Flood protection priorities change; agency wants to build, not litigate

Water rushes through the Pope-Chaucer street bridge on San Francisquito Creek between Palo Alto and Menlo Park on Feb. 9, 2017. Post photo.

Daily Post Correspondent

Faced with the prospect of a contentious process that could drag on for years, a multi-city creek authority has scaled back expectations for its next project, which is aimed at improving flood protection along San Francisquito Creek upstream of Highway 101.

Rather than trying to achieve protection from a 100-year flood, one that has a 1% chance of occurring in any year, the San Francisquito Creek Joint Powers Authority is now looking to avoid an overflow on par with the flood of February 1998, which affected about 1,700 properties and caused $28 million in damage.

That flood is considered a roughly 60-year event, with slightly less than a 2% chance of occurring in any year.

“We decided that we wanted something we could actually build, not something we could fight over for 10 years,” Len Materman, executive director of the San Francisquito Creek JPA, said during a community meeting last month.

For a project to provide protection from a flood similar to that in 1998, the JPA is leaning toward an option in which the bridge at Pope-Chaucer streets would be replaced to improve creek flows, and the creek channel would be widened at specific “bottleneck” locations between Highway 101 and Euclid Avenue.

Other alternatives include building one or more retention basins toward the western end of the water- shed; installing flood walls along the creek channel between Highway 101 and the Pope-Chaucer bridge; or constructing an underground culvert to whisk floodwaters away. As is customary in environmental documents, the impact of doing nothing will also be evaluated.

Public comment period closes tomorrow

The JPA is open to adding other ideas to the list to be considered in the environmental document. The deadline to submit comments is tomorrow (Feb. 21, 2017) at 5 p.m.

“Are there alternatives out there that we’re missing?” Materman said.

Following the close of the comment period, work will begin on the environmental impact report. The JPA estimates that the document would be released in September, followed by another opportunity for public comment. Construction could begin in mid-2019 and be completed by the end of 2020.

The improvements upstream of Highway 101 would work in concert with other projects that are in the works, including the JPA’s project now under construction downstream of 101. Caltrans is widening the creek channel at 101.

Newell Road bridge under review

And the city of Palo Alto is eyeing a replacement of the Newell Road bridge, built in 1911. The city host- ed a community meeting on the project in September 2015. Consultants are now studying the bridge, ac- cording to the city’s website.

In 2013, the JPA was at a similar stage in planning a project upstream of Highway 101. At that time, the agency was aiming for 100-year flood protection through a project that included multiple elements. A baseline project would widen bottlenecks at certain points in the creek and modify bridges at Newell Road, University Avenue, Pope-Chaucer streets and Middlefield Road. But to achieve 100-year flood protection, additional work would be needed, which might be installing 1.5 miles of floodwalls from Highway 101 to the Pope-Chaucer bridge or building an underground culvert or upstream retention basins.

But planning for a project providing 100-year protection stalled due to its substantial expected impacts and lack of funding.

Materman said that additional elements could be added at a later date to the currently preferred project, which would widen creek bottlenecks and replace the Pope-Chaucer bridge.

“We may still get there,” Materman said of reaching 100-year flood protection. “We didn’t want to hold up progress.”

Flood insurance requirements

The scaled-back project would remove some, but not all, residents from flood zones that require them to buy flood insurance. Among those are owners of nearly 900 properties in Menlo Park who pay for flood insurance, amounting to $1.1 million in premiums per year, Materman said. It’s estimated that a 100-year flood event for San Francisquito Creek would damage over 5,500 properties.

The flood that occurred on Dec. 23, 2012, when the creek jumped its banks in several spots, is consid- ered a 20-year event with a 5% chance of occurring in any given year.

The San Francisquito Creek JPA was formed following the flood of February 1998 to work on flood protection. The JPA includes the cities of Palo Alto, East Palo Alto and Menlo Park, as well as San Mateo County and the Santa Clara Valley Water District. Palo Alto’s representative on the JPA is Mayor Greg Scharff.

Comments on the JPA’s project upstream of Highway 101 may be emailed to [email protected]; or sent to Senior Project Manager Kevin Murray at the San Francisquito Creek Joint Powers Authority, 615- B Menlo Ave., Menlo Park, CA 94025.