floodplain.

· Wetland area should increase with the operation of the water control

structure.

Recommendations

· Continuous monitoring of the water table is necessary to determine the

hydrologic characteristics of the wetland.

100

· Longer retention of water on the floodplain may improve removal efficiencies

and enhance subsurface water storage.

Wetland Vegetation

Conclusions

· Overstory is dominated by Fraxinus pennsylvanica (green ash) and Celtis

occidentalis (hackberry). Green ash is water tolerant and should not be

affected by higher water table water levels. Hackberry is FACU and may

decline because of the higher water levels.

· The understory is dominated by Acer negundo (box elder) and hackberry. Box

elder is tolerant to high water level, but hackberry may decline.

· The groundcover layer is dominated by Lonicera japonica (Japanese

honeysuckle) and Toxicodendron radicans (poison ivy). Neither species is

desirable for diverse plant communities. These species may decline with

water inundation.

Recommendations

· Additional flooding of the wetland during the drier periods is not necessary to

establish vegetation characteristic of wetlands as proposed by the City of

Greensboro.

· Desirable wetland plant species should be planted in disturbed areas. In

addition, the soil should be properly prepared with additional organic matter

and aeration as needed before planting to ensure higher survival.

101

· Monitoring and maintenance of planted vegetation should continue until

specimens become well established. Maintenance may include removal of

dead and invasive species, removal of weeds, and replanting.

102

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Welborn, T.J. 2002. City of Greensboro Stormwater Management Division Action ID. No. 2002120540. Chief Wetlands, Coastal and Watersheds Branch, United States Environmental Protection Agency, Atlanta, GA. Letter to J.W. DeLony, United States Army Corps of Engineers, Wilmington, NC. January 17, 2002.

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110

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111

APPENDICES

112

APPENDIX A: SITE PHOTOGRAPHS

Figure A1: Upstream Main SBC at Vanstory Figure A2: Upstream Main SBC along Drive Meadowview Avenue.

Figure A3: Upstream Main flowing under I- Figure A4: SBC along I-40/US-220 access 40. ramp.

Figure A5: Upstream entering project area. Figure A6: Upstream of stream crossing

113

Figure A7: Project area, maintenance Figure A8: Pipes of road crossing stream crossing.

Figure A9: Road crossing during storm Figure A10: Project area, sanitary sewer event line.

Figure A11: Stable banks and vegetation Figure A12: Passive sediment sampler flood plain within study site. with study site.

114

Figure A13: Bank erosion on SBC with Figure A14: Bank erosion study site.

Figure A15: Northern flood plain stable Figure A16: Sanitary sewer crossing at vegetation and southern flood plain small bank top and trailer park on the southern band of trees. flood plain.

Figure A17: Downstream of project area, Figure A18: Downstream sampling station flowing under I-40. at Farragut Street.

115

Figure A19: Operation of Obermeyer Hydro Figure 20A: Gate assembly of Obermeyer Inc. water control structure.* Hydro Inc. structure.*

Figure A21: Inflatable bladder that operates the water control structure.* *Pictures obtained from www.obermeyerhydro.com

116 APPENDIX B: WATER QUALTIY RESULTS

Table B1: Ambient Stream Conditions for South Buffalo Creek and Reference Sites AMBIENT Stream Condtions Fecal Coliform (CFU/100ml) Min 25% Median 75% Max Mean Count Upstream SBC 33 90 260 2550 5100 1431 11 Project 9 137 440 1025 2400 768 11 SBC Up WWTP 17 83 240 515 4800 986 11 Reference 4 33 84 165 710 151 18 Reference 33 89 125 238 940 196 18

Nitrate + Nitrite (mg/l) Min 25% Median 75% Max Mean Count Upstream SBC <0.1 0.10 0.19 0.40 0.80 0.30 12 Project <0.1 0.15 0.26 0.31 0.37 0.24 12 SBC Up WWTP <0.1 0.11 0.19 0.40 0.97 0.31 12 Reference 0.03 0.08 0.10 0.15 0.50 0.10 15 Reference 0.01 0.03 0.08 0.12 0.25 0.10 20

TKN (mg/l) Min 25% Median 75% Max Mean Count Upstream SBC 0.30 0.50 0.50 0.70 0.90 0.59 11 Project 0.30 0.50 0.50 0.55 0.90 0.55 11 SBC Up WWTP 0.4 0.5 0.5 0.65 0.8 0.6 11 Reference 0.30 0.33 0.45 0.63 1.00 0.50 14 Reference 0.20 0.30 0.39 0.58 0.90 0.74 18

Phosphorus, Total (mg/l) Min 25% Median 75% Max Mean Count Upstream SBC 0.02 0.04 0.05 0.07 0.15 0.06 17 Project 0.02 0.03 0.04 0.07 0.09 0.05 17 SBC Up WWTP 0.01 0.03 0.05 0.07 0.11 0.05 16 Reference 0.01 0.03 0.04 0.05 0.50 0.07 15 Reference 0.01 0.02 0.03 0.05 0.10 0.04 20

Suspended Solids, Total (mg/l) Min 25% Median 75% Max Mean Count Upstream SBC 1 4 7 10 76 15 12 Project 1 1 2 4 22 4 14 SBC Up WWTP 1 1 2 3 14 3 13 Reference 2 4 5 7.5 8 5 8 Reference 4 5 6 10 11 7 9

Turbidity (NTU) Min 25% Median 75% Max Mean Count Upstream SBC 5.2 8.3 21.3 55.5 194.0 51.3 12.0 Project 4.7 4.0 5.5 8.0 45.0 8.0 12.0 SBC Up WWTP 2.8 4.8 7.2 11.1 129.0 18.6 12.0 Reference 1.0 5.4 8.3 8.9 16.0 8.0 19.0 Reference 3.1 11.5 16.0 20.0 30.0 16.4 21.0

116

Table B2: Ambient Stream Results for South Buffalo Creek at Proposed Stormwater Treatment Wetland

Date Average St Dev 25% median 75% Max count Units Cadmium 0.00012 0.00015 0.00004 0.00006 0.00012 0.0005 16 mg/l Copper 0.0035 0.0023 0.0020 0.0028 0.0040 0.0100 14 mg/l Lead 0.0009 0.0008 0.0003 0.0006 0.0011 0.0026 13 mg/l Zinc 0.009 0.006 0.005 0.005 0.013 0.021 14 mg/l Alkalinity 56 18 43 57 68 84 12 mg/l BOD 2.7 1.3 2 2 2.9 6.4 12 mg/l COD 22.5 5.8 20 20 20 40.2 16 mg/l Fecal Coliform 768 904 136 440 1025 2400 11 CFU/100ml hardness 76 22 64.5 67 88 121 11 mg/l Nitrate Nitrogen 0.27 0.19 0.11 0.23 0.38 0.78 14 mg/l Nitrite Nitrogen 0.1 0 0.1 0.1 0.1 0.1 17 mg/l TDS 145.4 39.6 122.5 140 159.5 225 11 mg/l TSS 4.3 6.4 1 1.5 3.75 22 14 mg/l TKN 0.55 0.19 0.5 0.5 0.55 0.9 11 mg/l T. Phosphorus 0.05 0.02 0.03 0.04 0.07 0.09 17 mg/l pH 12.4 7.6 6.7 7.2 18.4 24.8 12 su Temperature 12.9 6.8 7.6 11.0 16.1 28.9 12 Celsius DO 49 45 9 41 82 128 12 % Turbidity 17 20 7 11 15 77 12 NTU Conductivity 222 49 198 236 246 295 12 µmhos/cm Last Rain 8 9.65 4 5.5 8 45 18 days

117

Table B3: Project Area Stormwater Results MIN 1st quartile Median 3rd quartile MAX Average Count Units FC 2800 3450 4100 4600 5100 4000 3 CFU/100ml Ammonia 0.18 0.5 0.5 0.5 0.5 0.45 7 mg/l T-P 0.08 0.15 0.2 0.23 0.26 0.18 5 mg/l Ortho-P 0.04 0.04 0.06 0.07 0.1 0.06 5 mg/l TKN 0.70 0.83 0.95 1.08 1.30 0.97 6 mg/l BOD 7.5 7.5 7.5 7.5 7.5 7.5 1 mg/l Nox 0.30 0.34 0.40 0.57 0.74 0.46 6 mg/l TSS 18.9 83.5 112 171.5 362 143 7 mg/l Cd 0.00008 0.00013 0.00015 0.00015 0.00050 0.00019 6 g/l Cr 0.0067 0.0069 0.0071 0.0072 0.0074 0.0071 2 g/l Cu 0.005 0.008 0.011 0.015 0.016 0.011 6 g/l Fe 1 2 3.7 4.7 6.5 3.6 5 mg/l Pb 0.002 0.005 0.007 0.009 0.010 0.007 6 g/l Ni 0.002 0.004 0.005 0.005 0.006 0.004 5 mg/l Zn 0.0056 0.03125 0.0375 0.0535 0.088 0.043 6 g/l Turbidity 16 19.75 29.5 49.75 130 46.3 6 NTU

118 Table B4: Comparison of Median Storm Concentrations

Storm:Median Values Upstream Project Downstream Reference Units Ammonia-Nitrogen 0.5 0.5 0.5 0.5 mg/l Nitrate+Nitrite-nitrogen 0.415 0.36 0.45 0.47 mg/l TSS 104 109 124 165 mg/l Total Kjeldahl Nitrogen 1.3 0.9 1.25 0.7 mg/l Phosphorus, total 0.175 0.2 0.17 0.1 mg/l Cadmium 0.00019 0.00015 0.00019 0.00006 mg/l Chromium 0.00535 0.0074 0.00515 0.0056 mg/l Copper 0.0115 0.009 0.0105 0.004 mg/l Lead 0.00635 0.0067 0.0078 0.0051 mg/l Nickel 0.006 0.005 0.004 0.002 mg/l Zinc 0.055 0.032 0.0435 0.013 mg/l Turbidity 148 25 79.6 205 mg/l

Storm:1st Quartile Values Upstream Project Downstream Reference Units Ammonia-Nitrogen 0.5 0.5 0.3 0.315 mg/l Nitrate+Nitrite-nitrogen 0.2575 0.33 0.28 0.215 mg/l TSS 80.5 58 64.25 81.25 mg/l Total Kjeldahl Nitrogen 1.125 0.8 1.075 0.55 mg/l Phosphorus, total 0.1075 0.15 0.1275 0.05 mg/l Cadmium 0.00013 0.00012 0.00013 0.00004 mg/l Copper 0.008 0.007 0.008 0.003 mg/l Lead 0.0046 0.0048 0.0058 0.0014 mg/l Nickel 0.004 0.004 0.003 0.002 mg/l Zinc 0.042 0.031 0.034 0.009 mg/l Turbidity 90.5 18 54.2 90.8 mg/l

Storm: 3rd Quartile Values Upstream Project Downstream Reference Units Ammonia-Nitrogen 0.5 0.5 0.5 0.5 mg/l Nitrate+Nitrite-nitrogen 0.59 0.44 0.6325 0.73 mg/l TSS 183.5 112 235.25 475.5 mg/l Total Kjeldahl Nitrogen 1.775 1.1 1.775 1.6 mg/l Phosphorus, total 0.2425 0.23 0.3725 0.24 mg/l Cadmium 0.00036 0.00015 0.00027 0.00008 mg/l Copper 0.022 0.009 0.015 0.009 mg/l Lead 0.0143 0.0079 0.015 0.0135 mg/l Nickel 0.010 0.005 0.006 0.006 mg/l Zinc 0.07875 0.043 0.0595 0.027 mg/l Turbidity 295.5 34 148 673 mg/l

119 Table B5: Estimation of Total Stream Flow for South Buffalo Creek at the Proposed Stormwater Treatment Wetland

ft3 m3 ft3/s m3/s

1999 644,269,128 18,245,702 20.43 0.58 2000 629,176,925 17,818,291 19.95 0.57 Mean 636,723,027 18,031,997 20.19 0.57

Table B6: Annual Load of Pollutants in South Buffalo Creek at the Proposed Stormwater Treatment Wetland

EMC Mean annual Load to stream Parameter (mg/l) storm flow (L) (mg) Kg/yr lb/yr tons/yr MT/yr TSS 110.5 18,031,997,000 1,992,535,668,500 1,992,536 4,388,845 2,194 1,997 Ammonia 0.5 18,031,997,000 9,015,998,500 9,016 19,859 10 9 TKN 0.95 18,031,997,000 17,130,397,150 17,130 37,732 19 17 Nox 0.4 18,031,997,000 7,212,798,800 7,213 15,887 8 7 T-P 0.2 18,031,997,000 3,606,399,400 3,606 7,944 4 4 Ortho-P 0.06 18,031,997,000 1,081,919,820 1,082 2,383 1.2 1.1 BOD 7.5 18,031,997,000 135,239,977,500 135,240 297,885 149 136 Cd 0.00015 18,031,997,000 2,704,800 3 6 0.003 0.003 Cr 0.00705 18,031,997,000 127,125,579 127 280 0.140 0.127 Cu 0.011 18,031,997,000 198,351,967 198 437 0.218 0.199 Fe 3.7 18,031,997,000 66,718,388,900 66,718 146,957 73 67 Pb 0.0073 18,031,997,000 131,633,578 132 290 0.14 0.13 Ni 0.005 18,031,997,000 90,159,985 90 199 0.10 0.09 Zn 0.0375 18,031,997,000 676,199,888 676 1,489 0.74 0.68

Table B7: Annual Yield of Pollutants in South Buffalo Creek at the Proposed Stormwater Treatment Wetland Parameter EMC (mg/l) kg/km2/yr lb/mi2/yr tons/mi2/yr MT/km2/yr g/m2/yr TSS 110.5 56,930 325,100 163 57 57 Ammonia 0.5 258 1,471 0.74 0.26 0.26 TKN 0.95 489 2,795 1.40 0.49 0.49 Nox 0.4 206 1,177 0.59 0.21 0.21 T-P 0.2 103 588 0.29 0.10 0.10 Ortho-P 0.06 31 177 0.09 0.03 0.03 BOD 7.5 3,864 22,066 11 4 3.86 Cd 0.00015 0.1 0.4 0.00022 0.00008 0.00008 Cr 0.00705 4 21 0.010 0.004 0.004 Cu 0.011 6 32 0.016 0.006 0.006 Fe 3.7 1,906 10,886 5 2 1.91 Pb 0.0073 4 21 0.011 0.004 0.004 Ni 0.005 3 15 0.007 0.003 0.003 Zn 0.0375 19 110 0.055 0.019 0.019

120

Table B8: Annual Estimate of Total Load to Proposed Stormwater Treatment Wetland of South Buffalo Creek (7.7% of SBC Pollutant Load)

Parameter EMC (mg/l) Kg/yr lb/yr tons/yr MT/yr TSS 110.5 154,422 340,135 170 155 Ammonia 0.5 699 1,539 0.77 0.70 TKN 0.95 1,328 2,924 1.46 1.33 Nox 0.4 559 1,231 0.62 0.56 T-P 0.2 279 616 0.31 0.28 Ortho-P 0.06 84 185 0.09 0.08 BOD 7.5 10,481 23,086 12 11 Cd 0.0002 0.2096 0.4617 0.0002 0.0002 Cr 0.0071 9.8522 21.7010 0.0109 0.0099 Cu 0.011 15 34 0 0 Fe 3.7 5,171 11,389 6 5 Pb 0.0073 10 22 0.01 0.01 Ni 0.005 7 15 0.01 0.01 Zn 0.0375 52 115 0.06 0.05

Table B9: Annual Estimate of Yield Load to Proposed Stormwater Treatment Wetland of South Buffalo Creek (7.7% of SBC Pollutant Yield)

Parameter EMC (mg/l) kg/km2/yr lb/mi2/yr tons/mi2/yr MT/km2/yr g/m2/yr TSS 110.5 4,412 25,195 12.6 4 4.41 Ammonia 0.5 19.96 114.01 0.06 0.02 0.02 TKN 0.95 37.93 216.61 0.11 0.04 0.04 Nox 0.4 15.97 91.20 0.05 0.02 0.02 T-P 0.2 7.99 45.60 0.02 0.01 0.01 Ortho-P 0.06 2.40 13.68 0.007 0.002 0.002 BOD 7.5 299 1,710 0.86 0.30 0.30 Cd 0.0002 0.01 0.03 0.00002 0.00001 0.00001 Cr 0.0071 0.28 1.61 0.0008 0.0003 0.0003 Cu 0.011 0 3 0.0013 0.0004 0.0004 Fe 3.7 148 844 0.42 0.15 0.15 Pb 0.0073 0.29 1.66 0.0008 0.0003 0.0003 Ni 0.005 0.20 1.14 0.0006 0.0002 0.0002 Zn 0.0375 1.50 8.55 0.0043 0.0015 0.0015

121

APPENDIX C: TOTAL SUSPENDED SOLIDS

Figure C-1: Storm Hydrograph and TSS Concentration on September 20, 2001 (Rain Total = 1.32 cm) 400 2.00

TSS (mg/l) 1.80 350 Stage (m) 1.60 300 1.40 250 1.20

200 1.00 TSS mg/l 0.80 Stage (m) 150 0.60 100 0.40 50 0.20

0 0.00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 COMP

Figure C-2. Storm Hydrograph and TSS Concentration on December, 10-11 2001 (Rain Total = 3.51 cm)

