Urban neighborhoods that contain residential, commercial, and industrial land uses along with parks and natural areas make up the eight major drainage areas of San Francisco. Each land use is underlain with specific topography, hydrology, soils, vegetation and water resources that create unique opportunities and challenges for drainage and stormwater management. These all come together in diverse neighborhoods with unique identities and physical forms which can inform where and how to best implement Low Impact Design (LID) throughout the City. The SFPUC intends to analyze the historical land uses and all of the above-mentioned information and work with the various city and federal agencies and community groups in these areas to identify opportunities for LID.
Urban Watershed Planning Charrette
On September 6th and 27, 2007 the SFPUC’s Wastewater Planning and Regulatory Compliance division hosted a brainstorming charrette intended to identify green stormwater management strategies in four of San Francisco’s eastern watershed basins: Channel Basin, Islais Creek Basin, Yosemite Basin, and Sunnydale Basin. A charrette is an intensive brainstorming activity in which a group of people collaborates to complete a design project in a finite amount of time. Green stormwater management, also called Low Impact Design (LID) or best management practices (BMPs), refers to the practice of mimicking natural watershed processes. By increasing natural storage and infiltration of rainwater, cities like San Francisco can begin to reduce the quantity and improve the quality of urban stormwater runoff. Examples of green stormwater strategies are rainwater harvesting, green roofs, cisterns, rain gardens, permeable paving, stream daylighting, detention basins, swales, and constructed wetlands.
Approximately seventy participants attended the charrette, representing public agencies, engineering and design companies, nonprofit organizations, community groups, stormwater experts, and unaffiliated San Francisco citizens. Participants divided into groups by watershed basin, and over the course of five hours, each group developed a set of green stormwater management recommendations for its particular basin through the format of a game. The game was played turn by turn, with one group member at a time placing a LID measure (e.g. a cistern, a set of eco-roofs, etc) on a large map of the watershed. Capital costs as well as peak flow and volume reductions were estimated for each LID measure, and the object of the game was to meet specified stormwater reduction targets within a finite budget. Stormwater reduction targets consisted of both peak flow reductions and overall stormwater volume reduction goals that were unique to each watershed. After the game, each group presented their recommendations to other groups who were working on the same watershed. Ideas that either were shared by several groups or were particularly unique were then presented to the entire charrette audience at the end of the evening. The SF PUC will use the creative ideas generated during the charrette to identify and prioritize future stormwater management efforts in San Francisco.
Staff Charrette
A smaller version of this charrette was held on September 6, 2007 for San Francisco employees. The intent of this prior event was two-fold: to learn which parts of the charrette exercise worked well and which needed improvement before running the city-wide event, as well as to educate city staff about green stormwater management and planning in a spatial way that was also enjoyable. Approximately twenty staff from the Public Utilities Commission’s wastewater and water enterprises, the Department of Public Works (DPW), and the San Francisco Port participated in this planning exercise. Although structured in the same way as described above, only Sunnydale and Islais Creek Basins were examined because of the smaller group size. Because many of the participants were engineers, hydrologists, and water planning specialists, this internal charrette yielded many useful ideas that complement the ideas proposed by the citizens during the September 27 charrette.
To download PDF copies of the watershed-specific reference maps and historical context materials that were provided to all charrette participants, click on a watershed name below.
For finer resolution images of these maps, please contact greenstormwater@sfwater.org
Download a summary of the Charrettes below.
Attachments: (Help)
Bayside Basins Summary Report (BBSR) - Cover and Executive Summary (333 KB)
