Lockhart Power Company, Inc.; Notice of Availability of Draft Environmental Assessment

Federal RegisterDec 19, 2013

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Project No. 13590-001]

Lockhart Power Company, Inc.; Notice of Availability of Draft Environmental Assessment

In accordance with the National Environmental Policy Act of 1969 (NEPA) and the Federal Energy Regulatory Commission's (Commission or FERC) regulations, 18 CFR part 380, the Office of Energy Projects has reviewed Lockhart Power Company, Inc.'s application for license for the Riverdale Hydroelectric Project (FERC Project No. 13590-001), located on the Enoree River, near the town of Enoree, in Spartanburg and Laurens Counties, South Carolina. The project does not occupy federal lands.

Staff prepared a draft environmental assessment (DEA), which analyzes the potential environmental effects of licensing the project, and concludes that licensing the project, with appropriate environmental protective measures, would not constitute a major federal action that would significantly affect the quality of the human environment.

A copy of the DEA is available for review at the Commission in the Public Reference Room or may be viewed on the Commission's Web site at

http://www.ferc.gov

using the “eLibrary” link. Enter the docket number excluding the last three digits in the docket number field to access the document. For assistance, contact FERC Online Support at

FERCOnlineSupport@ferc.gov

, at (866)208-3676 (toll free), or, 202-502-8659 (TTY).

You may also register online at

http://www.ferc.gov/docs-filing/esubscription.asp

to be notified via email of new filings and issuances related to this or other pending projects. For assistance, contact FERC Online Support.

Any comments should be filed within 45 days from the date of this notice.

The Commission strongly encourages electronic filing. Please file comments using the Commission's eFiling system at

http://www.ferc.gov/docs-filing/efiling.asp.

Commenters can submit brief comments up to 6,000 characters, without prior registration, using the eComment system at

http://www.ferc.gov/dcos-filing/ecomment.asp.

You must include your name and contact information at the end of your comments. For assistance, please contact FERC Online Support.

In lieu of electronic filing, please send a paper copy to: Secretary, Federal Energy Regulatory Commission, 888 First Street NE., Washington, DC 20426. The first page of any filing should include docket number P-13590-001.

For further information, contact Sarah Salazar by phone at 202-502-6863, or by email at

sarah.salazar@ferc.gov.

Dated: December 12, 2013.

Kimberly D. Bose,

Secretary.

Draft Environmental Assessment for Hydropower License

Riverdale Hydroelectric Project, FERC Project No. 13590-001, South Carolina

Federal Energy Regulatory Commission, Office of Energy Projects, Division of Hydropower Licensing, 888 First Street NE., Washington, DC 20426

December 2013

Table of Contents

LIST OF FIGURES

iii

LIST OF TABLES

iii

ACRONYMS AND ABBREVIATIONS

EXECUTIVE SUMMARY

vii

1.0 INTRODUCTION

1.1 APPLICATION

1.2 PURPOSE OF ACTION AND NEED FOR POWER

1.2.1 Purpose of Action

1.2.2 Need for Power

1.3 STATUTORY AND REGULATORY REQUIREMENTS

1.3.1 Federal Power Act

1.3.2 Clean Water Act

1.3.3 Endangered Species Act

1.3.4 Coastal Zone Management Act

1.3.5 National Historic Preservation Act

1.4 PUBLIC REVIEW AND CONSULTATION

1.4.1 Scoping

1.4.2 Interventions

1.4.3 Comments on the License Application

2.0 PROPOSED ACTION AND ALTERNATIVES

2.1 NO-ACTION ALTERNATIVE

2.1.1 Existing Project Facilities

2.1.2 Project Safety

2.1.3 Existing Project Operation and Environmental Measures

2.2 APPLICANT'S PROPOSAL

2.2.1 Proposed Project Facilities

2.2.2 Proposed Project Operations

2.2.3 Proposed Environmental Measures

2.3 STAFF ALTERNATIVE

2.4 ALTERNATIVES CONSIDERED BUT ELIMINATED FROM FURTHER ANALYSIS

2.4.1 Issuing a Non-power License

2.4.2 Project Decommissioning

3.0 ENVIRONMENTAL ANALYSIS

3.1 GENERAL DESCRIPTION OF THE RIVER BASIN

3.2 SCOPE OF CUMULATIVE EFFECTS ANALYSIS

3.2.1 Geographic Scope

3.2.2 Temporal Scope

3.3 PROPOSED ACTION AND ACTION ALTERNATIVES

3.3.1 Geologic and Soil Resources

3.3.2 Aquatic Resources

3.3.3 Terrestrial Resources

3.3.4 Threatened and Endangered Species

3.3.5 Recreation and Land Use

3.3.6 Cultural Resources

3.4 NO-ACTION ALTERNATIVE

4.0 DEVELOPMENTAL ANALYSIS

4.1 POWER AND DEVELOPMENTAL BENEFITS OF THE PROJECT

4.2 COMPARISON OF ALTERNATIVES

4.2.1 No-action Alternative

4.2.2 Lockhart Power's Proposal

4.2.3 Staff Alternative

4.3 COST OF ENVIRONMENTAL MEASURES

5.0 CONCLUSIONS AND RECOMMENDATIONS

104

5.1 COMPARISON OF ALTERNATIVES

104

5.2 COMPREHENSIVE DEVELOPMENT AND RECOMMENDED ALTERNATIVE

109

5.3 UNAVOIDABLE ADVERSE EFFECTS

124

5.4 FISH AND WILDLIFE AGENCY RECOMMENDATIONS

124

5.5 CONSISTENCY WITH COMPREHENSIVE PLANS

130

6.0 FINDING OF NO SIGNIFICANT IMPACT

132

7.0 LITERATURE CITED

133

8.0 LIST OF PREPARERS

142

List of Figures

Figure 1.

Location of the Riverdale Project

Figure 2.

Percent of time during each month that inflows to the Riverdale Project are greater than 170 cfs and less than or equal to 500 cfs (i.e. when peaking with drawdown operation can occur under Lockhart Power's proposed operations), less than or equal to 170 cfs (i.e. flow below turbine minimum turbine capacity plus 50 cfs minimum flow), and > 500 cfs (i.e. flows greater than maximum turbine capacity plus 50 cfs minimum flow)

Figure 3.

Illustration of the front of the 2.25-inch headrace trashrack

Figure 4.

Illustration of the front of the 1-inch headrace trash rack

List of Tables

Table 1.

Major statutory and regulatory requirements for the Riverdale Project

Table 2.

Select characteristics of mapped soil units at the Riverdale Project

Table 3.

Synthesized monthly flow data (cfs) for the Riverdale Project from USGS gage No. 02160390 Enoree River at Woodruff, South Carolina

Table 4.

South Carolina water quality standards for freshwaters

Table 5.

Fish species and number collected in the vicinity of the Riverdale Project during baseline sampling on June 10-11 and July 6-7, 2010

Table 6.

Spawning dates and habitat requirements for eight Conservation Species observed in the Riverdale bypassed reach

Table 7.

Flows through the bypassed reach at FERC licensed projects in the Broad River Basin, South Carolina

Table 8.

Minimum flow required for fish in streams identified by Tennant (1976)

Table 9.

Calculation of intake cross-sectional area for the 2.25-inch and 1-inch trashracks

Table 10.

Burst swim speeds of four species found in the Riverdale impoundment

Table 11.

Minimum fish total lengths susceptible to impingement at 1-inch and 2.25-inch trashracks, based on trashrack bar spacing and fish width-at-length relationship (i.e. width = α × total length

) alone and exclusive of burst swim speeds

Table 12.

Parameters for the economic analysis of the proposed Riverdale Project

Table 14.

Summary of annual cost, power benefits, and annual net benefits of the alternatives for the Riverdale Project

Table 14.

Cost of environmental mitigation and enhancement measures considered in assessing the environmental effects of refurbishing, operating, and maintaining the Riverdale Project

Table 15.

Comparison of Alternatives for the Riverdale Project

104

Table 16.

Fish and wildlife agency recommendations for the Riverdale Project

125

Acronyms and Abbreviations

APE area of potential effects

applicant Lockhart Power Company, Inc.

BMPs Best Management Practices

°C degrees Celsius

certificate Water Quality Certificate

cfs cubic feet per second

Commission Federal Energy Regulatory Commission

Conservation Species South Carolina Priority Species

Council Advisory Council on Historic Preservation

Corps U.S. Army Corps of Engineers

CWA Clean Water Act

CZMA Coastal Zone Management Act

DO dissolved oxygen

DOI U.S. Department of the Interior

EA environmental assessment

EPA U.S. Environmental Protection Agency

°F degrees Fahrenheit

fps feet per second

FERC Federal Energy Regulatory Commission

FPA Federal Power Act

FWS U.S. Fish and Wildlife Service

LIP low inflow protocol

Lockhart Power Lockhart Power Company, Inc.

MADF mean annual daily flow

MW megawatt

MWh megawatt-hour

mg/L milligrams per liter

msl mean sea level

National Register National Register of Historic Places

NEPA National Environmental Policy Act

NERC North American Electric Reliability Council

NHPA National Historic Preservation Act

NMFS National Marine Fisheries Service

NPDES National Pollutant Discharge Elimination System

NRCS Natural Resource Conservation Service

NGVD National Geodetic Vertical Datum

PM&E measure protection, mitigation, and enhancement measure

Riverdale LLC Riverdale Development Venture, LLC

ROR run-of-river

ROW rights-of-way

SERC Southeastern Electric Reliability Council

SCORP Statewide Comprehensive Outdoor Recreation Plan

SHPO State Historic Preservation Officer

South Carolina DHEC South Carolina Department of Health and Environmental Control

South Carolina DNR South Carolina Department of Natural Resources

South Carolina DPRT South Carolina Department of Parks, Recreation, and Tourism

South Carolina EPPC South Carolina Exotic Pest Plant Council

South Carolina WRC South Carolina Water Resources Commission

THPO Tribal Historic Preservation Officer

USGS U.S. Geological Survey

Water District Woodruff-Roebuck Water District

Water Plan South Carolina Water Plan

Executive Summary

Proposed Action

On August 31, 2010, Lockhart Power Company, Inc. (Lockhart Power or applicant), filed a license application for the Riverdale Hydroelectric Project (Riverdale Project or project) with the Federal Energy Regulatory Commission (Commission or FERC). Lockhart Power proposes to repair existing facilities and return the project,

which has been inoperable since 2001, to operation. The proposed 1.24-megawatt (MW) project is located on the Enoree River near the city of Enoree, in Spartanburg and Laurens Counties, South Carolina. The project does not occupy any federal lands.

The project was originally licensed to Inman Mills as FERC No. 4362 on September 29, 1982.

Inman Mills,

20 FERC ¶ 62,586 (1982).

Project Description

The Riverdale Project is located at river mile 52 of the 110-mile-long Enoree River in northwestern South Carolina. The proposed project would consist of the following: (1) An existing 425-foot-long, 12-foot-high concrete gravity dam with three evenly spaced, integral sand gates, and 2-foot-high flashboards; (2) an existing 6.6-acre impoundment with a gross storage of 22.0 acre-feet; (3) an existing 85-foot-long, 50-foot-wide concrete headrace canal with an intake structure equipped with trash racks with 2.25-inch bar spacing; (4) an existing 9-foot-diameter, 340-foot-long steel penstock equipped with a second set of trash racks with bar spacing of about 10 inches; (5) an existing wood frame powerhouse containing one 1.24-MW capacity generating unit; (6) an existing 510-foot-long tailrace; (7) an existing 700-foot-long transmission line from the powerhouse to an existing Duke Energy distribution line; (8) an existing approximately 1,376-foot-long, 20-foot-wide paved access road; and (9) appurtenant facilities. Flow diverted to the powerhouse creates a 1,400-foot-long bypassed reach downstream from the dam.

Since the project became in-operable 12 years ago, all flows have passed over the dam and into the 1,400-foot-long bypassed reach. The 2-foot-high flashboards were partially damaged during high flow events in 2012 and 2013.

Proposed Facilities

Because Lockhart Power is not the current licensee or current owner of the project and has not had full access to the project, it plans to spend the first year following license issuance assessing the condition of project facilities and finalizing any engineering design needed to refurbish the project. To make the project operational, Lockhart Power expects it would, at a minimum need to: (1) Repair or replace the sand gates and gate operators; (2) repair or replace the 2-foot flashboards on the dam; (3) replace a 193-foot-long above ground section of the penstock; (4) modify the bar spacing on the penstock trashrack from 10 to 5 inches; (5) refurbish the turbine generator; (6) repair the plant controls and governor; (7) repair the powerhouse roof; and (8) dredge sediment and debris from the tailrace.

Lockhart Power would operate the project using a combination of run-of-river (ROR) and peaking modes. Lockhart Power would typically operate the project in a ROR mode, with project outflow approximately equaling project inflow, such that the impoundment surface elevation stays within 1 foot (+/−10 percent) of the top of the flashboards. When inflows are insufficient to operate the turbine at its maximum hydraulic capacity i.e. of 450 cubic feet per second (cfs) and provide a continuous minimum flow of 50 cfs to the bypassed reach (i.e. when inflow is less than 500 cfs), Lockhart Power would operate the project in a “peaking” mode. Peaking events would occur no more than once daily, until either the daily period of increased need for power ends or until the impoundment surface elevation is drawn down a maximum of 4 feet (+/−10 percent) below the top of the flashboards. Following each peaking event, Lockhart Power would suspend operation and store inflow, minus the minimum flow to the bypassed reach, to refill the impoundment (likely overnight) to its normal elevation of within 1 foot (+/−10 percent) of the top of the flashboards, allowing it to return to ROR mode until the next peaking event. Lockhart Power expects that peaking operation would occur less than half of the days in any given year.

Proposed Environmental Measures

Lockhart Power proposes, once the project is operational, the following measures to protect or enhance environmental resources at the project:

• Implement a sediment management plan that consists of using the existing sand gates to draw down the impoundment below the normal operating range for periodic inspections and maintenance and, if possible, avoiding drawdowns from March 15 through June 1 to prevent significant accumulation of sediments in the project impoundment and untimely releases of sediment downstream.

• Monitor water quality as may be required by South Carolina Department of Health and Environmental Council (South Carolina DHEC).

• Maintain a minimum flow of 50 cfs in the bypassed reach and a total minimum continuous flow of 60 cfs, or inflow if less, in the Enoree River downstream from the confluence of the tailrace and the bypassed reach to protect aquatic habitat. The minimum flow in the bypassed reach would be provided through one or more of the three sand gates selected in consultation with South Carolina DNR, Interior, and NMFS, after repairs. Lockhart Power would develop a rating curve for the sand gates and verify it once every 6 years to ensure defined minimum flows are being provided. The remaining 10 cfs would be provided via leakage through the turbine.

• When average daily inflows are less than or equal to 80 cfs (+/−10 percent), release all inflow into the bypassed reach (i.e. low inflow protocol [LIP]) to protect aquatic resources downstream from Riverdale dam, including during the fish spawning season.

• Implement best management practices (BMPs) to protect vegetation

within the project boundary, such as limiting vegetation and ground-disturbing activities and maintaining a minimum 25-foot-wide forested riparian buffer on project shorelines, as long as this does not interfere with Lockhart Power's ability to perform project-related activities.

• Construct and maintain: (1) A canoe take-out located approximately 220 feet upstream of the dam; (2) a canoe put-in located approximately 1,075 feet downstream from the dam; (3) a 1,650-foot-long portage trail connecting the proposed canoe take-out and put-in; (4) a parking area located adjacent to the proposed portage trail; and (5) signage to improve public access at the project and to the Enoree River.

• Provide informal public access for fishing at the project impoundment, tailrace, and bypassed reach.

Alternatives Considered

This draft environmental assessment (draft EA) considers the following alternatives: (1) Lockhart Power's proposal; (2) Lockhart Power's proposal with staff modifications (staff alternative); and (3) the no-action alternative, meaning that Lockhart Power would not refurbish the hydroelectric facilities and resume project operations.

