Niagara Power Project FERC No. 2216

ASSESSMENT OF THE POTENTIAL EFFECTS OF WATER LEVEL AND FLOW

FLUCTUATIONS AND NYPA LAND MANAGEMENT PRACTICES ON RARE, THREATENED,

AND ENDANGERED SPECIES OF THE UPPER NIAGARA RIVER TRIBUTARIES - PHASE II

HTML Format. Text only

Prepared for: New York Power Authority

Prepared by: Riveredge Associates, LLC

August 2005

___________________________________________________

Copyright © 2005 New York Power Authority

preface

The subject of this report is the second phase of investigations into the potential effects of water level and flow fluctuations and NYPA land management practices on rare, threatened, and endangered species. The first phase report was entitled “Assessment of the Potential Effects of Water Level and Flow Fluctuations and Land Management Practices on Rare, Threatened, and Endangered Species at the Niagara Power Project” (Riveredge 2005a) and was released in draft in January 2004. This second investigation phase has the same objectives and goals as the first, but includes areas that were not examined previously. These areas, collectively referred to hereafter as the “expanded investigation area”, include the upper Niagara River between Strawberry Island and the Peace Bridge, the ice boom storage area, and additional upper Niagara River tributaries that may be influenced by water level fluctuations in the upper Niagara River.

ABBREVIATIONS

Agencies

FERC Federal Energy Regulatory Commission

INBC International Niagara Board of Control

NOAA National Oceanic and Atmospheric Administration

NYSCD New York State Conservation Department

NYSDEC New York State Department of Environmental Conservation

NYSDOS New York State Department of State

NYHP New York Natural Heritage Program

NYPA New York State Power Authority

OMNR Ontario Ministry of Natural Resources

OPG Ontario Power Generation

USFWS United States Fish and Wildlife Service

Units of Measure

C Celsius, Centigrade

cfs cubic feet per second

cm centimeter

F Fahrenheit

fps feet per second

ft feet

IGLD 1985 International Great Lakes Datum 1985

in inch

m meter

mm millimeter

MW Megawatt

USLSD U.S. Lake Survey Datum 1935

Environmental

EAV emergent aquatic vegetation

SAV submerged aquatic vegetation

EXECUTIVE SUMMARY

Riveredge Associates examined records of federal and state RTE species and significant occurrences of natural communities in the expanded investigation area and performed a literature-based assessment of the potential effects of water level and flow fluctuations and NYPA land management practices on these species and communities. All species known to occur in or near the expanded investigation area that are currently designated T or E by NYSDEC or USFWS were included in this analysis. In addition, those species designated as special concern (SC) or rare (R) by NYSDEC were also included. Some unprotected (U) species and significant occurrences of natural communities were included in this analysis because they are unusually rare, declining, or exceptionally important or unique to the local ecology. Unprotected species and natural communities considered in this analysis include significant natural communities and all extant occurrences of rare freshwater mussels.

Factors that could affect RTE species and significant occurrences of natural communities include fluctuations in water level and flow, sedimentation, and erosion. Water level and flow fluctuations in the upper Niagara River and its tributaries are caused by a number of factors in addition to the operation of the Niagara Power Project (NPP). These include water withdrawals for the production of electricity by Ontario Power Generation (OPG), flow variations from Lake Erie, regional and long-term precipitation patterns that affect lake levels, control of Niagara Falls flow for scenic purposes, the operation of the New York State Barge Canal, wind effects, boat wakes, inflow from upstream sources in the tributaries, and other natural and anthropogenic factors. It is not possible to accurately determine the extent of water level and flow fluctuation attributable to each factor. For this investigation, the analysis of potential effects was conducted by considering all causal factors of water level and flow fluctuations combined. Water level fluctuations in the upper Niagara River from all causes are normally less than 1.5 feet per day.

