Yadkin-Pee Dee River Hydroelectric Project FERC No Progress Energy APPLICATION FOR LICENSE. Executive Summary

Transcription

1 FERC No Progress Energy APPLICATION FOR LICENSE Executive Summary 2006 Progress Energy

2 TABLE OF CONTENTS Section Title Page No. EXECUTIVE SUMMARY...1 ES-i

3 Executive Summary A Question of Balance on the Pee Dee River Progress Energy owns and operates two hydroelectric developments on the Pee Dee River in North Carolina - the upstream 84 megawatt (MW) Tillery Development and the downstream 24.8 MW Blewett Falls Development. The two facilities are separated by a 22-mile unobstructed reach of the Pee Dee River. Downstream of the Blewett Falls Development, the Pee Dee River flows unobstructed for another188 miles eventually entering the Atlantic Ocean at Winyah Bay in South Carolina. The Pee Dee River flows from North Carolina into South Carolina about 15 miles below Blewett Falls Dam. Hence, the river is an important multi-purpose resource for both states. Understanding the physical setting of the Project is important to understanding the resource values associated with the Project area. From the upper reaches of Lake Tillery to the Blewett Falls Dam and its affected downstream reach, the Project covers an area extending from the North Carolina Piedmont to the upper South Carolina Coastal Plain. In the Project vicinity, the Pee Dee River transitions from a moderate gradient, low sinuosity Piedmont Fall Line river to a low gradient, high sinuosity Coastal Plain river. The rich diversity of aquatic and terrestrial resources associated with this region reflects the dynamic river environment. The North Carolina portion of the Yadkin-Pee Dee River Basin is punctuated by the presence of six manmade impoundments; the two lower ones owned by Progress Energy and the four upper ones owned by Alcoa Power Generating, Inc. (APGI). Active storage for all six impoundments is primarily located in High Rock Lake, the uppermost impoundment in the Yadkin-Pee Dee chain of lakes. The six lakes stretch for approximately 84 miles from river mile (RM) 272 to RM 188. Inflows to Progress Energy s Tillery Development are almost totally dependent upon releases from APGI s upstream reservoir system, especially during the frequent periods of low flow in the river basin. Lake Tillery is a 15 mile long, 5,697 acre mesotrophic reservoir supporting a healthy and diverse aquatic community including over 40 species of native and non-native fishes. Under Progress Energy s current operation, the lake is well known as having an excellent fishery for largemouth bass and crappie, as well as other game fish. Lake Tillery also provides a significant amount of water-based recreational activity, ranging from boat and bank fishing, motor boating and waterskiing, jet-skiing, and wildlife viewing. Approximately 56 percent of the shoreline is developed for residential and commercial use; and therefore, the lake is also important economically to the surrounding area. Below Lake Tillery, the Pee Dee River flows unobstructed through a rural area of the Piedmont to the headwaters of Blewett Falls Lake. The immediate tailwater area below Lake Tillery currently supports a substantial aquatic resource even though flow and water quality in this area is significantly affected by the operations of the Tillery plant. Of particular interest, a large nesting colony of Great Blue Heron resides along the west bank of the Pee Dee immediately below Tillery Dam, with numerous birds (most notably great egrets and great blue herons with other wading and non-wading species) are frequently seen foraging in the waters just below the plant during low flow periods. The existing flow regime of the hydroelectric plant has likely contributed to the effective foraging environment for these wading birds. A bald eagle nest is also located in the tailwater area, and bald eagles are known to frequent the area for foraging and roosting. ES-1

