Middle Fork Project Project Description

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Middle Fork Project Middle Fork Project

Project Description Project Description

April 25, 2006April 25, 2006

April 2006April 2006 2

Middle Fork American River Middle Fork American River Hydroelectric ProjectHydroelectric Project

Provide a Project OverviewProvide a Project Overview Describe Major Project FeaturesDescribe Major Project Features Describe Supporting InfrastructureDescribe Supporting Infrastructure Discuss Operating ConstraintsDiscuss Operating Constraints Describe General Operations and Describe General Operations and

MaintenanceMaintenance Summary of Recreation FacilitiesSummary of Recreation Facilities Questions Questions


MFP - OverviewMFP - Overview Developed as a Water Supply and Developed as a Water Supply and

Generation ProjectGeneration Project

Initial Operation 1967Initial Operation 1967

224 MW Nameplate Generating Capacity224 MW Nameplate Generating Capacity

120,000 Acre-Feet Water Supply120,000 Acre-Feet Water Supply

Operated by Placer County Water AgencyOperated by Placer County Water Agency

PG & E Acquires Power OutputPG & E Acquires Power Output


Major Project FeaturesMajor Project Features

Two Large Dams and Storage Two Large Dams and Storage ReservoirsReservoirs

Two Medium Dams and ReservoirsTwo Medium Dams and Reservoirs

Three Small Dams and Diversion PoolsThree Small Dams and Diversion Pools

Five PowerhousesFive Powerhouses

Five TunnelsFive Tunnels


Supporting InfrastructureSupporting Infrastructure

Electrical Switchyards and SubstationElectrical Switchyards and Substation

Access Roads and TrailsAccess Roads and Trails

Communication and Power LinesCommunication and Power Lines

Stream GagesStream Gages

Maintenance and Dormitory FacilitiesMaintenance and Dormitory Facilities


Duncan Creek DiversionDuncan Creek Diversion

Spillway Crest - 5,265 ft Elevation Spillway Crest - 5,265 ft Elevation

Diversion - Concrete Gravity - 165 ft LongDiversion - Concrete Gravity - 165 ft Long

Diversion Capacity - 400 cfsDiversion Capacity - 400 cfs

Surface Area - Approximately 1 AcreSurface Area - Approximately 1 Acre

Gross Storage - 20 Acre-Feet Gross Storage - 20 Acre-Feet


Duncan Creek - Middle Fork Duncan Creek - Middle Fork TunnelTunnel

1.5 Miles Long1.5 Miles Long

10 ft Horseshoe Cross-Section10 ft Horseshoe Cross-Section

Capacity 400 cfs*Capacity 400 cfs*

Intake With Trash RackIntake With Trash Rack


French Meadows DamFrench Meadows Damand Reservoirand Reservoir


French Meadows DamFrench Meadows Damand Reservoirand Reservoir

Spillway Crest at 5,273 ft ElevationSpillway Crest at 5,273 ft Elevation

French Meadows Dam - Gravel and French Meadows Dam - Gravel and Earthfill - 2,700 ft LongEarthfill - 2,700 ft Long

Surface Area - 1,404 Acres Maximum,Surface Area - 1,404 Acres Maximum,434 Minimum434 Minimum

Gross Storage - 134, 993 Acre-Feet Gross Storage - 134, 993 Acre-Feet

Shoreline - 9 MilesShoreline - 9 Miles


French Meadows - Hell Hole French Meadows - Hell Hole TunnelTunnel

2.6 miles long2.6 miles long

12.3 ft Horseshoe Cross-Section12.3 ft Horseshoe Cross-Section


Intake in French Meadows Reservoir and Intake in French Meadows Reservoir and Trash RackTrash Rack

Terminates in a 6.25 ft Diameter - 691 ft Terminates in a 6.25 ft Diameter - 691 ft Long Penstock to the French Meadows Long Penstock to the French Meadows PowerhousePowerhouse


French Meadows PowerhouseFrench Meadows Powerhouse


French Meadows PowerhouseFrench Meadows Powerhouse

Located on Hell Hole ReservoirLocated on Hell Hole Reservoir

Water Supply - Discharge from French Water Supply - Discharge from French Meadows - Hell Hole TunnelMeadows - Hell Hole Tunnel

