The URL can be used to link to this page

Home My WebLink About004_KT_FLA_Exhibit_ADuke Energy Carolinas, LLC License Application Keowee - Toxaway Project (FERC No. 2503) Exhibit A: Project Description Table of Contents Al. Project Overview ........................................................................... ............................... AM A2. Project Facilities ............................................................................. ............................... A2 -1 A2.1 Dams and Spillways ........................................................... ............................... A2 -4 A2.2 Reservoirs .......................................................................... ............................... A2 -6 A2.3 Powerhouse, Generator, and Turbine Data ........................ ............................... A2 -7 A2.4 Transformers and Switchyard ............................................ ............................... A2 -9 A2.5 Transmission Lines and Additional Equipment ................. ............................... A2 -9 A3. Federal Lands ................................................................................. ............................... A3 -1 A4. Literature Cited .............................................................................. ............................... A4 -1 Duke Energy Carolinas, LLC A -i License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) List of Tables Table Al -1 Physical Features of the Jocassee Development ................ ............................... Al -3 Table Al -2 Physical Features of the Keowee Development ................. ............................... Al -4 List of Figures Figure A 1 -1 Project Location Map ......................................................... ............................... AI-2 Figure A2 -1 Jocassee Development Location Map ................................ ............................... A2 -2 Figure A2 -2 Keowee Development Location Map ................................ ............................... A2 -3 Duke Energy Carolinas, LLC A -ii License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Al. Project Overview The Keowee - Toxaway Project (Project) (FERC No. 2503) is located in the upper Savannah River Basin and consists of two developments: Jocassee and Keowee (Figure Al -1). Project lands occupy portions of Pickens and Oconee Counties, South Carolina with the northernmost portions of Lake Jocassee being located in Transylvania County, North Carolina. The Jocassee Development (Table Al -1) is the upstream development. Most of Lake Jocassee lies within Pickens and Oconee Counties, South Carolina with the uppermost part of the reservoir in Transylvania County, North Carolina. Jocassee Pumped Storage Station is located on the Keowee River approximately 20 miles north of Seneca, and 5.5 miles northeast of Salem, South Carolina. Water released from Jocassee Pumped Storage Station flows directly into Lake Keowee, and conversely, during pumping operations, Lake Keowee water is pumped directly into the Lake Jocassee forebay. The Keowee Development (Table Al -2) is located on the Keowee River and Little River. The Keowee Development lies within Pickens and Oconee Counties, South Carolina. Keowee Hydro Station is located approximately eight miles north of Seneca, South Carolina, and approximately 12 miles downstream of Jocassee Pumped Storage Station. Water released from Keowee Hydro Station flows directly into Hartwell Lake, a United States Army Corps of Engineers (USACE) reservoir on the Savannah River. Duke Energy Carolinas, LLC AM License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Figure Al -1 Project Location Map TraASYy 64 64 (/ s i rs1 Ilorsepashu a Rimer 7'axaway it Gorges aJ G on Nan III al�.. sere Rark " " "ppp a tional Forest Highland �`' rl✓ iN�p P�` rz s�uTT Thompson Rimer � f -�'�-L r� f �.. G- M con WhiletvaterRiver- 7 a a Timmera.n x Res u�ces AY. NO ) BrdCreck YP y }1.