Niagara Power Project FERC No. 2216
SURFACE WATER QUALITY OF THE NIAGARA RIVER AND ITS U.S. TRIBUTARIES
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Prepared for: New York Power Authority
Prepared by: URS Corporation and Gomez and Sullivan Enigeers, P.C.
August 2005
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Copyright © 2005 New York Power Authority
PREFACE
This is the Draft of the NYPA Niagara Power Project relicensing report for Issue 30, Surface Water Quality of the Niagara River and U.S. Tributaries. The objectives of this investigation are to: (1) determine if and how Project operations affect dissolved oxygen and turbidity of the Niagara River, its U.S. tributaries and Lewiston Reservoir; (2) describe sources of turbidity in the Niagara River, its U.S. tributaries, and Lewiston Reservoir; and (3) document and determine if surface water quality of the Niagara River, its U.S. tributaries, and Lewiston Reservoir complies with New York State Water Quality Standards for surface water. The original objectives of this study included describing sources of sedimentation, however the Shoreline Erosion and Sedimentation Assessment Study (Baird 2004) is examining sources of sedimentation and related erosion sites in the River and tributaries, so that specific issue will not be discussed here.
It should be noted that data collected for the Surface Water Quality study will be used to address other environmental issues associated with Project relicensing (in other reports). Conversely, this study will use water quality data collected as part of other monitoring programs, both related and unrelated to relicensing of the Project to assess the overall surface water quality. Relevant data collected from other NYPA studies and the associated analyses and conclusions will also be referenced in this report. These studies include Issue 21 – Ecological Condition of Fish, Gill and Cayuga Creeks (URS et al. 2004a), Issue 23 – Water Level and Flow Fluctuation Study (URS et al. 2003b), Issue 25 – Effect of Project Operations on Water Temperatures (URS 2004), Issue 26 – Groundwater (URS et al. 2004b), Issue 42/46 – Shoreline Erosion and Sedimentation Assessment Study (Baird 2004), Issue 50 – Buckhorn Marsh Fish Study (NYPA and Gomez and Sullivan 2004), and the Tributary Backwater Study (URS et al. 2004c). Additionally, sediment quality in the upper Niagara River, Lewiston Reservoir and the lower Niagara River was investigated by NYPA in 2002 (ESI 2003) in which sediment samples were analyzed for multiple constituents, including the 18 priority toxic pollutants identified in the Niagara River Toxics Management Plan.
This report documents the surface water quality of the Niagara River, its U.S. tributaries and the Lewiston Reservoir. In addition to the upper and lower Niagara River and Lewiston Reservoir, the tributaries to the Niagara River studied included: Cayuga Creek, Gill Creek, Fish Creek, Tonawanda Creek, Ellicott Creek, Burnt Ship Creek, Woods Creek, Gun Creek, Spicer Creek and Big Sixmile Creek.
The objectives of this investigation are to: (1) determine if and how Project operations affect dissolved oxygen and turbidity of the Niagara River, its U.S. tributaries and Lewiston Reservoir; (2) describe sources of turbidity in the Niagara River, its U.S. tributaries, and Lewiston Reservoir; and (3) document and determine if surface water quality of the Niagara River, its U.S. tributaries, and Lewiston Reservoir complies with New York State Water Quality Standards for surface water. The original objectives of this study included describing sources of sedimentation; however the Shoreline Erosion and Sedimentation Assessment Study (Baird 2004) is examining sources of sedimentation and related erosion sites in the River and tributaries, and so that specific issue will not be discussed here. Refer to (ESI 2003) for an analysis of sedimentation in Lewiston Reservoir.
It should be noted that separating the effects of Project operations from other factors is difficult, particularly the effects of water level fluctuations. Water level fluctuations in the Niagara River are caused by a number of natural and manmade factors which are interrelated and dynamic. Natural factors include flow surges, wind, ice conditions, and regional and long-term precipitation patterns that affect lake levels, while manmade factors include regulation of Niagara Falls flows for scenic purposes, operation of power plants on the Canadian side of the river, and operation of the Niagara Power Project. Because the water level in the Niagara River at any location at any time is a complex function of natural and manmade factors, distinguishing the exact amount of water level fluctuation attributable to each factor is difficult.