400 2.0

1.8 350 TSS (mg/L) 1.6 300 Level (m) 1.4 250 1.2

200 1.0 Level (m) TSS mg/L 0.8 150 0.6 100 0.4 50 0.2

0 0.0 17:00 18:30 20:00 21:30 23:00 0:30 2:00 3:30 COMP

122 Figure C-3 : Storm Hydrograph and TSS Concentrations on December 18, 2002 (Rain Total = 1.27 cm)

400 2.00

TSS (mg/l) 1.80 350 Stage (m) 1.60 300 1.40 250 1.20

200 1.00 Stage (m) TSS (mg/l) 0.80 150 0.60 100 0.40 50 0.20

0 0.00 21:30 23:00 0:30 2:00 3:30 5:00 6:30 8:00

Figure C-4: Storm Hydrograph and TSS concentrations on February 6-7, 2002 (Rain Total = 2.11 cm) 400 2 TSS (mg/) 1.8 350 Stage (m) 1.6 300 1.4 250 1.2

200 1 Stage (m) TSS (mg/l) 0.8 150 0.6 100 0.4 50 0.2

0 0 21:00 22:30 0:00 1:30 3:00 4:30 6:00 7:30

123 Figure C-5 : Storm Hydrograph and TSS Concentration on March 2-3, 2002 (Rain Total = 3.25 cm)

400 2.0

TSS (mg/l) 1.8 350 Stage (m) 1.6 300 1.4 250 1.2

200 1.0 Stage (m) TSS (mg/l) 0.8 150 0.6 100 0.4 50 0.2

0 0.0

16:00 17:29 19:00 20:29 22:00 23:29 1:00 2:29 COMP

Figure C-6 : Storm Hydrograph and TSS Concentration on March 31, 2002 (Rain Total = 0.64 cm)

400 2.0000

TSS (mg/l) 1.8000 350 Stage (m) 1.6000 300 1.4000 250 1.2000

200 1.0000 Stage (m)

TSS (mg/l) 0.8000 150 0.6000 100 0.4000 50 0.2000

0 0.0000 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00

124 Figure C-7: Storm Hydrograph and TSS concentrations on May 2, 2002 (Rain Total = 0.69 cm)

400 2.000

TSS (Mg/l) 1.800 350 Stage (m) 1.600 300 1.400 250 1.200

200 1.000 mg/l

0.800 Stage (m) 150 0.600 100 0.400 50 0.200

0 0.000 1:00 3:00 4:00 6:00 7:00 9:00 10:00 12:00

Figure C-8 : Storm Hydrograph and TSS Concentration on May 4-5, 2002 (Rain Total = 0.99 cm)

400 2.0

TSS (mg/l) 1.8 350 Stage (m) 1.6 300 1.4 250 1.2

200 1.0 Stage (m) TSS (mg/l) 0.8 150 0.6 100 0.4 50 0.2

0 0.0 15:00 16:30 18:00 19:30 21:00 22:30 0:00 1:30 COMP

125 Figure C-9 : Storm Hydrograph and TSS Concentration on May 30-31, 2002 (Rain Total = 0.64 cm)

400 2 TSS (mg/l) 1.8 350 Stage (m) 1.6 300 1.4 250 1.2

200 1 Stage (m) TSS (mg/l) 0.8 150 0.6 100 0.4 50 0.2

0 0 17:00 18:00 19:00 20:00 21:00 22:00 23:00 0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00

Figure C-10 : Storm Hydrograph and TSS Concentrations on June 6-7, 2002 (Rain Total = 0.20 cm)

400 2.0 TSS (mg/l) 1.8 350 Stage (m) 1.6 300 1.4 250 1.2

200 1.0 Stage (m) TSS (mg/l) 0.8 150 0.6 100 0.4 50 0.2

0 0.0 21:30 22:59 0:30 1:59 3:30 4:59 6:30 7:59 COMP

126

Table C-1: TSS concentrations for hyrdrographs downstream of the project (mg/l)

Date/Hours 0 1.5 3 4.5 5 6.5 8 9.5 Composite 9/20/2001 320 62 106 88 64 42 30 *** 102 12/11/2001 3 311 66 288 376 120 139 64 205 12/18/2001 173 205 164 84 63 49 34 15 122 2/7/2002 20 37 33 113 89 71 53 41 95 3/2/2002 14 57 164 178 103 63 40 35 127 3/31/2002 13 13 16 7 9 5 4 5 *** 5/2/2002 229 386 249 141 99 64 51 38 *** 5/4/2002 78 51 52 35 25 19 19 36 46 5/30/2002 52 21 12 *** *** 7 6 5 13 6/6/2002 164 115 61 54 56 33 31 30 93 Units mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l *** = no data

Table C2: Single Factor ANOVA for Station Effect Degree Freedom Sum of Squares Mean Square F-Value Station 5 3725152 745030 4.218 Residual 331 58470341 176647

127

Table C3: Fisher’s Mulitple Comparison Test for Total Solids (mg/l) Effect: Station-Bottle Significance Level: 5 % S = Significant NS = Not Station-Bottle Mean Diff. Critical. Diff. P-Value Significant 1-1, 1-2 1.6 284.2 0.991 NS 1-1, 1-3 -22.5 393.8 0.911 NS 1-1, 1-4 15.5 588.4 0.959 NS 1-1, 2-1 -14.2 238.0 0.907 NS 1-1, 2-2 -221.9 327.6 0.184 NS 1-1, 2-3 -465.5 588.4 0.121 NS 1-1, 4-1 -227.5 224.6 0.047 S 1-1, 4-2 -287.4 251.2 0.025 S 1-1, 4-3 -456.7 264.9 0.001 S 1-1, 4-4 -507.5 432.4 0.022 S 1-1, 5-1 -135.5 224.6 0.236 NS 1-1, 5-2 -276.1 251.2 0.031 S 1-1, 5-3 -341.0 270.5 0.014 S 1-1, 5-4 -504.7 365.9 0.007 S 1-1, 6-1 -81.2 221.2 0.471 NS 1-1, 6-2 -352.8 244.0 0.005 S 1-1, 6-3 -579.5 284.2 <.0001 S 1-1, 6-4 -503.8 344.5 0.004 S 1-1, 7-1 22.0 222.8 0.846 NS 1-1, 7-2 -222.0 251.2 0.083 NS 1-1, 7-3 -439.7 313.8 0.006 S 1-1, 7-4 -387.7 365.9 0.038 S 1-2, 1-3 -24.2 424.8 0.911 NS 1-2, 1-4 13.8 609.6 0.964 NS 1-2, 2-1 -15.8 286.4 0.914 NS 1-2, 2-2 -223.5 364.3 0.228 NS 1-2, 2-3 -467.2 609.6 0.133 NS 1-2, 4-1 -229.1 275.4 0.103 NS 1-2, 4-2 -289.0 297.4 0.057 NS 1-2, 4-3 -458.4 309.1 0.004 S 1-2, 4-4 -509.2 460.8 0.030 S 1-2, 5-1 -137.1 275.4 0.328 NS 1-2, 5-2 -277.7 297.4 0.067 NS 1-2, 5-3 -342.7 314.0 0.033 S 1-2, 5-4 -506.3 399.1 0.013 S 1-2, 6-1 -82.8 272.6 0.551 NS 1-2, 6-2 -354.5 291.4 0.017 S 1-2, 6-3 -581.2 325.8 0.001 S 1-2, 6-4 -505.5 379.6 0.009 S 1-2, 7-1 20.3 273.9 0.884 NS 1-2, 7-2 -223.7 297.4 0.140 NS 1-2, 7-3 -441.4 351.9 0.014 S 1-2, 7-4 -389.3 399.1 0.056 NS 1-3, 1-4 38.0 667.8 0.911 NS 1-3, 2-1 8.4 395.4 0.967 NS 1-3, 2-2 -199.4 455.0 0.389 NS 1-3, 2-3 -443.0 667.8 0.193 NS 1-3, 4-1 -204.9 387.5 0.299 NS 1-3, 4-2 -264.8 403.5 0.198 NS

128 Table C3 (continued) 1-3, 4-3 -434.2 412.1 0.039 S 1-3, 4-4 -485.0 535.4 0.076 NS 1-3, 5-1 -113.0 387.5 0.567 NS 1-3, 5-2 -253.5 403.5 0.217 NS 1-3, 5-3 -318.5 415.8 0.133 NS 1-3, 5-4 -482.2 483.3 0.051 NS 1-3, 6-1 -58.6 385.5 0.765 NS 1-3, 6-2 -330.3 399.1 0.104 NS 1-3, 6-3 -557.0 424.8 0.010 S 1-3, 6-4 -481.3 467.3 0.044 S 1-3, 7-1 44.5 386.5 0.821 NS 1-3, 7-2 -199.5 403.5 0.331 NS 1-3, 7-3 -417.2 445.2 0.066 NS 1-3, 7-4 -365.2 483.3 0.138 NS 1-4, 2-1 -29.6 589.4 0.921 NS 1-4, 2-2 -237.4 631.0 0.460 NS 1-4, 2-3 -481.0 798.1 0.237 NS 1-4, 4-1 -242.9 584.2 0.414 NS 1-4, 4-2 -302.8 594.9 0.317 NS 1-4, 4-3 -472.2 600.8 0.123 NS 1-4, 4-4 -523.0 691.2 0.138 NS 1-4, 5-1 -151.0 584.2 0.612 NS 1-4, 5-2 -291.5 594.9 0.336 NS 1-4, 5-3 -356.5 603.3 0.246 NS 1-4, 5-4 -520.2 651.7 0.117 NS 1-4, 6-1 -96.6 582.9 0.745 NS 1-4, 6-2 -368.3 591.9 0.222 NS 1-4, 6-3 -595.0 609.6 0.056 NS 1-4, 6-4 -519.3 639.9 0.111 NS 1-4, 7-1 6.5 583.5 0.983 NS 1-4, 7-2 -237.5 594.9 0.433 NS 1-4, 7-3 -455.2 623.9 0.152 NS 1-4, 7-4 -403.2 651.7 0.224 NS 2-1, 2-2 -207.7 329.5 0.216 NS 2-1, 2-3 -451.4 589.4 0.133 NS 2-1, 4-1 -213.3 227.4 0.066 NS 2-1, 4-2 -273.2 253.7 0.035 S 2-1, 4-3 -442.6 267.2 0.001 S 2-1, 4-4 -493.4 433.8 0.026 S 2-1, 5-1 -121.3 227.4 0.295 NS 2-1, 5-2 -261.9 253.7 0.043 S 2-1, 5-3 -326.9 272.9 0.019 S 2-1, 5-4 -490.5 367.6 0.009 S 2-1, 6-1 -67.0 224.0 0.557 NS 2-1, 6-2 -338.7 246.6 0.007 S 2-1, 6-3 -565.4 286.4 0.000 S 2-1, 6-4 -489.6 346.3 0.006 S 2-1, 7-1 36.1 225.7 0.753 NS 2-1, 7-2 -207.9 253.7 0.108 NS 2-1, 7-3 -425.6 315.8 0.008 S 2-1, 7-4 -373.5 367.6 0.046 S 2-2, 2-3 -243.6 631.0 0.448 NS 2-2, 4-1 -5.6 320.0 0.973 NS 2-2, 4-2 -65.5 339.1 0.704 NS

129 Table C3 (continued) 2-2, 4-3 -234.8 349.4 0.187 NS 2-2, 4-4 -285.6 488.7 0.251 NS 2-2, 5-1 86.4 320.0 0.596 NS 2-2, 5-2 -54.2 339.1 0.754 NS 2-2, 5-3 -119.1 353.7 0.508 NS 2-2, 5-4 -282.8 431.0 0.198 NS 2-2, 6-1 140.7 317.6 0.384 NS 2-2, 6-2 -130.9 333.9 0.441 NS 2-2, 6-3 -357.6 364.3 0.054 NS 2-2, 6-4 -281.9 413.1 0.180 NS 2-2, 7-1 243.8 318.7 0.133 NS 2-2, 7-2 -0.1 339.1 0.999 NS 2-2, 7-3 -217.8 387.8 0.270 NS 2-2, 7-4 -165.8 431.0 0.450 NS 2-3, 4-1 238.1 584.2 0.423 NS 2-3, 4-2 178.2 594.9 0.556 NS 2-3, 4-3 8.8 600.8 0.977 NS 2-3, 4-4 -42.0 691.2 0.905 NS 2-3, 5-1 330.1 584.2 0.267 NS 2-3, 5-2 189.5 594.9 0.531 NS 2-3, 5-3 124.5 603.3 0.685 NS 2-3, 5-4 -39.2 651.7 0.906 NS 2-3, 6-1 384.4 582.9 0.195 NS 2-3, 6-2 112.7 591.9 0.708 NS 2-3, 6-3 -114.0 609.6 0.713 NS 2-3, 6-4 -38.3 639.9 0.906 NS 2-3, 7-1 487.5 583.5 0.101 NS 2-3, 7-2 243.5 594.9 0.421 NS 2-3, 7-3 25.8 623.9 0.935 NS 2-3, 7-4 77.8 651.7 0.814 NS 4-1, 4-2 -59.9 241.1 0.625 NS 4-1, 4-3 -229.3 255.4 0.078 NS 4-1, 4-4 -280.1 426.6 0.197 NS 4-1, 5-1 92.0 213.3 0.397 NS 4-1, 5-2 -48.6 241.1 0.692 NS 4-1, 5-3 -113.6 261.2 0.393 NS 4-1, 5-4 -277.2 359.0 0.130 NS 4-1, 6-1 146.3 209.7 0.171 NS 4-1, 6-2 -125.4 233.7 0.292 NS 4-1, 6-3 -352.1 275.4 0.012 S 4-1, 6-4 -276.4 337.3 0.108 NS 4-1, 7-1 249.4 211.5 0.021 S 4-1, 7-2 5.4 241.1 0.965 NS 4-1, 7-3 -212.3 305.8 0.173 NS 4-1, 7-4 -160.2 359.0 0.381 NS 4-2, 4-3 -169.4 279.0 0.233 NS 4-2, 4-4 -220.2 441.2 0.327 NS 4-2, 5-1 151.9 241.1 0.216 NS 4-2, 5-2 11.3 266.0 0.934 NS 4-2, 5-3 -53.7 284.4 0.711 NS 4-2, 5-4 -217.3 376.2 0.257 NS 4-2, 6-1 206.2 238.0 0.089 NS 4-2, 6-2 -65.5 259.3 0.620 NS 4-2, 6-3 -292.2 297.4 0.054 NS

130 Table C3 (continued) 4-2, 6-4 -216.5 355.5 0.232 NS 4-2, 7-1 309.3 239.5 0.012 S 4-2, 7-2 65.3 266.0 0.629 NS 4-2, 7-3 -152.4 325.8 0.358 NS 4-2, 7-4 -100.3 376.2 0.600 NS 4-3, 4-4 -50.8 449.1 0.824 NS 4-3, 5-1 321.3 255.4 0.014 S 4-3, 5-2 180.7 279.0 0.204 NS 4-3, 5-3 115.7 296.6 0.443 NS 4-3, 5-4 -48.0 385.5 0.807 NS 4-3, 6-1 375.6 252.4 0.004 S 4-3, 6-2 103.9 272.6 0.454 NS 4-3, 6-3 -122.8 309.1 0.435 NS 4-3, 6-4 -47.1 365.3 0.800 NS 4-3, 7-1 478.7 253.8 0.000 S 4-3, 7-2 234.7 279.0 0.099 NS 4-3, 7-3 17.0 336.5 0.921 NS 4-3, 7-4 69.0 385.5 0.725 NS 4-4, 5-1 372.1 426.6 0.087 NS 4-4, 5-2 231.5 441.2 0.303 NS 4-4, 5-3 166.5 452.5 0.470 NS 4-4, 5-4 2.8 515.2 0.991 NS 4-4, 6-1 426.4 424.8 0.049 S 4-4, 6-2 154.7 437.1 0.487 NS 4-4, 6-3 -72.0 460.8 0.759 NS 4-4, 6-4 3.7 500.2 0.988 NS 4-4, 7-1 529.5 425.7 0.015 S 4-4, 7-2 285.5 441.2 0.204 NS 4-4, 7-3 67.8 479.6 0.781 NS 4-4, 7-4 119.8 515.2 0.648 NS 5-1, 5-2 -140.6 241.1 0.252 NS 5-1, 5-3 -205.6 261.2 0.123 NS 5-1, 5-4 -369.2 359.0 0.044 S 5-1, 6-1 54.3 209.7 0.611 NS 5-1, 6-2 -217.4 233.7 0.068 NS 5-1, 6-3 -444.1 275.4 0.002 S 5-1, 6-4 -368.3 337.3 0.032 S 5-1, 7-1 157.4 211.5 0.144 NS 5-1, 7-2 -86.6 241.1 0.481 NS 5-1, 7-3 -304.3 305.8 0.051 NS 5-1, 7-4 -252.2 359.0 0.168 NS 5-2, 5-3 -65.0 284.4 0.654 NS 5-2, 5-4 -228.6 376.2 0.233 NS 5-2, 6-1 194.9 238.0 0.108 NS 5-2, 6-2 -76.8 259.3 0.561 NS 5-2, 6-3 -303.5 297.4 0.046 S 5-2, 6-4 -227.7 355.5 0.209 NS 5-2, 7-1 298.0 239.5 0.015 S 5-2, 7-2 54.0 266.0 0.690 NS 5-2, 7-3 -163.7 325.8 0.324 NS 5-2, 7-4 -111.6 376.2 0.560 NS 5-3, 5-4 -163.7 389.4 0.409 NS 5-3, 6-1 259.9 258.3 0.049 S 5-3, 6-2 -11.8 278.1 0.933 NS

