Cutting the risk of winter floods

Water Agency workers have begun clearing debris, silt and vegetation from 30 Sonoma County creeks to lessen the chance of winter flooding.

The $3 million project includes work on some of the most troublesome creeks, including Hinebaugh and Coleman creeks in Rohnert Park. Both creeks flooded in January, backing rainwater into a mobile home park and a neighborhood.

At the same time, workers are reconfiguring the creeks to make the waterways more friendly for steelhead and salmon.

"We are doing flood protection on streams, but it is more balanced with stream habitat," said Ron Benkert, a Sonoma County Water Agency maintenance coordinator.

Trees along the creeks are being pruned and new ones, such as alders and Oregon ash, are being planted for shade. Santa Barbara and torrent sedge also are planted in the streams.

Low-flow channels also are being dug to provide slow-moving water for fish to rest.

The creek work is being shaped by the federal Endangered Species Act of 1995. Chinook salmon are protected as an endangered species, while coho salmon and steelhead are listed as threatened.

When that act went into effect, the Water Agency stopped all sediment removal and curtailed creek work for five years while it studied how to balance flood protection and the needs of fish.

Any creek work now requires permits from state Fish and Game, U.S. Army Corps of Engineers or other regional water boards, a costly and time-consuming process, said Jon Niehaus, a Water Agency environmental specialist.

Some permits can take six months to process and cost more than the creek work itself, Niehaus said.

To streamline the process, the Water Agency is developing stream maintenance guidelines and a program for routine work without having to continually get new permits.

This year, Water Agency workers will be in 30 streams, removing 25,000 cubic yards of silt and 100 truckloads of trees and shrubs, and planting 2,000 alders and Oregon ash trees, which are well-suited to being on stream banks.

On Tuesday, workers thinned out brush and trees on Coleman Creek near Snyder Lane in Rohnert Park, which experienced flooding in January.

They also will work on Hinebaugh and Copeland creeks in Rohnert Park, which should ease the threat of flooding in the Rancho Verde Mobile Home Park, Niehaus said.

In the Hinebaugh project, workers will erect a cofferdam, drain the creek after relocating any fish and turtles downstream, remove 12,000 cubic yards of sediment and dig a low-flow channel.

In three weeks, workers will begin a three-month project on Santa Rosa Creek between Stony Point and Willowside roads. The project will require closing a popular bicycle trail flanking the creek for part of the day.

You can reach Staff Writer

Bob Norberg at 521-5206 or bob.norberg@pressdemocrat.com.