In San Francisco, all water is seen to be of value; as little as possible should be wasted. So much so that, in 2012, San Francisco became the ﬁrst municipality in the country to adopt groundbreaking legislation to allow onsite non-potable water systems.
Tapping from alternative water sources
The Non-potable Water Ordinance allows for the use of alternative water sources like rainwater, greywater, stormwater, foundation drainage, and blackwater. Soon, they developed the Non-potable Water Programme. This provides the design and development community with a streamlined permitting process to develop such projects on building sites.
The San Francisco Public Utilities Commission (SFPUC) collaborates with city partners including the San Francisco Department of Public Health, Department of Building Inspection and Public Works Department to provide oversight and management of the use of treated non-potable water (water that is not clean enough to drink). In this way they ensure that the public health is not endangered.
“These onsite non-potable water systems are transforming the way we live and do business in San Francisco”, says Steven R. Ritchie, SFPUC Assistant General Manager, Water. He says they are pioneering new ways to collect and treat water for reuse within buildings and neighborhoods. “We recognise the opportunity to build upon our centralised water infrastructure by integrating smaller, onsite water treatment systems to produce water ﬁt for toilet ﬂushing and irrigation. This approach not only matches the right resource to the right use, but helps us stretch our drinking water supplies.”
Always upwards and onwards
Since 2012, the programme has expanded to allow for district-scale projects. Now, two or more parcels of land can share alternative, treated water sources. In 2015, the programme became a mandatory requirement for new commercial, mixed-use, and multi-family development projects over 23 225 m².
Today, recycling water is integral to a reliable, long-term water supply to the city. Wastewater is now an essential part of the resources mix that the city relies on. Others include water supply diversiﬁcation, water transfers and water conservation.
- It’s not the first time I’ve looked at San Francisco for examples of how to work with water in cities….check it out – we can learn a lot more from them
- This blog is part of an ongoing series tackling the problem of how we will live with less water (and this is why we will have to). The first article looked at how cities developed, and what went wrong. The second, looked at how a new direction in how we develop the places we live can help solve our water problems (it’s an overview of Water Sensitive Urban Design and the concept of a ‘livable’ place). The third dug into the details of South Africa’s water crisis (it’s not a pretty picture). Then, we looked at the one thing that cities that need water MUST do.
- The whole movement of so-called water resilient cities started with stormwater. To be more precise, it started with sustainable drainage systems or SuDS.
- And, what about our dirty water? We can use that too, and this blog on San Fran shows, but this blog will give you the details of what the potential in our dirty water really is
- None of this would have been possible without the support of the Water Research Commission (WRC) in South Africa. The series of blogs are excerpts from the book I wrote for them on Water Resilient Cities. If you don’t have a copy yet, get in touch, or leave a comment below. I’ll send you one (it’s free!)