The study objectives were achieved in several ways. To document the existing conditions, a literature review of relevant water quality data was conducted. There is extensive information available on the past and present water quality conditions on the main Niagara River, as well as clear direction on how governmental agencies intend on improving water quality. In addition, recent water quality studies associated with NPP relicensing have been used to assess current conditions and to identify factors that could affect water quality conditions in the study area. During the relicensing process, various stakeholders have indicated specific concerns over the potential effects of water levels fluctuations on turbidity and dissolved oxygen. The data collected in 2003 specifically for this study consisted of continuous water level data in conjunction with discrete turbidity and dissolved oxygen data under various weather conditions.
To supplement the water level, turbidity and dissolved oxygen data collected for this study, NYPA conducted other investigations that were useful in describing existing surface water quality conditions. These include investigations of: erosion and sedimentation in the Project area, groundwater flow patterns and their effect on surface water quality, the effect of water level fluctuations on water temperatures, and the ecological condition of Gill, Fish and Cayuga Creeks. Also, data collected by New York and Canadian environmental agencies were used to assess the current water quality conditions of the water bodies listed above.
A review of the surface water quality data in the literature as well as the data collected in 2003 reveal that the water quality of the upper and lower Niagara River has improved greatly over the past 20 years. Likewise, the current surface water quality conditions in the Niagara River, Lewiston Reservoir and U.S. tributaries are generally good. However, problems associated with persistent organic contaminants in sediment and fish tissue in the Niagara River are still prevalent. These problems have impaired some of the designated uses of the target water bodies in this study.
From the data collected in 2003, there does not appear to be any negative effects due to U.S./Canadian power generation on the surface water quality of the upper and lower Niagara River and Lewiston Reservoir. Data also indicate that there are no negative effects on turbidity in the U.S. tributaries of the upper Niagara River due to U.S./Canadian power generation. The study documented that dissolved oxygen levels in some U.S. tributaries did not meet the state standard at times. From the data collected it appears a number of factors may be contributing to localized dissolved oxygen suppression including: high background levels of turbidity which may lead to an oxygen demand, poor quality source water in tributaries, stormwater discharges and non-point source runoff, and groundwater influx.
Turbidity in the main channel of the upper Niagara River is predominantly related to weather and inflow conditions from Lake Erie. Localized areas of elevated turbidity can be present in the upper Niagara River due to outflow from highly turbid tributaries particularly after runoff events. One possible source of turbidity in the upper Niagara River may be erosion. The primary factors for observed bank erosion areas on the upper Niagara River are most likely waves (wind and boat-generated) and currents (Baird 2004) and not water level fluctuation due to U.S./Canadian power generation. The lower Niagara River was relatively clear and there are no apparent turbidity effects from the Lewiston Reservoir/RMNPP discharges. The data collected in 2003 shows that turbidity levels in the Lewiston Reservoir are low and not related to water level fluctuations. There are combined sewer overflows (CSOs) as well as nonpoint sources that may affect the turbidity in the upper and lower Niagara River during wet weather events. Like the upper Niagara River, the primary factors for observed bank erosion areas along the lower Niagara River downstream of RMNPP are most likely waves (wind and boat-generated) and currents and not water level fluctuations (Baird 2004).