Single Francis TurbineSingle Francis Turbine

15.3 MW / 60,000 Volts15.3 MW / 60,000 Volts

Discharges to Hell Hole Reservoir Discharges to Hell Hole Reservoir


Hell Hole Dam and ReservoirHell Hole Dam and Reservoir


Hell Hole Dam and ReservoirHell Hole Dam and Reservoir

Spillway Crest at 4,650 ft ElevationSpillway Crest at 4,650 ft Elevation

Hell Hole Dam - Rockfill - 1,570 ft LongHell Hole Dam - Rockfill - 1,570 ft Long

Surface Area - 1,253 Acres Maximum, 185 Surface Area - 1,253 Acres Maximum, 185 Acres MinimumAcres Minimum

Gross Storage - 207,500 Acre-Feet Gross Storage - 207,500 Acre-Feet

Shoreline - 11 MilesShoreline - 11 Miles


Hell Hole PowerhouseHell Hole Powerhouse


Hell Hole PowerhouseHell Hole Powerhouse

Located at Outlet from Hell Hole DamLocated at Outlet from Hell Hole Dam

Water Supply - Hell Hole Dam Discharge Water Supply - Hell Hole Dam Discharge ConduitConduit


0.725 MW / 12,000 Volts0.725 MW / 12,000 Volts

Discharges to Rubicon River Discharges to Rubicon River


Hell Hole - Middle Fork TunnelHell Hole - Middle Fork Tunnel




Intake in Hell Hole ReservoirIntake in Hell Hole Reservoir

Terminates in a 9 - 7.5 ft dia. - 3,653 ft Terminates in a 9 - 7.5 ft dia. - 3,653 ft Long Penstock to the Middle Fork Long Penstock to the Middle Fork PowerhousePowerhouse


North Fork Long Canyon Creek North Fork Long Canyon Creek DiversionDiversion


North Fork Long Canyon Creek North Fork Long Canyon Creek DiversionDiversion

Dam Crest at 4,720 ft Elevation Dam Crest at 4,720 ft Elevation


Diversion Capacity 100 cfsDiversion Capacity 100 cfs

Surface Area - Less than 1 AcreSurface Area - Less than 1 Acre

Pipe and Shaft to the Hell Hole - Middle Pipe and Shaft to the Hell Hole - Middle Fork TunnelFork Tunnel


South Fork Long Canyon Creek South Fork Long Canyon Creek DiversionDiversion


South Fork Long Canyon Creek South Fork Long Canyon Creek DiversionDiversion



Diversion Capacity 200 cfsDiversion Capacity 200 cfs

Surface Area - Less than 1 AcreSurface Area - Less than 1 Acre

Pipe and Shaft to the Hell Hole - Middle Pipe and Shaft to the Hell Hole - Middle Fork TunnelFork Tunnel


Middle Fork PowerhouseMiddle Fork Powerhouse


Middle Fork PowerhouseMiddle Fork Powerhouse

Located on Middle Fork Interbay ReservoirLocated on Middle Fork Interbay Reservoir

Water Supply- Hell Hole - Middle Fork Water Supply- Hell Hole - Middle Fork TunnelTunnel

Two Pelton WaterwheelsTwo Pelton Waterwheels

122.4 MW / 60,000 Volts122.4 MW / 60,000 Volts

Discharges to Middle Fork Interbay Discharges to Middle Fork Interbay Reservoir Reservoir


Middle Fork Interbay DamMiddle Fork Interbay Damand Reservoirand Reservoir


Middle Fork Interbay DamMiddle Fork Interbay Damand Reservoirand Reservoir


Interbay Dam - Concrete Gravity - 233 ft Interbay Dam - Concrete Gravity - 233 ft LongLong