One fish species, state-listed as threatened, and nine rare but unprotected species of native mussels are found in the expanded investigation area. A geographic information system (GIS) analysis was used to compare the occurrence records of these RTE species to the portions of the investigation area influenced by water level and flow fluctuations. To determine where areas of potential Project effects might occur, documented occurrences of RTE species were compared with water level and flow data from permanent and temporary gauges established in the upper river and its tributaries. A literature search was conducted to determine the potential effects of water level and flow fluctuations on the natural history or habitat requirements of the RTE species in the expanded investigation area.

The state-listed fish (threatened) is the longear sunfish (Lepomis megalotis). The nine rare unprotected native mussel species are Amblema plicata, Fusconaia flava, Lampsilis ovata, Leptodea fragilis, Ligumia recta, Potamilus alatus, Ptychobranchus fasciolaris, Truncilla truncata and Villosa iris. These species occur in Tonawanda Creek and Mud Creek (a tributary to Tonawanda Creek) over 13.5 miles upstream of the confluence of the Niagara River and Tonawanda Creek. No RTE species are known to occur in the lower 13.5 miles of the creek, 11.6 miles of which are part of the New York State Barge Canal system. In addition, no extant RTE species occurrences were found in the remainder of the expanded investigation area.

At the confluence of the Niagara River and Tonawanda Creek, the median water level fluctuation during the 2003 tourist season was 0.58 feet at the Tonawanda Island gauge (URS et al. 2005a). Water level fluctuations in the Barge Canal and Tonawanda Creek are less at all points upstream of this gauge, and decrease to zero at or near two riffle sections (located approximately 13.6 and 14.1 miles upstream of the upper Niagara River and just west of Transit Road at Millersport, New York) that likely act as hydraulic controls to the influence of water levels from the upper Niagara River.

The longear sunfish and the rare native mussels are most vulnerable to periods of naturally occurring low water levels that could leave sunfish nests or the native mussels exposed or stranded due to dewatering. Longear sunfish spawn in August, typically the period of lowest water level and flow in this reach of Tonawanda Creek. The analysis conducted for this investigation revealed that during August the minimum water surface elevation of the upper Niagara River is lower than the water surface elevation of Tonawanda Creek at the site of occurrence of these RTE species (URS et al. 2005b). This means that minimum water levels where these RTE species occur are likely controlled more by the water level and flow in the upper reaches of Tonawanda Creek and less by water levels in the upper Niagara River. During August, the maximum extent of influence for the minimum August elevation of the upper Niagara River (USLSD 1935 564.96 or NGVD 564.45) is 13.5 miles upstream of the mouth of Tonawanda Creek. This was estimated by drawing a straight line from the known water surface elevation of the river to a point where it intersects the creek bottom based on FEMA stream bottom profiles. This point is downstream of the known area of occurrence of the RTE species in Tonawanda Creek. The extent of influence for the August median elevation (USLSD 1935 566.10 or NGVD 565.59) is greater and approaches the area of occurrence of RTE species in Tonawanda Creek, but the topography of the stream channel rises relatively rapidly in the riffle areas compared to the flat hydraulic slope of the dredged Barge Canal, and a one foot increase in water level may only extend the area of influence 0.1 miles upstream, still below the area of occurrence of these RTE species. Therefore, fluctuations in water level and flow in the upper Niagara River likely have no effect on RTE species where they occur in Tonawanda Creek and Mud Creek.

1.0 INTRODUCTION

The Niagara Power Project (NPP) in Lewiston, Niagara County, New York, is one of the largest non-federal hydroelectric facilities in North America. It is constructed on the Niagara River, a 37-mile strait connecting Lakes Erie and Ontario. In 1957, a 50-year license for operation of the NPP was issued by the Federal Power Commission (now the Federal Energy Regulatory Commission, or FERC) to the Power Authority of the State of New York (now also known as the New York Power Authority, or NYPA). The NPP first produced electricity in 1961. The operating license for the NPP expires in August 2007. As part of its relicensing process, NYPA is conducting a number of ecological, engineering, and other investigations in the vicinity of the NPP.

