Finding New Ways of Providing Flood Protection
Ross Valley Ballot Notice
Community Workshop 3--Presentation
Flood Zone 9 Public Meeting
Official Notice to Property Owners
Engineer's Report
On December 31, 2005, at 3am, a flow of about 763,000 gallons per minute broke creek banks and flooded our streets—during a 100-year storm. Engineers use that term to describe a storm that has a 1% chance of occurring in any given year, not a storm that occurs only once in 100 years. In fact, Ross Valley has experienced three 100-year storms in the past few decades (1982, 1986, and 2006). Much of the Ross Valley storm drainage system currently provides about 5-year protection, meaning that it can be overwhelmed by a storm that has a 20% chance of occurring in any given year.
The Flood Control District is contracting with Marin-based engineers to study the feasibility of adding detention basins to the watershed to retain rainfall runoff during large storms thereby controlling the flow that reaches the creek. Water will be held until the storm subsides and then released gradually. Although the studies will be carried out, civil engineering/public works projects can only be undertaken with sufficient funding, which will come from local, State and Federal sources.