131 Table C3 (continued) 5-3, 6-3 -238.5 314.0 0.136 NS 5-3, 6-4 -162.8 369.5 0.387 NS 5-3, 7-1 363.0 259.7 0.006 S 5-3, 7-2 119.0 284.4 0.411 NS 5-3, 7-3 -98.7 341.0 0.569 NS 5-3, 7-4 -46.7 389.4 0.814 NS 5-4, 6-1 423.5 356.9 0.020 S 5-4, 6-2 151.9 371.5 0.422 NS 5-4, 6-3 -74.8 399.1 0.712 NS 5-4, 6-4 0.9 444.0 0.997 NS 5-4, 7-1 526.6 358.0 0.004 S 5-4, 7-2 282.7 376.2 0.140 NS 5-4, 7-3 64.9 420.6 0.762 NS 5-4, 7-4 117.0 460.8 0.618 NS 6-1, 6-2 -271.7 230.4 0.021 S 6-1, 6-3 -498.4 272.6 0.000 S 6-1, 6-4 -422.7 335.0 0.014 S 6-1, 7-1 103.1 207.8 0.330 NS 6-1, 7-2 -140.9 238.0 0.245 NS 6-1, 7-3 -358.6 303.3 0.021 S 6-1, 7-4 -306.5 356.9 0.092 NS 6-2, 6-3 -226.7 291.4 0.127 NS 6-2, 6-4 -151.0 350.5 0.397 NS 6-2, 7-1 374.8 232.0 0.002 S 6-2, 7-2 130.8 259.3 0.322 NS 6-2, 7-3 -86.9 320.4 0.594 NS 6-2, 7-4 -34.9 371.5 0.854 NS 6-3, 6-4 75.7 379.6 0.695 NS 6-3, 7-1 601.5 273.9 <.0001 S 6-3, 7-2 357.5 297.4 0.019 S 6-3, 7-3 139.8 351.9 0.435 NS 6-3, 7-4 191.8 399.1 0.345 NS 6-4, 7-1 525.8 336.1 0.002 S 6-4, 7-2 281.8 355.5 0.120 NS 6-4, 7-3 64.1 402.2 0.754 NS 6-4, 7-4 116.1 444.0 0.607 NS 7-1, 7-2 -244.0 239.5 0.046 S 7-1, 7-3 -461.7 304.5 0.003 S 7-1, 7-4 -409.6 358.0 0.025 S 7-2, 7-3 -217.7 325.8 0.190 NS 7-3, 7-4 52.1 420.6 0.808 NS

Table C4: Correction Coefficients for Hypothesized Correlation = 0. Correlation Count Z-Value P-Value 95% Lower 95% Upper TSS, Discharge 0.123 336 2.256 0.0241 0.016 0.227 TSS, Days Dry -0.118 336 -2.163 0.0306 -0.222 -0.011 TSS, Rain Amount 0.11 327 1.987 0.469 0.001 0.216

132

APPENDIX D: MACROINVERTEBRATE RESULTS

Table D1: Complete list of macroinvertebrate species upstream of the proposed stormwater treatment wetland between Meadowview Avenue and I-40.

Phylum Class Order Family Genus/Species T.V.** F.F.G. 2000 2001 *** Mollusca Bivalvia Veneroida Corbiculidae Corbicula fluminea 6.12 FC 7 2 Mollusca Physidae Physella sp. 8.84 CG 5 4 Mollusca Gastropoda Limnophila Ancylidae Ferrissia spp. 6.6 CG 1 Annelida Oligochaeta Haplotaxida Lumbricidae 7.03 CG 6 9 Annelida Oligochaeta Lumbriculida Lumbriculidae Stylodrilus 7.03 CG 1 heringianus Annelida Oligochaeta Haplotaxida Naididae Nais sp. 8.88 CG 2 Annelida Oligochaeta Haplotaxida Naididae Allonais pectinata . CG 1 Annelida Oligochaeta Haplotaxida Naididae Bratislavia 6 CG 1 unidentata Annelida Oligochaeta Haplotaxida Naididae Dero furcata . CG 1 Annelida Oligochaeta Haplotaxida Naididae . CG 1 Annelida Oligochaeta Haplotaxida Naididae Nais variabilis 8.9 CG 1 Annelida Oligochaeta Haplotaxida Naididae Pristina leidyi 9.56 CG 1 Annelida Oligochaeta Haplotaxida Naididae Slavina 7.06 CG 1 appendiculata Annelida Oligochaeta Haplotaxida Tubificidae w.o.h.c. 7.11 CG 4 Annelida Oligochaeta Haplotaxida Tubificidae 5.8 CG 18 Annelida Oligochaeta Haplotaxida Tubificidae Branchirua 8.4 CG 1 sowerbyi Annelida Oligochaeta Haplotaxida Tubificidae Limnodrilus 9.4 CG 2 hoffmeisterei Annelida Oligochaeta Haplotaxida Tubificidae Tubifex tubifex 10 CG 1 Annelida Hirudinea Branchiobdellida Erpobdellidae Erpobdella spp. 8.33 P 17 Arthropoda Acari 5.5 P 1 Arthropoda Crustacea Amphipoda Crangonyctidae Crangonyx sp. 7.87 CG 1 Arthropoda Crustacea Decapoda Cambaridae 8.1 CG 1 2 Arthropoda Insecta Ephemeroptera Baetidae Baetis c.f. 6.58 CG 20 flavistriga Arthropoda Insecta Ephemeroptera Baetidae Baetis intercalaris 5 OM 8 Arthropoda Insecta Odonata Aeshnidae Aeshna sp. *4 P 4 Arthropoda Insecta Odonata Coenagrionidae Enallagma sp. 8.91 P 2 Arthropoda Insecta Odonata Corduliidae Neurocordulia spp. 5.8 P 3 Arthropoda Insecta Odonata Coenagrionidae Argia spp. 8.2 P 1 Arthropoda Insecta Odonata Coenagrionidae Ischnura spp. 9.6 P 3 Arthropoda Insecta Trichoptera Hydropsychidae *4 FC 3 Arthropoda Insecta Trichoptera Hydropsychidae Cheumatopsyche 6.22 FC 1 95 sp. Arthropoda Insecta Trichoptera Hydropsychidae Hydropsyche 7.78 FC 101 33 betteni gp. Arthropoda Insecta Diptera Chironomidae CG 3 Arthropoda Insecta Diptera Chironomidae Ablabesmyia spp. 8.4 CG 11 Arthropoda Insecta Diptera Chironomidae Ablabesmyia 7.19 P 5 1 mallochi Arthropoda Insecta Diptera Chironomidae Chironomus spp. 9.6 CG 11

133 Table D1 (continued) Arthropoda Insecta Diptera Chironomidae Conchapelopia gp. 8.3 P 11 Arthropoda Insecta Diptera Chironomidae Cricotopus sp. *7 CG 5 Arthropoda Insecta Diptera Chironomidae Cricotopus 8.54 CG 11 6 bicinctus Arthropoda Insecta Diptera Chironomidae Cricotopus . CG 5 reversus gp Arthropoda Insecta Diptera Chironomidae Cricotopus . CG 1 triannulator Arthropoda Insecta Diptera Chironomidae Cryptochironomus 6.38 P 4 fulvus Arthropoda Insecta Diptera Chironomidae Dicrotendipes 8.1 CG 3 neomodestus Arthropoda Insecta Diptera Chironomidae Nanocladius spp. 7.1 CG 5 Arthropoda Insecta Diptera Chironomidae Phaenopsectra sp. 6.5 SC 3 1 Arthropoda Insecta Diptera Chironomidae Polypedilum fallax 6.39 SH 3 Arthropoda Insecta Diptera Chironomidae Polypedilum 7.31 SH 10 halterale Arthropoda Insecta Diptera Chironomidae Polypedilum 9 SH 11 76 illinoense Arthropoda Insecta Diptera Chironomidae Rheocricotopus 7.28 CG 11 8 robacki Arthropoda Insecta Diptera Chironomidae Tanytarsus spp. 6.7 FC 1 Arthropoda Insecta Diptera Chironomidae Thienemannimyia 8.42 P 13 gp. Arthropoda Insecta Diptera Chironomidae Zavrelimyia spp. 9.1 P 5 Arthropoda Insecta Diptera Empididae 7.57 P 1 Arthropoda Insecta Diptera Empididae Hemerodromia sp. 7.57 P 1 3 Arthropoda Insecta Diptera Simuliidae Simulium sp. 4 FC 8 Arthropoda Insecta Diptera Tipulidae Antocha sp. 4.25 CG 1 1 Arthropoda Insecta Diptera Tipulidae Tipula sp. 7.33 SH 5 11

TOTAL NO. OF ORGANISMS 266 355 TOTAL TAXA RICHNESS 40 31 EPT TAXA RICHNESS 3 4

NCBI (using abundance value) 7.56 7.30 EPT SCORE 1 1 NCBI 1 2 SCORE MEAN SCORE 1.0 1.5 EPT N 13 33 FINAL BIOCLASSIFICATION P P

134 Table D2: Complete list of macroinvertebrate species upstream of the proposed stormwater treatment wetland on an unnamed tributary in downstream of Rolling Roads Park.

Phylum Class Order Family Genus/Species T.V.** F.F.G. 2000 2001 *** Platyhelminthes Turbellaria Tricladida Planariidae Dugesia spp. 7.2 OM 10 Mollusca Gastropoda Basommatophora Physidae Physella spp. 8.8 SC 20 Mollusca Bivalvia Veneroida Corbiculidae Corbicula fluminea 6.12 FC 10 20 Mollusca Gastropoda SC 4

Mollusca Gastropoda Basommatophora Ancylidae Ferrissia rivularis 6.55 SC 49 Annelida Oligochaeta Haplotaxida Naididae *8 CG 2 Annelida Oligochaeta Haplotaxida Naididae Aulodrilus pigueti 5.52 CG 1 Annelida Oligochaeta Haplotaxida Naididae Branchirua 8.4 CG 2 sowerbyi Annelida Oligochaeta Haplotaxida Naididae Homochaeta *8 CG 1 naidina Annelida Oligochaeta Haplotaxida Naididae Nais sp. 8.88 CG 3 1 Annelida Oligochaeta Haplotaxida Naididae Pristina sp. 9.56 CG 1 Annelida Oligochaeta Haplotaxida Naididae Pristina aequiseta 9.56 CG 3 Annelida Oligochaeta Haplotaxida Naididae Pristina breviseta 9.56 CG 1 Annelida Oligochaeta Haplotaxida Naididae Pristinella osborni 6 CG 2 Annelida Oligochaeta Haplotaxida Tubificidae 5.8 CG 10 Annelida Oligochaeta Haplotaxida Tubificidae w.o.h.c. 7.11 CG 15 Annelida Oligochaeta Lumbriculida Lumbriculidae 7.03 CG 2 Annelida Hirudinea Branchiobdellida Erpobdellidae Erpobdella spp. 8.33 P 41 56 Annelida Hirudinea Branchiobdellida Glossiphoniidae Helobdella *6 P 10 27 triserialis Arthropoda Crustacea Cladocera Bosminidae Bosmina FC 28 longirostris Arthropoda Crustacea Cladocera Daphnidae Ceriodaphnia sp. FC 8 Arthropoda Crustacea Cyclopoida FC 3 Arthropoda Crustacea Ostracoda CG 1 Arthropoda Crustacea Decapoda Cambaridae 8.1 CG 3 Arthropoda Crustacea Decapoda Cambaridae Procambarus sp. 9.49 SH 2 Arthropoda Crustacea Isopoda Asellidae Caecidotea spp. 9.1 CG 1 Arthropoda Insecta Ephemeroptera Baetidae Baetis c.f. 6.58 CG 42 flavistriga Arthropoda Insecta Ephemeroptera Baetidae Baetis intercalaris 5 OM 1 Arthropoda Insecta Ephemeroptera Caenidae Caenis spp. 7.4 CG 1 Arthropoda Insecta Heteroptera Notonectidae Notonecta irrorata 8.71 P 1 Arthropoda Insecta Odonata Coenagrionidae *9 P 11 Arthropoda Insecta Odonata Coenagrionidae Enallagma sp. 8.91 P 1 Arthropoda Insecta Odonata Coenagrionidae Ischnura sp. 9.52 P 8 Arthropoda Insecta Odonata Cordulegastridae Cordulegaster spp. 5.7 P 1 Arthropoda Insecta Odonata Gomphidae Progomphus 8.2 P 1 obscurus Arthropoda Insecta Odonata Gomphidae Stylogomphus 4.7 P 1 albistylus Arthropoda Insecta Odonata Libellulidae *9 P 2 Arthropoda Insecta Odonata Odonata Argia spp. 8.2 P 4 Arthropoda Insecta Odonata Odonata Ischnura spp. 9.6 P 4 Arthropoda Insecta Trichoptera Hydropsychidae *4 FC 21

135 Table D2 (continued) Arthropoda Insecta Trichoptera Hydropsychidae Cheumatopsyche 6.22 FC 153 sp. Arthropoda Insecta Trichoptera Hydropsychidae Hydropsyche 7.78 FC 57 63 betteni gp. Arthropoda Insecta Coleoptera Carabidae P 1 Arthropoda Insecta Coleoptera Elmidae Stenelmis sp. 5.1 SC 19 9 Arthropoda Insecta Coleoptera Hydrophilidae Berosus sp. 8.43 CG 3 36 Arthropoda Insecta Coleoptera Hydrophilidae Tropisternus sp. 9.68 P 2 Arthropoda Insecta Coleoptera Psephenidae Psephenus herricki 2.35 SC 1 3 Arthropoda Insecta Diptera Chironomidae Ablabesmyia 7.19 P 1 9 mallochi Arthropoda Insecta Diptera Chironomidae Cricotopus sp. *7 CG 1 3 Arthropoda Insecta Diptera Chironomidae Cricotopus 8.54 CG 1 3 bicinctus Arthropoda Insecta Diptera Chironomidae Dicrotendipes 8.1 CG 1 neomodestus Arthropoda Insecta Diptera Chironomidae Phaenopsectra sp. 6.5 SC 1 Arthropoda Insecta Diptera Chironomidae Polypedilum spp. 6 SH 1 Arthropoda Insecta Diptera Chironomidae Polypedilum . SH 8 flavum Arthropoda Insecta Diptera Chironomidae Polypedilum fallax 6.39 SH 21 Arthropoda Insecta Diptera Chironomidae Polypedilum 7.31 SH 4 halterale Arthropoda Insecta Diptera Chironomidae Polypedilum 9 SH 4 5 illinoense Arthropoda Insecta Diptera Chironomidae Rheocricotopus 7.28 CG 1 robacki Arthropoda Insecta Diptera Chironomidae Rheopelopia spp. 2 P 4 Arthropoda Insecta Diptera Chironomidae Rheotanytarsus sp. 5.89 FC 1 Arthropoda Insecta Diptera Chironomidae Tanytarsus sp. 6.76 FC 1 7 Arthropoda Insecta Diptera Chironomidae Thienemannimyia 8.42 P 9 gp. Arthropoda Insecta Diptera Chironomidae Zavrelimyia spp. 9.1 P 2 Arthropoda Insecta Diptera Empididae Hemerodromia sp. 7.57 P 2 Arthropoda Insecta Diptera Muscidae 8.4 P 2 Arthropoda Insecta Diptera Simuliidae Simulium sp. 4 FC 1 Arthropoda Insecta Diptera Tipulidae Tipula sp. 7.33 SH 6 20 TOTAL NO. OF ORGANISMS 244 658 TOTAL TAXA RICHNESS 39 42 EPT TAXA RICHNESS 6 9 NCBI (using abundance value) 7.13 7.02 EPT SCORE 1 1 NCBI SCORE 2 2 MEAN SCORE 1.5 1.5 EPT N 12 40 FINAL BIOCLASSIFICATION P F

*Hilsenhoff Tolerance Values used when North Carolina Tolerance Values are not available **North Carolina Tolerance Values range from 0 for organisms very intolerant of organic wastes to 10 for organisms very tolerant of organic wastes ***F.F.G.-Functional Feeding Group: CG=Collector/Gatherer, FC=Filtering/Collectors, SC=Scrapers, SH=Shredders, P=Predators and PI=Piercer ****Not included in analysis

136 Table D3: Complete list of macroinvertebrate species within the project area of the proposed stormwater treatment wetland between US-220 and I-40.