Under the staff alternative, the project would be operated and maintained as proposed by Lockhart Power with the modifications and additional measures described below. Our recommended modifications and additional environmental measures include, or are based on, recommendations made by federal and state resource agencies that have an interest in resources that may be affected by operation of the proposed project, as well as those identified by staff.

The staff alternative includes the following additional measures and modifications to Lockhart Power's proposal:

• Develop and implement a site-specific soil erosion and sediment control plan, which includes the BMPs described in the South Carolina DHEC's Stormwater BMP Handbook, to minimize erosion and sedimentation during soil-disturbing activities associated with project construction and repairs.

• Develop and implement a sediment management plan to (a) test impoundment sediments for heavy metals and other contaminants, prior to beginning in-water construction activities and initial operation to prevent the release of any toxic substances, and (b) annually monitor and manage sediment accumulation in the impoundment to prevent the potential release of large quantities of sediment during maintenance activities.

• Develop and implement a shoreline stabilization plan to identify and stabilize eroding shorelines to minimize potential shoreline erosion from impoundment and flow fluctuations during peaking operation.

• Develop and implement a water quality monitoring plan to monitor dissolved oxygen (DO), temperature, and turbidity and implement corrective actions, if necessary, to protect aquatic resources located downstream of the dam.

• Release a continuous minimum flow of 75 cfs into the bypassed reach to protect aquatic habitat.

• Develop and implement a plan to determine the feasibility of using the sand gates as a mechanism for providing minimum flows to the bypassed reach and to evaluate methods to distribute minimum flows into the bypassed reach to protect aquatic habitat.

• Develop and implement a low inflow protocol/drought contingency plan to define periods of extended drought and low inflow protocols to minimize adverse effects on generation, and fish, wildlife, and water quality in the bypassed reach and downstream from the tailrace.

• Develop and implement an operation compliance monitoring plan to document impoundment fluctuations and minimum flow releases.

• Develop and implement an invasive vegetation monitoring and control plan to prevent the spread of alligatorweed and other invasive non-native plants during project refurbishment, operation, and maintenance activities.

• Determine whether the existing project transmission line is consistent with Avian Power Line Interaction Committee (APLIC) guidelines and identify measures to minimize potential electrocution hazards to birds, if needed.

• Modify Lockhart Power's proposed signage measures to include: (1) Identification of the canoe take-out and put in; (2) directions from the parking area to river access points; and (3) information regarding garbage disposal in order to improve public information available at the project and protect environmental resources.

• Stop work and notify the South Carolina SHPO and the Catawba Indian Nation if any unknown archaeological resources are discovered as a result of project construction, operation, or project-related activities to avoid, lessen, or mitigate potential adverse effects on historic resources.

Under the no-action alternative, the project would continue to be inoperable and no new environmental protection, mitigation, or enhancement measures would be implemented.

Public Involvement and Areas of Concern

Before filing its license application, Lockhart Power conducted a pre-filing consultation process under the traditional licensing process. The intent of the Commission's prefiling process is to initiate public involvement early in the project planning process and to encourage citizens, governmental entities, tribes, and other interested parties to identify and resolve issues prior to an application being formally filed with the Commission. After the application was filed, we conducted scoping to determine what issues and alternatives should be addressed. A scoping document was distributed to interested parties on May 15, 2012. On July 13, 2012, we issued the Ready for Environmental analysis notice, requesting comments, recommendations, terms and conditions, and prescriptions.

The primary issues associated with licensing the project include erosion and sediment control, sediment management, minimum flows to protect aquatic species and shoal habitat in the 1,400-foot-long bypassed reach, a low inflow protocol during extended droughts, invasive vegetation management, and recreation improvements.

Staff Alternative

Geology and Soils

Refurbishing the hydropower facilities, dredging the tailrace, and constructing the recreation improvements would temporarily increase soil erosion. Implementing staff's recommended site-specific soil erosion and sediment control plan would minimize adverse effects on aquatic and terrestrial resources.

Project repairs and the initial operation of the project would likely result in a discharge of a large amount of sediment downstream that could contain heavy metals and other contaminants. Staff's recommended testing of sediment for contaminants and developing a contingency plan, if needed, for removal and proper disposal of any contaminated sediment prior to beginning in-water construction activities and operation would prevent the unexpected release of any toxic substances and potential adverse effects on aquatic resources.

Because the Enoree River is heavily sediment laden, regular management of sediment bed-load from the impoundment may be needed to maintain project operation. Developing and implementing staff's recommended sediment management plan, which would include Lockhart Power's proposal to avoid drawing down the impoundment below the normal operating range for periodic inspections and maintenance from March 15 through June 1, would minimize adverse effects of sediment releases and lower impoundment levels on fish spawning in and downstream from the impoundment. The plan would also ensure that sediment in the impoundment is regularly monitored and managed, preventing excessive sediment accumulation and ensuring that sediment management activities occur when they are least likely to cause adverse effects on downstream resources.

Because of areas of highly erodible soils along the project shoreline, peaking operation could cause bank sloughing and erosion. Developing and implementing a shoreline stabilization plan and maintaining a 25-foot forested buffer around the impoundment as recommended by staff would help prevent bank erosion and loss of riparian habitat.

Aquatic Resources

In addition to the short-term increases in turbidity during project refurbishment, the diversion of flow for project operations would reduce flows in the bypassed reach, which could reduce DO levels and raise water temperatures in the bypassed reach. Monitoring water quality prior to the start of construction, during construction, and for 1 year after beginning operation as recommended by staff, would ensure that erosion control measures and minimum instream flows are adequately protecting water quality and allow for the timely identification of any needed corrective measures.

Lockhart Power's proposed minimum continuous flow of 60 cfs (16 percent of mean annual daily flow [MADF]) downstream from the tailrace and 50 cfs (13 percent of MADF) in the bypassed reach would not maintain aquatic resources in the bypassed reach. As defined by Tennant (1976),

such flows provide “fair or degrading” conditions, and close to “poor or minimum” conditions during the dry and wet seasons, respectively. Compared to Lockhart's proposed flow, staff's recommended year-round minimum flow of 75 cfs (20 percent of MADF) would better protect aquatic resources because this flow represents “good” conditions and close to “fair or degrading” conditions, as defined by Tennant (1996), during the dry and wet seasons, respectively.

The Tennant method establishes streamflow requirements on the basis of a percentage of the mean annual flow, and associates aquatic-habitat conditions with different percentages of mean annual flow.

Using the sand gates to release the bypassed reach minimum flows as proposed by Lockhart Power may not be feasible because the sand gates are currently inoperable. Also, sand gates are generally not designed for such activities and may become blocked with debris, preventing the release of specified flows. Developing and implementing staff's recommended minimum instream flow release plan would assess the feasibility of using the sand gates to release the minimum flows, identify which gate(s) best distribute flows across the bypassed reach, and identify alternative means to release minimum flows should using the gates prove impracticable.

Developing a low inflow protocol/drought contingency plan, as recommended by staff, would allow Lockhart Power and the resource agencies to adjust operation and minimum instream flow requirements as specified by the plan during periods of extended drought that minimize adverse effects on generation, and on fish, wildlife, and water quality in the bypassed reach and downstream from the tailrace.

Staff's recommended operation compliance monitoring plan would provide the Commission a mechanism to monitor compliance with Lockhart Power's proposed limits on impoundment fluctuations, minimum instream flow releases, and low inflow operation protocols.

Terrestrial Resources

Limiting disturbances to soil and vegetation and maintaining a minimum 25-foot-wide forested riparian buffer along project shorelines, as proposed by Lockhart Power, would preserve existing vegetation and habitat for wildlife. Staff's recommended invasive plant management plan, would minimize the introduction or spread of non-native invasive vegetation within the project boundary, and would protect native plant communities and the fish and wildlife that depend on them. Implementing staff's recommended avian protection plan would facilitate a determination on whether the project transmission lines pose a risk of avian injury or mortality due to electrocution and identify mitigation measures, if needed.

Recreation and Land Use

Lockhart Power's proposed canoe portage trail, put-in and take-out, parking, and directional signage at the project would enhance recreation amenities on a reach of the Enoree River designated for recreation use and future water trail development. Staff's recommended signage requesting that visitors pack out their garbage would reduce the likelihood that recreation use at the project would negatively affect the surrounding environment. Continued project operation would not affect land use.

Cultural Resources

No historic properties were identified within the project's area of potential effects. The South Carolina SHPO concurred that the proposed project would have no adverse effect on historic properties. Stopping work and notifying the South Carolina SHPO and Catawba Indian Nation if any unknown archaeological resources are discovered during project construction, operation, or other project-related activities, would allow Lockhart Power to define the appropriate treatments necessary to avoid, lessen, or mitigate for potential adverse effects from the inadvertent discovery.

Conclusions

Based on our analysis, we recommend licensing the project as proposed by Lockhart Power, with some staff modifications and additional measures.

In section 4.2 of the EA, we compare the likely cost of alternative power for each of the three alternatives identified above. Under the no-action alternative, the project would not be rehabilitated as proposed; therefore, the project would not produce any electricity. Our analysis shows that during the first year of operating the project as proposed by the applicant, project power would cost $265,378, or $54.21/MWh more than the likely alternative cost of power. Under the staff alternative, project power would cost $297,487, or $68.07/MWh more than the likely alternative cost of power.

We chose the staff alternative as the preferred alternative because: (1) The project would provide a dependable source of electrical energy for the region (4,370 MWh annually); (2) the 1.24 MW of electric energy capacity comes from a renewable resource that does not contribute to atmospheric pollution, including greenhouse gases; and (3) the recommended environmental measures proposed by Lockhart Power, as

modified by staff, would protect and enhance environmental resources affected by the project. The overall benefits of the staff alternative would be worth the cost of the proposed and recommended environmental measures.

We conclude that issuing a new license for the project with the staff-recommended measures would not be a major federal action significantly affecting the quality of the human environment.

Environmental Assessment

Federal Energy Regulatory Commission, Office of Energy Projects, Division of Hydropower Licensing, Washington, DC

Riverdale Hydroelectric Project, FERC Project No. 13590-001—South Carolina

1.0 Introduction

1.1 Application

The 1.24-megawatt (MW) project is located on the Enoree River near Enoree, in Spartanburg and Laurens Counties, South Carolina (figure 1). The project does not occupy any federal lands. The project is currently inoperable, but as proposed by Lockhart Power, it would generate an average of about 4,895 megawatt-hours (MWh) of energy annually.

On September 29, 1982, the Riverdale Project was licensed to Inman Mills under FERC Project No. 4362. The project has not operated since January of 2001. Inman Mills' license expired on August 31, 2012, and was subsequently issued an authorization for continued project operation until the Commission issues someone else a license for the project or otherwise orders disposition of the project. Inman Mills did not file a notice of intent to relicense the project. On November 29, 2007, the Commission issued a notice soliciting applications for subsequent license by August 31, 2010. Lockhart Power filed the only timely license application and is therefore the only license applicant for the Riverdale Project.

1.2 Purpose of Action and Need for Power

1.2.1 Purpose of Action

The purpose of the Riverdale Project is to provide a source of hydroelectric power. Therefore, under the provisions of the Federal Power Act (FPA), the Commission must decide whether to issue a license to Lockhart Power for the Riverdale Project and what conditions should be placed on any license issued. In deciding whether to issue a license for a hydroelectric project, the Commission must determine that the project will be best adapted to a comprehensive plan for improving or developing a waterway. In addition to the power and developmental purposes for which licenses are issued (such as flood control, irrigation, or water supply), the Commission must give equal consideration to the purposes of: (1) Energy conservation; (2) the protection of, mitigation of damage to, and enhancement of fish and wildlife resources; (3) the protection of recreational opportunities; and (4) the preservation of other aspects of environmental quality.

BILLING CODE 6717-01-P

EN19DE13.003

BILLING CODE 6717-01-C

Issuing a license for the Riverdale Project would allow Lockhart Power to generate electricity for the term of a license, making electrical power from a

renewable resource available to the local utility Duke Energy, which would use it to serve its customers' needs.

This environmental assessment (EA) assesses the effects associated with refurbishment, operation, and maintenance of the project and alternatives to the proposed project. It also includes recommendations to the Commission on whether to issue a license, and if so, includes the recommended terms and conditions to become a part of any license issued.

In this EA, we assess the environmental and economic effects of refurbishing and operating the project: (1) As proposed by the applicant; and (2) as proposed with our recommended measures. We also consider the effects of the no-action alternative. Important issues that are addressed include erosion and sediment control, sediment management, minimum flows to protect aquatic species and shoals habitat in the 1,400-foot-long bypassed reach, a low inflow protocol during extended droughts, invasive vegetation management, and recreation improvements.

1.2.2 Need for Power

The Riverdale Project would provide hydroelectric generation to meet part of South Carolina's power requirements, resource diversity, and capacity needs. With staff's recommended measures, the project would have an installed capacity of 1.24 MW and would generate approximately 4,370 MWh per year.

The North American Electric Reliability Council (NERC) annually forecasts electrical supply and demand nationally and regionally for a 10-year period. The Riverdale Project is located in the VACAR sub-region

of the Southeastern Electric Reliability Council (SERC), which is one of eight regional reliability councils of NERC. According to NERC's 2012 forecast, annual energy requirement for the VACAR sub-region is projected to grow at a compound annual rate of 1.11 percent, from 2012 through 2022 (NERC, 2012).

The VACAR sub-region includes the states of Virginia, North Carolina, and South Carolina.

The power from the Riverdale Project would help meet a need for power in the VACAR sub-region of the SERC in both the short- and long-term. The project provides low-cost power that may displace non-renewable, fossil-fired generation and contributes to a diversified generation mix. Displacing the operation of fossil-fueled facilities may avoid some power plant emissions and create an environmental benefit.

1.3 Statutory and Regulatory Requirements

A license for the Riverdale Project is subject to numerous requirements under the Federal Power Act (FPA) and other applicable statutes. We summarize the major regulatory requirements in table 1 and describe them below.

Table 1—Major Statutory and Regulatory Requirements for the Riverdale Project

Requirement

Agency

Status

Section 18 of the FPA (fishway prescriptions)

U.S. Department of the Interior (Interior), National Marine Fisheries Service (NMFS)

Interior and NMFS reserved authority to prescribe fishways on September 10, and September 11, 2012, respectively.

Section 10(j) of the FPA

Interior, NMFS, and South Carolina Department of National Resources (South Carolina DNR)

Interior, South Carolina DNR, and NMFS provided section 10(j) recommendations on September 10, September 10, and September 11, 2012, respectively.

Clean Water Act—Water quality certification (certification)

South Carolina DNR

Application for water quality certification received on October 4, 2012; withdrawn and reapplied on September 20, 2013; due by September 20, 2014.

Endangered Species Act (ESA) Consultation

Interior, U.S. Fish and Wildlife Service (FWS)

The project would not affect any listed species because none are known to occur in the project vicinity; therefore, further consultation under the ESA is not necessary.

Coastal Zone Management Act (CZMA)

South Carolina Department of Health and Environmental Control (South Carolina DHEC)

South Carolina DHEC indicated by letter filed September 30, 2010, that the project is not located within South Carolina's coastal zone, that the proposed project poses no reasonably foreseeable effects on the coastal zone, and that no consistency certification is needed.

National Historic Preservation Act (NHPA)

South Carolina State Historic Preservation Office (SHPO)

By letter filed August 31, 2010, the South Carolina SHPO concurred with Lockhart Power's determination that no historic properties would be affected by the project.

1.3.1 Federal Power Act

1.3.1.1 Section 18 Fishway Prescriptions

Section 18 of the FPA states that the Commission is to require construction, operation, and maintenance by a licensee of such fishways as may be prescribed by the Secretaries of Commerce or the U.S. Department of the Interior. Interior and Commerce through NMFS, by letters filed on September 10 and 11, 2012, respectively, request that a reservation of authority to prescribe fishways under section 18 of the FPA be included in any license issued for the project.

