The rain started coming down this week just as the Marin Municipal Water District Watershed Committee members were discussing the threat of a flood.
Jack Curley and James Reilly, representing the Marin County Flood Control Zone 9 Board, presented details Thursday of a .
"Phoenix Lake has the largest capacity and is the key to this project," Reilly said of the efforts to avoid the next major flood.
The Flood Control Zone 9 Board (which is also the Board of Supervisors) identified four other potential sites on public land for detention basins as part of the project: Loma Alta Tributary and Lefty Gomez Field in Fairfax and San Anselmo's Memorial Park and Red Hill Community Park.
The detention basins would hold run-off during heavy rains to lessen the chances of a major flood. The flood plain includes San Anselmo, Fairfax, Ross, Kentfield and Larkspur.
The detention basin project at Phoenix Lake is estimated to cost $20 million. The California Department of Water Resources is offering $220 million, with grants worth up to $30 million each, with a 50 percent contribution from the local agency. Marin County must submit its grant application to the department by April 15.
"Ross Valley is flood-prone. It's been devastated by very large floods, most recently in 2005. It has a history of some catastrophic flood events," Reilly said.
Operating Phoenix Lake as a dual-purpose facility requires the MMWD to sign on to the agreement. The lake would continue to operate as a source of reserve water for MMWD customers and as a recreation area during normal periods. During times of heavy rain, however, water would then be diverted from the creek to prevent spillover and flooding. Water would then be allowed to flow back after the danger of flooding had passed.
Perhaps it was Thursday's storm, but the committee members seemed encouraged by the details of the proposal, though some questions remained.
Kentfield's Nancy Raetzel, sitting in the audience, suggested using Kent Lake to hold some of the spillover. The audience and committee members offered other suggestions, but no action was taken during Thursday's meeting.
The Watershed Committee also reviewed details of a financial agreement with the Department of Fish and Game for the Walker Creek Salmon Monitoring Program.