Phylum Class Order Family Genus/Species T.V.** F.F.G.*** 2000 2001 Mollusca Pelecypoda Heterodontida Corbiculidae Corbicula fluminea 6.1 FC 6 Mollusca Basommatophora Ancylidae Ferrissia rivularis 6.55 SC 1 Mollusca Physidae Physella sp. 8.84 CG 5 Annelida Oligochaeta Haplotaxida Lumbricidae CG 10 Annelida Oligochaeta Haplotaxida Naididae . CG 3 Annelida Oligochaeta Haplotaxida Naididae Nais spp. 8.9 CG 1 Annelida Oligochaeta Haplotaxida Naididae Nais communis 8.6 CG 3 Annelida Oligochaeta Haplotaxida Naididae Nais variabilis 8.9 CG 5 Annelida Oligochaeta Haplotaxida Naididae Pristina leidyi 9.56 CG 3 1 Annelida Oligochaeta Haplotaxida Naididae Pristinella osborni 6 CG 3 Annelida Oligochaeta Haplotaxida Naididae Branchirua 8.4 CG 1 sowerbyi Annelida Oligochaeta Haplotaxida Tubificidae 5.8 CG 6 Annelida Oligochaeta Haplotaxida Tubificidae 7.11 CG 10 w.o.h.c. Annelida Oligochaeta Haplotaxida Tubificidae Limnodrilus 9.47 CG 1 w.o.h.c. hoffmeisteri Annelida Oligochaeta Lumbriculida Lumbriculidae 7.03 CG 2 Arthropoda Acari 5.5 P 2 Annelida Hirudinea Branchiobdellida Erpobdellidae Erpobdella spp. 8.33 P 12 7 Annelida Hirudinea Branchiobdellida Glossiphoniidae Helobdella spp. *8 P 1 3 Arthropoda Insecta Collembola Isotomidae OM 1 Arthropoda Insecta Ephemeroptera Baetidae Baetis c.f. 6.58 CG 14 flavistriga Arthropoda Insecta Ephemeroptera Baetidae Baetis intercalaris 5 OM 12 Arthropoda Insecta Ephemeroptera Heptageniidae Stenonema 5.5 SC 1 modestum Arthropoda Insecta Odonata Coenagrionidae Argia sp. 8.17 P 2 9 Arthropoda Insecta Odonata Coenagrionidae Enallagma sp. 8.91 P 11 Arthropoda Insecta Odonata- Coenagrionidae Ischnura spp. 9.6 P 6 Zygoptera Arthropoda Insecta Odonata Corduliidae *5 P 1 Arthropoda Insecta Odonata- Corduliidae Neurocordulia spp. 5.8 P 1 Anisoptera Arthropoda Insecta Trichoptera Hydropsychidae *4 FC 9 Arthropoda Insecta Trichoptera Hydropsychidae Cheumatopsyche 6.22 FC 41 175 sp. Arthropoda Insecta Trichoptera Hydropsychidae Hydropsyche sp. *5 FC 7 Arthropoda Insecta Trichoptera Hydropsychidae Hydropsyche 7.78 FC 45 32 betteni gp. Arthropoda Insecta Coleoptera Elmidae Stenelmis sp. 5.1 SC 6 9 Arthropoda Insecta Coleoptera Hydrophilidae Berosus sp. 8.43 CG 1 Arthropoda Insecta Diptera Chironomidae CG 15 Arthropoda Insecta Diptera Chironomidae Ablabesmyia 7.19 P 11 26 mallochi Arthropoda Insecta Diptera Chironomidae Chironomus sp. 9.63 CG 2 Arthropoda Insecta Diptera Chironomidae Cricotopus sp. *7 CG 1 15 Arthropoda Insecta Diptera Chironomidae Cricotopus 8.54 CG 1 11 bicinctus Arthropoda Insecta Diptera Chironomidae Cricotopus *8 CG 4 tremulus

137 Table D3 (continued) Arthropoda Insecta Diptera Chironomidae Cryptochironomus 6.38 P 4 fulvus Arthropoda Insecta Diptera Chironomidae- Cryptochironmus 9.6 P 1 Chironominae spp. Arthropoda Insecta Diptera Chironomidae Dicrotendipes sp. 8.1 CG 5 4 Arthropoda Insecta Diptera Chironomidae Glyptotendipes sp. 9.47 FC 2 Arthropoda Insecta Diptera Chironomidae Nanocladius sp. 7.07 CG 2 Arthropoda Insecta Diptera Chironomidae- Nanocladius 2.4 CG 1 Orthocladiinae downesi Arthropoda Insecta Diptera Chironomidae- Orthocladius 8.5 CG 11 Orthocladiinae obumbratus Arthropoda Insecta Diptera Chironomidae Parachironomus 9.42 CG 2 sp. Arthropoda Insecta Diptera Chironomidae Polypedilum 4.93 SH 5 2 flavum (convictum) Arthropoda Insecta Diptera Chironomidae Polypedilum 7.31 SH 6 halterale Arthropoda Insecta Diptera Chironomidae Polypedilum 9 SH 11 65 illinoense Arthropoda Insecta Diptera Chironomidae- Polypedilum 8.4 SH 1 Chironominae scalaenum Arthropoda Insecta Diptera Chironomidae- Rheocricotopus 4 CG 1 Orthocladiinae spp. Arthropoda Insecta Diptera Chironomidae Rheocricotopus 7.28 CG 13 robacki Arthropoda Insecta Diptera Chironomidae Stictochironomus 6.52 OM 2 sp. Arthropoda Insecta Diptera Chironomidae Tanytarsus sp. 6.76 FC 11 15 Arthropoda Insecta Diptera Chironomidae Thienemannimyia 8.42 P 39 gp. Arthropoda Insecta Diptera Chironomidae- Zavrelimyia spp. 9.1 P 5 Tanypodinae Arthropoda Insecta Diptera Empididae Hemerodromia sp. 7.57 P 2 5 Arthropoda Insecta Diptera Psychodidae Psychoda sp. 9.64 CG 1 Arthropoda Insecta Diptera Simuliidae Simulium sp. 4 FC 1 33 Arthropoda Insecta Diptera Stratiomyidae CG 1 Arthropoda Insecta Diptera Tipulidae Antocha sp. 4.25 CG 1 2 Arthropoda Insecta Diptera Tipulidae Limonia sp. 9.64 SH 1 Arthropoda Insecta Diptera Tipulidae Tipula sp. 7.33 SH 1 3 TOTAL NO. OF ORGANISMS 226 582 TOTAL TAXA RICHNESS 37 44 EPT TAXA RICHNESS 5 7 NCBI (using abundance value) 7.33 7.289 EPT SCORE 1 1 NCBI SCORE 2 2 MEAN SCORE 1.5 1.5 EPT N 30 43

FINAL BIOCLASSIFICATION P P *Hilsenhoff Tolerance Values used when North Carolina Tolerance Values are not available **North Carolina Tolerance Values range from 0 for organisms very intolerant of organic wastes to 10 for organisms very tolerant of organic wastes ***F.F.G.-Functional Feeding Group: CG=Collector/Gatherer, FC=Filtering/Collectors, SC=Scrapers, SH=Shredders, P=Predators and PI=Piercer Table D4: Complete list of macroinvertebrate species for downstream of the proposed stormwater treatment wetland between Farragut Street and Randleman Road.

138 Phylum Class Order Family Genus/Species T.V.** F.F.G. 1999 2000 2001 *** Mollusca Gastropoda Basommatophora Physidae Physella spp. 8.8 SC 2 Mollusca Pelecypoda Heterodontida Corbiculidae Corbicula fluminea 6.1 FC 19 Mollusca Bivalvia Veneroida Corbiculidae Corbicula fluminea 6.12 FC 14 19 3 Mollusca Physidae Physella sp. 8.84 CG 2 2 Annelida Oligochaeta Haplotaxida Lumbricidae CG 12 Annelida Oligochaeta Haplotaxida Naididae *8 CG 1 Annelida Oligochaeta Lumbriculida Lumbriculidae 7.03 CG 2 Annelida Oligochaeta Haplotaxida Tubificidae 5.8 CG 3 Annelida Oligochaeta Haplotaxida Tubificidae 7.11 CG 14 w.o.h.c. Annelida Oligochaeta Haplotaxida Tubificidae Limnodrilus 9.47 CG 1 w.o.h.c. hoffmeisteri Annelida Hirudinea Branchiobdellida Erpobdellidae Erpobdella spp. 8.33 P 1 4 Annelida Hirudinea Rhynchobdellida Glossiphoniidae Helobdella spp. P 3 Annelida Oligochaeta Haplotaxida Naididae Chaetogaster spp. . CG 1 Annelida Oligochaeta Haplotaxida Naididae Homochaeta . CG 1 naidina Annelida Oligochaeta Haplotaxida Naididae Limnodrilus 9.4 CG 1 hoffmeisterei Annelida Oligochaeta Haplotaxida Naididae Nais spp. 8.9 CG Annelida Oligochaeta Haplotaxida Naididae Nais communis 8.6 CG Annelida Oligochaeta Haplotaxida Naididae Nais variabilis 8.9 CG 1 Annelida Oligochaeta Haplotaxida Naididae Pristina aequiseta 9.56 CG 1 Annelida Oligochaeta Haplotaxida Naididae Pristina leidyi 9.56 CG 1 Annelida Oligochaeta Haplotaxida Naididae Pristinella osborni 6 CG Annelida Oligochaeta Haplotaxida Naididae Branchirua 8.4 CG sowerbyi Arthropoda Crustacea Isopoda Asellidae Caecidotea sp. 9.11 CG 2 Arthropoda Crustacea Decapoda Cambaridae 7.5/8. CG 3 2 1 Arthropoda Insecta Collembola Isotomidae OM 5 Arthropoda Acari 5.5 P Arthropoda Insecta Coleoptera Elmidae Stenelmis spp. 5.1 SC Arthropoda Insecta Ephemeroptera Baetidae Baetis c.f. 6.58/5 CG 19 flavistriga Arthropoda Insecta Ephemeroptera Baetidae Baetis intercalaris 5 OM 48 Arthropoda Insecta Ephemeroptera Heptageniidae Stenonema sp. *4/5.5 SC 1 Arthropoda Insecta Odonata Aeshnidae Aeshna sp. *4 P 2 Arthropoda Insecta Odonata Aeshnidae Basiaeschna 7.35 P 1 janata Arthropoda Insecta Odonata Calopterygidae Calopteryx sp. 7.78 P 7 Arthropoda Insecta Odonata Coenagrionidae Argia sp. 8.17 P 27 6 3 Arthropoda Insecta Odonata Coenagrionidae Enallagma sp. 8.91 P 4 Arthropoda Insecta Odonata Coenagrionidae Ischnura spp. 9.6 P 14 Arthropoda Insecta Odonata Corduliidae Neurocordulia spp. *5/5.5 P 4 2 Arthropoda Insecta Odonata Corduliidae Macromia sp. 6.16 P 3 Arthropoda Insecta Odonata Gomphidae Progomphus 8.22 P 4 1 obscurus Arthropoda Insecta Trichoptera Hydropsychidae *4 FC 1 Arthropoda Insecta Trichoptera Hydropsychidae Cheumatopsyche 6.22 FC 4 98 140 sp. Arthropoda Insecta Trichoptera Hydropsychidae Hydropsyche 7.78 FC 31 16 betteni gp. Arthropoda Insecta Coleoptera Dryopidae Helichus basalis 4.63 SC 1 1 Arthropoda Insecta Coleoptera Elmidae Dubiraphia vittata 4.05 SC 2 Arthropoda Insecta Coleoptera Elmidae Stenelmis sp. 5.1 SC 9 1

139 Table D4 (continued) Arthropoda Insecta Coleoptera Curculionidae Bagous spp. . SH 1 Arthropoda Insecta Diptera Chironomidae CG 17 Arthropoda Insecta Diptera Chironomidae Ablabesmyia 7.19 P 5 16 mallochi Arthropoda Insecta Diptera Chironomidae Chironomus sp. 9.63 CG 5 4 Arthropoda Insecta Diptera Chironomidae Cricotopus sp. *7 CG 1 4 Arthropoda Insecta Diptera Chironomidae Cricotopus 8.54 CG 2 bicinctus Arthropoda Insecta Diptera Chironomidae- Dicrotendipes 8.1 CG 1 Chironominae neomodestus Arthropoda Insecta Diptera Chironomidae- Dicrotendipes 9.7 CG 1 Chironominae nervosus Arthropoda Insecta Diptera Chironomidae Nanocladius sp. 7.07 CG 2 1 Arthropoda Insecta Diptera Chironomidae- Phaenopsectra 6.5 SH 3 Chironominae spp. Arthropoda Insecta Diptera Chironomidae Polypedilum 4.93 SH 1 Arthropoda Insecta Diptera Chironomidae Polypedilum fallax 6.39 SH 4 Arthropoda Insecta Diptera Chironomidae Polypedilum 7.31 SH 5 44 halterale Arthropoda Insecta Diptera Chironomidae Polypedilum 9 SH 3 11 26 illinoense Arthropoda Insecta Diptera Chironomidae- Polypedilum 4 SH 5 Chironominae simulans/digitifer Arthropoda Insecta Diptera Chironomidae- Rheocricotopus 4 CG 11 Orthocladiinae spp. Arthropoda Insecta Diptera Chironomidae Rheocricotopus 7.28 CG 3 36 robacki Arthropoda Insecta Diptera Chironomidae Rheotanytarsus sp. 5.89 FC 1 12 Arthropoda Insecta Diptera Chironomidae Tanytarsus sp. 6.76 FC 1 5 20 Arthropoda Insecta Diptera Chironomidae Thienemannimyia 8.42/8 P 2 5 32 gp. .8 Arthropoda Insecta Diptera Chironomidae- Thienemanniella 5.8 CG 1 Orthocladiinae spp. Arthropoda Insecta Diptera Chironomidae- Zavrelimyia spp. 9.1 P 5 Tanypodinae Arthropoda Insecta Diptera Empididae Hemerodromia 8.1 P spp. Arthropoda Insecta Diptera Simuliidae Antocha spp. CG Arthropoda Insecta Diptera Simuliidae Simulium sp. 4 FC 5 Arthropoda Insecta Diptera Tipulidae Tipula sp. 7.33 SH 1 4 TOTAL NO. OF ORGANISMS 74 331 471 TOTAL TAXA RICHNESS 15 38 44 EPT TAXA RICHNESS 2 5 8

NCBI (using abundance value) 7.2 6.99 7.186 EPT SCORE 1 1 2 NCBI SCORE 2 2 2 MEAN SCORE 1.5 1.5 2.0 EPT N 3 30 30 FINAL BIOCLASSIFICATION P P F *Hilsenhoff Tolerance Values used when North Carolina Tolerance Values are not available **North Carolina Tolerance Values range from 0 for organisms very intolerant of organic wastes to 10 for organisms very tolerant of organic wastes ***F.F.G.-Functional Feeding Group: CG=Collector/Gatherer, FC=Filtering/Collectors, SC=Scrapers, SH=Shredders, P=Predators and PI=Piercer ****Not included in analysis

140 APPENDIX E: Geomorphology

Table E1: Cross-section elevations and computation of area (m) for Station 79 on South Buffalo Creek, upstream of the proposed stormwater treatment wetland, in October 2001 October 2001 Station 79 Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (M^2) LT PIN 0 230.09 LT TOB 2.13 230.06 3.38 229.76 1.19 -0.09 0.62 0.27 0.32 4.57 229.05 0.38 0.62 0.95 0.79 0.30 4.95 228.72 0.84 0.95 1.53 1.24 1.04 5.79 228.14 0.21 1.53 1.90 1.71 0.37 LT EDGE BANK 6.00 227.77 1.31 1.90 1.95 1.93 2.52 LT EDGE WATER 7.32 227.72 0.24 1.95 2.27 2.11 0.52 7.56 227.40 1.16 2.27 1.94 2.11 2.44 BEDROCK 8.72 227.73 0.88 1.94 2.22 2.08 1.84 9.60 227.45 1.80 2.22 2.29 2.25 4.05 11.40 227.38 1.40 2.29 2.37 2.33 3.27 THALWEG 12.80 227.30 1.52 2.37 1.93 2.15 3.28 RT EDGE WATER 14.33 227.74 0.30 1.93 1.75 1.84 0.56 14.63 227.92 0.46 1.75 1.52 1.63 0.75 15.09 228.15 1.37 1.52 0.80 1.16 1.59 16.46 228.87 0.61 0.80 0.00 0.40 0.25 17.07 229.67 0.61 0.00 0.00 0.00 0.00 RT TOB 17.68 229.84 23.09 RT PIN 20.79 230.05

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

141

Table E2: Cross-section elevations and computation of area (m) for Station 79 on South Buffalo Creek, upstream of the proposed stormwater treatment wetland, in March 2002

March 2002 Station 79 Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (M^2) 0 230.09 LT PIN 0.73 230.11 1.86 230.05 LT TOP 2.47 229.97 3.08 229.80 FLAG 0.70 -0.15 0.22 0.04 0.02 3.78 229.43 0.70 0.22 0.62 0.42 0.29 4.48 229.03 0.52 0.62 1.04 0.83 0.43 5.00 228.61 0.67 1.04 1.43 1.23 0.83 5.67 228.22 0.21 1.43 1.89 1.66 0.35 5.88 227.76 LT EOW 0.98 1.89 1.92 1.90 1.86 6.86 227.73 BEDROCK 0.79 1.92 2.17 2.05 1.62 7.65 227.48 0.79 2.17 1.93 2.05 1.63 8.44 227.72 BEDROCK 0.85 1.93 2.18 2.06 1.75 9.30 227.47 1.13 2.18 2.31 2.24 2.53 10.42 227.34 0.94 2.31 2.25 2.28 2.15 11.37 227.40 1.34 2.25 2.34 2.29 3.08 12.71 227.31 THALWEG 0.64 2.34 2.21 2.28 1.46 13.35 227.44 0.88 2.21 1.93 2.07 1.83 14.23 227.72 RT EOW 0.18 1.93 1.68 1.81 0.33 14.42 227.97 0.61 1.68 1.38 1.53 0.93 15.03 228.27 1.25 1.38 0.81 1.09 1.36 16.28 228.84 BENCH 0.52 0.81 0.38 0.59 0.31 16.79 229.27 BENCH 0.03 0.38 0.00 0.19 0.01 16.82 229.65 RT BKF 1.04 0.00 0.00 0.00 0.00 17.86 229.75 18.29 229.98 RT TOB 18.32 229.92 22.77 20.79 230.05 230.04 RT PIN