1.3.1.2 Section 10(j) Recommendations

Under section 10(j) of the FPA, each hydroelectric license issued by the Commission must include conditions based on recommendations provided by federal and state fish and wildlife agencies for the protection, mitigation, or enhancement of fish and wildlife resources affected by the project. The Commission is required to include these conditions unless it determines that they are inconsistent with the purposes and requirements of the FPA or other applicable law. Before rejecting or modifying an agency recommendation, the Commission is required to attempt to resolve any such inconsistency with the agency, giving due weight to the recommendations, expertise, and statutory responsibilities of such agency.

Interior, South Carolina DNR, and NMFS timely filed on September 10, September 10, and September 11, 2012, respectively, recommendations under 10(j), as summarized in table 18 in section 5.4.1,

Recommendations of Fish and Wildlife Agencies.

In section 5.4,

we also discuss how we address the agency recommendations and comply with section 10(j).

1.3.2 Clean Water Act

Under section 401 of the Clean Water Act (CWA), a license applicant must obtain certification from the appropriate state pollution control agency verifying compliance with the CWA. On October 3, 2012, Lockhart Power applied to the South Carolina DHEC for certification of the Riverdale Project. South Carolina DHEC received this request on October 4, 2012. On September 20, 2013, Lockhart Power withdrew and re-filed for certification, and on the same day South Carolina DHEC received this request. South Carolina DHEC has not yet acted on the request. The certification is due by September 20, 2014.

1.3.3 Endangered Species Act

Section 7 of the Endangered Species Act requires federal agencies to ensure that their actions are not likely to jeopardize the continued existence of endangered or threatened species or result in the destruction or adverse modification of the critical habitat of such species. There are no federally listed endangered or threatened species or critical habitat known to occur in the Riverdale Project vicinity. Therefore, licensing the project would not affect listed species and no further consultation under section 7 is needed.

1.3.4 Coastal Zone Management Act

Under section 307(c)(3)(A) of the Coastal Zone Management Act (CZMA), 16 U.S.C. 1456(3)(A), the Commission cannot issue a license for a project within or affecting a state's coastal zone unless the state CZMA agency concurs with the license applicant's certification of consistency with the state's CZMA program, or the agency's concurrence is conclusively presumed by its failure to act within 180 days of its receipt of the applicant's certification.

The project is not located within the state-designated Coastal Management Zone, which extends to South Carolina's eight coastal counties (Jasper, Beaufort, Colleton, Berkeley, Dorchester, Charleston, Georgetown, and Horry), and the project would not affect South Carolina's coastal resources. Therefore, the project is not subject to South Carolina coastal zone program review and no consistency certification is needed for the action. By letter filed September 30, 2010,

the South Carolina DHEC concurred.

See

letter dated September 13, 2010 from W. McGoldrick, Stormwater Permit Coordinator, South Carolina DHEC, Charleston, South Carolina, to S. Boring, Kleinschmidt Associates, Lexington, South Carolina.

1.3.5 National Historic Preservation Act

Section 106 of the National Historic Preservation Act (NHPA) requires that every federal agency “take into account” how each of its undertakings could affect historic properties. Historic properties are districts, sites, buildings, structures, traditional cultural properties, and objects significant in American history, architecture, engineering, and culture that are eligible for inclusion in the National Register of Historic Places (National Register).

Pursuant to section 106, the applicant consulted with the South Carolina SHPO and affected Indian tribes to locate, determine National Register eligibility, and assess potential adverse effects to historic properties associated with the project. By letter filed August 31, 2010,

the South Carolina SHPO stated that it concurred with the applicant's assessment that no properties listed in or eligible for listing in the National Register would be affected by the by the federal licensing action. Staff reaffirmed the South Carolina SHPO's concurrence via teleconference on May 23, 2012.

See

letter dated December 7, 2009 from C. Wilson, Review and Compliance Coordinator, South Carolina State Historic Preservation Office, Columbia, South Carolina to J. Seay, Jr., Lockhart Power Company, Lockhart, South Carolina.

See

FERC. 2012a. Telephone Meeting Summary with the South Carolina State Historic Preservation Office for the Riverdale Hydroelectric Project No. 13590-001. Filed on May 24, 2012.

As a result of the findings made by Lockhart Power and the SHPO's concurrence that no historic properties would be affected by the project, the drafting of a programmatic agreement to resolve adverse effects on historic properties will not be necessary.

1.4 Public Review and Consultation

The Commission's regulations (18 CFR, § 4.38) require that applicants consult with appropriate resource agencies, tribes, and other entities before filing an application for a license. This consultation is the first step in complying with the Fish and Wildlife Coordination Act, the ESA, the NHPA, and other federal statutes. Pre-filing consultation must be complete and documented according to the Commission's regulations.

1.4.1 Scoping

Before preparing this EA, we conducted scoping to determine what issues and alternatives should be addressed. A Scoping Document 1 was distributed to interested agencies and other stakeholders on December 22, 2011. It was noticed in the

Federal Register

on December 22, 2011. A Scoping Document 2 was issued on May 15, 2012. The following entities provided written comments on Scoping Document 1:

Commenting entities

Date filed

Caitlin Totherow, Catawba Indian Nation Tribal Preservation Officer (THPO)

January 18, 2012.

South Carolina SHPO

January 20, 2012.

Woodruff-Roebuck Water District (Water District)

February 9, 2012.

Greg Sveinsson, Riverdale Development Venture, LLC (Riverdale, LLC)

February 15, 2012.

American Rivers

February 16, 2012

South Carolina DNR

February 21, 2012.

FWS

February 21, 2012.

NMFS

March 6, 2012.

1.4.2 Interventions

On May 7, 2012, the Commission issued a notice that Lockhart Power's application to license the Riverdale Project had been accepted for filing. This notice set July 6, 2012, as the deadline for filing protests and motions to intervene. In response to the notice, the following entities filed notices of intervention or motions to intervene (none opposed issuance of a license):

Intervenors

Date filed

Woodruff-Roebuck Water District

June 12, 2012.

American Rivers

June 19, 2012.

Interior

June 25, 2012.

South Carolina DNR

June 29, 2012.

National Oceanic and Atmospheric Administration (on behalf of NMFS)

July 5, 2012.

1.4.3 Comments on the License Application

The July 13, 2012 notice also stated that the application was ready for environmental analysis, and requested that comments, recommendations, terms and conditions, and prescriptions be filed. The following entities commented:

Commenting agencies and other entities

Date filed

Interior

September 10, 2012.

South Carolina DNR

September 10, 2012.

NMFS

September 11, 2012.

American Rivers

September 12, 2012.

The applicant, Lockhart Power, filed reply comments on October 24, 2012.

2.0 Proposed Action and Alternatives

2.1 No-Action Alternative

We use existing conditions as the baseline environmental condition for comparison with other alternatives. Under the no-action alternative, the project would not be refurbished and operated, the dam and other facilities would remain in place, and all flows would remain in the Enoree River by passing over the spillway or through leaks in the sand gates.

2.1.1 Existing Project Facilities

The Riverdale Project would consist of an existing 425-foot-long, 12-foot-high concrete gravity dam with three evenly spaced, integral sand gates,

and 2-foot-high flashboards that form a 6.6-acre impoundment with a gross storage of 22.0 acre-feet. On the north end of the dam is an existing 85-foot-long, 50-foot-wide concrete headrace canal with an intake structure equipped with trash racks with 2.25-inch bar spacing. The canal feeds an existing 9-foot-diameter, 340-foot-long steel penstock,

which is equipped with trash racks having bar spacing of about 10 inches. The penstock connects to an existing wood frame powerhouse building containing one 1.24-MW capacity generating unit. An existing 510-foot-long tailrace extends from the powerhouse to the Enoree River, and an existing 700-foot-long transmission line extends from the powerhouse to an existing Duke Energy distribution line. An existing paved access road, approximately 1,376 feet long and 20 feet wide extends from Highway 221 to the project powerhouse.

Three low level sand gates are located within three concrete-framed piers along the spillway dam.

Staff used GIS software to estimate the length of the penstock. Current Exhibit F drawings only defined the below ground portion of the penstock as 110 feet long.

The project boundary includes about 25.9 acres. The project boundary encloses the project impoundment, the existing hydropower facilities, the bypassed reach (including the braided channels), tailrace, project access road, and the proposed canoe take-out, put-in, portage trail, and parking area. Riverdale, LLC currently owns approximately 2.5 acres of land within Lockhart Power's proposed project boundary which encompasses the project powerhouse, intake structure, penstock, and tailrace. The Water District owns the majority of the remaining lands within the project boundary and retains an option to acquire the dam. Two other private individuals own the remaining parcels which are located on the south side of the impoundment.

2.1.2 Project Safety

The project has been inoperable for more than 12 years under the existing license; nonetheless, during this time, Commission staff has conducted inspections focusing on the continued safety of the structures, identification of unauthorized modifications, efficiency and safety of operations, compliance with the terms of the license, and proper maintenance. As part of the licensing process, the Commission would evaluate the adequacy of the proposed project facilities. Special articles would be included in any license issued, as appropriate. Commission staff would continue to inspect the project both during and after construction to repair existing project facilities. Before the project is refurbished, engineers from the Commission's Atlanta Regional Office would review the designs, plans and specifications of the proposed repairs to equipment and structures. Inspections during project refurbishment would concentrate on adherence to Commission-approved plans and specifications, special license articles relating to construction, and accepted engineering practices and procedures. Operational inspections would focus on the continued safety of the structures, identification of unauthorized modifications, efficiency, and safety of operations, compliance with the terms of the license, and proper maintenance.

2.1.3 Existing Project Operation and Environmental Measures

Inman Mills ceased operating the project (under FERC No. 4362) in 2001, when the adjacent textile mill closed. The 2-foot-high flashboards washed out during storm events in 2012 and 2013 and there is currently no practical way to control flows from Riverdale dam. The current owner demolished the original concrete and brick powerhouse and replaced it with a wood frame building. All flows pass over the dam and into the 1,400-foot-long bypassed reach. No environmental measures are currently being implemented at the project.

2.2 Applicant's Proposal

2.2.1 Proposed Project Facilities

Lockhart Power proposes to use the existing hydropower facilities described above, and rehabilitate all equipment rendering the project inoperable. Because Lockhart Power is not the current licensee or current owner of the project and has not had full access to the project, it plans to spend the first year following license issuance

assessing the condition of project facilities and finalizing any engineering design needed to refurbish the project. To make the project operational, Lockhart Power expects it would, at a minimum: (1) Repair or replace the sand gates and gate operators; (2) repair or replace the 2-foot flashboards on the dam; (3) replace a 193-foot above ground section of the penstock; (4) modify the bar spacing on the penstock trashrack from 10 to 5 inches; (5) refurbish the turbine generator;

(6) repair plant controls and governor; (7) repair the powerhouse roof; and (8) dredge the sediment and debris in the tailrace. There would be a total of 25.9 acres within the proposed project boundary, of which 11.3 acres are land and the remainder is occupied by waters of the impoundment, bypassed reach, and tailrace.

Lockhart Power anticipates that significant electrical, mechanical, and hydraulic system improvements and refurbishments will be necessary to restore the project to reliable long term operating condition. Certain improvements, such as turbine refurbishment, may improve the design efficiency of and thereby increase the rated capacity of the turbine-generator to a range of 1.2-1.45 MW.

2.2.2 Proposed Project Operations

Lockhart Power would operate the project using a combination of run-of-river (ROR) and peaking modes. The project would operate semi-automatically with an operator on standby. Lockhart Power would remotely monitor impoundment levels and control the water flow through the project's turbine to maintain impoundment levels. The Riverdale impoundment would fluctuate between 1 and 4 feet of the top of the flashboards.

Lockhart Power would typically operate the project in a ROR mode, with project outflow approximately equaling inflow, such that the impoundment surface elevation stays within 1 foot (+/−10 percent) of the top of the flashboards. When inflows are insufficient to operate the turbine at its maximum hydraulic capacity of 450 cubic feet per second (cfs) and provide a continuous minimum flow of 50 cfs to the bypassed reach (i.e. when inflow is less than 500 cfs), Lockhart Power would operate the project in a “peaking” mode. Peaking events would occur no more than once daily, until either the daily period of increased need for power ends or until the impoundment surface elevation is drawn down a maximum of 4 feet (+/− 10 percent) below the top of the flashboards. Following each peaking event, Lockhart Power would suspend operation and store inflow, minus the minimum flow to the bypassed reach, to refill the impoundment (likely overnight) to its normal elevation of within 1 foot (+/− 10 percent) of the top of the flashboards, allowing it to return to ROR mode until the next peaking event. Lockhart Power expects that peaking operation would occur less than half of the days in any given year (Lockhart Power, 2011a).

2.2.3 Proposed Environmental Measures

Lockhart Power proposes to construct and operate the project with the following environmental protection, mitigation, and enhancement (PM&E) measures:

• Implement a sediment management plan that consists of using the sand gates to draw down the impoundment below the normal operating range for periodic inspections and maintenance and, if possible, avoid drawdowns from March 15 through June 1 to prevent significant accumulation of sediments in the project impoundment and untimely releases of sediment downstream.

• Monitor water quality as may be required by the South Carolina DHEC.

• When average daily inflows are less than or equal to 80 cfs (+/− 10 percent), release all inflow into the bypassed reach (i.e. low inflow protocol [LIP]) to protect aquatic resources downstream from Riverdale dam, including during the fish spawning season.

• Implement best management practices (BMPs) to protect vegetation within the project boundary, such as limiting vegetation and ground-disturbing activities and maintaining a minimum 25-foot-wide forested riparian buffer on project shorelines, as long as this does not interfere with Lockhart Power's ability to perform project-related activities.

• Provide informal public access for fishing at the project impoundment, tailrace, and bypassed reach.

• Notify and consult with the South Carolina SHPO regarding any project-related construction or other ground-disturbing activities.

Although Lockhart Power proposes this measure in its license application, we consider Lockhart Power's consultation requirements under section 106 of the NHPA to be complete because of the SHPO's finding that no properties listed in or eligible for listing in the National Register would be affected by the project (letter from C. Wilson, Review and Compliance Coordinator, South Carolina SHPO, Columbia, South Carolina to J. Seay, Jr., Lockhart Power, Lockhart, South Carolina, December 7 2009). Therefore no further analysis of this measure is necessary.

2.3 Staff Alternative

The staff alternative includes the following additional measures and modifications to Lockhart Power's proposal:

• Develop and implement a sediment management plan that includes provisions to: (a) Test impoundment sediments for heavy metals and other contaminants prior to beginning in-water construction activities and initial operation; (b) prepare a contingency plan for proper disposal of any contaminated sediments should they be found in the impoundment; (c) monitor sediment accumulation in the impoundment annually to facilitate planning of sediment management activities; (d) develop criteria that would trigger sediment removal from the impoundment (i.e. by opening the sand gates, if appropriate, during high flow events, or via mechanical methods); (e) conduct sediment management activities during the months of November through January except during high rain events (e.g., tropical storms or hurricanes); (f) avoid maintenance activities that would draw down the impoundment below normal operating levels and potentially pass sediment into the bypassed reach from March 15 through June 1, if possible, to minimize adverse impacts to spawning fish; and (g) file annual reports with

sediment monitoring results, sediment management activities, and an evaluation of the effectiveness of the plan in minimizing sediment accumulation in the impoundment.

• Develop and implement a shoreline stabilization plan that includes provisions to: (a) Identify eroding or potential project-induced erosion sites on the impoundment shorelines and streambanks downstream from the dam and powerhouse prior to beginning operation; (b) stabilize areas of shoreline erosion using native vegetation, bio-engineering, slope flattening, toe armoring with anchored logs, and/or riprap that incorporates native vegetation plantings; (c) monitor shorelines after resuming operation and implement stabilization measures if project-induced erosion occurs; (d) conduct shoreline stabilization activities from September through February to protect aquatic species and wildlife; and (e) file annual reports describing monitoring results and any implemented shoreline stabilization measures.