4 The Rocky River, a major tributary of the Pee Dee River, enters the Pee Dee five miles below the Tillery Development. The water quality of the Rocky River is degraded by heavy sediment and nutrient loading from upstream urban areas in the watershed, especially during high precipitation and subsequent runoff events. The Rocky River s degraded water quality negatively affects the aquatic resources of the Pee Dee River in this reach; water quality effects extend into Blewett Falls Lake. The number of fish and macroinvertebrate species declines significantly in the Pee Dee River reach immediately below the Rocky River; however, there is a recovery in the communities with increasing flow and dilution of the Rocky River inflow downstream to Blewett Falls Lake. Blewett Falls Lake is a 12 mile, 2,866 acre eutrophic reservoir which receives inflow from releases from Lake Tillery and flows from the Rocky River, the Little River, and other smaller tributaries to the Pee Dee River. Blewett Falls Lake s eutrophic status is undoubtedly affected by the nutrient loading it receives from the Rocky River. However, Blewett Falls Lake supports a rich and diverse aquatic life with at least 48 fish species present in the Lake. The Lake supports a good largemouth bass fishery, an excellent crappie fishery, as well as good populations of such gamefish as white bass, striped bass, several non-native catfish species, and forage populations of shad. Blewett Falls Lake also appears to play an important role in the life history of the rare Carolina redhorse by providing habitat for juveniles and non-spawning adults. Most notable about Blewett Falls Lake may be the richness of its associated bottomland, wetland, and terrestrial resources. These include several areas unique to this region of North Carolina. The Grassy Islands and Tupelo Swamp/Smith Lake Oxbow natural areas are considered to be of statewide ecological significance. The Tupelo Swamp supports a mature, but actively growing stand of water tupelo; some of these trees are at least 250 years old. This natural area is very unique to the Project area and is the only such tupelo stand that is found in the Piedmont of North Carolina. Further, the lakeshore of Blewett Falls Lake is virtually undisturbed, with only a few cabins/residences located near the shore. The undisturbed nature of the lake has likely contributed to the preservation of these unique natural areas and provides a different recreational experience to users than at other Yadkin-Pee Dee lakes. Under Progress Energy s current operations, the lake supports both a very good fishery, and a rich waterfowl and avian community. Recreation tends to be more of those types considered low-impact due to the undeveloped nature of the lake, providing a balanced contrast to the recreation resource available at Lake Tillery. Blewett Falls Lake, under current operations, shows no evidence of having significant effects on aquatic or terrestrial species. Quite to the contrary, the lake and its tailwaters appear to benefit many species of fish, mussel, waterfowl, and birds due to its ability to act as a filter of the waters of the Rocky River and the rich and undisturbed nature of the intact surrounding riparian shoreline. Below the Blewett Falls Development, the Pee Dee River flows unobstructed for over 190 RMs to Winyah Bay. The effect of the current peaking operations at Blewett Falls extends a considerable distance downstream of the plant well into South Carolina, especially during low-flow conditions. However, the relicensing studies conducted by Progress Energy in accordance with study plans developed in collaboration with the many parties with an interest in the Project, have shown, contrary to what might have been expected that the tailwaters of Blewett Falls support great abundance and diversity of fish and other aquatic species. These diverse aquatic communities extend downstream into South Carolina as well. These aquatic resources include robust populations of the anadromous American shad and the catadromous American eel. Healthy populations of rare, threatened, and endangered mussel species are also inhabiting this river reach. Macroinvertebrate ES-2

5 species richness was usually good to excellent with high numbers of Empheroptera, Plecoptera, and Trichoperta species, which are sensitive indicators of water quality conditions. Although the Tillery and Blewett Falls developments might be considered small- to moderate-sized hydropower facilities, they are important to the generation resource mix of Progress Energy as explained below. The Tillery and Blewett Falls plants, just as they effectively serve different environmental roles, serve very different roles in Progress Energy s management of its electrical service control area. The Tillery Plant is Progress Energy s only hydroelectric source of loadfollowing in its entire system, and therefore is a unique and valuable component of Progress Energy s generation and transmission systems. When not operating in a load-following mode, it operates as a peaking facility. The plant has a hydraulic capacity of 18,000 cfs, a flow that is exceeded only four percent of the time at the station. This oversizing of the plant is a signature aspect of its design, given its role in peaking and load-following. In turn, each of the four units at Tillery are relatively large for the Pee Dee River, again in line with the unique purpose of the plant in Progress Energy s system. Hydroelectric units are uniquely capable of moving rapidly from one output to another within the units operating band while still maintaining relatively high efficiency. Some of the important tasks that the Tillery Plant is called upon to fulfill are: (1) automatic generation control, operating at the very upper end of the load curve; (2) power transfers across control areas; (3) grid stabilization (frequency and voltage control) in its area; (4) synchronous condensing; and (5) on-peak power generation. Progress Energy has no pumped storage or other large hydro units to depend upon if it were to lose the current load-following generation capabilities of the Tillery Plant. The Blewett Falls Plant currently operates about 50 percent of the time as a strict run-of-river hydroelectric station. This occurs anytime river flows exceed about 7,200 cfs. During the wetter months of January through April, Blewett Falls operates in a run-of-river mode over 80 percent of the time. During the remaining time, the Blewett Plant operates in block-loaded fashion. This block-loading output and timing is closely coordinated with the operation of the Tillery Plant, using the available (but limited) active storage in the Blewett Falls reservoir to reduce or eliminate inadvertent spill. Spills that would otherwise occur due to the difference in hydraulic capacities between the two power plants. The block-loading normally occurs during on-peak hours in Progress Energy s system. Therefore, one of Blewett s roles is to provide daily re-regulation of flows coming from the Tillery Plant. The task of re-regulating these flows requires that the Blewett Falls reservoir operate in a daily cycling mode, and it is customary that the Blewett Falls reservoir will fluctuate anywhere from 2 to 4 ft daily. Lake Tillery and Blewett Falls Lake each have sufficient active storage to provide daily to multi-day flow shaping, but not enough to provide weekly, monthly, or seasonal storage. Three primary environmental issues have been identified by participating stakeholders through the relicensing process. Each is of these issues is discussed below. Extensive fieldwork conducted by Progress Energy in accordance with agreed-upon study plans developed collaboratively with stakeholder groups have confirmed that at certain times of the year (mainly in the summertime months) the flows from both the Tillery and Blewett Falls plants do not meet the current state water quality standards for dissolved oxygen (DO). The Project s role in causing this variation from state standards is the formation of thermal stratification and subsequent ES-3