� � en'.'4 .... ,� C l n t �_ —_ �_ CAR L M A }`1J �v ```�•�. u S u m t e r' - \/ �bVliS FOB'+ National Forest r: - � �J-cassee >7am,' Trifrace and Spfflway.9rea a e LakE Qc ee Little River W a h a I I a :I 11 Pieklns +s A tZ 1 76 / e s m i n I$0 2 Kentucky Virginia Legend Keowee - Toxaway Relicensing - -- Project Boundary Lake FERC Project No. 2503 Tennessee — County Boundary National Forest 1 Natural Area North Carolina — Stream State Park! Natural Area US Highway Urban Area Project Location Map I South Carolina 1 abarna Georgia ! 0 2 4 6 B Data Source. Base data derived torn ESRI 9.3 Base Data Layers, 2908. Project Location Miles Projection: MAD 1983 StatePlane South Carolina International Feet Duke Energy Carolinas, LLC Al -2 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Table Al -1 Physical Features of the Jocassee Development Notes: AMSL — above mean sea level; cfs — cubic feet per second; MW - megawatt Duke Energy Carolinas, LLC Al -3 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Location River Keowee County /State Oconee and Pickens, South Carolina Transylvania, North Carolina Date of Commercial O eration Units 1&2 1973 Units 3 &4 1975 1 Reservoir Drainage Area 145 square miles Full Pond Elevation 1,110.0 feet AMSL Gross Storage Volume at Full Pond 1,206,798 acre -feet Usable Storage Volume 225,387 acre -feet (between 1110 feet AMSL and 1080 feet AMSL) Surface Area at Full Pond 7,980 acres Shoreline including Islands at Full Pond 92.4 miles Jocassee Dam Type Rock fill with earthen core Total Length 1,800 feet Height 385 feet Saddle Dike 1 Type Rolled Earthfill Total Length 825 feet Height 35 feet Saddle Dike 2 T ype Rolled Earthfill Total Length 500 feet Height 25 feet Powerhouse Structure Semi - outdoor Turbine Type Reversible pump Number of Units 4 Authorized Installed Capacity er Unit 177.525 MW Total Authorized Installed Capacity 710.10 MW Maximum Hydraulic Capacity 36,200 cfs Maximum Pumping Rate 31,720 cfs Notes: AMSL — above mean sea level; cfs — cubic feet per second; MW - megawatt Duke Energy Carolinas, LLC Al -3 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Table Al -2 Physical Features of the Keowee Development Location River Keowee and Little County/state Oconee and Pickens, South Carolina Date of Commercial Operation: 1971 Reservoir Drainage Area 435 square miles Full Pond Elevation 800.0 feet AMSL Gross Storage Volume at Full Pond 869,338 acre -feet Usable Storage Volume 364,884 acre -feet (per Existing License, between 800 feet AMSL and 775 feet AMSL) 90,319 acre -feet (current operation, between 800 feet AMSL and 794.6 feet AMSL) 161,727 acre -feet (proposed, between 800 feet AMSL and 790 feet AMSL Surface Area at Full Pond 17,660 acres Shoreline including Islands at Full Pond 387.9 miles Little River Dam Type Compact Earthfill Total Length 1,800 feet Height 165 feet Keowee Dam Type Compact Earthfill Total Length 3,500 feet Height 165 feet Saddle Dike A Type Compact Earthfill Total Length 1,900 feet Height 50 feet Saddle Dike B Type Compact Earthfill Total Length 225 feet Height 15 feet Saddle Dike C Type Compact Earthfill Total Length 350 feet Height 15 feet Saddle Dike D Type Compact Earth Fill Total Length 650 feet Height 40 feet ONS Intake Dike Type Compact Earthfill Total Length 1,200 feet Height 110 feet Duke Energy Carolinas, LLC Al -4 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Powerhouse Structure Concrete Turbine Type Diagonal Flow Number of Units 2 Authorized Installed Capacity er Unit 78.75 MW Total Authorized Installed Capacity 157.5 MW Maximum Hydraulic Capacity 24,920 cfs Notes: AMSL — above mean sea level; cfs — cubic feet per second; MW - megawatt Duke Energy Carolinas, LLC Al -5 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) A2. Project Facilities Jocassee Development The 710.1- megawatt (MW) Jocassee Development includes Lake Jocassee, the Jocassee Dam, two saddle dikes (designated as 1 and 2), two intake structures, water conveyance tunnels, the powerhouse, and the gated spillway (Figure A2 -1). Jocassee Pumped Storage Station generates electricity through operation of four turbines that supply water through the two intake structures and tunnels during peak demands, typically during the day. The station pumps water from Lake Keowee back to Lake Jocassee during low demand periods, typically at night. The Normal Full Pond Elevation for Lake Jocassee is 1,110 ft Above Mean Sea Level (AMSL) with a minimum elevation for