The lower sections of tributaries to the upper Niagara River were influenced by water level fluctuations in the Chippawa-Grass Island Pool. The magnitude of daily water level fluctuations appears directly related to the creeks’ spatial relation to the Chippawa-Grass Island Pool in the upper Niagara River. Sources of turbidity in the U.S. tributaries primarily include (1) stream bank erosion; (2) stormwater runoff from watershed areas; and, (3) point and non-point discharges to a stream. The causes of erosion can include high flow runoff, waves, water level fluctuations, ice, debris, groundwater flow, weathering, and unstable banks. Turbidity data and findings from Baird 2004 indicate that Niagara River water level fluctuations do not affect the turbidity in the U.S. tributaries. Although erosion in the U.S. tributaries may contribute to creek turbidity, the primary factors causing erosion are not water level fluctuations. According to Baird 2004, the primary factor causing shoreline erosion in the navigable U.S. tributaries to the Niagara River is boat waves and in the non-navigable U.S. tributaries is high velocity flows that occur during the spring and following severe rainfall events. Summer and fall flow conditions, and any water level fluctuations that occur during these periods, do not appear to accelerate erosion (Baird 2004). Also, during wet weather, the turbidity levels in tributaries are most certainly affected by point source discharges from CSOs and stormwater outfalls and/or nonpoint source runoff in their respective watersheds. The characteristics of the surrounding land use and soil type are determinant factors contributing to nonpoint source runoff. These factors seem to have the greatest effect on turbidity levels in tributaries such as Spicer and Gun Creeks, where erodable soil types are prevalent.
The portions of Fish and Gill Creek that were sampled for this study are not influenced by water level fluctuations in the Chippawa-Grass Island Pool and hence the water quality in those portions of these streams is not affected by water level fluctuations. However, the water quality in these streams may be affected by the presence of Lewiston Reservoir and its influence on groundwater flow patterns. The groundwater inflow does not have a negative effect on the turbidity levels in these streams. Water quality in Gill Creek is positively affected by flow augmentation from Lewiston Reservoir.
In both the upper and lower Niagara River, dissolved oxygen levels maintain high standards and are not affected by U.S./Canadian power generation. In the upper Niagara River, there is no apparent effect on the dissolved oxygen levels due to water level fluctuations in the Chippawa-Grass Island Pool. The Lewiston Reservoir does not stratify with regards to temperature or dissolved oxygen due to the high flushing rates caused by the continuous pumping of water into the reservoir for storage and the outflow for generation. Therefore, dissolved oxygen levels in the lower Niagara River do not decrease due to outflow from RMNPP. In the lower Niagara River upstream of the tailrace, dissolved oxygen levels are good due, in large part, to the turbulence of the river in the Whirlpool and Devil’s Hole rapids (as well as Niagara Falls).
Determining the effects of Niagara River water level fluctuations on the dissolved oxygen levels near the mouths of tributaries is difficult because the dissolved oxygen readings were discrete measurements as opposed to continuous monitoring and the dissolved oxygen concentration in the creeks can be affected by many factors. These factors include loadings from point and nonpoint sources, land use, abundance of aquatic plants or algae, the amount of turbulence (surface to air mixing), water temperature, the organic sediment loading into the stream, and the influence of Niagara River water levels on tributary water levels. Reduced velocities in the tributaries may be caused by the influence of upper Niagara River water levels on creek water levels. This phenomenon is not unusual at the mouths of tributaries to large rivers. Likewise, water level fluctuations in the upper Niagara River can have a positive effect on tributary dissolved oxygen levels when water from the river (which generally contains higher dissolved oxygen than the tributaries) mixes with lower reaches of the creeks.
The Niagara River tributaries whose dissolved oxygen concentrations did not meet the standard of 4.0 mg/L for Class B and C waters at some point during this study were Cayuga Creek in the area of its confluence with Bergholtz Creek; Burnt Ship Creek near its mouth; Woods Creek (upstream and downstream portions); Gun Creek (upstream and downstream portions); and downstream portions of Spicer Creek.
Gill Creek and Fish Creek in the area of Lewiston Reservoir were positively affected with regard to stream dissolved oxygen levels. Lewiston Reservoir water is provided to Gill Creek in the summer months keeping it well oxygenated. In addition to flow augmentation to Gill Creek, flows in Gill Creek and Fish Creek are recharged by groundwater, which keeps stream temperatures relatively cool thereby increasing the streams potential to hold dissolved oxygen.
Results of the 2003 surface water chemistry analyses indicate that the water quality in the upper Niagara River in the area of the intakes is good, with all parameters meeting the standard for Class A-S waters in New York State. Based on those results, there are no apparent negative effects on the surface water quality of the upper Niagara River due to U.S./Canadian power generation.
