Proposed housing project sits in flood plain

The hot-button issues of building in the flood plain, annexing land into the city and traffic congestion took center stage Tuesday, when a 31-lot subdivision proposed on Corona Road came before the Petaluma Planning Commission.

The housing development is located in the 100-year flood plain, on land that sits within the city's urban growth boundary but outside of city limits. Neighbors and commissioners expressed concern Tuesday over myriad uncertainties related to annexing land and flood plain construction, ultimately forcing the developers to rethink several design aspects of the project before returning to the commission at a later date.

When the project was first proposed two years ago by Pleasant Hill developer Delco Builders, the 10.1-acre site was not in the Federal Emergency Management Agency's established flood plain. But recent changes to FEMA's flood maps put several portions of Corona Road east of North McDowell Boulevard into the flood plain -#8212; including the proposed development site. In response, Delco suggested building a large water detention basin that would lift the development and several nearby homes out of the flood zone.

Reactions to the water detention basin were mixed, several neighbors and commissioners questioned the effectiveness and design of the basin.

Neighbors of the proposed site said their homes -#8212; also built by Delco more than a decade ago -#8212; are often damaged by floodwater runoff. The frequent flooding raised concerns about building more homes in the area.

Corona Creek, which lies directly southwest of the development site, is supposed to provide flood relief to the Corona Road neighborhood. But residents of the area said the creek is overgrown with willows and vegetation that regularly transform the creek into a flooding hazard. City Engineer Curt Bates said his department is trying to determine whether the city or the Sonoma County Water Agency is responsible for maintaining that creek.

"I'm concerned about existing water damages going on in homes already built there," said Commissioner Richard Marzo. "I'd like to see a program that explains how the ongoing maintenance of the creek will be satisfied. A detention basin with a clogged creek doesn't make sense to me."

Further complicating this particular housing subdivision is its location in an unincorporated part of the city that falls within the city's urban growth boundary -#8212; which dictates where development can be built. In order to build the subdivision, the City of Petaluma would need to annex the land into city limits and provide the site with water and sewer services. If the city decides to move forward, the proposal will require approval from the county's Land Agency Formation Commission (LAFCO), which handles annexation requests.

City Senior Planner Heather Hines said staff continues to work with LAFCO on the project, but added that the county agency has asked the city to annex an additional stretch of Corona Road beyond the project site. The road in question lies just outside the city's voter-approved urban growth boundary, which would require a public vote to change the urban growth boundary.

Adding the extra portion of Corona Road into the city's urban growth boundary as LAFCO has requested directly conflicts with the city's general plan for development and is likely to be shot down by the city council, said city staff. Hines said that while LAFCO can't force the city to add any road into its urban growth boundary, the request could complicate the development's fate.

Voters approved the city's urban growth boundary -#8212; which states that no development will be built outside a designated area of city limits -#8212; in an effort to maintain the green spaces that surround the city and create a scenic corridor into town. The current boundary expires in 2025.

The commission ultimately had too many unanswered questions to vote on the project. The hearing was continued to a future date, giving the developer more time to work with city staff on the proposal.

(Contact Janelle Wetzstein at janelle.wetzsten@arguscourier.com)