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

142

Table E3: Geomorphic measurements for Station 79 on South Buffalo Creek, upstream of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 23 23 23 A(bkf) m2 23.09 22.77 22.93 W(bkf) m 13.69 13.75 13.716 D(bkf) m 2.37 2.33 2.35 W/D 5.77 5.89 5.83 W(fpa) m 137 137 137 ER 10.01 9.97 9.99 S(ws) 0.002 0.002 0.002 K 1.03 1.03 1.03 D50 (mm) Gravel Gravel Gravel

Dmax (bkf) m 2.47 2.49 2.48

Dmax (TOB) m 2.76 2.74 2.75 BHR 1.12 1.10 1.11

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

143

Table E4: Cross-section elevations and computation of area (m) for the upstream tributary the proposed stormwater treatment wetland on South Buffalo Creek in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m^2) LT PIN 0 226.93 1.52 226.99 3.35 226.92 5.79 227.02 7.01 226.94 LT TOB 8.23 226.92 8.53 226.82 LT BKF 8.84 226.44 0.46 0.00 0.69 0.35 0.16 9.30 225.75 0.46 0.69 1.25 0.97 0.44 9.75 225.19 0.40 1.25 1.89 1.57 0.62 LT EOW 10.15 224.55 0.46 1.89 1.93 1.91 0.87 THALWEG 10.61 224.51 2.19 1.93 1.85 1.89 4.15 RT EOW 12.80 224.59 1.52 1.85 1.74 1.79 2.73 14.33 224.70 1.52 1.74 1.52 1.63 2.48 15.85 224.92 0.52 1.52 0.99 1.25 0.65 16.37 225.45 0.40 0.99 0.58 0.79 0.31 16.76 225.86 0.82 0.58 0.00 0.29 0.24 RT BKF 17.59 226.44 0.49 0.00 0.00 0.00 0.00 RT TOB 18.07 226.73 12.67 18.59 226.80 20.12 226.81 RT PIN 22.10 227.07

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

144 Table E5: Cross-section elevations and computation of area (m) for the upstream tributary the proposed stormwater treatment wetland on South Buffalo Creek in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m^2) LT PIN 0 226.93 1.52 227.00 3.05 226.93 RF 3.51 226.93 4.57 227.02 6.40 227.01 7.62 226.96 7.92 226.94 LT TOB 8.35 226.94 8.53 226.86 8.72 226.63 8.84 226.40 LT BKF 9.02 226.32 0.12 0.00 0.25 0.13 0.02 9.14 226.07 0.15 0.25 0.51 0.38 0.06 9.30 225.81 0.15 0.51 0.61 0.56 0.09 9.45 225.71 0.27 0.61 1.03 0.82 0.23 9.72 225.29 0.30 1.03 1.25 1.14 0.35 10.03 225.07 0.09 1.25 1.54 1.39 0.13 10.12 224.78 0.12 1.54 1.69 1.61 0.20 LT EOW 10.24 224.63 0.43 1.69 1.76 1.73 0.74 10.67 224.56 0.30 1.76 1.78 1.77 0.54 10.97 224.54 0.30 1.78 1.78 1.78 0.54 11.28 224.54 0.30 1.78 1.79 1.78 0.54 11.58 224.53 0.30 1.79 1.78 1.78 0.54 11.89 224.54 0.30 1.78 1.77 1.77 0.54 12.19 224.55 0.30 1.77 1.75 1.76 0.54 12.50 224.57 0.30 1.75 1.73 1.74 0.53 12.80 224.59 0.49 1.73 1.68 1.70 0.83 13.29 224.64 1.04 1.68 1.61 1.64 1.70 13.72 224.66 1.22 1.66 1.57 1.62 1.97 14.33 224.71 0.61 1.61 1.57 1.59 0.97 14.94 224.75 0.30 1.57 1.54 1.55 0.47 15.24 224.78 0.30 1.54 1.50 1.52 0.46 15.54 224.82 0.30 1.50 1.45 1.47 0.45 15.85 224.87 0.30 1.45 1.31 1.38 0.42 16.15 225.01 1.22 1.31 0.00 0.66 0.80 RT BKF 17.37 226.32 0 0.00 0.00 0.00 0.00 17.68 226.48 13.64 17.98 226.62 18.29 226.76 RT TOB 18.59 226.80 19.51 226.81 20.73 226.91 RT PIN 22.22 227.09

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

145 Table E6: Geomorphic measurements for the upstream tributary of the proposed stormwater treatment wetland on South Buffalo Creek Stream Type October March Average 2001 2002 DA (km2) 7.8 7.8 7.8 A(bkf) m2 12.67 13.64 13.16 W(bkf) m 8.75 8.35 8.54964 D(bkf) m 1.93 1.79 1.86 W/D 4.54 4.68 4.61 W(fpa) m 168 168 168 ER 19.2 20.1 19.66 S(ws) 0.004 0.004 0.004 K 1.04 1.04 1.04 D50 (mm) sand sand sand

Dmax (bkf) m 1.98 1.73 1.86

Dmax (TOB) m 2.41 2.41 2.41 BHR 1.22 1.39 1.30

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

146

Table E7: Cross-section elevations and computation of area (m) for Station 622 on South Buffalo Creek, upstream of the proposed stormwater treatment wetland, in October 2001 October 2001 2 Description Station (X) Elevation Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m ) (Y) LT EDGE VEG 0 229.40 LT TOB 1.07 229.36 1.83 229.21 LT BANKFULL 2.13 228.91 0.4572 -0.08 0.30 0.11 0.05 2.59 228.53 1.0058 0.30 0.77 0.53 0.54 3.60 228.06 0.5182 0.77 1.80 1.29 0.67 LT EOW 4.11 227.03 2.0117 1.80 1.97 1.89 3.80 THALWEG 6.13 226.86 2.4079 1.97 1.84 1.91 4.59 8.53 226.99 1.2802 1.84 1.43 1.64 2.10 BEDROCK 9.81 227.40 1.8898 1.43 1.44 1.44 2.72 BEDROCK 11.70 227.39 1.3411 1.44 1.30 1.37 1.84 BEDROCK 13.05 227.53 1.8898 1.30 1.68 1.49 2.82 BEDROCK 14.94 227.15 0.1219 1.68 1.24 1.46 0.18 15.06 227.59 0.1524 1.24 1.84 1.54 0.24 RT EOW 15.21 226.99 1.5545 1.84 1.05 1.44 2.25 16.76 227.78 1.6459 1.05 0.50 0.78 1.28 18.41 228.33 2.6213 0.50 0.00 0.25 0.65 RT 21.03 228.83 -21.031 0.00 0.00 0.00 0.05 BANKFULL 23.75

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

147 Table E8: Cross-section elevations and computation of area (m) for Station 622 on South Buffalo Creek, upstream of the proposed stormwater treatment wetland, in March 2002 March 2002 2 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m ) Lt. Pin 0 229.40 0.70 229.34 LT TOB 1.83 229.16 LT BKF 2.04 228.92 0.67 -0.14 0.30 0.08 0.05 2.71 228.48 0.76 0.30 0.73 0.52 0.39 3.47 228.05 0.49 0.73 1.27 1.00 0.49 3.96 227.51 0.34 1.27 1.83 1.55 0.52 LT EOW 4.30 226.95 0.67 1.83 1.94 1.88 1.26 4.97 226.84 0.61 1.94 1.97 1.95 1.19 THALWEG 5.58 226.81 0.79 1.97 1.92 1.94 1.54 6.37 226.86 0.73 1.92 1.90 1.91 1.40 7.10 226.88 0.58 1.90 1.89 1.89 1.10 7.68 226.89 0.64 1.89 1.90 1.89 1.21 8.32 226.88 0.61 1.90 1.87 1.89 1.15 8.93 226.91 0.88 1.87 1.89 1.88 1.66 RT EOW 9.81 226.89 0.94 1.89 1.52 1.70 1.61 10.76 227.26 0.61 1.52 1.49 1.50 0.92 11.37 227.29 0.61 1.49 1.59 1.54 0.94 11.98 227.19 0.58 1.59 1.50 1.54 0.89 12.56 227.28 0.64 1.50 1.47 1.48 0.95 13.20 227.31 0.61 1.47 1.81 1.64 1.00 13.81 226.97 0.85 1.81 1.66 1.74 1.48 BANK 14.66 227.12 0.37 1.66 1.29 1.48 0.54 15.03 227.49 0.61 1.29 1.13 1.21 0.74 15.64 227.65 0.61 1.13 1.17 1.15 0.70 16.25 227.61 0.61 1.17 0.90 1.03 0.63 16.86 227.88 0.40 0.90 0.83 0.87 0.34 17.25 227.95 0.91 0.83 0.48 0.66 0.60 18.17 228.30 1.13 0.48 0.21 0.35 0.39 19.29 228.57 1.52 0.21 0.00 0.11 0.17 RT BKF 20.82 228.78 -20.82 0.00 0.00 0.00 -0.03 23.83 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

148 Table E9: Geomorphic measurements for the Station 622 on South Buffalo Creek, upstream of the proposed stormwater treatment wetland Stream Type October 2001 March 2002 Average DA (km2) 23 23 23 A(bkf) m2 23.75 23.83 23.79 W(bkf) m 18.90 18.78 18.84 D(bkf) m 1.98 1.96 1.97 W/D 9.57 9.57 9.57 W(fpa) m 213 213 213 ER 11.27 11.34 11.31 S(ws) 0.002 0.002 0.002 K 1.03 1.03 1.03 D50 (mm) Cobble Cobble sand

Dmax (bkf) m 2.05 2.11 2.08

Dmax (TOB) m 2.50 2.35 2.43 BHR 1.22 1.11 1.17

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

149 Table E10: Cross-section elevations and computation of area (m) for Station 5386 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.95 1.52 225.75 3.05 225.76 4.57 225.84 LT BKF 6.10 226.01 1.52 -0.03 0.03 0.00 0.00 7.62 225.95 1.83 0.03 0.24 0.13 0.25 9.45 225.74 1.16 0.24 0.32 0.28 0.33 10.61 225.66 0.37 0.32 0.46 0.39 0.14 10.97 225.52 0.61 0.46 1.28 0.87 0.53 11.58 224.70 0.61 1.28 1.79 1.53 0.93 12.19 224.19 0.30 1.79 2.14 1.96 0.60 12.50 223.84 0.15 2.14 2.75 2.44 0.37 12.65 223.23 0.27 2.75 2.83 2.79 0.77 LT EOW 12.92 223.15 1.71 2.83 2.95 2.89 4.93 14.63 223.03 1.52 2.95 3.13 3.04 4.63 16.15 222.85 2.44 3.13 3.37 3.25 7.92 THALWEG 18.59 222.61 1.22 3.37 3.05 3.21 3.92 19.81 222.93 1.83 3.05 3.06 3.05 5.59 21.64 222.92 2.13 3.06 2.81 2.93 6.26 RT EOW 23.77 223.17 0.61 2.81 1.81 2.31 1.41 24.38 224.17 0.61 1.81 1.21 1.51 0.92 24.99 224.77 0.30 1.21 0.80 1.01 0.31 25.30 225.18 0.30 0.80 0.52 0.66 0.20 25.60 225.46 0.30 0.52 0.00 0.26 0.08 RT BKF 25.91 225.98 0.61 0.00 0.00 0.00 0.00 RT TOB 26.52 226.29 40.07 28.04 226.68 29.57 226.82 RT PIN 30.94 226.84

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

150 Table E11: Cross-section elevations and computation of area (m) for Station 5386 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.95 0.52 225.85 1.49 225.76 2.35 225.72 3.26 225.80 4.18 225.88 5.09 225.97 LT BKF 6.00 226.05 1.22 -0.04 0.01 -0.02 -0.02 7.22 226.01 0.91 0.01 0.05 0.03 0.03 8.14 225.96 0.91 0.05 0.25 0.15 0.14 9.05 225.76 0.61 0.25 0.26 0.26 0.16 9.66 225.76 0.91 0.26 0.29 0.28 0.25 10.58 225.72 0.30 0.29 0.47 0.38 0.12 10.88 225.55 0.61 0.47 0.77 0.62 0.38 11.49 225.25 0.30 0.77 1.43 1.10 0.33 11.80 224.59 0.30 1.43 1.72 1.58 0.48 12.10 224.29 0.30 1.72 1.99 1.86 0.57 12.41 224.02 0.21 1.99 2.88 2.44 0.52 LT EOW 12.62 223.13 0.76 2.88 3.06 2.97 2.26 13.38 222.96 0.70 3.06 3.08 3.07 2.15 14.08 222.93 0.61 3.08 3.15 3.12 1.90 14.69 222.87 0.76 3.15 3.22 3.18 2.42 15.45 222.80 0.79 3.22 3.20 3.21 2.54 16.25 222.81 0.73 3.20 3.18 3.19 2.33 16.98 222.84 0.88 3.18 3.28 3.23 2.85 17.86 222.74 0.58 3.28 3.20 3.24 1.88 18.44 222.81 0.24 3.20 3.37 3.29 0.80 THALWEG 18.68 222.64 0.52 3.37 3.27 3.32 1.72 19.20 222.75 0.40 3.27 3.06 3.16 1.25 19.60 222.96 0.82 3.06 2.84 2.95 2.43 20.42 223.17 0.70 2.84 3.03 2.94 2.06 21.12 222.99 0.79 3.03 3.09 3.06 2.43 21.92 222.92 0.85 3.09 2.97 3.03 2.59 22.77 223.05 0.61 2.97 2.95 2.96 1.81 23.38 223.06 0.61 2.95 2.82 2.89 1.76 RT EOW 23.99 223.19 0.21 2.82 2.03 2.43 0.52 24.20 223.98 0.24 2.03 1.82 1.92 0.47 24.44 224.20 0.46 1.82 1.48 1.65 0.75 24.90 224.54 0.30 1.48 1.14 1.31 0.40 25.21 224.88 0.30 1.14 0.73 0.93 0.28 25.51 225.28 0.24 0.73 0.48 0.60 0.15 25.76 225.54 0.15 0.48 0.00 0.24 0.04 RT BKF 25.91 226.02 0.82 0.00 0.00 0.00 0.00 RT TOB 26.73 226.38 40.74 27.65 226.65 28.56 226.77 30.24 226.86 RT PIN 31.00 226.84 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

151 Table E12: Geomorphic measurements for the Station 5368 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland Stream Type October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 40.07 40.74 40.40 W(bkf) m 19.81 19.90 19.86 D(bkf) m 3.37 3.37 3.37 W/D 5.88 5.90 5.89 W(fpa) m 393 393 393 ER 19.84 19.75 19.79 S(ws) 0.002 0.002 0.002 K 1.35 1.35 1.35 D50 (mm) sand sand sand

Dmax (bkf) m 3.40 3.41 3.41

Dmax (TOB) m 3.68 3.74 3.71 BHR 1.08 1.09 1.09

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

152 Table E13: Cross-section elevations and computation of area (m) for Station 5556 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.76 0.91 225.67 LT BKF 1.98 225.32 1.07 0.00 0.21 0.106 0.11 3.05 225.11 0.61 0.21 0.48 0.347 0.21 3.66 224.84 0.30 0.48 0.86 0.671 0.20 3.96 224.46 0.43 0.86 2.51 1.683 0.72 LT EOW 4.39 222.81 1.71 2.51 2.39 2.450 4.18 6.10 222.93 2.29 2.39 2.51 2.450 5.60 THALWEG 8.38 222.81 1.98 2.51 2.30 2.404 4.76 10.36 223.02 0.91 2.30 2.27 2.287 2.09 RT EOW 11.28 223.05 0.91 2.27 2.18 2.229 2.04 12.19 223.14 1.52 2.18 1.87 2.026 3.09 13.72 223.45 1.52 1.87 2.17 2.019 3.08 15.24 223.15 1.52 2.17 1.78 1.975 3.01 16.76 223.54 1.52 1.78 1.83 1.806 2.75 18.29 223.49 1.52 1.83 2.00 1.915 2.92 19.81 223.32 0.61 2.00 2.46 2.231 1.36 20.42 222.86 0.61 2.46 0.69 1.578 0.96 21.03 224.63 0.61 0.69 0.26 0.476 0.29 21.64 225.06 0.15 0.26 0.00 0.130 0.02 RT BKF 21.79 225.32 0.15 0.00 0.00 0.000 0.00 21.95 225.83 37.40 22.86 226.02 RT PIN 23.62 226.03