The analytical results from the surface water samples collected from two locations in the Lewiston Reservoir in 2003 demonstrate that the surface water quality of the Lewiston Reservoir is similar to the upper Niagara River. Concentrations of metals, nutrients and biological parameters in samples collected from the reservoir all met the respective water quality standards for Class A-S waters. Trace quantities of monomethyl mercury were detected in the sample collected from the east end of the reservoir on October 9, 2003. The results of the laboratory analyses for organic contaminants revealed all parameters were below the quantitation limit for these two sites, except for both samples collected in November from the reservoir where trace quantities of the pesticide delta-BHC were estimated. Possible sources of delta-BHC in reservoir water samples are upper Niagara River water, airborne transport of pesticides resulting from area application for agricultural purposes, and groundwater in the City of Niagara Falls transported via the conduit drainage system and forebay.
The reservoir does recharge the surrounding bedrock which
provides inflow to both Fish and Gill creeks as they flow by the reservoir (via
the rock cut channels). For both creeks,
the influent groundwater supplements whatever surface water originates from
upstream areas. For Gill Creek, all
parameters that were sampled for in 2003 except total dissolved solids were in
compliance with NYS surface water quality standards for Class C waters. Volatile organics, semivolatile organics,
pesticides, PCBs and dioxins were all non-detect in surface water samples
collected from Gill Creek. For Fish
Creek, the analytical surface water results report a high level of total
coliforms from one sample. All other
parameters were within water quality standards.
Concentrations for both TDS and
coliforms were much lower in reservoir
samples indicating that the higher values in the creeks are not related to
reservoir operations.
ABBREVIATIONS
Agencies
CHS Canadian Hydrographic Service
EC Environment Canada
FEMA Federal Emergency Management Agency
FERC Federal Energy Regulatory Commission
IJC International Joint Commission
INBC International Niagara Board of Control
NOAA National Oceanic and Atmospheric Administration
NYSDEC New York State Department of Environmental Conservation
NYSDOH New York State Department of Health
OMOE Ontario Ministry of the Environment
USEPA United States Environmental Protection Agency
USGS United States Geological Survey
Units of Measure
C Celsius, Centigrade
cfs cubic feet per second
cm centimeter
F Fahrenheit
gpm gallons per minute
L liter
m milli (prefix for one-thousandth)
μ micro (prefix for one-millionth)
μg microgram
mg milligram
mgd million gallons per day
ml milliliter
NTU Nephelometric Turbidity Unit
ppb parts per billion
ppm parts per million
USLSD U.S. Lake Survey Datum 1935
Regulatory
AOC Area of Concern
CFR Code of Federal Regulations
NPDES National Pollution Discharge Elimination System
SPDES State Pollution Discharge Elimination System
RAP Remedial Action Plan
Environmental
BOD biochemical oxygen demand
DO dissolved oxygen
PAH polynuclear aromatic hydrocarbon
PCB polychlorinated biphenyl
SAV submerged aquatic vegetation
TDS total dissolved solids
TSS total suspended solids
Miscellaneous
ALP Alternative Licensing Procedure
CGIP Chippawa-Grass Island Pool
CSO Combined Sewer Overflow
FSCR First Stage Consultation Report
LPGP Lewiston Pump Generating Plant
NRTMP Niagara River Toxics Management Plan
NPP Niagara Power Project
NYPA New York Power Authority
NYS New York State
OPG Ontario Power Generation
RIBS Rotating Intensive Basin Study
RMNPP Robert Moses Niagara Power Plant
WWTP wastewater treatment plant
The New York Power Authority (NYPA) is engaged in the relicensing of the Niagara Power Project (NPP) in Lewiston, Niagara County, New York. The present operating license of the plant expires in August 2007. As part of its preparation for the relicensing of the Niagara Power Project, NYPA is developing information related to the ecological, engineering, recreational, cultural, and socioeconomic aspects of the Project. This report is part of the relicensing effort and presents the results of surface water quality monitoring conducted from May through November 2003.
