Petaluma OKs two flood control projects

Two significant flood control projects are moving forward in Petaluma, the latest steps in the city’s long-term quest to fortify itself against rising waters.

The Petaluma City Council on Monday authorized a $1.4 million project for a section of the city’s Capri Creek, which will bolster flood protections in the area around Sunrise Parkway and North McDowell Boulevard. The work will also include habitat improvements and the installation of educational materials.

A separate $3.1 million project authorized in July will improve protections in an area of the Petaluma River upstream of Corona Road, while also adding a riverfront stretch of bicycle and pedestrian pathway. It is the third and final phase of recent flood protection work in the area known as Denman Reach.

On the heels of the completion of a major $41.5 million floodwall project spanning north from Lakeville Street, the work is another milestone in a long-term flood control effort in Petaluma, said Dan St. John, the city’s director of public works and utilities.

“For us, it’s really the last of a number of these large, legacy projects to try to improve the watershed that contributes to the Petaluma River, and deals with environmental and flooding issues,” he said.

Paid for largely through outside grants, the Capri and Denman work is among several significant channel improvement projects Petaluma identified a decade ago as part of a wider initiative known as the Bay Area Regional Water Management Plan. The regional entity serves as a clearinghouse for awarding certain funds available for surface water-related projects in the Bay Area.

The work for Capri and the Denman Reach will include a reshaping of the channels to increase their capacity, a method known as terracing.

“It gives the floodwaters a place to go, so it doesn’t go up as much,” St. John said.

Past floods have caused millions of dollars of damage in Petaluma, including a storm in 1982 that cause the Petaluma River to jump its banks and inundate the homes and businesses in the city’s Payran neighborhood. The incomplete floodwall and channel improvements built to protect the neighborhood from rising waters was put to the test during a major New Year’s Eve storm in 2005.

“The flood project, quite frankly, really worked,” he said.

Yet while the project helped the Payran area escape its fate of 20 years prior, the storm still caused an estimated $56 million in damage, according to Petaluma’s most recent Floodplain Management Plan. Among the worst affected areas was the Petaluma Village Premium Outlets, in the area of the Denman Reach.

The Denman project, joining two phases already completed, will significantly improve flood control for the area, St. John said.

“Now, we’re focused up river,” he said of the city’s broader flood control work.

Both the Capri and Denman projects are expected to begin in the next several weeks, he said.

The Sonoma County Water Agency, which is helping to fund both projects, has also worked with Petaluma on major creek channel maintenance projects over the past five years, said Jon Niehaus, an agency coordinator. More than 21,000 linear feet of channels were cleared and vegetation conditions in the area improved during that time.

“What we’ve doing the last several years has really put, particularly the Petaluma area, in a pretty good position,” he said.