2.0 BACKGROUND

In 2001, Riveredge Associates, LLC (Riveredge) contracted with NYPA to conduct literature reviews and field surveys for rare (including species of special concern (SC)), threatened, and endangered (RTE) species and significant occurrences of natural communities in the vicinity of the NPP (Riveredge 2002). The existence of RTE species and significant occurrences of natural communities was determined through the review of New York Natural Heritage Program (NYNHP) inventory records (NYNHP 2001), original NYNHP field survey forms, published museum records, discussions with selected knowledgeable individuals in the region, and field surveys. As part of that study, field surveys were conducted to confirm existing NYNHP records. Field surveys for native mussels were conducted for a separate study (Riveredge 2005b).

These studies documented species listed as RTE by the New York State Department of Environmental Conservation (NYSDEC) in the vicinity of the NPP. One of these species, the bald eagle (Haliaeetus leucocephalus), is the only one that is also federally listed (threatened) by the United States Fish and Wildlife Service (USFWS). These studies also documented a number of species and significant occurrences of natural communities on the NYNHP active inventory list (NYNHP 2003b). Although these species and significant occurrences of natural communities are considered unprotected under New York law, they may be protected under other legislation such as the federal Migratory Bird Treaty Act.

Riveredge (2002) noted that most RTE species and significant occurrences of natural communities known to occur in the vicinity of the NPP are plants of the Niagara River gorge and Niagara escarpment, wetland birds found in Buckhorn Island State Park, grassland birds found at and near the Niagara Falls Air Reserve Station (NFARS), or species associated with the Niagara River and its tributaries.

In 2002, Riveredge was contracted to conduct a literature-based analysis of the potential effects of water level and flow fluctuations and land management practices on RTE species and significant occurrences of natural communities (Riveredge 2005a). Where data were lacking, limited field surveys were conducted to gather new information on the distribution of species and the potential effects of Niagara Power Project operations. In particular, the analysis included field surveys for grassland birds and the monitoring of nests of the threatened pied-billed grebe (Podilymbus podiceps). The investigation area for that study included lands within New York State adjacent to the Niagara River, the Niagara River proper, and tributaries of the river (within New York State) from just upstream of the southern tip of Grand Island downstream to the river mouth at Lake Ontario, as well as all NYPA-owned lands near the Project facilities, forebay, and reservoir. At the time, this investigation area was thought to fully encompass the area influenced by U.S./Canadian power generation (Riveredge 2005a). However, subsequent analysis revealed this influence can extend to somewhere between Frenchman’s Creek and the Peace Bridge in the mainstem (URS et al. 2005a) and further upstream in several creeks than originally thought (URS et al. 2005b). Therefore, a subsequent investigation (Phase II) was conducted to determine the potential presence of RTE species and significant occurrences of natural communities in those additional areas (“expanded investigation area”) and to determine whether they are affected by the water level and flow fluctuations of the upper Niagara River. This report is the subject of the Phase II investigation and includes a description of the NPP and water level and flow fluctuations, results from a review of records on the occurrence of RTE species and significant occurrences of natural communities in the expanded investigation area, descriptions of the natural history and habitat requirements of RTE species in the expanded investigation area, and an assessment of the potential effects of water level and flow fluctuations on these RTE species. The expanded investigation area is described in Section 4.1.

3.0 DESCRIPTION OF PROJECT AND WATER LEVEL FLUCTUATIONS

The 1,880-MW (firm power output) 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 1958. Construction of the Project began in 1958, and electricity was first produced in 1961.