The study area for this work is the Lewiston Reservoir and the Niagara River Corridor from the Peace Bridge to the mouth of the Niagara River at Lake Ontario, and the U.S. tributaries to the upper and lower Niagara River (Big Sixmile, Burnt Ship, Cayuga, Woods, Gun, Spicer, Gill, Fish, Tonawanda, and Ellicott Creeks). The water quality survey consisted of discrete monitoring of dissolved oxygen and turbidity as well as continuous monitoring of surface water levels in the upper and lower Niagara River, Lewiston Reservoir and U.S. tributaries.
This report is organized as follows. This introductory section provides background on the NPP, identifies the objectives of this study and presents a physical description of each target water body. One of the tasks for this study was to conduct a literature review of existing water quality information in the study area. Section 2 provides an overview of this information and presents a summary of the water quality of the Niagara River based upon long-term monitoring programs conducted by U.S. and Canadian agencies. The primary factors that have the potential to affect the quality of the surface water in the study area are discussed in Section 3. Section 4 describes the data collection and analysis methods and Section 5 presents the results of the 2003 data collection effort as well as any other relevant water quality information obtained from the literature review. A discussion of the factors affecting water quality conditions in each water body is the focus of Section 6, and Section 7 presents the study conclusions.
The 1,880-MW (firm capacity) Niagara Power Project is one of the largest non-federal hydroelectric facilities in North America. The Project was licensed to the Power Authority of the State of New York (now the New York Power Authority) in 1957. Construction of the Project began in 1958, and electricity was first produced in 1961.
The Project has several components. Twin intakes are located approximately 2.6 miles above Niagara Falls. Water entering these intakes is routed around the Falls via two large low-head conduits to a 1.8-billion-gallon forebay, lying on an east-west axis about 4 miles downstream of the Falls. The forebay is located on the east bank of the Niagara River. At the west end of the forebay, between the forebay itself and the river, is the Robert Moses Niagara Power Plant (RMNPP), NYPA’s main generating plant at Niagara. This plant has 13 turbines that generate electricity from water stored in the forebay. Head is approximately 300 feet. At the east end of the forebay is the Lewiston Pump Generating Plant (LPGP). Under non-peak-usage conditions (i.e., at night and on weekends), water is pumped from the forebay via the plant’s 12 pumps into the 22-billion-gallon Lewiston Reservoir, which lies east of the plant. During peak usage conditions (i.e., daytime Monday through Friday), the pumps are reversed for use as generators, and water is allowed to flow back through the plant, producing electricity. The forebay therefore serves as headwater for the RMNPP and tailwater from the LPGP. South of the forebay is a switchyard, which serves as the electrical interface between the Project and its service area.
For purposes of generating electricity from Niagara Falls, two seasons are recognized: tourist season and non-tourist season. By the 1950 Niagara River Water Diversion Treaty, at least 100,000 cfs must be allowed to flow over Niagara Falls during tourist season (April 1 – October 31) daytime hours, and at least 50,000 cfs at all other times. Canada and the United States are entitled by international treaty to share equally the remaining available flow in the river for hydroelectric power production.
NYPA studied water level and flow fluctuations from 1991-2002 (URS et al. 2003b). From this study it was learned that water level fluctuations in both the upper and lower Niagara River are caused by a number of factors including U.S./Canadian power generation. Other factors affecting water level and flow fluctuations include wind, natural flow variations and ice conditions, water levels of Lake Erie and Lake Ontario, and control of Niagara Falls flow for scenic purposes (URS et al. 2003b). Water level fluctuations in the Chippawa-Grass Island Pool (CGIP), in the upper Niagara River are limited to 1.5 feet per day by an International Niagara Board of Control directive.
During tourist season, water level fluctuations in the lower Niagara River (upstream of the RMNPP tailrace) from all causes are normally around 12 feet per day. Most of this daily fluctuation is due to the change in the treaty-mandated control of flow over Niagara Falls. Water level fluctuations downstream of the RMNPP tailrace are much less. The average daily water level fluctuation 1.4 miles downstream of the RMNPP tailrace, during the 2003 tourist season, was approximately 1.44 feet. The average daily water level fluctuation at this location during the 2002 tourist season was approximately 1.5 feet (URS et al. 2003b).