• Develop and implement a water quality monitoring plan with provisions to: (a) Monitor dissolved oxygen (DO), temperature, and turbidity prior to the start of construction, during construction, and for 1 year after project operation begins to ensure the levels specified by the current state water quality standards are met and aquatic resources are protected; (b) define sampling methods, timing, and locations for monitoring these parameters in consultation with South Carolina DHEC, FWS, and NMFS; and (c) file a report that presents the monitoring data, describes any project-related effects and identifies corrective actions, if necessary.

• Release a continuous minimum flow of 75 cfs into the bypassed reach to protect aquatic habitat.

• Develop and implement a plan to release required minimum flows into the bypassed reach that includes: (a) A feasibility assessment for using the sand gates as a flow-release mechanism; (b) if found to be feasible, a flow study to determine how the sand gates would be used to distribute flow into the bypassed reach to protect aquatic habitat; (c) if the sand gates are not feasible, a description of how the minimum instream flows would be provided to the bypassed reach; (d) a report documenting the outcome of the feasibility assessment, flow study, and consultation with the agencies; and (e) an implementation schedule.

• Develop and implement a low inflow protocol/drought contingency plan to define periods of extended drought and the low inflow protocols to minimize adverse effects on generation, and on fish, wildlife, and water quality in the bypassed reach and downstream from the tailrace.

• Develop and implement an operation compliance monitoring plan that includes: (a) A rating curve to provide the seasonally defined flows; (b) protocols to monitor and document compliance with required flows; (c) protocols to monitor and document impoundment fluctuations; and (d) an implementation schedule.

• Develop and implement an invasive

vegetation monitoring and control plan that includes: (a) Survey methods to determine the extent of alligatorweed in the impoundment and riparian area prior to beginning refurbishment activities; (b) BMPs, as well as monitoring and control methods to prevent the spread of alligatorweed in the impoundment to areas downstream from the dam during project refurbishment; (c) monitoring protocols to detect the introduction or spread of other invasive plants within the project boundary during operation and maintenance; (d) criteria that would determine when control measures would be required; and (e) a schedule for filing monitoring reports and any recommended control measures with the Commission.

For the purposes of this document, an “invasive species” is defined, consistent with Executive Order 13112, as a species that is: (1) Non-native (or alien[/exotic]) to the ecosystem under consideration; and (2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health (USDA, 2012).

• Determine whether the existing project transmission line is consistent with Avian Power Line Interaction Committee (APLIC) guidelines. Identify, in consultation with FWS, measures to minimize potential electrocution hazards to birds and file a report with the Commission describing the results of the evaluation and any measures recommended by FWS.

• Modify the applicant's proposal for signage at recreation sites to include: (1) Identification of the canoe take-out and put in; (2) directions from the parking area to river access points; and (3) information regarding garbage disposal in order to improve public information available at the project and protect environmental resources.

2.4 Alternatives Considered but Eliminated From Further Analysis

2.4.1 Issuing a Non-Power License

A non-power license is a temporary license that the Commission will terminate when it determines that another governmental agency will assume regulatory authority and supervision over the lands and facilities covered by the non-power license. At this point, no agency has suggested a willingness or ability to do so. No party has sought a non-power license and we have no basis for concluding that the project should no longer be used to produce power. Thus, we do not consider issuing a non-power license a realistic alternative to relicensing in this circumstance.

2.4.2 Project Decommissioning

Project decommissioning could be accomplished with or without dam removal. Both Interior and American Rivers recommended that the Commission analyze project decommissioning with dam removal as an alternative in this EA. Because Lockhart Power neither owns nor operates the project under the existing license, the Commission cannot require Lockhart Power to remove the dam. Decommissioning the project would involve denial of Lockhart Power's license application and then the surrender or termination of Inman Mills' existing license with appropriate conditions under separate action by the Commission.

Decommissioning with dam removal would remove the only barrier to fish movement in the Enoree River from its confluence with the Broad River to its headwaters, allow for natural sediment movement through the project area, eliminate the need to portage canoes around the project, remove lake recreation, and eliminate a potential source of renewable energy. However, as we explain herein, the project's power would serve to meet regional energy needs. Further, a license can be conditioned to address adverse environmental effects of project operation such that project benefits can be retained with minimal effects on the environment. Considering there is a willing developer of the project, we see no reason not to develop the project power. Therefore, we do not consider project decommissioning with or without dam removal as a reasonable alternative to Lockhart Power's proposal.

3.0 Environmental Analysis

In this section, we present: (1) A general description of the project

vicinity; (2) an explanation of the scope of our cumulative effects analysis; and (3) our analysis of the proposed action and other recommended environmental measures. Sections are organized by resource area. Under each resource area, historic and current conditions are first described. The existing condition is the baseline against which the environmental effects of the proposed action and alternatives are compared, including an assessment of the effects of proposed mitigation, protection, and enhancement measures, and any potential cumulative effects of the proposed action and alternatives.

We present the estimated cost of the proposed and recommended measures in section 4.0,

Developmental Analysis.

Our conclusions and recommended measures are discussed in section 5.2,

Comprehensive Development and Recommended Alternative.

Unless otherwise indicated, our information is taken from the license application for this project (Lockhart Power, 2010a) and Lockhart Power's responses to the Commission staff's additional information requests (Lockhart Power, 2011a; 2011b; 2012).

3.1 General Description of the River Basin

Situated within the Piedmont Physiographic Region and encompassing approximately 731 square miles within the lower portion of the Broad River Basin, the Enoree River Basin spans portions of Greenville, Spartanburg, Union, and Newberry Counties in northwestern South Carolina. The Enoree River originates near the city of Travelers Rest and then flows 110 miles to its confluence with the Broad River. The Broad River flows into the Congaree, which merges with the Wateree to form the Santee River. The Santee River flows into the Atlantic Ocean.

The Enoree River is the primary source of water for the project. Tributaries to the Enoree River include Beaverdam Creek

as well as Warrior and Duncan creeks. Approximately 29 miles upstream of the project, are the remains of the Pelham dam

and Pelham Mills, closed in the 1930's. There are no other dams on the Enoree River upstream of, or downstream from, the Riverdale dam. The nearest dam is Parr Shoals dam (FERC Project No. 1984), located on the Broad River 65 miles downstream from the confluence of the Enoree and Broad rivers.

Beaverdam Creek enters the Enoree River approximately 0.5 mile upstream of the project.

There are no records of a hydroelectric license at the Pelham dam location (Federal Power Commission, 1970).

The Enoree River has a variety of aquatic habitats, including seven shoal reaches and frequent long stretches of riffles and runs separated with short sections of glides and pools. The topography of the basin is generally moderate, varying from steep to rolling hills. Land uses in the basin and surrounding the Riverdale Project are primarily forest or agriculture with small developed areas near the headwaters of the Enoree River and along main roads in the project area.

Climate in the Enoree River Basin is subtropical, marked by high summer humidity and moderate winters that rarely drop below freezing. The average annual temperature is 60 °F to 70 °F. Rainfall is high year-round, with an annual average of 40 to 60 inches, typically greatest during the summer.

3.2 Scope of Cumulative Effects Analysis

According to the Council on Environmental Quality, a cumulative effect under NEPA is the impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such other actions 40 CFR 1508.7 (2013). Cumulative effects can result from individually minor but collectively significant actions taking place over a period of time, including hydropower and other land and water development activities.

Based on our review of the license application, agency and public comments from scoping, and other filings related to the project, we have identified fisheries as a resource that could be cumulatively affected by the proposed project in combination with other actions such as sand mining operations in the Enoree River Basin.

3.2.1 Geographic Scope

The geographic scope of the analysis defines the physical limits or boundaries of the proposed action's effects on the resources. Because the proposed action would affect the resources differently, the geographic scope for each resource may vary. For fisheries, we identified the geographic scope to extend from the remains of the Pelham dam downstream to the mouth of the Broad River.

3.2.2 Temporal Scope

The temporal scope of our cumulative effects analysis in the EA includes a discussion of past, present, and future actions and their effects on these resources. Based on the potential term of license, we will look 30 to 50 years into the future, concentrating on the effect on the resources from reasonably foreseeable future actions. The historical discussion is limited, by necessity, to the amount of available information. We identify the present resource conditions based on the license application, agency comments, and comprehensive plans.

3.3 Proposed Action and Action Alternatives

In this section, we discuss the effect of the project alternatives on environmental resources. For each resource, we first describe the affected environment, which is the existing condition and baseline against which we measure effects. We then discuss and analyze the site-specific environmental issues.

Only the resources that would be affected, or about which comments have been received, are addressed in detail in this EA. We have not identified any substantive issues related to aesthetic resources or socioeconomics associated with the proposed action, and, therefore, these issues are not assessed in this EA.

3.3.1 Geologic and Soil Resources

3.3.1.1 Affected Environment

The Enoree River is located within the greater Broad River Drainage Basin and flows through the geologic region known as the Piedmont. The Piedmont geologic region extends from the Blue Ridge region to the fall line, at Columbia, South Carolina, and consists of stream and river valleys and rolling hills with elevations ranging from 375 to over 1,000 feet mean sea level (msl).

Bedrock in this region is dominated by granite which is found mostly below the surface, except at shoals within streams. The Enoree River passes through various geologic formations including the Six Mile Thrust Sheet, the Laurens Thrust Stack, and the Charlotte Terrane before entering the Broad River, approximately 52 miles downstream from the project. Surficial geological material within the project area and within the vicinity of the project consists of fluvial deposited sediments, as well as weathered felsic igneous and metamorphic rocks of the Piedmont uplands.

Elevations in this document are based on the National Geodetic Vertical Datum 1929 (NGVD 29).

Dominant soils within the project area and general vicinity of the project include the following series: Cartecay, Congaree, and Enoree (entisols);

and

Cecil, Madison, and Pacolet (ultisols)

(NRCS, 2013a). In particular, the northern shoreline of the Riverdale impoundment is composed of Cartecay-Toccoa complex, Pacolet sandy clay loam with 10 to 15 percent slopes, and Pacolet sandy loam with 25 to 40 percent slopes. The southern shoreline of the impoundment consists largely of Enoree soils. Downstream from the dam, bordering the bypassed reach, tailrace, and Enoree River are Madison & Pacolet soils with 15 to 40 percent slopes and wet, mixed alluvial land.

Table 2 describes key features of these soils.

Entisols are mineral soils that typically occur in areas where the rate of erosion or deposition of soil parent materials exceeds the rate of soil horizon development (NRCS, 2012).

Ulitsols are highly weathered soils rich in clays and minerals commonly found in mesic forests in the Lower Broad River Basin (Andersen

et al.,

2001).

Alluvial land is an area such as a portion of a stream channel or floodplain where stream-born sediment has been deposited (Chernicoff and Ramesh, 1995).

Table 2—Select Characteristics of Mapped Soil Units at the Riverdale Project

[Source: Lockhart Power, 2010A]

Soil type

Slope

Landform

Drainage class

Flooding

Capacity to

transmit water

Erodibility

Northern Shoreline

Cartecay-Toccoa complex

0-2

Floodplain

Somewhat poorly drained

Occasional

High

0.24

Pacolet sandy clay loam

15-25

Interfluves

Well drained

None

Mod. high to high

0.20

Pacolet sandy loam

25-40

Interfluves

Well drained

None

Mod. high to high

0.20

Southern Shoreline

Enoree

0-2

Depressions/floodplain

Poorly drained

Frequent

Mod. high to high

0.32

Downstream from Riverdale Dam

Madison & Pacolet

0-2

Floodplain

Moderately well drained

Frequent

High

0.32

mixed alluvial land

15-40

Interfluves

Well drained

None

Mod. high to high

0.20

Measured as Ksat, or saturated hydraulic capacity, as an indicator of seepage potential in the upper 60 inches.

Measured as the K factor, or the erodibility of soil and other surface substrates, taking into account soil texture, content (e.g., clay, silt, organic matter, minerals, rocks), and structure (NRCS, 2013b). Values range from 0.02 to 0.69. The higher the value, the more susceptible the soil is to sheet and rill erosion by water. Moderate range is about 0.20-0.40.

Upland landform located between two adjacent valleys containing streams.

The characteristics of dominant soil types along with active local mining operations likely contribute to the load of suspended solids in the Enoree River. According to the Natural Resource Conservation Service (NRCS), the majority of lands in the Enoree watershed, including those of the project, represent a resource concern due to erosion and are classified as `highly erodible lands.' As shown in table 2, the soils bordering the project impoundment have a K factor that indicates moderate erodibility. In addition, there are several mine sites upstream of the Riverdale Project, including granite, vermiculite, and sand mines (South Carolina DHEC, 2013a; 2013b).

During licensing studies conducted the summer of 2010,

Lockhart Power collected qualitative data on substrate content and bank stability at the Riverdale Project.

The substrates were dominated by silt and sand in the impoundment and at the confluence of the Enoree River and Two-Mile Creek. Boulders and bedrock occur immediately downstream from the dam. Clay, gravel, pebble, cobble, detritus, and mud were also found in the substrates within the project boundary. The study results indicated areas of stable shorelines and some areas with evidence of erosion and undercutting. The current extent of erosion is not known at this time, but the majority of the project shoreline is forested with portions armored by bedrock.

The survey report for Carolina heelsplitter, a freshwater mussel species, provided qualitative information on substrate content and compactness, sand and gravel bars, woody debris, beaver activity, bank stability, riparian buffer width and vegetation types, land use, turbidity, and water level.

Survey locations included the impoundment and the Enoree River in the riffle habitat immediately upstream of the impoundment, Two-Mile Creek, the tailrace, the bypassed reach, and the Enoree River downstream from the project near a road (i.e. SC 49) crossing.

Heavy metals and other contaminants from an industrial spill are known to occur in the Upper Enoree River watershed. In 1985, a galvanizing facility spilled 75,700 liters of hydrochloric acid, zinc, lead, barium, chromium, and other contaminants from a ruptured waste containment pond. The contaminants infiltrated the soil and seeped into the groundwater at the headwaters of the Enoree River near Travelers Rest, South Carolina. Also in 1985, the U.S. Environmental Protection Agency (EPA) removed contaminated materials from the waste containment ponds, from soil around the facility, as well as drums and other containers of stored hazardous materials, some of which appeared to have leaked (South Carolina DHEC, 2005). Studies conducted in 1999 and 2000 documented the residual adverse effects of these contaminants on salamanders, fish, dragonfly and damselfly larvae, and other aquatic species in the Enoree River (Worthen,

et al.,

2001; Worthen, 2002). While South Carolina DHEC determined that the surface water, sediment, soils, and groundwater adjacent to the facility pose no public health hazard,

a South Carolina DHEC's survey in October 2004 indicated that zinc concentrations in surface water and sediments were above ambient conditions and could negatively impact aquatic species at the headwaters of the Enoree River (South Carolina DHEC, 2005). The type and quantity of contaminants that may have

been transported in the Enoree River and deposited within the sediments of the project impoundment since the 1985 industrial spill is unknown at this time.

According to South Carolina DHEC, the levels of chemicals measured at the spill site do not pose a risk to people who may ingest or come in contact with water and sediment in the area; however, the threshold for adverse effects to aquatic organisms is much lower.

The Enoree watershed is transport limited, meaning that material, primarily eroding soils, collects at a faster rate than river flows can transport. In small impoundments such as the one at the project, sediments tend to collect seasonally or during low flow periods. This is exemplified by the large amount of fine sediments (e.g., sand, silt, and clay), tree trunks, branches, and other debris that have accumulated within the project impoundment, including in front of the intake structure and the dam spillway (FERC, 2012b; 2013). Some of the sediments and debris in these areas are covered by mats of alligatorweed and other vegetation (Lockhart Power, 2012). Turbidity and thick vegetation growing along the canal between the intake structure and the penstock limited visual inspection during recent project inspections (FERC, 2012b; 2013). The precise volume of sediment deposits in the impoundment and the canal are unknown at this time.

3.3.1.2 Environmental Effects

Construction-Related Effects

At this time, Lockhart Power cannot define exactly what will be required to make the project operable. However, anticipated activities associated with replacing the approximately 193-foot-long section of the penstock, dredging the tailrace, repairing the powerhouse, and constructing the canoe put-in, take-out, portage trail, and parking area would result in soil-disturbing activities that could cause erosion and sedimentation in the impoundment and Enoree River. Soil erosion and subsequent sedimentation of aquatic habitats can adversely affect fish and wildlife habitat and degrade water quality.