hydropower operations per the existing FERC license of 1,080 ft AMSL. Lake Jocassee also serves as the lower reservoir for the Bad Creek Hydroelectric Project (Bad Creek Project) (FERC Project No. 2740). When electricity is generated at the Bad Creek Project, water stored in the upper Bad Creek Reservoir is conveyed through the powerhouse and released into Lake Jocassee through an underwater opening or discharge portal located on the Whitewater River arm of Lake Jocassee. During pump -back operations, station turbines are reversed to pump water back from Lake Jocassee into the upper Bad Creek Reservoir. The Bad Creek Project began operating in 1991 and its separate FERC license expires in 2027. Keowee Development The 157.5 -MW Keowee Development consists of the Keowee Dam; the Little River Dam; four saddle dikes designated as A, B, C, and D; the Oconee Nuclear Station (ONS) intake dike; gated concrete ogee spillway; the powerhouse; an excavated tailrace; and an intake structure (Figure A2 -2). The powerhouse, left abutment of Keowee Dam, and the gated spillway lie in Pickens County on the east side of the old Keowee River channel. The right abutment of Keowee Dam, the four saddle dikes, Little River Dam, and the ONS intake dike lie in Oconee County. ONS lies just beyond the right abutment of the Keowee Dam. Duke Energy Carolinas, LLC A2 -1 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Figure A2 -1 Jocassee Development Location Map Tennessee 4, Georgia Alatrarna r Map Location /* /* r * North Carolina South Carolina Legend —•— Project Boundary Access Roads -- River Mile I I I'II ;l � � L CN IV Keowee- Toxaway Relicensing FERC Project No. 2503 Lake Jocassee Darn, Tailrace and Spillway Area Facilities Map D 0.25 0.5 0.75 ❑ata Seurce, ESRI 2009, (help:!rgolo.aregisonline.con+ psAftrld_Imagery) Miles Prof® N— MAI) 1963 StatsPlana 8ou6i Carolina Inters L—I Feet Duke Energy Carolinas, LLC A2 -2 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Figure A2 -2 Keowee Development Location Map IN TO r J —1 vd J ..$. 4 1 3 Tennessee_,,v - "' North Carolina 3SO.1h ina Georgia Map Locati �a7 T X324 Jjj o L �„:-E Legend Keowee - Toxaway Relicensing —•— Project Boundary IFERC Project No. 2503 Access Roads Lake Keowee Dam and Tailrace Area Facilities & Little River Dam Area _L_ Rver Mite Facilities Site Map 0 o.s t t.s Oa4: Saurae'FSRI 70%N},(http' "gWa arorJiegnlrnn— W—pOAtrld..I m.NPry) Mons PF*cbGn MAP esa, sratePtane sawn Carob- Imemah—I Fee, Duke Energy Carolinas, LLC A2 -3 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) A2.1 Dams and Spillways Jocassee Development Jocassee Dam The Jocassee Development main dam (Figure A2.1 -1) is 385 ft high, 1,800 ft long, and was constructed as a zoned embankment dam with an earthen core, transitional filter, and rock -filled shells. The dam includes two cylindrical intake structures, each made out of structural steel and reinforced concrete and having eight screened waterways approximately 24 ft high by 15 ft wide at the bottom of the structure. The intake waterways are positioned between elevation 1,043 and 1,067 ft AMSL. The waterways can be closed by means of a cylindrical steel gate that fits like a sleeve inside the intake structure. A power tunnel extends from the intake structures to two penstocks that bifurcate to each unit in the powerhouse. The crest of Jocassee Dam has a gravel roadway used for Project-related dam maintenance and monitoring. There are two benches on the downstream slope of Jocassee Dam, a 20 -ft -wide bench at elevation 925 ft AMSL and a 40- ft -wide bench at elevation 810 ft AMSL. The lower bench serves as an access road to the powerhouse. The crest of the dam is approximately 30 ft wide at elevation 1,125 ft AMSL. The dam axis is slightly curved into the reservoir with a general axis azimuth trending northeast - southwest. Saddle Dikes There are two homogeneous rolled earthfill saddle dikes west of Jocassee Dam to contain the reservoir pool. Saddle Dike 1 is located approximately 3,000 ft southwest of Jocassee Dam and is approximately 35 ft high and 825 ft long. Saddle Dike 1 has an axis azimuth trending northwest- southeast. Saddle Dike 2 is located approximately 8,000 ft west of