Operations of the NPP normally result in water level fluctuations in the Lewiston Reservoir of 3-18 feet per day, and as much as 36 feet per week (URS et al. 2003b). At night, when electricity demand is low, the Lewiston units operate as pumps, transporting water from the forebay up to the plant’s reservoir. During the daytime, when electricity use peaks, the Lewiston pumps are reversed and become generators, similar to those at the Moses plant. In this way, the water can be used to produce electricity twice, increasing production and efficiency.
The objectives of this investigation are to: (1) determine if and how Project operations affect dissolved oxygen, and turbidity of the Niagara River, its U.S. tributaries and Lewiston Reservoir; (2) describe sources of turbidity in the Niagara River, its U.S. tributaries, and Lewiston Reservoir; and (3) document and determine if surface water quality of the Niagara River, its U.S. tributaries, and Lewiston Reservoir complies with New York State Water Quality Standards for surface water. Note the original objectives of this study included describing sources of sedimentation, however the Shoreline Erosion and Sedimentation Study (Baird 2004) is examining sources of sedimentation and related erosion sites in the River and tributaries, so that specific issue will not be discussed here. Also, continuous water temperature data was collected from many of the same water level and dissolved oxygen/turbidity sites. The reader is referred to the Water Temperature report (URS 2004) for the analysis of water temperatures.
During the Alternative Licensing Procedure (ALP) scoping process, there was concern over the effect of Project operations on surface water quality in the Project area. Specific issues were raised regarding the effects of water level fluctuations on dissolved oxygen and turbidity; therefore, there is emphasis on the turbidity and dissolved oxygen dynamics in the study area in this report.
Turbidity refers to how clear the water is. The greater the amount of total suspended solids (TSS) in the water, the higher the measured turbidity. In streams, there are 3 major types of particles that cause turbidity: algae, detritus (dead organic material), and silt (inorganic, or mineral, suspended sediment). Sources of sediment in the Niagara River include Lake Erie, erosion within the river, discharge from tributaries, and point-source discharges. Primary sources of sediment in the tributaries include non-point source runoff (agriculture fields, construction sites, and urban areas), point source discharges including stormwater and wastewater discharges, and stream bank erosion. Water level fluctuations can affect the rate and the type of shoreline erosion, and whether it occurs at all (Baird 2004). The erosion caused by water level fluctuations has the potential to increase suspended sediment in a stream thereby increasing turbidity levels.
Dissolved oxygen concentrations in freshwater are important to the health of aquatic communities because many aquatic organisms require oxygen to survive. The dissolved oxygen concentration in a stream is affected by the presence of aquatic plants or algae, the amount of turbulence, water temperature, and the waste loading into the stream. Where the air and water meet, the difference in concentration causes oxygen molecules in the air to dissolve into the water. More oxygen dissolves into water when the surface is disturbed by wind or turbulence (i.e. rapids, waterfalls). As waves or high velocities create more surface area, more diffusion can occur. It is normal to observe daily variations in dissolved oxygen concentrations in streams because photosynthesis (which increases dissolved oxygen levels) occurs exclusively during daylight hours, while respiration and decomposition (which decrease dissolved oxygen levels) occur continuously. Therefore dissolved oxygen concentrations may steadily decline overnight. In lakes and reservoirs that stratify thermally, it is common to see low dissolved oxygen levels in the bottom layers of the water body during the summer. This is caused by the lack of mixing of surface and bottom layers due to the thermal stratification and absence of light near the bottom, which prevents oxygen producing photosynthesis. When organic matter decomposes, it is fed upon by aerobic bacteria. In this process, organic matter is broken down and oxidized which in turn reduces dissolved oxygen levels. Biochemical oxygen demand (BOD), a measure of the quantity of oxygen used by microorganisms in the decomposition process, can also affect dissolved oxygen levels in the water.
Another physical process that affects dissolved oxygen concentrations is the relationship between water temperature and gas saturation. Cold water can hold more of any gas, in this case oxygen, than warmer water. As water becomes warmer it can hold less and less dissolved oxygen. So, during the summer months, the total amount of oxygen present may be limited by temperature. Also, any mixing of water at the confluences of water bodies and the resulting temperature differences of these waters has the potential to affect dissolved oxygen levels in these mixing zones. The water surface elevation of the Niagara River may influence the water surface elevations of its tributaries. This may reduce stream velocities and consequently surface water to air mixing. The deposition in these areas where velocities slow may result in a higher oxygen demand.