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

153 Table E14: Cross-section elevations and computation of area (m) for Station 5556 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.76 0.85 225.70 LT TOB 1.77 225.42 0.91 0.00 0.23 0.113 0.10 2.68 225.20 0.61 0.23 0.40 0.312 0.19 LT BKF 3.29 225.02 0.52 0.40 0.62 0.509 0.26 3.81 224.81 0.37 0.62 0.92 0.770 0.28 4.18 224.50 0.24 0.92 1.29 1.105 0.27 4.42 224.13 0.24 1.29 1.71 1.501 0.37 4.66 223.71 0.03 1.71 2.51 2.112 0.06 4.69 222.91 0.12 2.51 2.67 2.592 0.32 4.82 222.75 0.61 2.67 2.55 2.609 1.59 5.43 222.88 0.79 2.55 2.47 2.509 1.99 6.22 222.95 0.58 2.47 2.48 2.475 1.43 6.80 222.95 0.70 2.48 2.55 2.512 1.76 7.50 222.88 0.70 2.55 2.57 2.556 1.79 8.20 222.86 0.58 2.57 2.61 2.586 1.50 THALWEG 8.78 222.82 0.67 2.61 2.44 2.524 1.69 9.45 222.98 0.76 2.44 2.34 2.390 1.82 10.21 223.09 1.01 2.34 2.35 2.342 2.36 RT EOW 11.22 223.08 0.30 2.35 2.11 2.227 0.68 BEDROCK 11.52 223.32 1.22 2.11 2.07 2.086 2.54 BEDROCK 12.74 223.36 0.76 2.07 2.06 2.063 1.57 BEDROCK 13.50 223.36 1.13 2.06 2.20 2.131 2.40 BEDROCK 14.63 223.22 0.73 2.20 2.42 2.309 1.69 BEDROCK 15.36 223.01 1.34 2.42 1.90 2.156 2.89 BEDROCK 16.70 223.53 0.61 1.90 1.83 1.865 1.14 BEDROCK 17.31 223.59 0.91 1.83 1.91 1.870 1.71 18.23 223.52 0.91 1.91 2.27 2.089 1.91 19.14 223.15 0.61 2.27 2.23 2.251 1.37 RT EOW 19.75 223.20 0.46 2.23 1.72 1.972 0.90 20.21 223.71 0.46 1.72 1.31 1.513 0.69 20.67 224.11 0.30 1.31 0.93 1.119 0.34 20.97 224.50 0.30 0.93 0.68 0.802 0.24 21.28 224.75 0.46 0.68 0.28 0.477 0.22 21.73 225.15 0.18 0.28 -0.31 -0.017 0.00 RT BKF 21.92 225.73 0.12 -0.31 0.00 -0.155 -0.02 22.04 225.86 38.07 22.80 226.01 RT PIN 23.71 225.76 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

154 Table E15: Geomorphic measurements for the Station 5556 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 37.40 38.07 37.74 W(bkf) m 19.81 18.62 19.22 D(bkf) m 2.51 2.21 2.36 W/D 7.90 8.44 8.17 W(fpa) m 390 390 390 ER 19.69 20.94 20.29 S(ws) 0.002 0.002 0.002 K 1.35 1.35 1.35 D50 (mm) cobble cobble cobble

Dmax (bkf) m 2.51 2.92 2.71

Dmax (TOB) m 3.22 3.19 3.20 BHR 1.28 1.09 1.18

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

155 Table E16: Cross-section elevations and computation of area (m) for Station 5772 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.65 1.52 225.69 3.05 225.72 3.66 225.71 LT TOB 6.40 225.54 LT BKF 7.32 225.22 0.6096 0.00 0.59 0.30 0.18 7.92 224.63 0.6096 0.59 1.22 0.90 0.55 8.53 224.00 0.6096 1.22 1.50 1.36 0.83 9.14 223.72 0.6096 1.50 2.01 1.76 1.07 9.75 223.21 0.6096 2.01 2.35 2.18 1.33 10.36 222.87 0.1524 2.35 2.67 2.51 0.38 LT EOW 10.52 222.55 1.0668 2.67 2.69 2.68 2.86 11.58 222.53 0.9144 2.69 2.70 2.70 2.47 THALWEG 12.50 222.52 1.8288 2.70 2.70 2.70 4.94 14.33 222.52 1.8288 2.70 2.66 2.68 4.91 16.15 222.56 1.524 2.66 2.64 2.65 4.04 17.68 222.58 1.9812 2.64 2.63 2.64 5.22 RT EOW 19.66 222.59 0.4572 2.63 2.42 2.53 1.16 20.12 222.80 0.4572 2.42 1.85 2.14 0.98 20.57 223.37 0.762 1.85 1.21 1.53 1.17 21.34 224.01 0.6096 1.21 0.70 0.96 0.58 21.95 224.52 0.6096 0.70 0.26 0.48 0.29 22.56 224.96 0.3048 0.26 0.00 0.13 0.04 RT BKF 22.86 225.22 0.00 0.00 0.00 0.00 23.47 225.48 33.00 RT TOB 24.69 225.73 26.21 225.68 RT PIN 29.26 225.88

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

156 Table E17: Cross-section elevations and computation of area (m) for Station 5772 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.65 1.58 225.70 2.80 225.70 4.02 225.72 5.24 225.65 LT TOB 6.46 225.53 7.07 225.31 LT BKF 7.38 225.15 0.67 0.00 0.58 0.29 0.19 8.05 224.57 0.55 0.58 1.13 0.85 0.47 8.60 224.02 0.46 1.13 1.31 1.22 0.56 9.05 223.84 0.46 1.31 1.65 1.48 0.68 9.51 223.50 0.46 1.65 1.98 1.81 0.83 9.97 223.17 0.46 1.98 2.32 2.15 0.98 10.42 222.83 0.21 2.32 2.53 2.43 0.52 LT EOW 10.64 222.62 0.85 2.53 2.61 2.57 2.19 11.49 222.54 1.16 2.61 2.66 2.63 3.05 12.65 222.49 1.58 2.66 2.63 2.65 4.19 14.23 222.52 0.94 2.63 2.60 2.62 2.47 15.18 222.55 0.88 2.60 2.58 2.59 2.29 16.06 222.57 1.07 2.58 2.59 2.58 2.76 17.13 222.56 0.67 2.59 2.55 2.57 1.72 17.80 222.60 0.76 2.55 2.54 2.55 1.94 18.56 222.61 0.70 2.54 2.57 2.56 1.79 19.26 222.58 0.61 2.57 2.55 2.56 1.56 RT EOW 19.87 222.60 0.30 2.55 2.34 2.44 0.74 20.18 222.81 0.09 2.34 2.03 2.19 0.20 20.27 223.12 0.30 2.03 1.81 1.92 0.59 20.57 223.34 0.12 1.81 1.60 1.71 0.21 20.70 223.55 0.40 1.60 1.30 1.45 0.58 21.09 223.85 0.40 1.30 1.14 1.22 0.48 21.49 224.01 0.21 1.14 1.00 1.07 0.23 21.70 224.15 0.30 1.00 0.67 0.84 0.26 22.01 224.48 0.30 0.67 0.48 0.57 0.18 22.31 224.67 0.30 0.48 0.13 0.30 0.09 22.62 225.02 0.30 0.13 -0.04 0.04 0.01 RT BKF 22.92 225.19 0.30 -0.04 0.00 -0.02 -0.01 23.23 225.32 31.76 23.53 225.46 RT TOB 24.14 225.65 24.75 225.73 26.27 225.68 27.80 226.05 RT PIN 29.32 225.88 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

157 Table E18: Geomorphic measurements for the Station 5772 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 33.00 31.76 32.38 W(bkf) m 15.54 15.54 15.54 D(bkf) m 2.70 2.66 2.68 W/D 5.76 5.84 5.80 W(fpa) m 366 366 366 ER 23.54 23.54 23.54 S(ws) 0.002 0.002 0.002 K 1.35 1.35 1.35 D50 (mm) sand sand sand

Dmax (bkf) m 2.70 2.70 2.70

Dmax (TOB) m 3.21 3.16 3.19 BHR 1.19 1.17 1.18

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

158 Table E19: Cross-section elevations and computation of area (m) for Station 5923 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Descsription Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.40 1.52 225.32 3.05 225.08 4.57 224.99 5.64 225.17 6.71 225.31 LT TOB 7.92 225.46 9.14 225.24 LT BKF 10.36 224.76 0.46 0.00 1.10 0.55 0.25 10.82 223.66 0.46 1.10 2.28 1.69 0.77 11.28 222.48 1.22 2.28 2.36 2.32 2.83 12.50 222.40 1.22 2.36 2.39 2.37 2.89 THALWEG 13.72 222.37 2.13 2.39 2.28 2.33 4.98 15.85 222.48 2.59 2.28 2.32 2.30 5.96 18.44 222.44 1.52 2.32 2.27 2.30 3.50 19.96 222.49 0.46 2.27 1.72 1.99 0.91 20.42 223.04 0.46 1.72 1.30 1.51 0.69 20.88 223.46 0.46 1.30 0.06 0.68 0.31 21.34 224.70 0.15 0.06 -0.01 0.03 0.00 RT BKF 21.49 224.77 0.30 -0.01 0.00 0.00 0.00 21.79 225.18 23.11 22.25 225.44 23.16 225.72 RT TOB 25.30 225.77 RT PIN 30.18 225.58

159 Table E20: Cross-section elevations and computation of area (m) for Station 55923 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Descsription Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.40 0.85 225.37 1.77 225.29 2.99 225.13 4.51 225.02 5.73 225.17 6.95 225.03 LT TOB 7.92 225.48 8.47 225.39 9.08 225.26 9.69 225.10 10.00 224.99 LT BKF 10.30 224.77 0.30 -0.08 0.41 0.17 0.05 10.61 224.28 0.37 0.41 0.89 0.65 0.24 10.97 223.80 0.24 0.89 1.60 1.25 0.30 11.22 223.09 0.15 1.60 2.14 1.87 0.29 LT EOW 11.37 222.55 0.76 2.14 2.25 2.20 1.68 12.13 222.44 0.61 2.25 2.32 2.29 1.39 THALWEG 12.74 222.37 0.52 2.32 2.30 2.31 1.20 13.26 222.39 0.58 2.30 2.30 2.30 1.33 13.84 222.39 0.82 2.30 2.27 2.29 1.88 14.66 222.42 0.52 2.27 2.23 2.25 1.17 15.18 222.46 0.49 2.23 2.23 2.23 1.09 15.67 222.46 0.88 2.23 2.21 2.22 1.96 16.55 222.48 0.76 2.21 2.24 2.23 1.70 17.31 222.45 0.76 2.24 2.22 2.23 1.70 18.07 222.47 0.85 2.22 2.25 2.24 1.91 18.93 222.44 0.61 2.25 2.27 2.26 1.38 19.54 222.42 0.67 2.27 2.18 2.23 1.49 RT EOW 20.21 222.51 0.15 2.18 2.10 2.14 0.33 20.36 222.59 0.09 2.10 1.68 1.89 0.17 20.45 223.01 0.37 1.68 1.58 1.63 0.60 20.82 223.11 0.24 1.58 1.32 1.45 0.35 21.06 223.37 0.21 1.32 0.70 1.01 0.22 21.28 223.99 0.15 0.70 0.00 0.35 0.05 RT BKF 21.43 224.69 0.15 0.00 0.00 0.00 0.00 21.58 224.86 22.48 21.88 225.18 22.19 225.37 RT TOB 22.49 225.52 23.10 225.69 24.02 225.79 25.54 225.77 27.07 225.72 28.59 225.75 RT PIN 30.11 225.56

160 Table E21: Geomorphic measurements for the Station 5923 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 23.11 22.48 22.80 W(bkf) m 11.13 11.13 11.13 D(bkf) m 2.39 2.32 2.35 W/D 4.65 4.80 4.73 W(fpa) m 328 328 328 ER 29.48 29.48 29.48 S(ws) 0.009 0.009 0.009 K 1.35 1.35 1.35 D50 (mm) sand sand sand

Dmax (bkf) m 2.28 2.40 2.34 Dmax (TOB) m 3.33 3.15 3.24 BHR 1.46 1.31 1.38

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

161 Table E22: Cross-section elevations and computation of area (m) for Station 6207 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 226.31 1.52 226.07 3.05 225.62 4.88 225.33 6.10 225.16 7.62 224.79 9.14 225.01 10.67 225.23 LT TOB 11.28 225.32 LT BKF 11.80 225.09 0.40 -0.01 0.56 0.28 0.11 12.19 224.52 0.30 0.56 1.07 0.82 0.25 12.50 224.01 0.30 1.07 1.35 1.21 0.37 12.80 223.73 0.30 1.35 1.65 1.50 0.46 13.11 223.43 0.30 1.65 1.77 1.71 0.52 13.41 223.31 0.30 1.77 1.99 1.88 0.57 13.72 223.09 0.30 1.99 2.34 2.16 0.66 14.02 222.74 0.30 2.34 2.69 2.51 0.77 14.33 222.39 0.46 2.69 2.72 2.71 1.24 LT EOW 14.78 222.36 0.91 2.72 2.84 2.78 2.54 15.70 222.24 0.76 2.84 2.71 2.78 2.12 16.46 222.37 0.76 2.71 2.81 2.76 2.11 THALWEG 17.22 222.27 1.37 2.81 2.73 2.77 3.80 18.59 222.35 1.52 2.73 2.70 2.72 4.14 20.12 222.38 1.83 2.70 2.97 2.84 5.19 21.95 222.11 0.70 2.97 2.78 2.88 2.02 RT EOW 22.65 222.30 0.03 2.78 1.74 2.26 0.07 22.68 223.34 0.18 1.74 0.86 1.30 0.24 22.86 224.22 0.40 0.86 0.54 0.70 0.28 23.26 224.54 0.15 0.54 0.21 0.38 0.06 23.41 224.87 0.06 0.21 0.00 0.10 0.01 RT BKF 23.47 225.08 0.30 0.00 0.00 0.00 0.00 23.77 225.29 27.51 24.08 225.41 24.38 225.51 RT TOB 24.69 225.52 26.37 225.24 RT PIN 28.19 225.22

162 Table E23: Cross-section elevations and computation of area (m) for Station 6207 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 226.31 1.58 226.07 3.11 225.63 4.94 225.35 5.85 225.26 6.77 224.92 7.68 224.79 9.20 224.99 10.42 225.11 LT TOB 11.34 225.32 11.64 225.32 LT BKF 11.95 225.04 0.30 -0.05 0.34 0.14 0.04 12.25 224.65 0.30 0.34 0.89 0.62 0.19 12.56 224.10 0.30 0.89 1.17 1.03 0.31 12.86 223.82 0.30 1.17 1.54 1.36 0.41 13.17 223.45 0.46 1.54 1.92 1.73 0.79 13.62 223.07 0.18 1.92 2.19 2.06 0.38 13.81 222.80 0.58 2.19 2.52 2.35 1.36 14.39 222.47 0.30 2.52 2.60 2.56 0.78 LT EOW 14.69 222.39 0.61 2.60 2.70 2.65 1.62 15.30 222.29 0.49 2.70 2.73 2.72 1.32 15.79 222.26 0.82 2.73 2.61 2.67 2.20 16.61 222.38 0.52 2.61 2.71 2.66 1.38 17.13 222.28 0.49 2.71 2.69 2.70 1.32 17.62 222.30 0.79 2.69 2.65 2.67 2.12 18.41 222.34 1.07 2.65 2.62 2.64 2.81 19.48 222.37 0.79 2.62 2.63 2.63 2.08 RT EOW 20.27 222.36 0.88 2.63 2.71 2.67 2.36 21.15 222.28 0.70 2.71 2.86 2.78 1.95 21.85 222.13 0.46 2.86 2.87 2.86 1.31 THALWEG 22.31 222.12 0.24 2.87 2.83 2.85 0.69 22.56 222.16 0.30 2.83 2.63 2.73 0.83 22.86 222.36 -0.24 2.63 1.65 2.14 -0.52 22.62 223.34 0.15 1.65 1.23 1.44 0.22 22.77 223.76 0.15 1.23 0.81 1.02 0.16 22.92 224.18 0.30 0.81 0.39 0.60 0.18 23.23 224.60 0.12 0.39 0.00 0.20 0.02 RT BKF 23.35 224.99 0.18 0.00 0.00 0.00 0.00 23.53 225.17 26.32 24.14 225.45 RT TOB 24.75 225.55 25.36 225.49 25.97 225.34 27.49 225.22 RT PIN 28.86 225.18

163 Table E24: Geomorphic measurements for the Station 6207 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 27.51 26.32 26.91 W(bkf) m 11.67 11.40 11.54 D(bkf) m 2.82 2.73 2.78 W/D 4.14 4.17 4.16 W(fpa) m 442 442 442 ER 37.86 38.77 38.31 S(ws) 0.002 0.002 0.002 K 1.35 1.35 1.35 D50 (mm) sand sand sand