The Project has several components, including water intakes, conduits, a forebay, a reservoir and two generating plants. Twin water intakes on the Niagara River are located approximately 2.6 miles above Niagara Falls. Water entering these intakes is routed around the Falls via two large underground conduits to a forebay, lying on an east-west axis about four 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, 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. Under non-peak-usage conditions (i.e., at night and on weekends), water is pumped from the forebay via the plant’s 12 pumps/generators into the 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 Robert Moses plant and tailwater from the Lewiston Plant. 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 the Niagara River, two seasons are recognized: tourist season and non-tourist season. By international treaty, at least 100,000 cubic feet per second (cfs) must be allowed to flow over Niagara Falls during tourist season (April 1-October 31), daytime and evening hours, and at least 50,000 cfs at all other times. Canada and the United States are entitled by treaty to produce hydroelectric power with the remainder.

According to a 1993 Directive of the International Niagara Board of Control (INBC), water level fluctuations in the Chippawa-Grass Island Pool (in the upper Niagara River, i.e., above Niagara Falls) are limited to 1.5 feet per day within a three foot range for normal conditions. For extreme conditions (i.e. high flow, low flow, ice, etc.), the allowable range of Chippawa-Grass Island Pool water levels is extended to four feet.

NYPA has conducted a comprehensive study of water level and flow fluctuations at the Project (URS et al. 2005a). This investigation examined water level data from gauges in the upper and lower Niagara River for the past 12 years (1991-2002) as well as data from a number of temporary gauges established in the upper and lower river during 2001 and 2002. Additionally, water level data were gathered from the U.S. tributaries to the Niagara River using temporary gauges in 2003 (URS and Gomez and Sullivan 2005).

Water level fluctuations in both the upper and lower Niagara River are caused by a number of factors in addition to the operation of the Niagara Power Project. These include wind, natural flow and ice conditions, regional and long-term precipitation patterns that affect lake levels, control of Niagara Falls flow for scenic purposes, operation of power plants on the Canadian side of the river, and the backwater effect from Lake Ontario. Water level fluctuations in the upper Niagara River from all causes are normally less than 1.5 feet per day (Stantec et al. 2005).

4.0 METHODS

4.1 Expanded Investigation Area

The expanded investigation area includes the waters of the upper Niagara River from Strawberry Island to the Peace Bridge, the ice boom storage area, and waters of the mainland tributaries of upper Niagara River that may be affected by water level fluctuations in the upper Niagara River. The mainland tributaries include Tonawanda Creek, Ellicott Creek, Sawyer Creek, Bull Creek, Ransom Creek, Black Creek, and Got Creek. The reaches of each tributary examined are described in URS et al. (2005b) and in the tributary mapping and habitat characterization study (Gomez and Sullivan and E/PRO 2005). Transit Road in Millersport was the limit of investigation for Tonawanda Creek upstream of its confluence with the New York State Barge Canal. Transit Road is upstream of two riffle sections that likely act as hydraulic controls limiting the upstream influence of Niagara River water level fluctuations due to U.S./Canadian power generation on creek water levels. The first riffle is located 13.6 miles upstream of the mouth and the second 14.1 miles upstream of the mouth. Transit Road crosses Tonawanda Creek at the upstream end of the second riffle.

4.2 Occurrence Records for the Expanded Investigation Area

The occurrences of RTE species and natural communities in the expanded investigation area were documented through an examination of records of the New York Natural Heritage Program (NYNHP 2004), a literature review, and limited field surveys. The presence of RTE species and significant occurrences of natural communities was determined through a review of NYNHP inventory records (NYNHP 2001, NYNHP 2003a, NYNHP 2004), original NYNHP field survey forms, NYNHP reports (Evans et al. 2001a, 2001b, 2001c) published museum records, discussions with selected knowledgeable individuals in the region, Christmas bird counts (BirdSource 2003), and field surveys for RTE grassland birds, native mussels (Riveredge 2005b), and pied-billed grebe. In addition to the earlier data provided by NYNHP (NYNHP 2001, NYNHP 2003a), an updated data set provided by NYNHP (NYNHP 2004) that covered much of Erie and Niagara Counties was reviewed for the preparation of this report.

