Over 50 city officials, contractors and residents watched as San Francisco Public Utilities Commission employees sprayed gallons of recycled water on a Holloway Avenue parking lane. The rough pavement absorbed the water before any of it could reach the gutter.
The spectacle, courtesy of a special, porous concrete, was the main event at a Aug. 18 ribbon-cutting ceremony for the Holloway Green Street, the first of eight green infrastructure projects planned as part of the SFPUC’s 20-year, $7 billion Sewer System Improvement Program.
A collaboration between the SFPUC, the Department of Public Works and the San Francisco Municipal Transportation Agency, the project is an experiment in multipurpose infrastructure.
Other cities, including Philadelphia, Seattle and New York, have also experimented with similar projects, according to Sarah Minick, a project manager at the SFPUC.
“We’re so excited to kick off one of our earliest green infrastructure projects and not only because of its sustainability, but also its affordability,” SFPUC General Manager Harlan Kelly said in a short speech. “This is one of the projects that we were able obtain $7.4 million in low interest financing [from the Clean Water State Revolving Fund].”
While conventional concrete funnels rainwater into the sewer system, the light gray, porous cement and the sidewalk cutouts surrounding the gardens in the Holloway Green Street project allow rainwater to filter directly into the soil below, reducing strain on the city’s sewer system. The eight blocks on Holloway Avenue will divert 850,000 gallons of water from the sewer system to the aquifer each year.
“The goal is to have one project in each of our eight main watersheds,” said Minick. The Holloway Green Street project is in the Lake Merced watershed, which stretches from the Ingleside to Ocean Beach.
Bulbouts along the green street project are meant to calm traffic along Holloway Avenue, which is part of the city’s bike network. The bulbouts reduce the length between street crossings for pedestrians. The SFPUC will be responsible for maintenance of the project.
Mary Dickow, a resident living a block from Holloway Avenue, was impressed with the final project.
“It feels like this is going to give the neighborhood new life,” Dickow said. “If you improve the environment people live in, it improves the way people live and play.”
A nearby business owner who asked not to be named expressed disappointment that the project had removed parking spaces and narrowed the entrance to Holloway Avenue.