Flow Ad Hoc Group Activities

Peggy Roefer, FLAHG Chair

TWG Meeting

October 14, 2020 
Past Flow Ad Hoc Group (FLAHG) meetings

• Developed Charge 

• Developed objectives for improvement and objectives for monitoring

• GCMRC developed hydrograph using Reclamation scheduled maintenance
June 2, 2020 FLAHG Meeting

• GCMRC discussed the potential hydrograph 

• GCMRC discussed the projected impacts of the hydrograph 

to resources

• FLAHG requested a document to be written summarizing the 

potential effects to resources

• Reclamation provided feedback on the appropriateness of 

the hydrograph and discussed potential scheduling conflicts

• GCMRC started writing Potential Effects to Resources 

document
August 6, 2020 FLAHG Meeting

• GCMRC had released the first version of the Predicted Effects to 

Resources document on July 24 and a revision was made and rereleased on July 31 (Version 1 and 2)

• GCMRC made a presentation on the changes to the hydrograph and 

discussed the Predicted Effects to Resources document

• Ad Hoc Group members felt that the Predicted Effects to Resources 

document was not as robust as it should have been. There was a 

suggestion to use a Knowledge Assessment framework.

• There was no recommendation to the TWG.
August 20, 2020 AMWG Meeting

• Based on input at the June 2020 TWG meeting, GCMRC developed Project 

O to provide the monitoring necessary to determine the impacts of the FLAHG hydrograph

• AMWG made the following motion on Project O

AMWG acknowledges and appreciates the effort to develop Project O in response to 

elements for the TWG Recommendation for the 2021-2023 Triennial Budge and Work Plan, consistent with guidance from the Secretary’s Designee (memo issued August 14, 

2019), and in support of the Flow Ad Hoc Group charge. GCMRC is commended for 

their effort.

AMWG members will submit written comments to GCMRC and Reclamation and make 

revisions based on comments received and will submit the revised Project O plan for 

TWG consideration by Wednesday, October 7, 2020 for discussion at the October 2020 

TWG meeting. AMWG directs the TWG to review the revised Project O and to forward 

a revised Project O recommendation for AMWG consideration no later than Friday, 

October 30, 2020. The AMWG will act of the TWG recommendation no later than 

Friday, November 20, 2020.

• In order for the AMWG motion to be satisfied the FLAHG hydrograph needs 

to be approved.
September 18, 2020 FLAHG Meeting

• Version 3 of Predicted Effects to Resources document sent out 

9/14

• GCMRC shared their response to comments (version 2) on the 

Predicted Effects to Resources document and the additional 

analyses performed for the Knowledge Assessment

• Motion to the TWG passed

The FLAHG, working with GCMRC, has identified a higher spring release 

within power plant capacity hydrograph that meets the requirements set 

forth by the LTEMP ROD and considers high value resources of concern to 

the GCDAMP (including recreational beaches, aquatic food base, rainbow 

trout fishery, hydropower, humpback chub and other native fish, cultural 

resources, and vegetation), fills critical data gaps, and helps to reduce 

scientific uncertainties. The FLAHG submits this hydrograph to the TWG 

for their consideration.
Predicted Effects to Resources Document

• Comments were received from NPS, Reclamation, CREDA, 

SNWA, and WAPA

• Document re-written to incorporate response to comments 

(version 4)

• Document sent to FLAHG on October 6, 2020