To address the issue of erosion and sedimentation at the project, Lockhart Power would limit ground-disturbing activities whenever possible on lands acquired for project purposes. South Carolina DNR recommends Lockhart Power consult with state and federal agencies to implement construction and maintenance

BMPs described in the South Carolina DHEC's Stormwater BMP Handbook (South Carolina DHEC, 2005).

Both Lockhart Power's proposal and South Carolina DHEC's recommendation appear to apply to all future ground-disturbing maintenance activities. While we are not opposed to such protective measures, we cannot analyze the effects of undefined, broad measures. Therefore, this EA only considers the effects of refurbishing the project and general operation and maintenance of the project. Any future modifications that result in ground-disturbing activities may require prior Commission approval.

Our Analysis

Lockhart Power anticipates that construction and repairs of the hydroelectric facilities and installation of the proposed recreation facilities would be confined to about 2 acres. Ground-disturbing activities would occur predominantly within the footprint of the former textile mill, parking lots, and roadways, minimizing effects to undisturbed areas. Implementing standard industry BMPs for controlling erosion would ensure adverse effects are minor and temporary. Such BMPs could include the use of silt fences, sediment traps, stabilized construction entrances, and alternative techniques that may be approved after consultation with the South Carolina DHEC (South Carolina DHEC, 2013a; 2013b; 2005).

Operation and Maintenance-Related Effects

Heavy sediment loads in the Enoree River and years of in-operation have resulted in significant sediment deposits and the establishment of vegetation in the project impoundment. The exact amount of sediment deposit is unknown. Repairs to the sand gates prior to project operation would likely require lowering the impoundment which could release large quantities of sediments downstream. Any heavy metals and other contaminants that may have been deposited and covered by the sediment over the years could be suspended and released downstream.

Resuming project operation and maintenance activities could affect several geomorphological processes and/or conditions such as stream bank and shoreline erosion, bed scour, and sediment accumulation within the impoundment, and sediment transport to downstream river reaches. Because of the heavy sediment loads and lower velocities in the impoundment, sediments would continue to accumulate in the impoundment during project operation. Periodic maintenance activities, such as inspections or repairs to the sand gates that would require lowering the project impoundment below the normal operating levels, could result in untimely flushing of sediments and the accidental releases of large quantities of sediment. During peaking operation, impoundment fluctuations of up to 4 feet could cause bank erosion and sedimentation in the impoundment.

To prevent significant accumulation of sediments in the project impoundment and untimely releases of sediment downstream, Lockhart Power proposes to implement a sediment management plan, which consists of the following: Lockhart Power would use the sand gates to draw down the impoundment below the normal operating range (i.e. for periodic inspections and maintenance purposes) and avoid drawdowns from March 15 through June 1. These measures are intended to minimize sediment releases that could affect fish spawning in the project impoundment and downstream areas.

South Carolina DNR recommends that Lockhart Power develop and implement a sediment management plan with provisions to: (a) Monitor stream-borne sediment accumulations in the impoundment; (b) regularly flush sediments downstream or remove them from the impoundment; (c) prepare annual reports describing monitoring and management activities and evaluating the overall effectiveness of the plan; (d) conduct sediment management activities from November through January, if possible; and (e) consult with the South Carolina DHEC to address the potential presence of contaminated sediments in the impoundment.

Interior also recommends Lockhart Power develop and implement its sediment management plan with guidelines for periodic inspections and maintenance drawdowns, as well as the following additional provisions: (a) Test impoundment sediment for heavy metals and other contaminants; (b) develop a schedule and criteria that would trigger sediment removal from the impoundment, by opening the sand gates, if appropriate, during high flow events, or via mechanical methods; (c) develop a method to monitor future sediment accumulation in the impoundment; and (d) conduct maintenance drawdowns in late fall and winter to avoid impacts to spawning fish upstream and downstream of the dam.

To protect project shorelines from water level fluctuations associated with peaking operation, Interior recommends Lockhart Power develop and implement a shoreline stabilization plan. As part of the plan, Lockhart Power would be required to identify and address any existing areas of active erosion along the impoundment, as well as areas downstream from the dam with the potential for erosion due to project operation. Interior recommends that Lockhart Power use native vegetation and techniques such as bio-engineering, slope flattening, toe armoring with anchored logs, and/or riprap that

incorporates native vegetation plantings to stabilize shorelines subject to potential erosion.

Our Analysis

Sediment Management

Refurbishing the dam, sand gates, and intake structures, and beginning initial operation would likely result in the re-suspension and subsequent transport of a large quantity of sediments downstream from the project. High loads of suspended solids [sediment] increase turbidity in riverine habitats leading to reduced light penetration, decreased primary productivity, which then can lead to adverse effects to the rest of the food chain. Sedimentation can modify the substrate surfaces and morphology of a stream channel, reducing habitat availability and smothering and killing aquatic flora and fauna (Wood and Armitage, 1997). If heavy metals and other contaminants are present in the impoundment, they could also be suspended and transported in the water column, harming fish and wildlife.

Conducting an initial test for heavy metals and other contaminants in the impoundment sediments prior to beginning project operations, as recommended by Interior, would determine if such contaminants are in the project impoundment. The test results would also help Lockhart Power, the resource agencies, South Carolina DHEC, and the Commission to identify suitable methods for removing and disposing of any contaminated sediments, preventing the inadvertent re-suspension and release of contaminants. The information would also help to design appropriate methods for short- and long-term sediment management at the project.

Avoiding impoundment draw downs between March 15 and June 1 to initially repair the sand gates and to conduct any maintenance once it is operational, would avoid adverse effects on spawning fish and reproductive success. Limiting any such maintenance actions to the late fall and winter, as recommended by Interior, would also protect a broad range of aquatic species, which undergo less critical life-cycle events during this time of year and are often dormant or less active. In addition, during the fall and winter there would likely be sufficient flows to keep any suspended sediment moving downstream instead of settling in the shoal habitat of the bypassed reach.

Regular management of impoundment sediment loads would help prevent sediment buildup and the accidental release of large quantities of sediment during scheduled and unscheduled maintenance activities that could have adverse effects on downstream resources. Such an event occurred in October of 2011 at the Neal Shoals Hydroelectric Project (FERC Project No. 2315) which is located on the Broad River about 16 miles upstream from the confluence with the Enoree River. About 112,841 cubic yards of sediment was released

during a reservoir drawdown associated with the replacement of four sand gates, installation of new trash racks on the sand gates, temporary installation and removal of a bulkhead in the sand gate opening, and the replacement of the controls for the sand gates and trash racks.

The Commission was informed that the sediment release resulted in a fish kill and affected water quality in the Broad River.

Analysis of the effects the sediment release on aquatic resources downstream from the Neal Shoals Project is ongoing.

See

letter from Michael C. Summer, General Manager, Fossil/Hydo Technical Services, South Carolina Electric and Gas Company (SCE&G), Cayce, South Carolina, filed on January 25, 2012.

See

letter from Michael C. Summer, General Manager, Fossil/Hydo Technical Services, SCE&G, Cayce, South Carolina, to Charles D. Wagner, Regional Engineer, FERC, Atlanta Regional Office, Duluth, Georgia, filed on March 7, 2011.

See

letter from Thomas J. LoVullo, Chief, Aquatic Resources Branch, FERC, Division of Hydropower Administration and Compliance to Michael C. Summer, General Manager, Fossil/Hydo Technical Services, SCE&G, Cayce, South Carolina, issued on November 14, 2011.

See

letter from Michael C. Summer, General Manager, Fossil/Hydo Technical Services, SCE&G, Cayce, South Carolina, filed on August 8, 2013.

Developing a sediment management plan would facilitate detection and timely management of sedimentation at the project, which would protect aquatic and riparian resources at and near the project. The plan would be most effective if it includes regular monitoring of sediment loads, defines criteria for when sediment loads are reaching levels requiring flushing or removal, and establishes a schedule for flushing sediments or mechanically removing the sediments during periods when such releases would be least harmful to aquatic resources. Annual sediment management reports, as recommended by South Carolina DNR, would ensure continued stakeholder involvement in sediment management activities at the project and that sedimentation is managed effectively from year to year. Such report(s) would be most informative if they include sediment monitoring results, sediment management activities that were undertaken, and an evaluation of the effectiveness of the sediment management plan in minimizing adverse effects on downstream resources.

Fluctuating Water Levels

Resuming project operations, as Lockhart Power proposes, would result in impoundment fluctuations of up to 4 feet that could compromise the stability of soils along the project shorelines. The total length of the impoundment shoreline is about 2,394 feet.

Since the shoreline contains areas of highly erodible soils, such fluctuations could cause physical weathering through saturation, subsequent drying, exposure to rainfall, runoff, and freeze/thaw conditions. These mechanisms can cause slumping of soils and fracturing of rocks on the shorelines. Bank slumping and erosion is likely to be greatest during the initial years of operation. Identifying and stabilizing areas of active erosion, as well as areas that exhibit the potential for erosion prior to commencing project operation would prevent and/or minimize potential shoreline erosion problems. Annually monitoring the banks for erosion and implementing corrective measures as needed would minimize future adverse effects of bank erosion on fish and wildlife habitat. Using native vegetation and techniques such as bio-engineering, slope flattening, toe armoring with anchored logs, and/or riprap that incorporates native vegetation plantings would effectively stabilize eroding shorelines and provide habitat for wildlife and aquatic species that use the riparian zone, littoral zone of the impoundment, and bank areas of stream reaches in the project area. Monitoring banks and shorelines after Lockhart Power resumes project operation as well as implementing stabilization techniques if erosion is observed, would address any areas of future shoreline erosion. Installing shoreline or bank stabilizers during the fall and winter (i.e. September through February), except under emergency situations, would help minimize potential disturbances to aquatic species and wildlife. As with the sediment management plan discussed above, annual reports documenting the results of monitoring and any shoreline stabilization activities would ensure continued stakeholder involvement in activities to minimize erosion and protect littoral, bank, and riparian areas within the project area over the term of any license issued for the project.

Staff used GIS software to estimate the length of the impoundment shoreline. The individual lengths of the northern and southern impoundment shorelines are 1,234 feet and 1,160 feet, respectively.

3.3.2 Aquatic Resources

3.3.2.1 Affected Environment

Water Quantity

The project impoundment has a surface area of 6.6 acres at the normal pool elevation of 512 feet above msl and a gross storage capacity of 22 acre-feet. The impoundment extends 0.25 mile upstream of the dam to a bedrock ledge about 225 feet downstream from the Highway 221 Bridge. The impoundment is about 250 to 300 feet wide, shallow, and includes mid-channel sandbars and large woody debris. All flows currently pass over the dam and flow into the project's 1,400-foot-long bypassed reach.

The impoundment drainage area is 280.5 square miles. The estimated mean annual daily flow (MADF) at the project is 374 cfs.

The maximum peak flow for the period of record was approximately 52,200 cfs on August 27, 1995, as a result of Tropical Storm Jerry (table 3). As expected, the lowest flow periods occur during the summer and early fall (June-November).

This MADF is based on data collected during the following period of record: January 1, 1994 through December 31, 2012, as pro-rated from U.S. Geological Survey (USGS) gage No. 02160390, located on the Enoree River near Woodruff, SC.

Table 3—Synthesized Monthly Flow Data (CFS) for the Riverdale Project From USGS Gage No. 02160390 Enoree River at Woodruff, South Carolina

[Source: Lockhart Power, 2010

; USGS, 2013, as modified by staff]

Month

Minimum

90 Percent

exceedance

75 Percent

exceedance

Mean

Maximum

25 Percent

exceedance

10 Percent

exceedance

January

153

180

252

475

6938

492

828

February

156

193

267

503

5853

521

803

March

191

247

298

590

8204

586

895

April

164

218

258

442

4656

498

709

May

127

160

188

343

463

359

557

June

107

140

300

2915

341

544

July

122

269

6893

263

489

August

307

22600

283

467

September

271

7255

276

414

October

115

256

5311

272

406

November

131

296

4497

301

512

December

101

149

188

439

5198

475

748

Note:

Period of Record is January 1, 1994 through December 31, 2012. The Woodruff gage is located about 6.7 miles upstream of the project and has a drainage area of about 249 square miles. Flows were pro-rated to the project using the formula 280.5/249.

Water Use

Public water supply is the primary surface water use of the Enoree River. The Enoree River serves as the water supply for Lauren and Spartanburg counties. The town of Whitmire and city of Clinton withdraw water from the Enoree River downstream from the project. There are no current water withdrawals occurring at the project. However, the Woodruff-Roebuck Water District, South Carolina anticipates future withdrawals of 5 million gallons per day or 7.74 cfs from the Riverdale impoundment to support probable increases in area water demands.

See

letter from Curtis M. Dillard, PE, General Manager, Woodruff-Roebuck Water District, Woodruff, South Carolina, filed on February 9, 2012.

Water Quality

South Carolina DHEC designated the Enoree River waters at the project as freshwater, suitable for primary and secondary contact recreation, and as a source for drinking water supply after conventional treatment in accordance with the requirements of the South Carolina DHEC. State water quality standards that would be applicable for project discharge are described in table 4.

Table 4—South Carolina Water Quality Standards for Freshwaters

[Source: South Carolina Regulation 61-68—Water classifications and standards]

Quality standards for freshwaters

Items

Standards

a. Garbage, cinders, ashes, oils, sludge, or other refuse

None allowed.

b. Dissolved oxygen

Daily average not less than 5.0 mg/l with a low of 4.0 mg/1.

E. coli

Not to exceed a geometric mean of 126/100 ml based on at least four samples collected from a given sampling site over a 30 day period, nor shall a single sample maximum exceed 349/100 ml.

d. Temperature

Temperature of all freshwaters which are free flowing shall not be increased more than 5°F (2.8°C) above natural temperature conditions and shall not exceed a maximum of 90°F (32.2°C) as a result of the discharge of heated liquids unless a different site-specific temperature standard has been established, a mixing zone has been established, or a Section 316(a) determination under the Federal Clean Water Act has been completed.

e. Turbidity (except for lakes)

Not to exceed 50 NTUs provided existing uses are maintained.

In general, water quality of the Enoree River upstream of, and downstream from, the project fully supports aquatic life, but recreational uses are only partially supported because of high fecal coliform levels (South Carolina DHEC, 2007). South Carolina DHEC's 2007 Water Quality Assessment identified 23 locations that are impaired in the Enoree River for fecal coliform bacteria. Sources of these water quality impairments include pastureland, cropland, and active point sources discharging fecal coliform bacteria (2007). South Carolina DHEC (2007, 2012) notes that aquatic life uses in Beaverdam Creek, a tributary immediately upstream of the Riverdale Project, are not supported based on macroinvertebrate community data due to excess copper. However, South Carolina DHEC (2007) documents some stream reaches in the Enoree River watershed with significant decreasing trends in turbidity, total phosphorus, total nitrogen, five-day biological oxygen demand, and fecal coliform, as well as increasing trends in DO concentrations which suggest that the water quality conditions are improving in portions of the Enoree River.

Lockhart Power intended to collect temperature, DO, pH, conductivity, and turbidity data throughout the 2010 and 2011 sampling season. However, limited access to the project area permitted Lockhart Power to collect water quality data in the morning and evening of June 18 and 30, and August 2, 2010 in the following areas: One location upstream of the impoundment, two locations within the impoundment at a depth of 1.5- and 3-feet, one location each in the bypass reach, tailrace, and at the confluence of the Broad and Enoree Rivers. Lockhart Power also used USGS data collected at the Whitmire gage.

Impoundment samples taken during the evening on June 18, 2010, at both depths, fell below the minimum instantaneous standard for DO (4.0 mg/L). All other samples collected by Lockhart Power met South Carolina's state standards for DO, temperature, conductivity, and pH.

The USGS Whitmire gage (USGS 02160700 Enoree River at Whitmire, SC) collects water quality parameters and was sampled as a point of reference.