Surface Area - 7 AcresSurface Area - 7 Acres

Gross Storage - 175 Acre-FeetGross Storage - 175 Acre-Feet


Middle Fork TunnelMiddle Fork TunnelRalston TunnelRalston Tunnel


13.5’ Horseshoe Cross-Section13.5’ Horseshoe Cross-Section


Intake in Middle Fork Interbay Reservoir / Intake in Middle Fork Interbay Reservoir / Trash RackTrash Rack

Terminates in a 9.5 - 8 ft dia. - 1,670 ft Terminates in a 9.5 - 8 ft dia. - 1,670 ft Long Penstock to the Ralston PowerhouseLong Penstock to the Ralston Powerhouse


Ralston PowerhouseRalston Powerhouse


Ralston PowerhouseRalston Powerhouse

Located on Ralston Afterbay ReservoirLocated on Ralston Afterbay Reservoir

Water Supply - Middle Fork Tunnel - Water Supply - Middle Fork Tunnel - Ralston TunnelRalston Tunnel


79.2 MW / 60,000 Volts79.2 MW / 60,000 Volts

Discharges to Ralston AfterbayDischarges to Ralston Afterbay


Ralston Afterbay and Afterbay Ralston Afterbay and Afterbay DamDam


Ralston Afterbay and Afterbay Ralston Afterbay and Afterbay DamDam


Ralston Afterbay Dam - Concrete Ralston Afterbay Dam - Concrete Gravity - 560 ft LongGravity - 560 ft Long

Gross Storage - 2,782 Acre-FeetGross Storage - 2,782 Acre-Feet


Ralston - Oxbow TunnelRalston - Oxbow Tunnel



Capacity 1,075 cfs*Capacity 1,075 cfs*

Intake in Ralston Afterbay Reservoir / Intake in Ralston Afterbay Reservoir / Trash RackTrash Rack

Supplies Oxbow PowerhouseSupplies Oxbow Powerhouse


Oxbow PowerhouseOxbow Powerhouse


Oxbow PowerhouseOxbow Powerhouse

Located on Middle Fork American RiverLocated on Middle Fork American River


Generator - 6.1 MW / 60,000 VoltsGenerator - 6.1 MW / 60,000 Volts

Discharges to Middle Fork American River Discharges to Middle Fork American River below Ralston Afterbay Dambelow Ralston Afterbay Dam


Other Project ComponentsOther Project Components

Project Power and Communication LinesProject Power and Communication Lines

Stream Gaging StationsStream Gaging Stations

Project Roads and TrailsProject Roads and Trails

Microwave Reflector Stations and Radio Microwave Reflector Stations and Radio TowersTowers

Support FacilitiesSupport Facilities


Project Operations Project Operations

Operating ConstraintsOperating Constraints

Water Rights (Storage and Diversion Water Rights (Storage and Diversion Allowances)Allowances)

Minimum Pool RequirementsMinimum Pool Requirements

Stream Maintenance Flows (i.e. Stream Maintenance Flows (i.e. Minimum Instream Flows)Minimum Instream Flows)

Dam / Diversion Discharge CapacitiesDam / Diversion Discharge Capacities


Minimum Pool RequirementsMinimum Pool RequirementsMINIMUM POOL

French MeadowsReservoir

Forecast / FolsomReservoir (a/f)

> 2,000,0001,200,000 – 2,000,000

< 1,200,000

Minimum Pool (a/f)June-Sept Oct-May

60,000 50,00060,000 25,00028,000 8,700

Hell HoleReservoir

Forecast / FolsomReservoir (a/f)

> 2,000,0001,200,000 – 2,000,000

< 1,200,000

Minimum Pool (a/f)June-Sept Oct-May

70,000 50,00070,000 25,00026,000 5,500

Duncan CreekDiversion Maintain water surface elevation at 5,259 feet elev.