Dmax (bkf) m 2.82 2.79 2.80

Dmax (TOB) m 3.25 3.29 3.27 BHR 1.15 1.18 1.17

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

164 Table E25: Cross-section elevations and computation of area (m) for Station 6346 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) (X) LT PIN 0 226.33 1.52 225.99 3.05 225.58 4.57 225.23 6.10 224.94 7.62 224.56 9.14 224.64 10.36 224.86 LT TOB 11.28 224.95 LT BKF 11.98 224.86 0.21 -0.11 0.09 -0.01 0.00 12.19 224.66 0.30 0.09 0.60 0.35 0.11 12.50 224.15 0.30 0.60 0.92 0.76 0.23 12.80 223.83 0.30 0.92 1.30 1.11 0.34 13.11 223.45 0.30 1.30 1.45 1.38 0.42 13.41 223.30 0.30 1.45 1.90 1.68 0.51 13.72 222.85 0.30 1.90 2.32 2.11 0.64 14.02 222.43 0.61 2.32 2.34 2.33 1.42 14.63 222.41 0.61 2.34 2.35 2.35 1.43 15.24 222.40 1.52 2.35 2.42 2.38 3.63 LT EOW 16.76 222.33 0.61 2.42 2.64 2.53 1.54 17.37 222.11 1.22 2.64 2.69 2.67 3.25 18.59 222.06 0.61 2.69 2.79 2.74 1.67 19.20 221.96 0.61 2.79 2.86 2.82 1.72 19.81 221.89 0.61 2.86 3.02 2.94 1.79 20.42 221.73 0.61 3.02 3.19 3.10 1.89 21.03 221.56 0.30 3.19 3.18 3.18 0.97 BOTTOM 21.34 221.57 0.61 3.18 3.13 3.15 1.92 21.95 221.62 0.61 3.13 2.47 2.80 1.71 RT EOW 22.56 222.28 0.30 2.47 2.15 2.31 0.71 22.86 222.60 0.30 2.15 1.74 1.95 0.59 23.16 223.01 0.30 1.74 1.55 1.65 0.50 23.47 223.20 0.30 1.55 1.36 1.46 0.44 23.77 223.39 0.30 1.36 1.04 1.20 0.37 24.08 223.71 0.30 1.04 0.64 0.84 0.26 24.38 224.11 0.40 0.64 0.00 0.32 0.13 RT BKF 24.78 224.75 0.52 0.00 0.00 0.00 0.00 RT TOB 25.30 225.30 28.19 RT PIN 27.74 225.22

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

165 Table E26: Cross-section elevations and computation of area (m) for Station 6346 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 226.33 1.52 225.98 3.05 225.57 4.57 225.25 6.10 224.98 7.62 224.56 9.14 224.63 10.06 224.75 10.67 224.90 10.97 224.91 LT TOR 11.28 224.92 11.58 224.91 11.89 224.87 LT BKF 12.13 224.79 0.1 -0.04 0.14 0.05 0.01 12.25 224.61 0.1 0.14 0.34 0.24 0.03 12.37 224.41 0.2 0.34 0.68 0.51 0.09 12.56 224.07 0.4 0.68 1.22 0.95 0.35 12.92 223.53 0.5 1.22 1.55 1.39 0.68 13.41 223.20 0.2 1.55 1.89 1.72 0.26 13.56 222.86 0.2 1.89 2.25 2.07 0.50 13.81 222.50 0.3 2.25 2.37 2.31 0.77 LT EOW 14.14 222.38 0.2 2.37 2.38 2.38 0.58 14.39 222.37 0.5 2.38 2.36 2.37 1.08 14.84 222.39 0.7 2.36 2.39 2.37 1.66 15.54 222.36 0.8 2.39 2.43 2.41 1.83 16.31 222.32 0.9 2.43 2.46 2.44 2.23 17.22 222.29 0.1 2.46 2.71 2.58 0.24 17.31 222.04 1.0 2.71 2.70 2.70 2.64 18.29 222.05 0.9 2.70 2.83 2.76 2.53 19.20 221.92 0.6 2.83 2.87 2.85 1.74 19.81 221.88 0.6 2.87 2.95 2.91 1.77 20.42 221.80 0.9 2.95 3.11 3.03 2.77 THALWEG 21.34 221.64 0.5 3.11 3.07 3.09 1.60 21.85 221.68 0.2 3.07 2.94 3.00 0.55 22.04 221.81 0.3 2.94 2.64 2.79 0.94 22.37 222.11 0.3 2.64 2.36 2.50 0.76 RT EOW 22.68 222.39 0.2 2.36 2.15 2.26 0.55 22.92 222.60 0.2 2.15 1.69 1.92 0.47 23.16 223.06 0.3 1.69 1.47 1.58 0.43 23.44 223.28 0.2 1.47 1.41 1.44 0.35 23.68 223.34 0.2 1.41 1.10 1.26 0.27 23.90 223.65 0.5 1.10 0.69 0.90 0.41 24.35 224.06 0.2 0.69 0.26 0.48 0.09 24.54 224.49 0.2 0.26 0.00 0.13 0.03 RT BKF 24.78 224.75 0.1 0.00 0.00 0.00 0.00 24.90 225.11 28.22 24.99 225.21 RT TOB 25.30 225.30 26.21 225.24 RT PIN 27.74 225.16 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

166

Table E27: Geomorphic measurements for the Station 6346 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 28.19 28.22 28.20 W(bkf) m 12.8 12.6 12.73 D(bkf) m 3.19 3.12 3.15 W/D 4.01 4.06 4.04 W(fpa) m 419 419 419 ER 32.73 33.12 32.93 S(ws) 0.002 0.002 0.002 K 1.35 1.35 1.35 D50 (mm) sand sand sand

Dmax (bkf) m 3.30 3.15 3.23

Dmax (TOB) m 3.74 3.66 3.70 BHR 1.13 1.16 1.15

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

167 Table E28: Cross-section elevations and computation of area (m) for 6797 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 224.94 1.52 225.00 3.05 225.03 4.57 225.15 LT TOB 5.79 225.27 6.10 225.24 LT BKF 6.40 225.07 0.3 -0.79 -0.20 -0.49 -0.15 6.71 224.48 0.3 -0.20 -0.05 -0.12 -0.04 7.01 224.33 0.3 -0.05 0.05 0.00 0.00 7.32 224.23 0.5 0.05 0.29 0.17 0.08 7.77 223.99 0.8 0.29 0.68 0.48 0.37 8.53 223.60 0.6 0.68 1.04 0.86 0.52 9.14 223.24 0.3 1.04 2.01 1.53 0.47 LT EOW 9.45 222.27 0.6 2.01 2.27 2.14 1.31 LT THALWEG 10.06 222.01 0.3 2.27 2.15 2.21 0.67 10.36 222.13 0.4 2.15 2.05 2.10 0.90 RT EOW 10.79 222.23 1.4 2.05 1.96 2.01 2.81 SANDBAR 12.19 222.32 1.5 1.96 1.83 1.89 2.88 SANDBAR 13.72 222.45 1.5 1.83 1.86 1.84 2.80 SANDBAR 15.24 222.42 3.0 1.86 1.88 1.87 5.70 SANDBAR 18.29 222.40 0.8 1.88 2.01 1.94 1.54 LT EOW 19.08 222.27 1.0 2.01 2.15 2.08 2.15 RT THALWEG 20.12 222.13 0.8 2.15 2.12 2.14 1.76 20.94 222.16 0.8 2.12 2.01 2.07 1.64 RT EOW 21.73 222.27 0.5 2.01 1.89 1.95 0.89 22.19 222.39 0.2 1.89 1.24 1.57 0.38 22.43 223.04 0.1 1.24 0.68 0.96 0.12 22.56 223.60 0.2 0.68 0.00 0.34 0.08 RT BKF 22.80 224.28 0.4 0.00 0.00 0.00 0.00 23.16 224.63 27.06 23.47 224.77 24.08 224.83 RT TOB 24.99 224.90 26.52 224.78 28.04 224.70 RT PIN 32.77 224.69

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

168 Table E29: Cross-section elevations and computation of area (m) for Station 6797 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 224.94 1.52 224.99 4.57 225.14 5.49 225.20 LT TOB 6.10 225.22 6.34 225.16 6.55 224.91 6.71 224.47 LT BKF 7.01 224.30 0.30 -0.06 0.04 -0.01 0.00 7.32 224.20 0.30 0.04 0.14 0.09 0.03 7.62 224.10 0.30 0.14 0.32 0.23 0.07 7.92 223.92 0.30 0.32 0.47 0.39 0.12 8.53 223.63 0.30 0.61 0.75 0.68 0.21 8.84 223.49 0.30 0.75 0.96 0.86 0.26 9.14 223.28 0.30 0.96 1.36 1.16 0.35 9.45 222.88 0.06 1.36 2.06 1.71 0.10 9.51 222.18 0.24 2.06 2.19 2.12 0.52 THALWEG 9.75 222.05 0.30 2.19 2.16 2.17 0.66 10.06 222.08 0.61 2.16 2.01 2.08 1.27 10.67 222.23 0.61 2.01 2.05 2.03 1.24 11.28 222.19 0.46 2.05 1.96 2.00 0.92 11.73 222.28 0.46 1.96 1.91 1.94 0.88 LT EOW 12.19 222.33 0.91 1.91 1.86 1.89 1.73 13.11 222.38 0.55 1.86 1.82 1.84 1.01 13.66 222.42 0.67 1.82 1.83 1.83 1.23 EOP 14.33 222.41 1.22 1.83 1.87 1.85 2.26 15.54 222.37 0.76 1.87 1.85 1.86 1.42 EOP 16.31 222.39 0.76 1.85 1.82 1.83 1.40 17.07 222.42 0.61 1.82 1.85 1.84 1.12 17.68 222.39 1.22 1.85 1.92 1.89 2.30 LT EOW 18.90 222.32 0.61 1.92 2.04 1.98 1.21 19.51 222.20 0.61 2.04 2.09 2.07 1.26 20.12 222.15 0.61 2.09 2.10 2.10 1.28 20.73 222.14 0.61 2.10 2.08 2.09 1.28 21.34 222.16 0.55 2.08 2.07 2.07 1.14 21.88 222.17 0.24 2.07 1.92 2.00 0.49 RT EOW 22.13 222.32 0.12 1.92 1.86 1.89 0.23 22.25 222.38 0.06 1.86 1.55 1.71 0.10 22.31 222.69 0.15 1.55 1.17 1.36 0.21 22.46 223.07 0.09 1.17 0.65 0.91 0.08 22.56 223.59 0.21 0.65 0.00 0.32 0.07 RT BKF 22.77 224.24 0.09 0.00 0.00 0.00 0.00 22.86 224.34 26.58 23.16 224.63 RT TOB 23.47 224.76 24.99 224.89 26.21 224.81 28.96 224.68 30.78 224.67 RT PIN 32.89 224.67 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

169 Table E30: Geomorphic measurements for the Station 6797 on South Buffalo Creek, within the area of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 27.06 26.58 26.82 W(bkf) m 16.40 15.76 16.40 D(bkf) m 2.27 2.19 2.23 W/D 7.24 7.20 7.22 W(fpa) m 198 198 198 ER 12.07 12.56 12.07 S(ws) 0.002 0.002 0.002 K 1.35 1.35 1.35 D50 (mm) gravel gravel gravel

Dmax (bkf) m 3.06 3.10 3.08

Dmax (TOB) m 3.27 3.16992 3.22 BHR 1.07 1.02 1.04

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

170 Table E31: Cross-section elevations and computation of area (m) for Station 7505 on South Buffalo Creek, downstream of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0.0 225.40 1.52 225.04 3.05 224.81 4.57 224.42 5.18 224.34 LT TOB 6.10 224.58 LT BKF 6.55 224.46 0.2 -0.02 0.17 0.08 0.01 6.71 224.27 0.3 0.17 0.63 0.40 0.12 7.01 223.81 0.3 0.63 1.16 0.89 0.27 7.32 223.28 0.3 1.16 1.46 1.31 0.40 7.62 222.98 0.0 1.46 2.33 1.89 0.06 LT EOW 7.65 222.11 0.1 2.33 1.85 2.09 0.19 7.74 222.59 0.2 1.85 2.68 2.26 0.41 7.92 221.76 0.6 2.68 2.69 2.68 1.63 8.53 221.75 1.2 2.69 2.66 2.67 3.26 9.75 221.78 0.9 2.66 2.58 2.62 2.39 10.67 221.86 1.2 2.58 2.57 2.57 3.14 11.89 221.87 0.9 2.57 2.57 2.57 2.35 12.80 221.87 1.2 2.57 2.63 2.60 3.17 14.02 221.81 0.9 2.63 2.67 2.65 2.42 14.94 221.77 0.9 2.67 2.79 2.73 2.50 15.85 221.65 0.6 2.79 2.84 2.82 1.72 THALWEG 16.46 221.60 0.9 2.84 2.79 2.81 2.57 17.37 221.65 1.3 2.79 2.32 2.56 3.43 RT EOW 18.71 222.12 0.2 2.32 2.19 2.26 0.41 18.90 222.25 0.3 2.19 1.41 1.80 0.55 19.20 223.03 0.5 1.41 0.95 1.18 0.54 19.66 223.49 0.3 0.95 0.30 0.63 0.19 19.96 224.14 0.3 0.30 0.00 0.15 0.05 RT BKF 20.27 224.44 0.5 0.00 0.00 0.00 0.00 20.73 224.32 31.78 21.03 224.58 22.25 224.74 24.38 224.97 RT PIN 29.11 225.22

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

171 Table E32: Cross-section elevations and computation of area (m) for Station 7505 on South Buffalo Creek, downstream of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 225.40 0.61 225.32 1.83 225.19 2.44 224.92 3.05 224.80 3.66 224.74 4.27 224.53 4.88 224.34 5.49 224.42 LT TOB 6.10 224.56 6.40 224.53 6.68 224.33 LT BKF 6.80 224.17 0.2 0.00 0.50 0.25 0.05 7.01 223.67 0.2 0.50 0.82 0.66 0.10 7.16 223.35 0.7 0.82 2.18 1.50 1.01 LT EOW 7.83 221.99 1.3 2.18 2.47 2.33 3.05 9.14 221.70 1.5 2.47 2.36 2.42 3.68 10.67 221.81 1.5 2.36 2.31 2.33 3.56 12.19 221.86 1.5 2.31 2.32 2.32 3.53 13.72 221.85 1.5 2.32 2.48 2.40 3.66 15.24 221.69 1.5 2.48 2.49 2.49 3.79 THALWEG 16.76 221.68 1.5 2.49 2.34 2.41 3.68 18.29 221.83 0.3 2.34 2.02 2.18 0.66 RT EOW 18.59 222.15 0.7 2.02 1.20 1.61 1.18 19.32 222.97 0.5 1.20 0.75 0.97 0.47 19.81 223.42 0.5 0.75 -0.12 0.32 0.17 RT BKF 20.36 224.29 0.5 -0.12 0.00 -0.06 -0.03 RT TOB 20.82 224.61 28.57 21.34 224.69 22.86 224.83 26.82 224.95 RT Pin (new) 28.96 225.18

LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

172 Table E33: Geomorphic measurements for the Station 7505 on South Buffalo Creek, downstream of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 31.78 28.57 30.18 W(bkf) m 13.72 13.56 13.72 D(bkf) m 2.85 2.47 2.66 W/D 4.81 5.49 5.15 W(fpa) m 20 20 20 ER 1.46 1.47 1.46 S(ws) 0.001 0.001 0.001 K 1.04 1.04 1.04 D50 (mm) sand sand sand

Dmax (bkf) m 2.85 2.59 2.72

Dmax (TOB) m 2.69 2.91 2.80 BHR 0.94 1.12 1.03

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

173 Table E34: Cross-section elevations and computation of area (m) for Station 7859 on South Buffalo Creek, downstream of the proposed stormwater treatment wetland, in October 2001 October 2001 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0.0 224.56 1.52 224.42 2.44 224.09 3.35 224.16 4.88 224.63 6.40 224.81 LT TOB 8.23 225.03 8.84 224.95 9.14 224.84 LT BKF 9.45 224.74 0.30 -0.05 0.30 0.128 0.04 9.75 224.39 0.30 0.30 0.76 0.53 0.16 10.06 223.93 0.30 0.76 1.20 0.98 0.30 10.67 223.49 0.61 1.20 1.80 1.50 0.91 11.28 222.89 0.61 1.80 2.35 2.08 1.27 11.89 222.34 0.61 2.35 2.48 2.41 1.47 12.19 222.21 0.30 2.48 2.64 2.56 0.78 LT EOW 12.89 222.05 0.70 2.64 2.72 2.68 1.88 13.26 221.97 0.37 2.72 2.67 2.69 0.98 14.63 222.02 1.37 2.67 2.66 2.66 3.65 15.85 222.03 1.22 2.66 2.74 2.70 3.29 THALWEG 17.37 221.95 1.52 2.74 2.65 2.70 4.11 17.83 222.04 0.46 2.65 2.66 2.65 1.21 19.20 222.03 1.37 2.66 2.65 2.65 3.64 RT EOW 20.12 222.04 0.91 2.65 2.57 2.61 2.39 21.34 222.12 1.22 2.57 2.39 2.48 3.02 22.56 222.30 1.22 2.39 2.03 2.21 2.70 23.01 222.66 0.46 2.03 1.42 1.73 0.79 23.44 223.27 0.43 1.42 1.05 1.24 0.53 23.77 223.64 0.34 1.05 0.00 0.52 0.18 RT BKF 23.16 224.69 -0.61 0.00 0 0.00 0.00 23.47 224.80 33.29 TOP 23.77 224.85 24.08 224.97 24.38 225.16 24.99 225.45 25.60 225.59 RT TOB 26.21 225.82 27.13 226.02 RT PIN 29.26 226.47 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