Fishery Resources

The 6.6-acre impoundment is mostly riverine in nature with substrates of silt, clay, sand, and/or detritus. Upstream of the dam, just below the HWY 221 Bridge, a small shelf composed of boulder and bedrock provides shoal habitat. Littoral habitat in the impoundment includes shallow banks composed of sand, mud and submerged aquatic vegetation. The riparian forest at the edge of the impoundment provides overhanging vegetation with occasional snags and roots.

The tailrace is approximately 5 to 6 feet wide and 8 inches to 1 foot deep. The most prevalent substrate is sand, which covers bedrock, boulders and cobble. Root mats, aquatic vegetation, and a few logs are also present (Carnagey Biological Services, 2010).

The Enoree River bypassed reach extends for approximately 1,400 feet downstream from the toe of the dam to the confluence with the project's powerhouse tailrace. The bypassed reach is largely composed of habitat consistent with shoals in Piedmont streams of the Southeastern U.S. (Mulholland and Lenat, 1992). Shoals only comprise 2 percent of all habitats in the Enoree River (Lockhart Power, 2011b). The project bypassed reach, which contains 10 percent of the available shoals habitat in the Enoree River, includes a natural ledge, a braided portion, and a main channel.

The natural ledge or fall stretches across the entire width of the river, approximately 15 to 20 feet below the dam. Downstream from the natural ledge, the main channel runs on the south side of the river, and flows over small and large boulders with aquatic vegetation dispersed throughout. The main channel provides a series of riffle, run and pool habitat types. The substrate in the main channel consists mostly of bedrock and sand, interspersed with some boulders, cobble and gravel. Logs, root mats, and aquatic vegetation are also present (Carnagey Biological Services, 2010).

The north side of the bypassed reach is more complex and splits into three braided channels. The braided channels are approximately 6.5 to 19.5 feet wide and from 4 inches to greater than 2 feet deep, with a canopy cover of 45 percent. Substrate in this area is composed of boulders, cobble, gravel, sand, and some bedrock. Snags, root mats, leaf packs, and some aquatic vegetation provide other habitat (Carnagey Biological Services, 2010).

To characterize the fish resources within the Riverdale Project area, Lockhart Power conducted a baseline fisheries survey on June 10-11 and July 6-7, 2010 (Lockhart Power, 2010a). Sampling was conducted at six stations: One station was in the impoundment, three stations were in the bypassed reach, and one station each was in the tailrace and the confluence of the tailrace with the Enoree River. During the baseline fisheries survey, 29 freshwater fish species were collected in the vicinity of the Riverdale Project (table 5). The highest number of species (20) occurred in the bypassed reach upstream of the braiding. Fewer species were collected in the main channel along the southern shoreline of the bypassed reach (13), the braided reach along the northern shoreline (11), and the Riverdale impoundment (12). The lowest number of species (6) was collected at the confluence of the Enoree River and the powerhouse tailrace, which is a relatively homogenous habitat composed mostly of woody debris and undercut banks.

EN19DE13.004

EN19DE13.005

Macroinvertebrates

Carnagey Biological Services (2010) conducted benthic macroinvertebrate surveys in the Riverdale Project vicinity on June 30, 2010. Collections of aquatic macroinvertebrates were made at six sampling stations. Stations were located above the Riverdale Project impoundment (i.e. reference location, station 1), in the tailrace (station 2), upstream of the braided area in the bypassed reach (station 3), in the main channel of the bypassed reach (station 4), in the braided flow channel of the bypassed reach (station 5), and at the confluence of the tailrace and the Enoree River (station 6). A total of 1,807 organisms, comprising 81 distinct taxa,

were collected. Station 4 had the most taxa and specimens collected, while station 6 had the fewest taxa and station 3 had the fewest specimens collected. The number of EPT taxa (i.e. insect orders Ephemeroptera, Plecoptera, and Trichoptera) was highest (17 taxa) at the reference station, lowest at stations 3 (11 taxa) and 6 (12 taxa), while stations 2, 4, and 5 had 15 to 16 EPT taxa.

Two indices were used to evaluate the quality of the environment for benthic macroinvertebrates. The North Carolina biotic index (NCBI) utilizes a pollution tolerance value developed over a wide range of conditions and pollution types to assess the amount of impact. The South Carolina DHEC bioclassification is determined by averaging scores for the NCBI and EPT index at each station. Based on NCBI, the environment at station 2 was “excellent” and all other stations were “good.” Based on the South Carolina DHEC bioclassification, the environment at station 2 was “good” and all others stations were “good-fair.”

Freshwater Mussels

Alderman Environmental Services conducted freshwater mussel and snail surveys July 6-8, 2010 (Lockhart Power, 2010a). Visual and tactile sampling occurred in five reaches. Reach 1 was upriver of the dam, reach 2 was in the tailrace, reach 3 was at the confluence of the tailrace and the Enoree River, reach 4 was in the vicinity of SC 49 crossing (~ 4.75 miles downstream from project), and reach 5 was in the bypassed reach. Although there was no evidence of any mussels, six snail species were observed, including the panhandle pebblesnail, which was found in reaches 4 and 5.

Special Status Aquatic Species

Fish

None of the species identified during the survey are state or federally listed as threatened or endangered. However, eight fish species collected in the survey are listed as Conservation Species: redeye bass, Santee chub, thicklip chub, greenfin shiner, flat bullhead, snail bullhead, Piedmont darter, and notchlip redhorse (table 5).

Redeye bass is a Conservation Species of Highest Priority due to its restricted range, as well as competitive displacement and hybridization when found together with the introduced, non-native spotted bass (SCDNR, 2005). The species typically inhabits small to medium sized headwater streams within the Appalachian foothills of Gulf and Atlantic Slope drainages (Boschung and Mayden, 1999). It spawns in the spring (April-June; table 6) in headwater streams in gravel nests built in eddy waters at the heads of pools (Wallus and Simon, 2008). Outside of the spawning season, adult and juvenile redeye bass appear to prefer areas close to shorelines with heavy canopy cover (Knight, 2011). Redeye bass were observed in the impoundment, bypassed reach, and at the confluence of the tailrace and the Enoree River (table 5).

The Santee chub is a Conservation Species of High Priority due to its limited distribution (South Carolina DNR, 2005). Within its distribution, the Santee chub is found in small- to medium-sized streams over gravel, sand, and rubble; however, it is most abundant in sand-bottomed runs of larger streams. The life-history of the Santee chub is not well understood (including spawning season), but is probably similar to the thicklip chub (table 6; Rohde

et al.,

2009). Santee chub were found in the bypassed reach, tailrace, and confluence during 2010 fish surveys (table 5).

The piedmont darter is a Conservation Species of High Priority, largely because one-third of its global distribution is in South Carolina and many of its preferred habitats are at risk (South Carolina DNR, 2005). Piedmont darter occupy cool to warm moderate-sized streams and rivers, but are usually found in riffles with gravel and rock substrate (Rohde

et al.,

2009). Little else is known about the life-history of this species, but it likely spawns in mid- to late-spring (table 6; Jenkins and Burkhead, 1993). Piedmont darter was found in all sections of the bypassed reach during 2010 fish surveys (table 5).

The thicklip chub is a Conservation Species of Moderate Priority because it occurs only in the Carolinas and Georgia and only within a few drainages. About one-half of the global distribution of the species is in South Carolina (South Carolina DNR, 2005). It is primarily found in warmer, clear to turbid streams and rivers of the Piedmont. Adults occupy runs and riffles over sand and gravel, as well as sites characterized by rubble, boulder and bedrock (Jenkins and Burkhead, 1993). Thicklip chub spawning biology is not well understood, but likely occurs from mid-May to late August (table 6; Jenkins and Burkhead, 1993). Thicklip chub was found in the bypassed reach, upstream of channel braiding during 2010 fish surveys (table 5).

Table 6—Spawning Dates and Habitat Requirements for Eight Conservation Species Observed in the Riverdale Bypassed Reach

[South Carolina DNR, 2005]

Species

Common name

Range

Literature source

Spawning dates

Range

Literature source

Habitat Use

Category

Literature source

Micropterus coosae

Redeye Bass

April-June

Mettee

et al.

(1996) Wallus and Simon (2008)

fluvial

specialist

Freeman and Marcinek (2006) Rohde

et al.

(2009)

Cyprinella zanema

Santee Chub

information not available

none

fluvial specialist

Rohde

et al.

(2009)

Cyprinella labrosa

Thicklip Chub

possibly mid-May—late August

Jenkins and Burkhead (1993)

fluvial specialist

Freeman and Marcinek (2006) Rohde

et al.

(2009)

Cyprinella chloristia

Greenfin Shiner

information not available

none

fluvial specialist

Freeman and Marcinek (2006) Rohde

et al.

(2009)

Ameiurus platycephalus

Flat Bullhead

June-July (impoundment population)

Olmsted and Cloutman (1979)

generalist

Rohde

et al.

(2009)

Ameriurus brunneus

Snail Bullhead

May—early June

Jenkins and Burkhead (1993)

fluvial specialist

Freeman and Marcinek (2006) Rohde

et al.

(2009)

Percina crassa

Piedmont Darter

mid- to late-spring

Jenkins and Burkhead (1993)

fluvial specialist

Rohde

et al.

(2009)

Moxostoma collapsum

Notchlip Redhorse

March—early June

Jenkins and Burkhead (1993) Grabowski and Isely (2007) Coughlan

et al.

(2007)

fluvial specialist

Freeman and Marcinek (2006) Rohde

et al.

(2009)

Fluvial specialists are species that require flowing water for most or all of their life cycle (Galat

et al.,

2005).

Habitat generalists are species that are capable of successfully utilizing a variety of habitats to complete their life-cycle.

The greenfin shiner is a Conservation Species of Moderate Priority because they only occur in the Carolinas and Georgia, and only within a few drainages. About two-thirds of the global distribution is in South Carolina (South Carolina DNR, 2005). The species is found over sandy and rocky pools and in the runs of larger creeks and small to medium-sized rivers (Rohde

et al.,

2009). The spawning biology of greenfin shiner is not well understood; however, it likely exhibits behavior similar to other species in its genera, which deposit eggs in crevices of submerged logs and rocks (Rohde

et al.,

2009). The greenfin shiner was found in the impoundment and bypassed reach during 2010 fish surveys (table 5).

The notchlip redhorse is a Conservation Species of Moderate Priority due to habitat degradation such as deforestation and siltation (South Carolina DNR, 2005). The species occurs in large creeks to large rivers on the inner Coastal Plain and Piedmont of South Carolina (Rohde

et al.,

2009). Its temporal spawning range may occur from March to early June (table 6), and it is thought to gather near shoals and flats to spawn over coarse gravel (Jenkins and Burkhead, 1993; Jennings

et al.,

1996). The notchlip redhorse was found in the braided and main channel of the bypassed reach during 2010 fish surveys (table 5).

The flat bullhead is a Conservation Species of Moderate Priority due to sedimentation, hydrologic modification, impoundments, nonpoint source pollution, and development, as well as competition with and predation by non-native catfish species like the flathead and blue catfish (South Carolina DNR, 2005). The species occupies a variety of habitats, including impoundments (Olmstead and Cloutman, 1979). Spawning biology is not well understood in stream or riverine environments, though spawning in Lake Norman, North Carolina occurs during June and July (table 6; Olmstead and Cloutman, 1979). The flat bullhead was found in the impoundment during 2010 fish surveys (table 5).

The snail bullhead is a Conservation Species of Moderate Priority for the same reasons as flat bullhead. The species is frequently found in warm and medium-sized rivers, often in rocky runs and riffles, and appears to prefer shoals compared to pools (Kennon, 2007; Rohde

et al.,

2009). Little is known about snail bullhead biology, but it likely spawns from May to early June (table 6). The snail bullhead was found in the main channel and upstream of braided sections of the bypassed reach during 2010 fish surveys (table 5).

All Conservation Priority Fish Species, with the possible exception of the flat bullhead, are fluvial specialists.

In contrast, habitat generalists,

such as flat bullhead, can be found in both lentic and lotic systems (Galat

et al.,

2005).

Fluvial specialists are species that require flowing water for most or all of their life cycle (Galat

et al.,

2005).

Habitat generalists are species that are capable of successfully utilizing a variety of habitats to complete their life-cycle.

Benthic macroinvertebrates

The panhandle pebblesnail is a Conservation Species of Highest Priority. Siltation of streams and rivers from agricultural runoff and erosion of unstable stream banks are the main factors affecting the distribution of the species (South Carolina DNR, 2005). The species is generally found in rivers and streams throughout the Piedmont—typically in rocky riffles with good flow and often with the hornleaf riverweed. Solid substrate seems to be a key habitat requirement. Its biology is not well understood; however, like all snails in the mud snail family it likely requires solid substrate to attach eggs (Dillon

et al.,

2006). The panhandle pebblesnail was found in the bypassed reach and about 4.75 miles downstream from the project during freshwater mussel and snail surveys (Lockhart Power, 2010a).

3.3.2.2 Environmental Effects

Effects of Project Refurbishment and Operation on Water Quality

As discussed in section 3.3.1,

Geologic and Soil Resources,

if erosion control measures do not adequately mitigate soil erosion and sedimentation, there may be temporary increases in turbidity above the current state standard of 50 NTU in the Enoree River. Similarly, drawing down the impoundment to repair the sand gates and initial operations may result in the discharge of a large amount of sediment from the project impoundment. Peaking operation may also affect DO and temperature within the impoundment, particularly during low flows. Releasing poorly oxygenated, warm water from the impoundment could affect fish, mussels, and other aquatic species in the bypassed reach.

Lockhart Power is willing to monitor water quality in the project vicinity, as required by South Carolina DHEC, but did not specifically propose any water quality monitoring.

Interior recommends that Lockhart Power: (1) Conduct water quality monitoring in the impoundment at all proposed operational drawdowns for a minimum of 1 year; and (2) submit water quality monitoring results to South Carolina DHEC, South Carolina DNR, NMFS, Interior, and the Commission.

Our Analysis

Our understanding of water quality in the project vicinity under existing conditions is limited because it is based on three water quality samples collected by Lockhart Power, as described above. Low DO concentrations for the June 18, 2010 sample may have been due to high levels of decomposed organic matter in the impoundment, water temperature, or water quality of the impoundment's inflows.

Because of the limited storage capacity of the project impoundment, ROR operation would likely predominate. Water quality conditions

within the impoundment are not expected to differ greatly from existing conditions during ROR operation because all inflow would continually pass through the project as it currently does. However, during peaking operation, which would occur during lower flow periods, DO levels could decrease and water temperatures could increase as water retention times increase. The extent to which these water quality parameters would be affected is unknown, and would depend on inflow rates and ambient conditions.

Because all flows currently spill over the dam into the bypassed reach, some degree of aeration occurs. Given the presence of several species of fish and macroinvertebrates, sufficient aeration is likely occurring. Once operation begins, flows in the bypassed reach would be limited to minimum flows provided through the low-level sand gates, except when inflow exceeds the project's hydraulic capacity. Although the flows would be less than that which occurs currently, flows would be constant and aeration over the shoals is likely to be sufficient to protect aquatic biota. Thermal stratification of the impoundment, which could affect DO levels in the bypassed minimum flow to the bypassed reach, is unlikely because of its shallow depth (Dodds

et al.,

2010).

Turbidity monitoring prior to the start of construction as well as during project rehabilitation would ensure that the erosion control and sediment management plan is meeting its objectives and that discharges are consistent with the current state water quality standards (table 4) and other permitting requirements throughout the project rehabilitation phase.

Monitoring water quality in the impoundment and in the bypassed reach prior to construction, during construction, and during the first year of project operation under the various operational levels, as recommended by Interior, would determine if operations are adversely affecting water quality parameters and if potential corrective actions are warranted. Depending on the results, monitoring may need to be extended beyond the first year.