MINIMUM INSTREAM FLOW

Duncan Creek

Forecast / Folsom ReservoForecast / FolsomReservoir (a/f)> 1,000,000< 1,000,000

Release (cfs)Lessor of 8 or natural flowLessor of 4 or natural flow

French MeadowsReservoir

Forecast / Folsom ReservoForecast / FolsomReservoir (a/f)> 1,000,000< 1,000,000

Release (cfs)8 at all times4 at all times

Hell HoleReservoir

Forcast / FolsomReservoir (a/f)> 1,000,000 a/f

< 1,000,000 a/f

Release (cfs)20 May 15 – Dec 1410 Dec 15 – May 14

10 June 1 – Oct 14 6 Oct 15 – May 31

Minimum Instream Flow Minimum Instream Flow RequirementsRequirements



South Fork LongCanyonDiversion Dam

Forecast / FolsomForecast / FolsomReservoir (a/f)

> 1,000,000< 1,000,000

Release (cfs)

lesser of 5 or natural flowlesser of 2.5 or natural flow

North Fork LongCanyonDiversion Dam

Releases to maintain streamflow of 2 cfs or the naturalflow, whichever is less, shallbe made at all times.





Middle ForkInterbay

Forecast / FolsomReservoir (a/f)> 1,000,000< 1,000,000

Release (cfs)lesser of 23 or natural flowlesser of 12 or natural flow

Oxbow

Releases shall be 75 cfs at all times as measureddownstream of the confluence with the North Forkof the Middle Fork.

Such releases shall not cause vertical fluctuations(measured in representative section) greater than 3feet per hour.


Dam and Diversion DischargesDam and Diversion Discharges

Duncan Creek Diversion

Stream Maintenance Pipe10 inch diameter8 cfs*

Sluice Pipe60 inch diameter

French Meadows Dam

Stream Maintenance Pipe8 inch diameter8 cfs*

Low Level Outlet6 feet diameter1,430 cfs60 inch diameter ring jet valve


Dam and Diversion Dam and Diversion DischargesDischarges

Hell Hole Dam

Stream Maintenance Pipe16 Inch diameter20 cfs*Howell-Bunger Valve

Discharge Conduit48 inch Diameter852 cfs*Howell-Bunger Valve

Powerhouse Water Supply20 inch diameter30 cfs*


Dam and Diversion DischargesDam and Diversion Discharges

North Fork Long Canyon Creek Diversion Stream Maintenance Pipe

12 Inch diameter2 cfs*

South Fork Long Canyon Diversion

Stream Maintenance Pipe12 Inch diameter5 cfs*

Middle Fork Interbay

Stream Maintenance Pipe20 inch diameter23 cfs*Howell-Bunger Valve

Sluice Pipe60 inch diameter890 cfs


MFP OperationsMFP Operations

Operated to Meet Water Supply Operated to Meet Water Supply RequirementsRequirements

Operated to Meet Minimum Operated to Meet Minimum Instream Flow RequirementsInstream Flow Requirements

Operated to Optimize Value of Operated to Optimize Value of GenerationGeneration


Operations OverviewOperations Overview

Operations Governed By:Operations Governed By:

MF Project FERC License Conditions MF Project FERC License Conditions

Water Rights PermitsWater Rights Permits

Contractual Obligations (Delivery of Contractual Obligations (Delivery of Water and Power)Water and Power)

Physical Constraints (Size of Tunnels, Physical Constraints (Size of Tunnels, Capacity of Powerhouses)Capacity of Powerhouses)

Power Market – High Value Periods of Power Market – High Value Periods of OperationOperation


Seasonal Pattern of OperationsSeasonal Pattern of Operations Reservoir Storage: Reservoir Storage:

French Meadows and Hell Hole Reservoirs, French Meadows and Hell Hole Reservoirs, 343,000 Acre-Feet Total Storage343,000 Acre-Feet Total Storage

Seasonal Pattern of Operations:Seasonal Pattern of Operations: Store Water During Winter and Spring Store Water During Winter and Spring

Precipitation and Runoff Periods (Refill Period)Precipitation and Runoff Periods (Refill Period) Releases During the Dry Summer and Fall Releases During the Dry Summer and Fall

Months (Drawdown Period)Months (Drawdown Period) Reservoirs are Operated to Maintain Relative Reservoirs are Operated to Maintain Relative

Balance between ReservoirsBalance between Reservoirs Dec. 31 Carry-Over Target for Dec. 31 of Dec. 31 Carry-Over Target for Dec. 31 of