167 Table E35: Cross-section elevations and computation of area (m) for Station 7859 on South Buffalo Creek, downstream of the proposed stormwater treatment wetland, in March 2002 March 2002 Description Station (X) Elevation (Y) Xi + X i+1 Yi Yi+1 (Yi + Yi+1)/2 Area (m2) LT PIN 0 224.42 1.52 224.36 3.05 224.02 4.57 224.49 6.10 224.64 7.92 224.95 LT TOB 8.23 224.96 8.84 224.90 9.17 224.83 LT BKF 9.75 224.72 0.58 -0.03 0.15 0.06 0.03 10.00 224.54 0.24 0.15 0.50 0.32 0.08 10.21 224.19 0.21 0.50 0.69 0.59 0.13 10.39 224.00 0.18 0.69 0.88 0.78 0.14 10.79 223.81 0.40 0.88 1.32 1.10 0.44 10.97 223.37 0.18 1.32 1.50 1.41 0.26 11.28 223.19 0.30 1.50 1.79 1.64 0.50 11.58 222.90 0.30 1.79 1.98 1.88 0.57 11.77 222.71 0.18 1.98 2.29 2.13 0.39 11.89 222.40 0.12 2.29 2.52 2.41 0.29 12.19 222.17 0.30 2.52 2.61 2.57 0.78 LT EOW 12.56 222.08 0.37 2.61 2.68 2.65 0.97 13.11 222.01 0.55 2.68 2.78 2.73 1.50 13.41 221.91 0.30 2.78 2.74 2.76 0.84 THALWEG 14.02 221.95 0.61 2.74 2.72 2.73 1.67 14.33 221.97 0.30 2.72 2.70 2.71 0.83 15.24 221.99 0.91 2.70 2.68 2.69 2.46 16.15 222.01 0.91 2.68 2.70 2.69 2.46 16.76 221.99 0.61 2.70 2.72 2.71 1.65 17.07 221.97 0.30 2.72 2.75 2.73 0.83 17.68 221.94 0.61 2.75 2.64 2.70 1.64 17.95 222.05 0.27 2.64 2.64 2.64 0.73 18.62 222.05 0.67 2.64 2.64 2.64 1.77 19.51 222.05 0.88 2.64 2.66 2.65 2.34 20.76 222.03 1.25 2.66 2.61 2.63 3.29 RT EDGE 21.67 222.08 0.91 2.61 2.55 2.58 2.36 22.19 222.14 0.52 2.55 2.44 2.49 1.29 22.56 222.25 0.37 2.44 2.54 2.49 0.91 23.65 222.15 1.10 2.54 1.17 1.85 2.03 24.26 223.52 0.61 1.17 0.00 0.59 0.36 RT BKF 23.23 224.69 -1.04 0.00 0.00 0.00 0.00 23.62 224.81 33.53 24.08 224.96 24.23 225.01 24.38 225.09 24.69 225.33 25.30 225.50 25.91 225.76 26.82 225.95 28.04 226.23 RT PIN 29.35 226.47 LT = Left RT = Right TOB = Top of Bank EOW = Edge of Water

175 Table E36: Geomorphic measurements for the Station 7859 on South Buffalo Creek, downstream of the proposed stormwater treatment wetland October 2001 March 2002 Average DA (km2) 35 35 35 A(bkf) m2 33.29 33.53 33.41 W(bkf) m 14.02 14.05 14.04 D(bkf) m 2.89 2.77 2.83 W/D 4.85 5.07 4.96 W(fpa) m 213 213 213 ER 15.19 15.16 15.18 S(ws) 0.001 0.001 0.001 K 1.04 1.04 1.04 D50 (mm) sand sand sand

Dmax (bkf) m 2.79 2.88 2.84 Dmax (TOB) m 3.88 3.02 3.45 BHR 1.39 1.05 1.21

DA = Drainage Area A(bkf) = Cross-sectional Area at Bankful W(bkf) = Width at Bankfull D(bkf) = Height of Bankfull - Depth at Thalweg W/D = W(bkf)/D(bkf) ER = Entrenchment Ratio [W(fpa)/W(bkf)] S(ws) = Slope of Water Surface K = Sinuosity D50 = average particle size of substrate BHR = Bank Height Ratio [D max(bkf)/D max(TOB)]

176

Cross Section at Meadowview Avenue: Riffle at Station 79

230.5

230.0

229.5 Lt. BKF Rt. BKF

2 229.0 DA = 23 km A(bkf) = 22.9 m 2 W (bkf) = 13.7 m 228.5 D (bkf) = 2.4 m W/D = 5.83 W fpa = 137 m 228.0 ER = 10.00 Slope = 0.002 meters above sea level K = 1.03 227.5 BHR = 1.11 October 2001 Bedrock Thalweg March 2002 227.0 0 5 10 15 20 25 me te rs Figure E1: Comparison of cross-sections for Station 79, upstream of the proposed stormwater treatment wetland.

177

Riffle at Rolling Roads Tributary

227.5

227.0

226.5

2 DA = 7.8 km . Lt. BKF Rt. BKF 226.0 A(bkf) = 13.2 m 2 W (bkf) = 8.6 m D(bkf) =1.9 m 225.5 W/D = 4.6 W(fpa) = 168 m Thalweg 225.0 ER = 19.6

meters above level sea Slope = 0.004 K = 1.04 Lt. EOW 224.5 D50 = sand BHR = 1.30 Rt. EOW October 2001 March 2002 224.0 0 5 10 15 20 25 meters

Figure FigureE2: Comparison E2: of cross-sections for tributary upstream of the proposed stormwater treatment wetland.

178

Riffle at Station 622

October 2001 March 2002

230.0 Fence Barrier 229.5 to Highway Lt. BKF Rt. BKF 229.0

DA =23 km 2 228.5 A(bkf) =23.8 m 2 W (bkf) = 18.8 m 228.0 D (bkf) = 2.0 m W/D = 9.6 m W (fpa) = 213 m 227.5 ER = 11.3 meters abovesea level Slope = 0.002 227.0 K = 1.03 Bedrock BHR = 1.17

226.5 0 5 10 15 20 25 meters

Figure E3: Comparison of cross-sections for Station 622, upstream of the proposed stormwater treatment wetland.

179

Station 5386 at Pool upstream of Bedrock

October 2001 March 2002

228.00

227.00 Rt. BKF Lt. 226.00

225.00 DA = 35 km2 A(bkf) = 40.4 m2 224.00 W (bkf) = 19.9 m D (bkf) = 3.4 m W/D = 5.89 223.00 ER = 19.8

meters abovelevel sea Slope = 0.002 K = 1.35 222.00 BHR = 1.09 Lt. EOW Rt. EOW 0 5 10 15 20Thalweg 25 30 35 me te rs

Figure E4: Comparison of cross-sections for Station 5386, with the area of the proposed stormwater treatment wetland.

180

Station 5556 at Bedrock

October 2001 March 2002

226.5

226.0

225.5

225.0

224.5 Lt. BKF DA = 35 km2 224.0 A(bkf) = 37.7 m2 W(bkf) = 19.2 m D (bkf) = 2.4 m 223.5 W/D = 8.2 meters above sea level ER = 20.3 Slope = 0.002 223.0 K = 1.35 Rt. EOW D50 = cobble 222.5 Bedrock BHR = 1.19 Thalweg 0 5 10 15 20 25 meters

Figure E5: Comparison of cross-sections for Station 5556, within the area of the proposed stormwater treatment wetland.

181

Riffle at Station 5772 October 2001 March 2002

227.00

226.00

Lt. BKF Rt. BKF 225.00

DA = 35 km 2 2 224.00 A(bkf) = 32.4 m W (bkf) = 15.5 m

Meters abovesea level D (bkf) = 2.7 m W/D = 5.8 m ER = 23.5 223.00 Slope = 0.002 K = 1.35 D50 = sand BHR = 1.18 Lt. EOW Rt. EOW

222.00 0 5 10 15 20 25 30 Meters

Figure E6: Comparison of cross-sections for Station 5772, within the area of the proposed stormwater treatment wetland.

182

Station Riffle 5923

October 2001 March 2002

Lt. TOB Rt. TOB 226.0

225.5

225.0 Lt. BKF Rt. BKF 224.5 DA = 35 km2 224.0 A(bkf) =22.8 m2 W (bkf) = 11.1 m 223.5 D (bkf) = 2.4 m W/D = 4.7 W fpa = 328 m meters above sea level meters 223.0 ER = 29.5 Slope = 0.009 222.5 BHR = 1.38 Thalweg 222.0 0 5 10 15 20 25 30 meters

Figure E7: Comparison of cross-sections for Station 5923, within the area of the proposed stormwater treatment wetland.

183

Station 6206

October 2001 March 2002 227.0

226.5

226.0 225.5

225.0 224.5 LT BKF RT BKF

224.0 2 DA = 35 km 2 223.5 A(bkf) = 26.9 m w 9bkf) = 11.5 m D (bkf) = 2.8 m meters above sea level 223.0 W/D = 4.16 222.5 ER = 38 Slope = 0.002 222.0 K = 1.35 BHR = 1.17 Thalweg 221.5 0 5 10 15 20 25 30 me te rs

Figure E7: Comparison of cross-sections for Station 6206, within the area of the proposed stormwater treatment wetland.

184

Station 6346 at Pool

October 2001 March 2002

227.0

226.0

225.0 Rt. BFK Lt. BKF 224.0 DA= 35 km 2 A(bkf) = 28.2 mt2 W (bkf) = 12.7 m D (bkf) = 3.2 m 223.0 W/D = 4.0 m meters above sea level W fpa = 419 m Rt. EOW ER = 33 222.0 Slope = 0.002 Lt. EOW K = 1.35 BHR = 1.15 221.0 0 5 10 15 20 25 30 meters

Figure E8: Comparison of cross-sections for Station 6346, within the area of the proposed stormwater treatment wetland.

185

Station 6797 at Riffle (Braided)

October 2001 March 2002 225.5

225.0

224.5

224.0 Rt. BKF DA = 35 km 2 223.5 A(bkf) = 26.8 m 2 W (bkf) = 15.8 m 223.0 D (bkf) = 2.2 m W/D = 7.09

meters above level sea 222.5 ER = 12.3 Slope = 0.002 K = 1.35 222.0 D50 = gravel Sand Bar BHR = 1.04 Thalweg 221.5 0 5 10 15 20 25 30 35 meters

Figure E9: Comparison of cross-sections for Station 6797, within the area of the proposed stormwater treatment wetland.

186

Station 7505 (Farragut St Monitoring Station)

Octrober 2001 March 2002

226.0

225.5 Lt. BKF Rt. BKF 225.0

224.5

224.0 DA = 35 k m2 223.5 A(bkf) = 30.2 m2 W (bkf) = 13.6 m 223.0 D (bkf) = 2.7 m W/D = 5.12 222.5 W fpa =20 m meters above level sea meters 222.0 ER = 1.47 Slope = 0.001 221.5 BHR = 1.03 Thalweg 221.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 meters

Figure E10: Comparison of cross-sections for Station 7505, downstrean of the proposed stormwater treatment wetland.

187 Station 7859 (Riffle)

October 2001 March 2002

227.0

226.0

LT BKF RT BKF 225.0

224.0 DA = 14 sq. mi. A(bkf) = 362 ft2 223.0 W (bkf) = 46 ft D (bkf) = 9.3 meters above sea level W/D = 4.95 W fpa = 1200 ft 222.0 ER = 26 Slope = 0.001 Thalweg K = 1.04 BHR = 1.05 221.0 0 5 10 15 20 25 30 meters

Figure E11: Comparison of cross-sections for Station 7859, downstream of the proposed stormwater treatment wetland.

188 Table E36: Summary of Rosgen classification parameters for stream cross-section stations

max DA* A(bkf) W(bkf) D(bkf) W/D W(fpa)* ER S(ws)* K* D50 Dmax D (TOB) BHR (km2) (m2) (m) (m) (m) (mm)* (bkf) (m) (m)

Upstream Tributary Tributary 7.8 13.16 8.55 1.86 4.61 168 19.66 0.004 1.04 sand 1.86 2.41 1.30 Upstream SBC Riffle 79 23 22.93 13.72 2.35 5.83 137 9.99 0.002 1.03 gravel 2.48 2.75 1.11 Riffle 622 23 23.79 18.84 1.969 9.57 216 11.31 0.002 1.03 sand 2.08 2.43 1.17 Average 23 23.36 16.28 2.161 7.70 176.5 10.65 0.002 1.03 sand 2.28 2.59 1.14 Project SBC Riffle 5556 35.0 37.74 19.22 2.36 8.17 390 20.29 0.002 1.35 cobble 2.71 3.20 1.18 Riffle 5772 35.0 32.38 15.54 2.68 5.80 366 23.54 0.002 1.35 sand 2.70 3.19 1.18 Riffle 5923 35.0 22.80 11.13 2.35 4.73 328 29.48 0.009 1.35 sand 2.34 3.24 1.38 Riffle 6207 35.0 26.92 11.54 2.78 4.16 442 38.31 0.002 1.35 sand 2.80 3.27 1.17 Riffle 6797 35.0 26.82 16.40 2.23 7.22 198 12.07 0.002 1.35 gravel 3.08 3.22 1.04 Average 35.0 29.33 14.76 2.48 6.01 345 24.74 0.003 1.35 sand 2.73 3.22 1.19 Downstream SBC Farragut 7505 35 30.18 13.72 2.66 5.15 20 1.46 0.001 1.04 sand 2.72 2.80 1.03 Riffle 7859 35 33.41 14.04 2.83 4.98 213 15.20 0.001 1.04 sand 2.84 3.45 1.21 Average 35 31.8 13.9 2.7 5.1 116.5 8.3 0.0 1.0 sand 2.8 3.1 1.1

189 APPENDIX F: Wetland Hydrology Results

190

191

192

193

194

195

196

197 Figure E17: Groundwater gradient for June to December 2001 (meters above sea level)

Figure E18: Groundwater gradient for January to August 2002 (meters above sea level)

198 APPENDIX G: Vegetation Results

Table G1: Vegetation Plots in Wetland Areas (Plot Size = 314 m2)

Density(species Plot Species Total Basal Area Count frequency /m^2) 1 FRAPE 0.857 31 0.94 0.099 1 ULMAM 0.010 2 0.06 0.006 1 total 33 2 FRAPE 0.558 16 0.80 0.051 2 ULMAM 0.005 1 0.05 0.003 2 SALNG 0.118 1 0.05 0.003 2 ACRUM 0.008 1 0.05 0.003 2 PLOCC 0.185 1 0.05 0.003 2 total 20 3 FRAPE 0.686 12 0.48 0.038 3 ACNGD 0.006 1 0.04 0.003 3 CEOCC 0.066 12 0.48 0.038 3 Total 25.0 4 FRAPE 0.962 16.5 0.75 0.053 4 ACNGD 0.098 4.5 0.20 0.014 4 ULMAM 0.024 1 0.05 0.003 4 Total 22 5 FRAPE 0.825 27 0.90 0.086 5 ULMAM 0.167 2 0.07 0.006 5 CEOCC 0.005 1 0.03 0.003 5 Total 30 6 FRAPE 0.721 18 0.90 0.057 6 ACNGD 0.016 1 0.05 0.003 6 CEOCC 0.013 1 0.05 0.003 6 Total 20 7 FRAPE 1.276 34 0.94 0.108 7 ACNGD 0.005 1 0.03 0.003 7 CEOCC 0.004 1 0.00 0.003 7 Total 36

ACNGD Acer negundo ACRUM Acer rubrum CEOCC Celtis occidentalis FRAPE Fraxinus pennslyvanica PLOCC Platanus occidentalis SALNG Salix nigra ULMAM Ulmus americana

199

Table G2: Ground Cover Vegetation Survey of Species <0.5 m height Herbaceous Species Number Absolute Relative Total Average Relative Importance (<0.5-m) of Plots Frequency Frequency Cover Cover Cover Value Bare Area 28 100 21 1402 50.1 53.5 58 Lonicera japonica 25 89 19 495 19.8 18.9 42 Toxicodendon radicans 15 54 11 352 23.5 13.4 26 Parthenocissus quinquefolia 17 61 13 93 5.5 3.5 26 Rhubus spp. 6 21 5 28 4.7 1.1 9 Cornus spp. 6 21 5 27 4.5 1.0 9 Carex spp. 4 14 3 31 7.8 1.2 6 Sambucus canadensis 3 11 2 15 5.0 0.6 5 Fragaria spp. 3 11 2 3 1.0 0.1 4 Vitus spp. 3 11 2 3 1.0 0.1 4 Lactura spp. 2 7 2 11 5.5 0.4 3 Smilax spp. 2 7 2 10 5.0 0.4 3 Celtis laevigata 1 4 1 5 5.0 0.2 2 Unknown 4 14 3 8 2.0 0.3 6 Unknown #1 3 11 2 71 23.7 2.7 5 Unknown #2 2 7 2 26 13.0 1.0 3 Unknown #3 3 11 2 11 3.7 0.4 4 Unknown #4 1 4 1 5 5.0 0.2 2 Unknown #5 1 4 1 5 5.0 0.2 2 Unknown #6 1 4 1 10 10.0 0.4 2 Unknown #7 1 4 1 10 10.0 0.4 2 Polygonum spp. 1 4 1 1 1.0 0.0 1 Rosa spp. 1 4 1 1 1.0 0.0 1

Table G3: Ground Cover Vegetation >0.5 m height Herbaceous Species Number Absolute Relative Total Average Relative (>0.5-m) of Plots Frequency Frequency Cover Cover Cover Acer negundo 2 7 11.8 50 25 13.3 Celtis occidentalis 1 4 5.9 50 50 13.3 Cornus amomun 2 7 11.8 55 27.5 14.6 Rhubus spp. 4 14 23.5 30 7.5 8.0 Robinia/unknown 2 7 11.8 6 3 1.6 Rosa spp. 2 7 11.8 101 50.5 26.8 Toxicodendon radicans 1 4 5.9 10 10 2.7 Ulmus rubra 1 4 5.9 5 5 1.3 Unknown #1 1 4 5.9 65 65 17.2 unknown #5 1 4 5.9 5 5 1.3

200