Effects of Project Refurbishment and Operation on Fishery Resources

Instream Flow Releases

The proposed Riverdale Project would divert existing river flows away from the bypassed reach and toward the turbines for hydropower generation. Flow diversions would ultimately reduce the volume of flow in the bypassed reach, resulting in dewatering of habitat and modifying aquatic habitat parameters in the 1,400 feet of complex shoals habitat in the bypassed reach. Peaking operations would result in flow fluctuations within the impoundment, and in the Enoree River below the tailrace confluence. Such fluctuations could strand and isolate fish in back channels and on gravel bars, causing increased risk of predation and natural mortality, or dewater fish nests in the impoundment and downstream from the tailrace, leaving eggs vulnerable to predation and desiccation.

Lockhart Power proposes to provide a continuous minimum flow of 50 cfs through the bypassed reach and a downstream continuous minimum flow of 60 cfs, or inflow, whichever is less. Lockhart Power plans to release at least 10 cfs into the tailrace when the project is not generating via leakage, or through gate operations if necessary. In the event of a plant outage, Lockhart Power would release flows into the bypassed reach via the dam's sand gates or over the spillway.

South Carolina DNR recommends Lockhart Power release flows in the bypassed reach that are consistent with the Water Plan. Based on an estimated MADF of 393 cfs for a period of record from 1994-2009, the minimum flows should meet or exceed the following: July-November, 20 percent of MADF (79 cfs); January-April, 40 percent of MADF (157 cfs); and May, June, and December, 30 percent of MADF (118 cfs). Interior,

NMFS, and American Rivers support the recommendations provided by South Carolina DNR.

See

email correspondence dated May 31, 2013 from Thomas McCoy, Deputy Field Supervisor, FWS, Charleston, South Carolina, to Sarah Salazar, FERC, Washington, DC, filed on June 6, 2013.

Although NMFS supports South Carolina DNR's proposed minimum flows, it also recommends Lockhart Power conduct an instream flow study after a license is issued, and when the project's sand gates are operational. NMFS states that this is because Lockhart Power could not provide an instream flow study to support flows needed to protect aquatic resources in the bypassed reach. NMFS recommends that Lockhart Power develop the study plan within 6 months of license issuance.

Our Analysis

The current licensee has not operated the project since 2001, and no river flow has been diverted for hydropower purposes since that time. Rather, all river flow has and continues to run over the dam/spillway and into the shoals of the 1,400-foot-long bypassed river channel. These conditions represent the no-action alternative.

Piedmont streams like the Enoree River naturally exhibit large seasonal variations in stream flow with varying amounts of habitat. High rates of evapotranspiration during the growing season deplete soil moisture content and reduce groundwater input to streams, resulting in average stream flows that are generally much lower during the summer compared with winter and early spring. During winter and early spring, evapotranspiration is very low and groundwater discharge is usually considerably higher, resulting in higher baseflows (Mulholland and Lenat, 1992).

Many fish species have evolved life history strategies in the context of natural flow regimes. Consequently, fishes are generally adapted to the monthly, seasonal, annual, and interannual variations in flow, and are capable of surviving flows from drought to flood conditions (Bunn and Arthington, 2002; Thompson and Larsen, 2004). Some fishes also benefit from particular magnitudes of flow during specific periods of the year. For example, higher flow during spring can provide access to spawning grounds for migratory species, or access to the floodplain, where nursery value and foraging opportunities are optimal for some fish species (Bunn and Arthington, 2002). Thus, certain seasonal components of an annual flow regime can be important for some fishes.

A diversity of species currently exist in the bypassed reach, which is composed of complex shoals habitat. Shoals represent only 2 percent of all habitat in the Enoree River, and the bypassed reach contains 10 percent of shoals habitat in the Enoree River (Lockhart Power, 2011b). Wharton (1978) describes a Piedmont shoal as “shallow, oxygenated water,” and shoals as “swift, rocky areas” that are abundant with life. Despite their rarity, they are structurally complex habitats that support a higher number of species than more homogenous habitats in Piedmont rivers (Kennon, 2007).

The bypassed reach had the highest number of species collected, compared to all other habitats sampled during the 2010 fish surveys (table 5). A total of 21 species was observed in the bypassed reach, and seven of those species are listed by South Carolina as Conservation Species (table 5). Each of these species is a fluvial specialist, requiring flowing water for most or all of their life cycle (Galat

et al.,

2005).

Redeye bass is one of the more unique species present in the bypassed reach, and is listed as Conservation Species of Highest Priority. This species is restricted to watersheds in northwest

South Carolina, and is currently in decline in the state due to hybridization with the introduced Alabama spotted bass (South Carolina DNR, 2008). Continued hybridization could eventually restrict redeye bass populations to isolated tributaries (Barwick

et al.,

2006).

The panhandle pebblesnail is another unique and rare species present in the bypassed reach, and also is listed as a Conservation Species of Highest Priority. In 1994, this species was under candidate review for listing under the Endangered Species Act; however, it was determined that persuasive data on biological vulnerability and threat were not available to support listing at the time (DOI, 1994). This species is only documented at seven locations in South Carolina (Dillon

et al.,

2006). Siltation of streams and rivers from agricultural runoff and erosion of unstable streambanks are the main factors affecting the distribution of the species (South Carolina DNR, 2005).

Because Lockhart Power could not conduct a controlled-flow study of the instream flows needed to support aquatic resources in the bypassed reach or downstream from the tailrace, it proposed to provide a minimum continuous flow of 60 cfs downstream from the tailrace and 50 cfs through the bypassed reach when operating. Lockhart Power asserts that such flows would meet 7Q10

requirements (56 cfs) in the Enoree River established by South Carolina DHEC.

The 7Q10 is the lowest 7-day average flow that occurs (on average) once every 10 years.

The 50-cfs minimum flow in the bypassed reach represents an increase from the 30-cfs minimum flow requirement of the existing license.

The proposed 50 cfs is 13 percent of the MADF, or 393 cfs. Lockhart Power states that this flow is within the range of minimum bypass flows for five other Commission-licensed projects located within South Carolina's Broad River Basin (table 7), each of which were built at a shoal site, have similar fish species as found at the Riverdale Project, and were based on flow studies. Lockhart Power asserts that if a field study could have been conducted at the Riverdale Project it would have yielded similar results, supporting a similar percent of MADF for minimum flows in the project bypassed reach. Consequently, Lockhart Power states that its proposed flow would adequately protect aquatic habitat in the bypassed reach and the Enoree River. However, for each of the projects cited by Lockhart Power (i.e. table 7), site-specific instream flow studies were conducted to support the minimum flows . No instream flow studies have been conducted in the Riverdale bypassed reach or downstream from the tailrace to support Lockhart Power's proposed minimum flows.

Table 7—Flows Through the Bypassed Reach at FERC Licensed Projects in the Broad River Basin, South Carolina

[Source: Lockhart Power]

Project Name

MADF

(cfs)

Range of flow through bypassed reach

(cfs)

Percent range of MADF

Gaston Shoals

2,170

150-350

7 to 16.

Lockhart

3,600

200-385

5 to 11.

Catawba

4,878

550-950

11 to 19.

Columbia

6,923

500-900

7 to 13.

Pacolet

505

22-49

4 to 9.

Riverdale Proposed

393

13.

Without a site-specific flow study, desktop standard-setting methods, such as 7Q10, the Water Plan, and Tennant (1976) can be used to provide minimum flow recommendations.

The 7Q10 flow is a hydrologically-based design flow that represents the lowest 7-day average flow that occurs, on average, once every 10 years. The 7Q10 flow does not necessarily take into account biological needs of aquatic resources. Nonetheless, Lockhart Power's proposed minimum flow of 50 cfs is not equivalent to the 7Q10 flow (56 cfs) in the bypassed reach; however, it is equivalent to the 7Q10 flow below the tailrace when combined with leakage through the turbine.

Where site-specific flow studies are not available, South Carolina DNR uses the state Water Plan

to recommend flows that will protect fishery resources in all waters of the state when natural streamflow regimes cannot be maintained. The Water Plan minimum flow requirements are based on instream flow studies conducted at six regulated reaches in the South Carolina Piedmont. These minimum flow requirements were designed to provide a useable width for migratory fish

passing through shoals during high flows, provide “generally adequate” flows to protect fisheries during low flows, provide “adequate” flows during periods when flows are increasing or decreasing, and provide flows that conform to seasonal variation in flow. These objectives resulted in three distinct minimum flow periods that capture high (January-April; 40 percent of MADF), low (July-November; 20 percent of MADF), and increasing (December; 30 percent of MADF) or decreasing (May, June; 30 percent of MADF) flow periods (Bulak and Jobsis, 1989).

The Water Plan states that the current policy for determining instream flow requirements for fishery resources can be found in

South Carolina Instream Flow Studies: A Status Report

(Bulak and Jobsis, 1989).

Striped bass were considered a migratory species of prime importance in the instream flow studies, and habitat suitability (i.e. stream width and depth requirements) was based on passage of this species.

Based on the stipulations of the Water Plan and the flow record at the time, which established a MADF of 393 cfs for the bypassed reach, South Carolina DNR, Interior, and NMFS concluded that the minimum flows should meet or exceed the following: 79 cfs from July-November (20 percent of MADF); 157 cfs from January-April (40 percent of MADF); and 118 cfs in May, June, and December (30 percent of MADF). Using the most current flow data available, staff calculated the MADF to be 374 cfs, which results in the following slightly lower flows: July-November, 75 cfs (20 percent of MADF); January-April, 150 cfs (40 percent of MADF); and May, June, and December, 112 cfs (30 percent of MADF). In contrast, Lockhart Power's proposed flows of 60 cfs (16 percent of MADF) downstream from the tailrace

and 50 cfs (13 percent of MADF) in the bypassed reach would fall below all of the Water Plan's minimum flows and would not be adequate to protect the existing fishery in the bypassed reach. In addition, unlike the Water Plan's seasonally variable minimum flows, Lockhart Power's proposed year-round flows would not maintain or mimic the natural flow regime, which according to the Water Plan, can be important because fish have evolved to spawn in synchrony with the seasonal hydrologic cycle.

One of the criteria used to establish minimum flow requirements of the Water Plan is to provide sufficient depth for passage of striped bass. Bulak and Jobsis (1989) concluded that in Piedmont streams, where striped bass are generally of prime importance, a minimum depth of 1.5 feet and passage width of 10 feet is necessary for unimpeded passage for the spawning migration. During high flow periods, study results from the six Piedmont reaches indicated that establishing a 1.5-foot-deep by 10-foot-wide passage route required flows at shoals to range from 39-70 percent of MADF (Bulak and Jobsis, 1989). Therefore, the 40 percent of MADF flow recommended by South Carolina DNR, Interior, and NMFS for the period between January and April represents the lower end of flows deemed necessary for maintaining a zone-of-passage for striped bass.

Striped bass are not present in the bypassed reach and a spawning migration does not occur up to the Riverdale Project due to the lack of passage at Parr dam, located 65 miles downstream from the Riverdale Project. Therefore, the passage requirements outlined in the Water Plan are not relevant for the Riverdale bypassed reach. While a 1.5-foot-deep by 10-foot-wide passage was determined to be suitable for striped bass, which at maturity can range in length from 18 inches to greater than 40 inches, the species with the largest adult size range that presently inhabits the Riverdale bypassed reach is redeye bass, which in South Carolina, can range from 6-17 inches in length (Rohde

et al.,

2009). Based on size, redeye bass do not require the same depths as striped bass for movement within the bypassed reach, nor is there evidence that other species require depths of 1.5 feet. Therefore, flows of 40 percent MADF from January to April are not necessary for maintenance of suitable habitat for the current fish community in the bypassed reach.

Based on the study conducted by Bulak and Jobsis (1989), flows ranging from 15 to 32 percent of MADF are acceptable from January to April if a channel 1.0-foot-deep by 10-feet-wide is adequate for the species present. Given the absence of striped bass and other anadromous species at the Riverdale Project, a minimum flow of 20 percent of MADF (75-cfs) between January and April should provide suitable passage conditions in the bypassed reach for the existing aquatic community. Bulak and Jobsis (1989) also concluded that a minimum flow of 20 percent MADF is generally adequate during the low flow period. Although a year-round minimum flow of 75 cfs would not mimic the seasonal variation in hydrology sought by the Water Plan, there is currently no evidence that the fishes or invertebrates in the bypassed reach, or downstream from the tailrace require such annual variation in flow to complete their life-cycle.

In addition to using the parameters of the Water Plan, we analyzed flows in the bypassed reach using the Tennant method. The Tennant method is based on the assumption that a proportion of MADF would maintain suitable depths and water velocities for fish. Although Tennant's method is derived from rivers in Montana, Wyoming, and Nebraska, analyses in the southeast exhibit general agreement with his recommendations (Wood and Whelan, 1962). Bulak and Jobsis (1989) also used Tennant as one of the factors to establish South Carolina's policy on minimum flows. Tennant concluded that 10 percent of MADF is the minimum instantaneous flow needed to sustain short-term survival and is considered the lower limits for aquatic life. Tennant also concluded that at 20 percent of MADF, the widths, depths, and velocities of most streams would be “good” during the dry season and close to “fair or degrading” during the wet season.

Table 8 shows the percentages of mean annual flows and corresponding narrative descriptions of the habitat created by these flows in the Enoree River using the Tennant method. According to this method, and using the most current flow data available (i.e. 1994-2012; MADF = 374 cfs), a flow of 60 cfs (15 percent of MADF) downstream of the tailrace and 50 cfs (13 percent of MADF) in the bypassed reach would provide fair or degrading conditions, and close to poor or minimum conditions during the dry and wet seasons, respectively. In contrast, the South Carolina DNR's recommended minimum flows of 20 percent of MADF during the dry season and 40 percent of MADF during the wet season, would provide good conditions year round at the project. A year-round minimum flow of 75 cfs (20 percent of MADF), would result in good, and close to fair or degrading conditions during the dry season and wet season, respectively.

Table 8—Minimum Flow Required for Fish in Streams Identified by Tennant

[1976]

Description of flow

% of MADF

Dry season

Wet season

Outstanding

Excellent

Good

Fair or degrading

Poor or minimum

Severe degradation

0-10

NMFS recommended that an instream flow study be conducted after the license is issued, and when the sand gates have been renovated to allow management of flows into the bypassed reach. However, as discussed above, we already have sufficient information to evaluate bypassed reach minimum flow alternatives. For this reason, an instream flow study is not needed for this project.

Fluctuating Water Levels

Lockhart Power's peaking operation would result in periods of daily discharge fluctuations downstream from the tailrace. Lockhart Power's proposed

peaking operations would also involve a 4-foot impoundment drawdown during peaking events.

Beyond the minimum flow alternatives described above, no one recommended changing proposed project operations.

Our Analysis

Lockhart Power states that peaking operation would occur when inflows to the project are greater than 170 cfs (i.e. 50 cfs minimum bypass flow and about 120 cfs minimum hydraulic capacity of the turbine). Lockhart Power also indicates that flow would be spilled over the dam when inflow is greater than 500 cfs (i.e. 50 cfs minimum bypass flow and about 450 cfs maximum hydraulic capacity of the turbine) (Lockhart Power, 2011b). Based on this proposed operation, peaking could occur when inflow to the project is greater than 170 cfs and less than or equal to 500 cfs. Accordingly, peaking could occur as little as 38.6 percent of the time in August, to as much as 75.2 percent of the time in April (figure 2). Peaking would occur greater than 50 percent of the time during January, February, March, April, May, June, and December (figure 2).

Downstream from the tailrace, the highest fluctuations would occur from December through June, when monthly mean flows range from 300-590 cfs (see table 3). During this period, daily flows downstream from the tailrace could range from 60 cfs when the project is not operating and the pond is refilling, to pulses of 500 cfs during operation.