150,000 Acre-Feet (Two Reservoirs)150,000 Acre-Feet (Two Reservoirs)


Reservoir OperationsReservoir Operations Operations during refill period to meet Operations during refill period to meet

demands, fill reservoirs, avoid spilldemands, fill reservoirs, avoid spill Operations during drawdown to meet demands, Operations during drawdown to meet demands,

hit end-of-year storage targethit end-of-year storage target Reservoir storage targets through the year:Reservoir storage targets through the year:

Generally based on historic practice Generally based on historic practice Refined during refill period based primarily Refined during refill period based primarily

on hydrologic conditions, with some on hydrologic conditions, with some consideration of power market conditionsconsideration of power market conditions

Storage managed during drawdown period Storage managed during drawdown period based on consumptive obligations and based on consumptive obligations and power market trends power market trends

At all times meet minimum release obligations At all times meet minimum release obligations


Generation SchedulingGeneration Scheduling

Watershed provides sufficient water to Watershed provides sufficient water to operate about half of the time at full load operate about half of the time at full load (50% capacity factor)(50% capacity factor)

Full-load operations are most efficient for Full-load operations are most efficient for generationgeneration

Project typically operates in “peaking” Project typically operates in “peaking” mode: 8-16 hours per day, during the mode: 8-16 hours per day, during the most valuable time periodsmost valuable time periods

Annual generation approximately 1 Annual generation approximately 1 million MW hours.million MW hours.


Scheduling and OperationsScheduling and Operations Project operations have been much the Project operations have been much the

same since the construction of the Projectsame since the construction of the Project

Variation in specific operations practices Variation in specific operations practices through time in response to:through time in response to:

Project maintenance requirementsProject maintenance requirements

Changes in California power marketsChanges in California power markets

Recreation demands downstream of the Recreation demands downstream of the ProjectProject


MaintenanceMaintenance Facility Testing (powerhouse equipment Facility Testing (powerhouse equipment

testing and maintenance, gate and valve testing and maintenance, gate and valve testing)testing)

Debris Removal ManagementDebris Removal Management

Sediment ManagementSediment Management

Vegetation and Pest ManagementVegetation and Pest Management

Facility PaintingFacility Painting

Road MaintenanceRoad Maintenance


Recreation FacilitiesRecreation Facilities

Recreation Plan developed as required by Recreation Plan developed as required by the licensethe license

Recreation Facilities include campgrounds, Recreation Facilities include campgrounds, picnic areas, boat launch areas, and one picnic areas, boat launch areas, and one scenic vistascenic vista

Operated by the Tahoe and Eldorado Operated by the Tahoe and Eldorado National ForestsNational Forests


Recreation SitesRecreation Sites

French Meadows ReservoirFrench Meadows Reservoir

Reservoir North Shore - picnicking, Reservoir North Shore - picnicking, camping, boat ramp and parking camping, boat ramp and parking (McGuire, Poppy)(McGuire, Poppy)

Reservoir East end - single-unit and Reservoir East end - single-unit and group campgrounds (Lewis, Coyote group campgrounds (Lewis, Coyote Group, gates Group and Ahart)Group, gates Group and Ahart)

Reservoir South Shore - picnicking, Reservoir South Shore - picnicking, camping, boat ramp and parking (French camping, boat ramp and parking (French Meadows Complex)Meadows Complex)


Recreation SitesRecreation Sites Hell Hole ReservoirHell Hole Reservoir

Hell Hole Reservoir - scenic vista, picnicking, Hell Hole Reservoir - scenic vista, picnicking, camping, boat ramp and parkingcamping, boat ramp and parking

Big Meadows CampgroundBig Meadows Campground Upper Hell Hole (boat-in/hike-in campground)Upper Hell Hole (boat-in/hike-in campground)

Ralston / OxbowRalston / Oxbow Ralston Picnic AreaRalston Picnic Area

South Fork Long CanyonSouth Fork Long Canyon One single-unit and one group campground (Big One single-unit and one group campground (Big

Meadows and Middle Meadows Group)Meadows and Middle Meadows Group)

Documents

Middle Fork Project Project Description