City tests flood barriers at 17th and Folsom

It’s a temporary solution to a long-term problem, but San Francisco officials are hoping removable barriers will protect businesses and residents at a flood-prone Mission District intersection this winter.

The San Francisco Public Utilities Commission this week began testing temporary flood barriers along two blocks near 17th and Folsom streets. The 400-foot-long water-tight plastic barriers are filled with water to stabilize them and can be deployed quickly when heavy rain and flooding is predicted, officials said.

Tyrone Jue, a spokesman for the SFPUC, said the agency deployed the barriers for the first time on Saturday and Sunday, and expects to put them in place again tomorrow in anticipation of heavier rains:

“We’re testing them on a limited area because we want to make sure they work.”

The $165,000 pilot project is intended to test not only whether the barriers protect properties from flooding caused by overflowing sewers and storm drains, but also whether they are worth the amount of labor required to deploy them and the inconvenience for residents, Jue said. Among other issues, the barriers block driveways, meaning some residents could find themselves stuck or unable to access businesses during periods of heavy rain.

Hans Art, the owner of an auto shop at 17th and Folsom that has been hit by flooding in the past, today said he would wait to see how the barriers work. Flooding in the area, caused by overflow from sewers and storm drains in a low-lying part of the city, is intermittent and hard to predict, and often occurs with little warning, he said.

Art said:

“When it looks like it might flood they’re going to run and put the pieces in place as quickly as they can, and that’s what I’m unsure of. … Oftentimes we have like six minutes to react when we think it’s going to flood or overflow.”

If the barriers are a success this winter, Jue said the city might expand their use to a larger area and to other neighborhoods with similar problems, including the areas around Cayuga Street and Alemany Boulevard and Wawona Street and 15th Avenue. Sewer overflows in those low-lying areas have triggered numerous complaints, claims against the city and lawsuits from angry residents.

In the longer term, the city is looking at sewer improvement projects for those areas estimated to cost around $250 million, with construction currently expected to start this year or next, according to the SFPUC. A task force is also working to develop a flood resilience study identifying potential improvements for the sewer and stormwater control system.

The city currently provides sandbags, encourages property owners to get flood insurance and is working on cleaning out clogged catch basins and increasing staffing and monitoring during storms.

Some funding is also available for property owners to protect themselves with projects like raised sidewalks, and Art said a number of people are taking advantage of that.

Still, Art said of the flooding:

“It’s a big pain when it happens. … We put up with it all these years, but we’d appreciate it if the city would fix it.”