Jocassee Dam with an axis azimuth trending east -west and is approximately 25 ft high and 500 ft long. The dikes are grass- covered with the exception of a riprap -lined zone for wave protection on their lower upstream slopes at and below Normal Full Pond Elevation and a riprap- covered toe drain on the lower one third of the downstream face of each dike. Spillway The service spillway is a double radial - gated, ogee -type structure constructed of mass concrete located approximately 1,800 ft southwest of Jocassee Dam. The spillway channel is approximately 50 ft wide and 800 ft long from the Tainter gates to Lake Keowee. There are two Duke Energy Carolinas, LLC A2 -4 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Tainter gates, 38 ft wide and 33 ft high, that rotate upward off concrete ogees with trunnions anchored in massive concrete blocks on each spillway wingwall and on a center separation wall. The hoists use an electric -motor drive with air compressor backup power. Additionally, hand cranks are available for manual operation of the hoists, if required. The spillway has a sill elevation of 1,077 ft AMSL. Spillway aprons and walls are concrete -lined leading to a concrete flip bucket located downstream of the spillway. The outlet channel downstream of the flip bucket is a concrete -lined trapezoidal channel leading to a set of four culverts that pass under the powerhouse access road. The remaining channel extending below the culvert is a natural ravine leading into Lake Keowee. The maximum capacity of the fully opened spillway at Normal Full Pond Elevation is estimated at 53,000 cubic feet per second (cfs). Keowee Development Keowee Dam The Keowee Dam is 3,500 ft long and has a crest elevation of 815 ft AMSL. The maximum height of the dam above the downstream toe is approximately 165 ft. The dam is a homogeneous embankment constructed out of compacted earthfill with a zoned internal drainage blanket beneath the downstream slope. The crest of Keowee Dam has a gravel roadway used for Project - related dam maintenance and monitoring. The Keowee Dam includes a single intake structure of similar design to the dual structures described previously for the Jocassee Dam. The eight intake waterways on the intake structure are each approximately 24 ft high by 15 ft wide and are positioned between 735 and 759 ft AMSL. The waterways can be closed by means of a cylindrical steel gate that fits like a sleeve inside the intake structure. A power tunnel extends from the intake structure to penstocks to each unit in the powerhouse. Little River Dam The Little River Dam is located approximately 3 miles north- northeast of Seneca, South Carolina and immediately upstream from Newry, South Carolina. The dam is a homogeneous embankment constructed out of compacted earthfill with a zoned internal drainage blanket beneath the downstream slope. The Little River Dam is approximately 1,800 ft long and has a crest elevation of 815 ft AMSL. The maximum height of the dam above the downstream toe is approximately 165 ft. Duke Energy Carolinas, LLC A2 -5 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Carlrlla T)ikPc Four saddle dikes (designated as A, B, C, and D), located within approximately 1.5 miles north of Little River Dam, lie on the eastern rim of the Little River portion of the reservoir. The saddle dikes are homogeneous embankments constructed out of compacted earthfill. Saddle Dikes A and D were constructed with zoned internal drainage blankets beneath their downstream slopes. Saddle Dikes B and C, which lie above the Normal Full Pond Elevation, were not constructed with internal drainage blankets. The design top elevation of the saddle dikes is 815 ft AMSL. Saddle Dike A has a maximum height of approximately 50 ft and a crest length of approximately 1,900 ft. Saddle Dikes B and C are approximately 15 ft high with 225 -ft and 350 -ft crest lengths, respectively. Saddle Dike D is approximately 650 ft long and 40 ft high. SC Hwy 130 is located on the crest of Saddle Dike A, while Saddle Dikes B, C, and D have grassed crests. ONS Intake Dike The ONS Intake Dike is located on the south side of ONS, at the end of an excavated canal that leads east from Keowee