Middle Fork Project Potential Project Betterments October 1, 2007

1 Potential Project Betterments PCWA’s evaluation of potential betterments has continued over last year PCWA’s evaluation of potential betterments has continued over last year Three betterments will be included in the PAD Three betterments will be included in the PAD  Hell Hole Reservoir Seasonal Storage Increase  French Meadows Powerhouse Capacity Upgrade  Ralston Powerhouse Capacity Upgrade

2 October 1, 2007 Betterments Analysis for Relicensing Flow Chart Betterments to carry forward in relicensing Project Description, June 2006 Engineering/environmental studies and agency/public consultation Include viable projects in License Application Initial data collection & screening - Conceptual design work PCWA inventory of potential betterments We are Here

3 October 1, 2007 Hell Hole Reservoir Seasonal Storage Increase Purpose Purpose  Increase seasonal storage in Hell Hole Reservoir by 9, ,000 acre-feet.

4 October 1, 2007 Hell Hole Reservoir Seasonal Storage Increase  Hell Hole Dam Spillway Crest Gates  Hell Hole Dam Spillway Crest Gate Control Building and Powerline near Hell Hole Dam  Parapet walls at Hell Hole Dam, Hell Hole- Middle Fork Tunnel Gatehouse, and French Meadows Powerhouse  South Fork Long Canyon Diversion crest gates or check valve  Generator Building at South Fork Long Canyon Diversion Dam Changes to Project Facilities

5 October 1, 2007 Hell Hole Dam Spillway

6 October 1, 2007 Hell Hole Reservoir Seasonal Storage Increase Operations Wet Years with Spills Wet Years with Spills  9, ,000 acre feet of additional water would be stored  Net generation increased  Inundation within the existing reservoir flood inundation zone – increase by approximately 37 acres

7 October 1, 2007 Hell Hole Reservoir Seasonal Storage Increase Operations Non-spill years Non-spill years  9,750 – 12,000 acre feet of additional storage could be used to defer early generation releases  Peaking generation increased  Reservoir inundation area temporarily increased by approximately 37 acres

8 October 1, 2007 Hell Hole Reservoir Seasonal Storage Increase Operations Dry Years Dry Years  Water not available for seasonal storage

9 October 1, 2007 French Meadows Powerhouse Capacity Upgrade Purpose Purpose  Increase MFP peaking generation capability  Provide Ancillary Services to the energy market

10 October 1, 2007 French Meadows Powerhouse Capacity Upgrade Changes to Project Facilities  French Meadows-Hell Hole Tunnel Intake Trash Rack  Second generation unit and penstock at French Meadows Powerhouse  Tunnel Surge Capacity at French Meadows – Hell Hole Tunnel (Surge shaft/tank or surge pipeline)  Temporary upgrade of Forest Road 14N09A

11 October 1, 2007 French Meadows Powerhouse Capacity Upgrade Changes to Project Facilities (continued)  Project Road from Forest Road 14N09A to tunnel surge capacity facilities  Add transformers/switching equipment to the French Meadows Powerhouse Switchyard  Upgrade Transformers/Switching Equipment at Middle Fork Powerhouse Switchyards

12 October 1, 2007 French Meadows Powerhouse Capacity Upgrade Operations All Water Year Types All Water Year Types  Run one or both units  Increase transfer capability between French Meadows and Hell Hole reservoirs  Increase generation during peak energy demand period  Provide Ancillary Services while on standby or running at partial load

13 October 1, 2007 Ralston Powerhouse Capacity Upgrade Purpose: Purpose:  Increase powerhouse operating efficiency  Improve Synchronized Operations with Middle Fork Powerhouse

14 October 1, 2007 Ralston Powerhouse Capacity Upgrade Changes to Existing Project Facilities  Upgrade Ralston Powerhouse mechanical and electrical systems  All modifications within the existing powerhouse

15 October 1, 2007 Ralston Powerhouse Capacity Upgrade Wet Years Wet Years  Increase generation during peak energy demand periods Dry Years Dry Years  May increase generation during peak energy demand periods