The study area for this work is the Lewiston Reservoir and the Niagara River Corridor from the Peace Bridge to the mouth of the Niagara River at Lake Ontario, and the U.S. tributaries in the upper Niagara River (Big Sixmile, Burnt Ship, Cayuga, Woods, Gun, Spicer, Gill, Fish, Tonawanda, and Ellicott Creeks). These water bodies are located in Niagara and Erie Counties in western New York State.
The study area is located within the Erie-Ontario Lake Plain physiographic province, which encompasses the relatively low, flat areas lying south of Lake Erie and Lake Ontario. This area is described as containing east-west escarpments that were formed by the Onondaga Limestone and Lockport Dolomite. The topography of this region has been modified by substantial glacial deposition of drumlin fields, recessional moraines and shoreline deposits (Isachsen et al. 1991). Although orchards, vineyards, and vegetable farming are important locally, a large percentage of the agriculture is associated with dairy operations (USEPA 2000).
A description of the physical characteristics such as drainage area, hydrology, and surrounding land use and soils for each of the targeted water bodies is presented in the following section. Figure 1.3-1 displays the water bodies included in this study and Table 1.3-1 lists the streams and their respective drainage areas.
The mainstem of the Niagara River is approximately 38 miles long and connects Lake Erie to Lake Ontario. The river is divided by the cascades of Niagara Falls and is referred to within this report as the upper Niagara River and the lower Niagara River. The collective drainage area at the mouth of the river in Youngstown, NY, is approximately 265,000 square miles and encompasses much of the north central United States and south central Canada, including four of the five Great Lakes. Within New York State, the river drains about 2,300 square miles of Northern Appalachian Plateau and lake shore lowlands (NYSDEC 1997). The mean annual flow at Fort Erie (based on 1991-2002 data), near the head of the river at the outlet of Lake Erie is approximately 213,000 cfs (URS et al. 2003b).
At Grand Island, the river divides into the west channel, known as the Canadian or Chippawa Channel, and the east channel, known as the American or Tonawanda Channel. The Chippawa Channel is approximately 11 miles long and varies in width from 2,000 to 4,000 feet. The Chippawa Channel carries approximately 58% of total river flow. The 15-mile-long Tonawanda Channel varies in width from 1,500 to 2,000 feet above Tonawanda Island. Downstream of the island it varies in width from 1,500 to 4,000 feet, with water velocities of 2-3 fps. At the north end of Grand Island, the channels unite to form the 3-mile-long Chippawa-Grass Island Pool (see Figure 1.3-1), at the downstream end of which is the International Control Structure. This structure extends from the Canadian shoreline to the approximate midpoint of the river. The Falls is located about 4,500 feet downstream of the control structure.
According to the most recent soil survey for Niagara County, soils along the upper Niagara River are classified as Canandaigua-Rynham-Rheinbeck from North Tonawanda to an area near the North Grand Island Bridge (Higgins et al. 1972). These soils are described as deep, somewhat poorly drained to very poorly drained soils having a dominantly medium textured to fine textured subsoil. From the North Grand Island bridge to the RMNPP tailrace area along the lower Niagara River, the soils are Odessa-Lakemont-Ovid association. The soils are described as deep, somewhat poorly drained to very poorly drained soils having a fine textured or moderately fine textured subsoil that is dominantly reddish in color. Downstream of the tailrace in the lower Niagara River, soils are either of the Rhinebeck-Ovid-Madalin association or Claverack-Cosad-Elnora association. The former is similar to the Odessa-Lakemont-Ovid association (deep, somewhat poorly drained to very poorly drained soils having a fine textured or moderately fine textured subsoil that is dominantly brown or olive in color). The latter are deep, moderately well drained and somewhat poorly drained soils have a coarse textured subsoil, over clay or fine sand. All soils in this area were formed in lake-laid sand, silt and clay.