Field surveys for rare native mussels were conducted in July (July 26, 27), August (August 28) and September (September 25, 26) 2004 in Ellicott Creek, Sawyer Creek, Bull Creek, Ransom Creek, Black Creek, Got Creek, Tonawanda Creek and Mud Creek. Selected mussel shells were forwarded to Dr. David Strayer of the Institute for Ecosystem Studies for confirmation of species identifications.

Location information and details about RTE species occurrences are considered sensitive. In accordance with the policies of NYNHP and the Endangered Species Unit of NYSDEC, this report contains no additional specific location information for sensitive RTE species in the expanded investigation area beyond what has been published by NYSDEC or other readily available published sources.

Species in this report are referred to by their scientific names, common names, or both. The use of scientific names and common names follows accepted usage. Some taxa, such as fish, are primarily referred to by their common names. Native mussels are primarily referred to by their scientific names.

4.3 Literature Review of Natural History and Habitat Requirements

Literature searches were conducted to establish the natural history characteristics and habitat requirements of species documented in the expanded investigation area. Breeding bird atlases were consulted for New York and Ontario, as well as species dossiers from NYSDEC. General references such as Scott and Crossman (1973) and DeGraaf and Rudis (1986) were consulted, as were specific references on the conservation of endangered species, such as Schneider and Pence (1992). Detailed, technical literature was also reviewed, such as the species accounts of The Birds of North America volume produced by the Academy of Natural Sciences and The American Ornithologists Union. In addition, sources with information specific to the Niagara region were reviewed. Summaries of the natural history and habitat requirements of species documented in the expanded investigation area are included in this report.

4.4 Determination and Description of Legal Status

In New York, all plant and animal species that are federally listed are automatically included on NYSDEC’s lists of threatened and endangered species. The RTE species laws in New York State consider plant and animal species according to different criteria and laws. NYSDEC’s species lists are passed into law by the state legislature after a period of public comment.

For animals, endangered (E), threatened (T), and special concern (SC) species are defined and designated in Title 6 of the New York Code of Rules and Regulations (6 NYCRR) Part 182. Threatened and endangered animal species are protected by Environmental Conservation Law of New York, Section 11-0535. Special Concern animal species do not receive legal protection under this law.

Plant species are defined as endangered (E), threatened (T), rare (R) or exploitably vulnerable (V) in 6 NYCRR Part 193 and are protected under Environmental Conservation Law Section 9-1503. Plants included on the New York State list of “Protected Native Plants” are protected under New York State Environmental Conservation Law Section 9-1503. It is a violation of this law to knowingly pick, pluck, sever, remove, damage by the application of herbicides or defoliants, or carry away, any protected plant without the prior consent of the landowner.

In New York, significant occurrences of natural communities are designated by NYNHP but have no formal protected legal status under the New York Code of Rules and Regulations or under the Environmental Conservation Law of New York.

It is important to note that species or natural communities listed as unprotected in this report only means they are unprotected under the specific laws and legislation pertaining to RTE species as described above. Species listed as unprotected may be protected by other laws. For example, migratory birds are protected by the Federal Migratory Bird Treaty Act. Mussels are shellfish and are protected by specific laws governing shellfish harvest. Fish are protected by laws governing seasons and harvest limits, and natural communities are often in protected State Parks. The legal status of each species was determined by consulting the current list of designated RTE species (NYSDEC 2001).

4.5 Effects Analysis

This qualitative analysis of the potential effects of water level and flow fluctuations and NYPA land management practices on RTE species and significant occurrences of natural communities began by assessing (1) which species and significant occurrences of natural communities occur in the expanded investigation area, (2) the extent of water level and flow fluctuations (from all causes) in the expanded investigation area, (3) where RTE species or significant occurrences of natural communities occur relative to water level and flow fluctuations and land management practices, and (4) the potential effects of these water level and flow fluctuations and land management practices on the natural history or habitat of these species and communities.