6 DO depletion within the reservoirs. This occurs fairly regularly in the deeper, larger Tillery reservoir than in the shallower Blewett Falls reservoir. Thermal stratification can result in the development of zones of low DO in the deeper areas of the lake, especially in front of the powerhouse intake. Due to the shallow nature and smaller volume of Blewett Falls Lake, the reduction in DO occurs with less frequency and to a lesser degree at Blewett Falls Lake than at Lake Tillery. Progress Energy has performed initial testing of draft tube venting at both plants. These initial tests have been promising and showed that the Blewett Falls Plant responds very positively to this simple method of DO enhancement; Tillery less so. Progress Energy, in consultation with the North Carolina Division of Water Quality (NCDWQ), has developed a comprehensive program of technology testing and implementation. The DO enhancement plan commits to full compliance with state DO water quality standards by December Progress Energy has committed to being in compliance by no later, and possibly sooner, than that date. The second substantive environmental issue is Progress Energy s role in helping resource agencies meet their goals as enumerated in the agencies Restoration Plan for the Diadromous Fishes of the Yadkin-Pee Dee River Basin dated March Progress Energy has worked closely with representatives of the U.S. Fish and Wildlife Service (USFWS), National Marine Fisheries Service (NMFS), North Carolina Wildlife Resources Commission (NCWRC), and South Carolina Department of Natural Resources (SCDNR) in developing a diadromous fish restoration plan that would meet the goals of the agencies Restoration Plan in a safe, timely, and effective manner. The species of focus for the resource agencies plan are American shad and American eel, both of which currently have robust populations on the Pee Dee River. Progress Energy is prepared to move forward in a joint and cooperative effort to enhance the populations of these species in the Pee Dee River, and the detailed implementation plan for doing so is contained in this License Application. Progress Energy believes the implementation plan should take a structured, stepwise approach in diadromous fish restoration in the river basin, along with objective measurements of the effectiveness of restoration measures. The third, and most challenging, environmental issue is the matter of continuous releases at both the Tillery and Blewett plants. All stakeholders have worked, and continue to work, cooperatively within the relicensing process to try to address this issue to mutual satisfaction. An IFIM model of both the river reach from Tillery Dam to the headwaters of Blewett Falls Lake and the river reach from Blewett Falls Dam to Interstate 95, approximately 90 miles from the Project near Florence, South Carolina was cooperatively and successfully developed with the IFIM Subgroup. Numerous alternative minimum flow scenarios were also modeled and discussed within the IFIM Subgroup. No agreement on minimum instream flows has been forthcoming as of this License Application. There are two factors preventing agreement at this time. The first factor is one of what constitutes baseline conditions. Progress Energy is examining the effects of alternative minimum flows on the current operations of the Project and the existing environment. The resource agencies are evaluating alternative future minimum flow scenarios from a theoretical baseline of no-dam in place or unimpaired hydrology baseline. The second factor is that Progress Energy is focused on preserving as much as possible the unique role the Tillery Plant plays in meeting its responsibilities as an electrical control area manager. As mentioned above, the Tillery Plant is Progress Energy s only hydropower-based load-following resource, and as such, plays a very important role in its electrical system management. Resource agencies are not concerned about the power side of the balancing equation when making flow recommendations for the Project and in particular, the role of Tillery in providing reliable generation in Progress Energy s service area. ES-4

