2105LG Water Temperature Alternative Development Sub-Group:  Bullet Points for Discussion of Alternatives 2, 3, and 4

 

Alternative A – Thermal Curtain at Prattville (To be presented by PG&E)

 

Alternative B – Swap/Re-operation of Canyon Dam (To be presented by Bechtel and PG&E)

(Bechtel Presentation)

·        D4 and D5

o      Operating options

o      Water delivery commitments

o      Modeled water temperatures

 

Alternative C – Mechanical Options (To be presented by PG&E and FS)

·        May or may not include ‘swap’ at powerhouses

·        Adit Piping

·        Chiller/Cooling Tower

o      Cooling unit (tower or chiller) at Rogers Flat location

§        Adequate size for footprint

§        Would cool Rock Creek reach

§        Potential issues:

·        Few possible sites

·        Little cooling if smaller sites used

·        Potential environmental effects

·        High energy and construction costs

·        Screening needed

·        Structure needed to divert flows in river to cooling tower/chiller

o      Two potential chiller locations for Belden Reach at Belden Dam and below Belden, at Tunnel Adit Bridge (1st bridge below Belden)

§        Tap the adit and use gravity flow to a chiller and then to river return

§        Potential issues:

·        Potential FYLF habitat

·        Recreation uses

·        Visual

·        Potential to use in-stream flows

·        High energy costs

·        Yellow Creek Diversion

o      Potential issues:

§        Potential ESA issues

§        Recreation uses

§        Visual

 

 

Alternative D – Upstream Mitigation: Off-site, in-kind headwaters restoration (To be presented by Plumas County)

·        First aim for within watershed (Feather River focus) but could be outside

·        Fish barrier removal – provide cold water refugia e.g. Rush Creek

·        License term approach - $$ for demonstrated effective restoration (seed dollars)

·        Archival management of data

·        Monitoring program (implementation and effectiveness)

·        Strategic plan for funding (partnering, grants, etc.)

·        Quantify – formula for dollar/mile effort

o      X miles for pond/plug (re-establish natural meadow function)

o      X miles riparian planting

o      Estimate $ amount and habitat affected

·        Funding for on-going repair and maintenance

·        PG&E: ~30 miles of affected reaches

o      Proportional to affected reach