4.5.1 Species and Natural Communities Included in the Analysis

NYPA is required to investigate the potential effects of water level and flow fluctuations and land management practices on threatened and endangered species as part of FERC relicensing. All species known to currently occur in or near the expanded investigation area that are currently designated threatened or endangered by NYSDEC or USFWS were included in this analysis. In addition, those extant species designated as special concern or rare by NYSDEC were also included in this analysis. Some unprotected species and all significant occurrences of natural communities were included in this analysis because they are unusually rare, declining, or exceptionally important or unique to the local ecology. Unprotected species considered in this analysis include all extant occurrences of rare freshwater mussels.

4.5.2 Potential Effects Included in this Analysis

Included in this analysis were all potential effects of water level and flow fluctuations and land management practices in the expanded investigation area. Factors that cause water level fluctuation in the upper Niagara River include water withdrawals for electrical production by the Niagara Power Project and Ontario Power Generation, flow variations from Lake Erie, wind, boat wakes, and other anthropogenic and natural factors. Because it is not possible to determine the exact extent to which each factor influences water levels, all contributing factors were considered in the analysis of the potential effects of water level fluctuations on RTE species and their habitats.

Several factors have been identified related to water level and flow fluctuations that could affect RTE species and significant occurrences of natural communities. These factors include but are not limited to fluctuations in water level or flow and erosion and sedimentation. The causes and extent of water level and flow fluctuations in the Niagara River were examined in two reports: Niagara River Water Level and Flow Fluctuations Study (URS et al. 2005a) and the Upper Niagara River Tributary Backwater Study (URS et al. 2005b). In addition, areas and causes of erosion and sedimentation were assessed for the upper river tributary investigation area. (Baird 2005).

The water level and flow study (URS et al. 2005a) estimated the relative effects of regulation and natural conditions on water level fluctuation in the Niagara River using hourly maximum water level and flow data from 1991 to 2002. The large database (over 5 million entries) included hourly data for 15 permanent and temporary water level gauges and three flow gauges in the upper and lower Niagara River. The second study examined the potential extent of water level fluctuations in the upper Niagara River tributaries caused by changes in upper Niagara River water levels through the development of backwater models for each tributary (URS et al. 2005b). The upstream limits of potential influence of Niagara River water levels on water levels in Tonawanda and Ellicott Creeks were not determined as part of that study. Water levels in both creeks are not solely influenced by upper Niagara River water levels. For both tributaries, dredging and flow diversions, for the purposes of navigation and flood control, have altered their hydraulics and hydrology and hence their relationship to the upper Niagara River. Instead, estimates of the extent of influence were based on the annual hourly maximum Niagara River water level and stream bottom profiles. These estimates of the extent of influence were considered conservative because the annual hourly maximum Niagara River water level occurred during a storm surge from Lake Erie and is not representative of the range of daily water levels due to U.S./Canadian power generation (URS et al. 2005b). Subsequent field work conducted to map and characterize the riparian habitats along these tributaries (Gomez and Sullivan and E/PRO 2005) and field surveys of Tonawanda Creek conducted for this investigation suggest that two riffles located at 13.6 miles and 14.1 miles upstream of the mouth likely act as hydraulic controls limiting the upstream influence of Niagara River water level fluctuations caused by the normal water level fluctuation due to U.S./Canadian power generation

4.6 Interactions of Species or Natural Communities and Project Operations

A geographic information system (GIS) analysis was used to compare the occurrence records of RTE species to the areas influenced by operation of the NPP. GIS coverages of the occurrences of RTE species and significant occurrences of natural communities from NYNHP (2004) were reviewed and compared to water level and flow data from permanent and temporary gauges established in the upper river (URS et al. 2005a), and activities in the ice boom storage area. The period of record for gauge data was 1991 to 2002. These gauges recorded water level fluctuations that occurred in the river from all causal factors; the relative contributions of natural and anthropogenic factors cannot be determined.

5.0 RESULTS

5.1