Reservoir, approximately 3/4 mile southwest of the Keowee powerhouse. The dike is approximately 1,200 ft long and has a maximum height of approximately 110 ft above the downstream toe. Spillway The spillway consists of an entrance channel with mass concrete wingwalls, a mass concrete gravity ogee structure fitted with four 38 -ft -wide by 35 -ft -high Tainter gates, a 311 -ft -long tapered chute section with reinforced concrete floor on 10 percent grade, mass concrete side walls, and a mass concrete flip bucket at the 100 -ft -wide base of the chute. The spillway has a sill elevation of 765 ft AMSL. The overall width of the spillway is 176 ft. With spill gates fully open, the spillage flow capacity is estimated to be 106,000 cfs at Normal Full Pond Elevation. A2.2 Reservoirs Jocassee Development Paired with Lake Keowee, Lake Jocassee serves as the upper reservoir for the Jocassee Pumped Storage Station. At Normal Full Pond Elevation of 1,110 ft AMSL, Lake Jocassee has a gross storage capacity of approximately 1,206,798 acre -feet (ac -ft), an approximate surface area of 7,980 acres, and 92.4 shoreline miles including island shoreline (HDR Engineering, Inc. 2010a). Duke Energy Carolinas, LLC A2 -6 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) The usable storage capacity based on the water storage volume between the Normal Full Pond Elevation and 1,080 ft AMSL is 225,387 ac -ft. The drainage basin upstream of the dam is approximately 145 square miles. There are no bypassed reaches at the Jocassee Development. Keowee Development Lake Keowee is formed by two parallel watersheds connected by a 2,000 -ft -long excavated canal approximately 100 ft deep. The canal is located approximately 0.5 miles north of ONS. Keowee Dam impounds the portion of the reservoir that lies in the Keowee River watershed. The Little River Dam, located approximately 5 miles south - southwest from Keowee Dam, impounds the portion of the reservoir in the Little River watershed. Lake Keowee forms the lower reservoir for the Jocassee Pumped Storage Station. The watershed draining into Lake Keowee is approximately 435 square miles. The reservoir has a surface area of approximately 17,660 acres and 388 shoreline miles at a Normal Full Pond Elevation of 800 ft AMSL. The gross storage capacity of the reservoir at full pond is approximately 869,338 ac -ft (HDR Engineering, Inc. 2010b). As shown in Table Al -2, the licensed usable storage capacity of the Keowee Development is 364,884 ac -ft (storage capacity between 800 ft AMSL and 775 ft AMSL). However, Duke Energy currently generally limits drawdowns of Lake Keowee to 794.6 ft AMSL, resulting in a current operating storage capacity of 90,319 ac -ft. In conjunction with Project relicensing, Duke Energy is proposing to modify current Keowee Development operations such that the proposed usable storage capacity will be 161,727 ac -ft, the storage volume between 800 ft AMSL and 790 ft AMSL. The Little River Bypassed Reach extends from the toe of the Little River Dam 0.3 miles to the Courtenay Mill Dam at Newry, South Carolina. Hartwell Lake backs up to the Courtenay Mill Dam. A2.3 Powerhouse, Generator, and Turbine Data Jocassee Development Jocassee Pumped Storage Station is located at the left abutment toe just downstream of a rock - cut slope. It is of the semi - outdoor type and contains four reversible pump - turbine units. Water flow is controlled by the wicket gates around the turbines for generating power or for pumping water back through the tunnels to Lake Jocassee. There is no excavated tailrace below the Duke Energy Carolinas, LLC A2 -7 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) Jocassee Pumped Storage Station; water released during power generation and intake water during pumping flows directly into or from Lake Keowee. The original authorized installed capacity of each unit was 153 MW for a total of 612 MW. Duke Energy replaced the runners for Units 3 and 4 in 2006 - 2007 and amended the authorized installed capacity to 661.05 MW. The maximum hydraulic capacity for the development increased from 31,300 cfs to 33,900 cfs because of this runner replacement. The FERC approved the amended capacity in a FERC order dated August 24, 2006, which was subsequently amended in an order dated February 13, 2008. Duke Energy also replaced the runners for Units 1 and 2 with new runners similar to those installed for Units 3 and 4. The Unit 1 and 2 upgrades increased the installed capacity to 7 10. 