7 Progress Energy believes the relicensing record demonstrates, on the whole, that an excellent opportunity exists at the Yadkin-Pee Dee River Project to arrive at a plan to balance non-power and power resources. The Tillery Plant is a very significant power resource, much more so than Blewett Falls; the river reach below Tillery has much less inherent potential for resource enhancement by increasing minimum flows than the river reach below Blewett Falls. From that basic consideration, a balance can be reached between flows and preserving the power resource. The Pee Dee River below the Tillery Plant travels 22 miles until it enters Blewett Falls Lake. The Pee Dee River below Blewett Falls travels 188 miles until it reaches Winyah Bay. The reach of river below Tillery has no other water users economically dependent upon the water flows in this reach; the reach below Blewett has a large number of users that rely on the flows to meet industrial, commercial, and municipal needs. The reach below Tillery has less resource potential due to the lack of highly complex shoal-island habitats; the reach below Blewett Falls has numerous high-value and complex shoal-island habitats systems that are more likely to benefit significantly from higher minimum flows. The reach below Tillery is dominated by non-native species of fish (e.g., smallmouth buffalo) and contains lower numbers of rare, threatened, and endangered mussel species; the reach below Blewett Falls has a species richness co-dominated by native species. The reach below Tillery contains no anadromous fish and much less inherent potential for anadromous fish population enhancement than the reach below Blewett which supports numerous anadromous species, many of which are not well-suited to the limited habitat below Tillery. And finally, most of the reach below Tillery (14 of 22 miles) has degraded water quality due to the poor water quality coming from the Rocky River (the Project does not affect the Rocky River in any way); the water quality in the river reach below Blewett is not affected to this degree from poor water quality. Progress Energy believes these important considerations lead, in this case, to an excellent opportunity to balance power and non-power resources. Progress Energy has developed a Preferred Plan of Future Operations (Preferred Plan) that increases the current minimum flows at each development, but in a manner and to a degree that recognizes the relative ecological importance of each river reach. At Tillery, Progress Energy proposes to increase the current flows five fold from the current 40 cfs (required by the current FERC license) to 200 cfs year round, except from April 1 to May 15 when the minimum flows will be 750 cfs (once American shad are passed at Blewett Falls). Because of the size and type of turbines at the Tillery Plant, and the role it plays, all feasible levels of new minimum flows would have to be bypassed at the hydroelectric plant without producing energy or being able to be used for load-following. At the minimum flows proposed by Progress Energy, the resulting reduction in on-peak energy production will be about 5.5 to 6 percent at the Tillery Plant. At Blewett Falls, Progress Energy proposes to increase the current minimum flows from 150 cfs (required by the current FERC license) to 1,200 cfs on an average daily basis (950 cfs instantaneous minimum over a six-fold increase) from May 16 to January 31, and to 2,400 cfs on an average daily basis (2,050 cfs instantaneous minimum over a 13-fold increase) from February 1 to May 15. These very significant increases in minimum flows at Blewett Falls reflect both the greater benefit of resource enhancements that can occur below Blewett Falls, the greater generation and reregulation flexibility at Blewett Falls, and the lesser importance of Blewett Falls to Progress Energy as a power resource. The specific levels of resource enhancements provided to individual species by these enhancements in each reach are provided in this License Application. Overall, on-peak power at Blewett Falls would be reduced about 5.8 percent, with most of this power being shifted to off- ES-5

8 peak hours. Blewett Falls does not provide as much on-peak power as Tillery, but more importantly, it does not provide any of the critical control area services that Tillery does. This License Application provides a compilation of all the data and information gathered through this relicensing process. It also contains the detailed justification for Progress Energy s Preferred Plan for Future Operations, a plan that promotes high-value resource enhancement and preserves high value, renewable power resources. ES-6