Lewiston Reservoir is a 1,900-acre reservoir used for pumped water storage (22-billion-gallon capacity) for the Niagara Power Project. The Niagara Power Project and the Lewiston Reservoir operate on a weekly cycle. On Monday morning, the reservoir is at its highest water level and typically at its lowest on Thursday or Friday evening. Each weekday, water is taken from storage during the daytime peak energy demand periods for power generation. Consequently, the reservoir water level decreases. Then each weekday night (during non-peak energy demand), the reservoir is partially refilled. On the weekend, the reservoir is completely refilled. Daily drawdown is normally 3-18 feet and weekly drawdown 11-36 feet, depending on the season and river flow. Weekly drawdowns are typically greater during the tourist season (21-36 feet) than the non-tourist season (11-30 feet) because water levels are higher during the non-tourist season when storage in the lowest part of the reservoir is held in reserve to compensate for reduced diversion caused by ice problems (URS et al. 2003b). Weekly drawdowns are also greater during low-flow periods than high-flow periods, as more water is rescheduled to generate electricity during peak demand periods.
It is important to note that NYPA’s water intakes on the upper Niagara have no control mechanisms for the diversion of water from the Chippawa-Grass Island Pool into the twin conduits that carry water to the Project forebay. The volume of water diverted through the conduits is a direct function of the difference in surface water elevation between the pool and forebay. Water that is pumped into Lewiston Reservoir is directly related to the quality of water in the upper Niagara River. The majority of the reservoir is considered a low-flow surface water body, except for the area near the intake/outlet area of the LPGP. Important features of the reservoir dike with respect to its ability to impound water include a clay core and bedrock grout curtain. Most of the side slopes of the reservoir are lined with boulder-sized rip-rap and the bottom is exposed, in some areas, during the end of the week due to drawdown
Cayuga Creek begins in the Town of Lewiston and runs through the Tuscarora Nation. The watershed encompasses 38.6 square miles (URS et al. 2004c) and the creek is 9.7 miles long. The flow in the upstream reach of Cayuga Creek is intermittent with seasonal flow. A pump house located on the creek just upstream of the Tuscarora lands is used to drain nearby agricultural fields during times of high water. Residents of the Tuscarora Nation often refer to Cayuga Creek in that area as “State Ditch” due to the artificially channelized nature of the stream. Downstream of the Tuscarora lands, Cayuga Creek travels through the Town of Wheatfield and then on through the Niagara Falls Air Force Base, the Niagara Falls International Airport and the Military Reservation upstream of Porter Road. The stream through these reaches is generally 10-20 feet wide. From here the stream flows through an area of the City of Niagara Falls that is developed residentially and commercially. Cayuga Creek discharges into the upper Niagara River via the Little River, which separates Cayuga Island from the mainland. Approximately 5,000 feet upstream of the mouth, Bergholtz Creek joins Cayuga Creek from the east.
Soils associated with the Cayuga Creek drainage basin were formed in lake-laid clays, silts and very fine sands. Soils along the upper reaches of the creek are included in the Odessa-Lakemont-Ovid association which are described as deep, somewhat poorly drained to very poorly drained soils having a fine textured or moderately fine textured subsoil that is dominantly reddish in color (Higgins et al. 1972). Soils along the lower reaches are classified as Canandaigua-Rynham-Rheinbeck. This association is described as having deep, somewhat poorly drained, to very poorly drained soils having a dominantly medium textured to fine textured subsoil.
Gill Creek headwaters are located on the Tuscarora Nation and in these upper reaches flow is seasonal. Flow for Gill Creek originates from a wetland complex on Tuscarora lands. Prior to the Project’s construction, the headwaters of Gill Creek flowed through what is now the southeast corner of the Lewiston Reservoir. During the construction of Lewiston Reservoir, Gill Creek was rerouted around the dike at the reservoir’s southeast corner. Downstream of the reservation, the creek runs south along the east dike of the Lewiston Reservoir, then in a westerly fashion along the south dike. Along the reservoir, Gill Creek is approximately 5-10 feet wide.
Water from Lewiston Reservoir is discharged to Gill Creek t