BILLING CODE 6717-01-P

EN19DE13.006

BILLING CODE 6717-01-C

Downstream Effects

Flow fluctuations associated with peaking may have negative consequences for fish occurring downstream from the tailrace. When flows are high, large areas of habitat can be used by fish for foraging, cover, or reproduction. However, when water levels recede, the connection between side channels and the main channel can be lost (Bradford, 1997). As a result, fish stranding can occur on gravel bars, back channels, or pot-holes that become isolated from the main flow (Cushman, 1985). These isolated off-channel habitats often expose fish to greater predation risk, lower DO, and higher water temperature, which can lead to stranding mortality (Nagrodski

et al.,

2012). Early-life stages (i.e. larvae, juveniles), which have a reduced swimming capacity compared to older fish, are particularly vulnerable to stranding and associated mortality, because they are unable to reach the main channel as flows decrease (Dabrowski

et al.,

1986). Furthermore, many riverine fishes, spawn on stony

substrate in off-channel locations that are susceptible to dewatering, which can leave eggs vulnerable to predation and desiccation (Nagrodski

et al.,

2012).

Alterations in discharge during the spawning season can particularly affect reproduction of species with short spawning seasons (Craven

et al.,

2010). Freeman

et al.

(2001) demonstrated that fish assemblages below projects with peaking operations in Piedmont rivers are dominated numerically by species that display prolonged spawning seasons (i.e. extending into July or later; Freeman

et al.,

2001). In contrast, species that spawn exclusively during the spring are less abundant below peaking projects compared to unregulated sites, due to unstable and sometimes unavailable spawning habitat (Freeman

et al.,

2001). Redeye bass, snail bullhead, Piedmont darter and notchlip redhorse are fluvial specialists that spawn exclusively during the spring. These species are currently present in the bypassed reach, but their populations could decline due to flow variability associated with peaking operation.

As discussed above, under Lockhart Power's proposed operation, daily flows downstream from the tailrace could range from 60 cfs when the project is not operating and the impoundment is refilling, to pulses of 500 cfs during operation. The magnitude of this flow fluctuation would be 440 cfs. Higher minimum instream flows recommended by South Carolina DNR would reduce the magnitude of the flow fluctuation proportionally and would result in less exposed shoreline downstream from the tailrace when the project is not generating.

Impoundment Effects

Fluctuating water levels may produce unfavorable spawning conditions and recruitment for resident fish species that occupy the Riverdale impoundment. Effects may be particularly pronounced for centrarchids, which build nests and spawn at shallow depths in the littoral zone during spring and summer. When water levels decrease during drawdowns, nests become exposed and egg desiccation can occur (Maraldo and MacCrimmon, 1981). Lower water levels can also result in reduced shoreline cover and increased predation on juvenile fish (Willis, 1986).

Inflows are greater than 170 cfs and less than 500 cfs, between 50.6 and 75.2 percent of the time during April through June, when most centrarchids build nests and spawn (figure 2). Thus, peaking operation, with up to a 4-foot drawdown, could occur daily about 50 to 75 percent of the time during April through June when centrarchids are building nests and spawning (figure 2).

Proposed peaking operation, with up to a 4-foot drawdown, would change the littoral zone fish habitat in the project impoundment, compared to the natural flow conditions that have been present at the project for the last 12 years. Frequent drawdowns from April through June have the potential to dewater fish nests, disturb spawning, and reduce reproductive success of the four centrarchid species occupying the impoundment (see table 5). Peaking operation at the project could affect each of these species. However, three centrarchids are multiple spawners (e.g., bluegill, red breast sunfish, and redear sunfish) and could spawn again if project operation disrupts initial spawning activities.

With regard to redeye bass, the impoundment likely does not possess significant amounts of spawning or juvenile habitat. The impoundment's littoral zone includes shallow banks composed of sand, mud, and submerged aquatic vegetation (Carnegey Biological Services, 2010). Redeye bass, however, spawn in gravel nests built in eddy waters at the heads of pools (Wallus and Simon, 2008) and juveniles appear to prefer areas close to shorelines with heavy canopy cover (Knight, 2011). These types of habitats are not present in the project impoundment, but are present in the bypassed reach, where Lockhart Power captured the most redeye bass during 2010 baseline fisheries survey (table 5).

Low Inflow/Drought Conditions

The project is located in the Southeast U.S., which is susceptible to severe drought events that can reduce water supplies for several years at a time. Recently, severe droughts occurred from 1998-2002, 2005-2007, and 2012. During these events, incoming flow can fall below minimum continuous flows, stressing aquatic resources and creating conflicts among competing uses, including generation, water supply, and recreation.

To address drought conditions, Lockhart Power developed what it terms a low inflow protocol (LIP), which states that “when average daily project inflow is less than approximately 80 cfs (+/− 10 percent), the following would be in effect: Continuous project outflow shall approximately (+/− 10 percent) equal project inflow.”

South Carolina DNR recommends Lockhart Power develop and implement a LIP for the project, consistent with the Water Plan. They also recommend that Lockhart Power implement the LIP during periods of extended drought and design it to provide instream flows to protect fish and wildlife and other water uses associated with the Enoree River in the Project vicinity.

Interior concurs with South Carolina DNR's recommended LIP.

Based on pro-rated inflow data from the USGS gage near Woodruff, SC (#02160390).

The Water Plan does not prescribe specific flows, recommends that a Water-shortage Contingency Plan (i.e., drought contingency plan) be developed and coordinated with appropriate federal and state agencies, local governments, and other stakeholders. The Water Plan also recommends that the Water-shortage Contingency Plan include water-shortage severity levels and water releases associated with each severity level.

Our Analysis

The overall objective of a LIP is to provide sufficient instream flows to protect fish, wildlife and other water uses in the project vicinity during droughts. Lockhart Power and stakeholders have agreed that the project needs a LIP to adequately protect fishery resources. The recent high frequency of severe drought events in the Southeast U.S. reinforces this need.

Severe drought events can affect fishes in a number of ways. Low streamflows during a drought reduce stream width and depth, limiting habitat availability and the ability of fish to move freely among habitats (Lohr and Fausch, 1997). Droughts also affect water temperature and DO concentrations, which can negatively affect reproduction and juvenile recruitment (Schlosser

et al.,

2001). This can reduce stream fish populations and change fish assemblage structure by favoring hypoxia-tolerant species and reducing intolerant species (Smale and Rabeni, 1995). Moreover, drought can simply kill fish directly (Lohr and Fausch, 1997).

Ideally, a LIP would be designed to provide flexibility to adjust minimum flows during drought periods so that the effects of low flows are balanced among competing uses, while still protecting fish and wildlife. As written, Lockhart Power's proposed LIP does not provide a mechanism to adjust minimum flows during drought periods; rather it proposes to ensure project outflow is equal to inflow when average daily inflow is less than 80 cfs. This would ensure no interruption of flow (i.e. storage of water) through the project to downstream resources when flows are 80 cfs or less. However, Lockhart Power's LIP is not clear as to how that flow would be passed through the project. In other words, would all flow be provided through the sand gates into the bypassed reach, or as a combination

of bypassed reach minimum flows and generation? The project's minimum operating hydraulic capacity of 120 cfs suggests that all inflow would be released into the bypassed reach when average daily inflow to the project is 80 cfs or lower.

Eighty cfs represents 20 to 21 percent of MADF, depending on whether the flow record includes 1994-2009 (MADF = 393 cfs) or the most complete record from 1994-2012 (MADF = 374 cfs), respectively. Bulak and Jobsis (1989) determined that during the low flow period (July-November) in South Carolina Piedmont streams, 20 percent of MADF was “generally adequate” for aquatic resources. If drought conditions were to extend into the high flow period (January-April), 20 percent of MADF was within the range (15-32 percent of MADF) of flow that provides a 1-foot-deep by 10-feet-wide stream of water. Thus, 80 cfs would provide good habitat in the bypassed reach and downstream from the tailrace. Any inflows that are lower would represent natural flow conditions that Lockhart Power could not control, and would result in the best aquatic habitat conditions possible given drought conditions. However it would also limit the project's ability to generate until drought conditions subside.

Lockhart Power also does not explain the basis for selecting an average daily inflow of 80 cfs to represent low flow/drought conditions, only noting that this was being discussed with resource agencies during its application development. Developing and implementing an LIP, as recommended by South Carolina DNR and Interior, would allow Lockhart Power and the resource agencies to cooperatively define water-shortage severity levels (i.e. drought conditions) and potentially adjust minimum flows, depending on the severity of the drought so that the effects of low flows are balanced among competing uses.

The LIPs recommended by South Carolina DNR inherently allow flows to drop below the minimum flow releases determined to be suitable for fish and benthic invertebrates in the bypassed reach. Although further reductions of minimum flow requirements are likely to have additional effects on aquatic habitat and fish populations, fishes have developed physiological and behavioral adaptations for coping with drought conditions. For example, some fishes move to pools that contain water (Gelwick, 1990) or larger downstream reaches (Magoulick and Kobza, 2003), and darters may survive in the hyporheic zone

(Tramer, 1977). Also, fishes tend to move back into an affected area as soon as a drought disturbance has subsided (Larimore

et al.,

1959; Peterson and Bayley, 1993), and fish assemblages can return to pre-disturbance levels within one year (Larimore

et al.,

1959; and Meffe and Sheldon 1990). Thus, a reduction in minimum flow requirements during drought periods may affect fishery resources in the bypassed reach and downstream from the tailrace temporarily; however, stream fish communities are resilient and can recover quickly from these temporary disturbances.

The hyporheic zone is a portion of the groundwater interface in streams where a mixture of surface water and groundwater can be found. Hyporheic zone waters can be found both beneath the active channel and within the riparian zone of most streams and rivers.

Releasing and Distributing Minimum Instream Flows Across the Bypassed Channel

As discussed above, Lockhart Power proposes to use one or more of the existing sand gates in the dam to provide its proposed minimum flows to the bypassed reach. Currently, the sand gates on the middle and right side of the dam are closed and inoperable, while the gate on the left side remains open.

Lockhart Power proposes to repair the sand gates, and work with the resource agencies to determine which gate(s) to use to provide the bypassed reach minimum flow. Lockhart Power also would develop a rating curve following the repairs and verify the rating curve once every 6 years.

The sand gate on the right side does not have any gate mechanism installed, and is permanently sealed. The operating mechanism for the middle sand gate is tilted relative to its foundation and appears to be damaged (FERC, 2013).

South Carolina DNR and Interior recommend Lockhart Power evaluate the feasibility and effectiveness of using the sand gates to provide flows on a permanent, continuous basis to the bypassed reach. South Carolina DNR also recommends that Lockhart Power evaluate flow distribution through the sand gates, and the gates be operated to optimize downstream aquatic habitat in the bypassed reach. In addition, American Rivers recommends the new license require: (1) A study of flow delivery alternatives to determine how to release flows from the dam to fully wet the shoals of the bypassed reach; and (2) the best method for delivering flows to the bypassed reach under all flow conditions. NMFS recommends conducting an instream flow study once the gates are operational.

Our Analysis

Under existing conditions, flows in the Enoree River are capable of covering the entire breadth of bypassed reach, creating complex shoal habitat that supports a diverse assemblage of 21 fish species. There is a natural ledge or fall immediately downstream from the dam that stretches across the entire width of the river for about 15 to 20 feet. Downstream from the natural ledge, the main channel runs on the south side of the river, and flows over small and large boulders with aquatic vegetation dispersed throughout (Carnagey Biological Services, 2010). The north side of bypassed reach is more complex and splits into three braided sections, each approximately 6.5 to 19.5-foot-wide and 4 inches to greater than 2-foot-deep, with 45 percent canopy cover (Carnagey Biological Services, 2010).

The distinct physical features between the north and south side of the bypassed reach enables a unique assemblage of fish to occupy each habitat. Lockhart Power's 2010 fish survey of the bypassed reach, demonstrated that fish species observed on the south side were often absent, or less common on the north side, and vice versa (table 5). For example, redeye bass and Piedmont darter, Highest Priority and High Priority Conservation Species, respectively, were collected most frequently on the north side, and absent on the south side (table 5). Whereas, the snail bullhead, a Moderate Priority Conservation Species, was collected most frequently on the south side, but absent on the north side (table 5).

Because Lockhart Power did not have control of the dam, it was unable to determine if the sand gates could be made operable, or how best to use them to release minimum flows on a continuous and permanent basis. If the gates cannot be made operational, or used in a manner to provide the required flows, alternative mechanisms would need to be identified. These alternatives would need to be functional prior to operating the project to ensure that the aquatic resources in the bypassed reach are protected.

Assuming that the bypassed flows can be provided through the sand gates, distributing the flows across the shoals to optimize benthic invertebrate and fish habitat may require delivering flows from one or more sand gates. While fully wetting the shoals would likely provide benthic invertebrate and fish habitat, it may not provide the best habitat for targeted channels supporting rare species. To determine which combination of gates to use would require a post-licensing flow study as

recommended by NMFS and American Rivers that examines depth, velocity, and wetted width across the shoals using various combinations of the sand gates to deliver the required flows. Targeted species and habitat conditions would need to be selected in consultation with the South Carolina DNR, FWS, NMFS, and American Rivers to define habitat suitability criteria.

Benthic Invertebrate and Fish Surveys

The shoals within the bypassed reach represents a unique habitat that is relatively rare and currently supports seven fish species and a snail (panhandle pebblesnail) recognized in the South Carolina Wildlife Action Plan as in need of conservation because of their restricted ranges and specialized habitat needs (table 5). Sediment discharges and minimum instream flows could lead to physical, chemical, and biological changes in the bypassed reach affecting the distribution and occurrence of these species in the bypassed reach.

Interior recommends that Lockhart Power conduct fish surveys before and after construction at the project, and again 1 year later, to provide information on the presence of the eight Conservation Species. Interior also recommends that Lockhart Power conduct invertebrate surveys before and after construction at the project, and again 1 year later, to provide information on the panhandle pebblesnail within the bypassed reach. Interior requests that Lockhart Power design the surveys in consultation with South Carolina DNR, South Carolina DHEC, NMFS, and FWS, and that sampling efforts be concentrated in the multiple habitat types in the bypassed reach. Interior states that additional surveys may be necessary depending on the results.

Our Analysis

Interior does not explain why surveys for the conservation species are needed before and after construction and again one year later, or the level of effort it anticipates would be required for such surveys.

Pre- and post-construction surveys of fish and benthic invertebrates in the bypassed reach would identify current locations of these species in the bypassed reach and their locations following initial operations. However, sufficient information already exists to document their occurrence in the bypassed reach and to evaluate how best to distribute flows to optimize aquatic habitat. Therefore, there is no need for this information.

Monitoring Compliance With Impoundment Levels and Minimum Flows

Lockhart Power proposes to limit impoundment fluctuations to 4 feet and to establish a rating curve of minimum flow releases through the sand gates and very the rating curves every six years.

No agency recommended measures to monitor compliance with these operations.

Our Analysis

Developing and implementing an operation compliance monitoring plan would provide additional detail about project operations. Such a plan would provide the Commission a means to monitor compliance with the minimum flow releases and the limits on impoundment fluctuations. To be effective, the plan would need to: (1) Define the criteria by which compliance with impoundment fluctuations and minimum flows would be measured; (2) specify the type and location of all equipment used to monitor impoundment levels and minimum flows; and (3) identify the data collection intervals and reporting procedures.

Fish Impingement and Entrainment

Water intake structures at hydropower projects can injure or kill fish that are either impinged on intake screens/trash racks, or entrained through turbines. Larger aquatic organisms (typically fish and larger invertebrates) can be trapped against the intake screens or trash racks by the water flowing into a penstock. This process is known as impingement, and can cause physical stresses and/or suffocation that lead to death of some organisms (EPRI, 2003).

If fish are able to pass through screens or trash racks (i.e. entrained), fish injury or mortality can result from collisions with turbine blades, or exposure to pressure changes, sheer forces in turbulent flows, and water velocity accelerations created by turbines (Knapp

et al.,

1982). The number of fish entrained and at risk of turbine mortality at a hydroelectric project is dependent upon site-specific factors, including physical characteristics of the project, as well as the size, age, and seasonal movement patterns of fish present within the impoundment (EPRI, 1992). Fish that are entrained and killed are removed from the river population and no longer available for recruitment to the fishery.

The project includes two sets of trash racks: One with 2.25-inch bar rack spacing that is located at the intake to the project headrace and a second located at the downstream end o

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