10 MW and increased the maximum hydraulic capacity to 36,200 cfs. The FERC approved the amended capacity in a FERC order dated December 1, 2010. Using the current definition of authorized installed capacity in FERC regulations at 18 C.F.R. § 11.1(i), the authorized installed capacity of each unit is 177.525 MW. An approximately 420 - ton - capacity electrically operated, gantry -type crane is installed at the Jocassee Pumped Storage Station. Electrically operated gantry cranes are used at Jocassee to handle stop logs and draft tube gates. Keowee Development The Keowee Hydro Station consists of a monolithic, mass concrete substructure and steel -frame superstructure and contains two turbine- generator units. An electrically operated bridge -type crane of approximately 270 -ton capacity is installed in the powerhouse. The generators, turbines, scroll casing, draft tubes, access galleries, and mechanical equipment gallery are all contained within the powerhouse. Keowee is a conventional hydro station with two Francis diagonal -flow, fixed -blade type turbines. Each unit has an authorized installed capacity of 78.750 MW for a total authorized installed capacity of 157.50 MW. Water flow through the units is controlled by the wicket gates around the turbines, providing control for generation output. Duke Energy Carolinas, LLC A2 -8 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) An approximately 270 - ton - capacity electrically operated, bridge -type crane is installed at the Keowee Hydro Station. Electrically operated gantry cranes are used at Keowee to handle stop logs and draft tube gates. A2.4 Transformers and Switchyard Jocassee Development The connections between the generator /motors and the generator step -up (GSU) transformers are made using an isolated phase bus. For Units 1, 3, and 4, switching is accomplished on the 230 kilovolt (kV) side of the GSU transformers. For Unit 2, switching is accomplished on the 14.4 kV side of its GSU transformer. Normal auxiliary power is supplied from the 100 -kV transmission system. Backup auxiliary power is supplied from Unit 2. Keowee Development Switching is accomplished at the 13.8 -kV level using generator circuit breakers. An isolated phase bus is used for connections between the generators, the generator circuit breakers, and the GSU transformers. Normal auxiliary power is supplied from the 13.8 -kV busses and backup power is supplied from a source within the ONS auxiliaries. A2.5 Transmission Lines and Additional Equipment Jocassee Development There are no primary transmission lines. Power from each Jocassee hydro unit is fed into the 230 -kV transmission system at a dedicated GSU transformer located at the powerhouse. Units 1, 3, and 4 GSU transformers are two - winding transformers rated at 230/14.4 W. The Unit 2 GSU transformer is a three- winding transformer rated at 230/14.4 kV. The circuit breaker and switch arrangement for the interconnection is depicted in Exhibit H, Figure H1.6 -2 Jocassee Development Single -Line Diagram. Keowee Development There are no primary transmission lines. Power from the Keowee hydro units is fed into the 230 - kV transmission system at a three- winding GSU transformer located at the powerhouse and rated at 230/13.2 kV. The circuit breaker and switch arrangement for the interconnection is depicted in Exhibit H, Figure H1.6 -1 Keowee Development Single -Line Diagram. Duke Energy Carolinas, LLC A2 -9 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) A3. Federal Lands There are no federal lands enclosed within the Project Boundary. Duke Energy Carolinas, LLC A3 -1 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503) A4. Literature Cited HDR Engineering, Inc. of the Carolinas. 2010a. Lake Jocassee Bathymetry Study Report. October 2010. 201 Ob. Lake Keowee Bathymetry Study Report. October 2010. Duke Energy Carolinas, LLC A4 -1 License Application — Exhibit A Keowee - Toxaway Project (FERC No. 2503)