Community Focused Socio-Environment-Economic Solutions to Watershed Challenges in San Francisco
Since 2006, the City of San Francisco has been pursuing the goal of integrating water sensitive strategies into numerous aspects of the urban landscape, strategies which will over time transform the fabric and form of the city. The City's Wastewater Utility is engaging a 30-year,
approximately 7 billion Sewer System Improvement Program (SSIP) to rebuild the aging wastewater infrastructure, including surface drainage and conveyance, collection system, and treatment facilities. Today, San Francisco's sewer system (including curbs, gutters, catch basins, collection
sewers, pump stations, treatment plants, and outfalls) is in compliance with regulatory requirements, but aging infrastructure, capacity constraints, climate change, and a vision for a more sustainable system are driving the need for substantial improvements. The San Francisco Public Utilities
Commission (SFPUC) is making significant investments in sewer system infrastructure as part of the SSIP to improve the reliability and efficiency of the system, meet future requirements, and resolve long-standing challenges.
To ensure long-term system sustainability, these new investments
must optimize ratepayer benefits and project costs and provide resiliency to potential future changes in environmental conditions and regulatory requirement. To that end SFPUC has established an inclusive and transparent process for planning and prioritizing collection system capital improvement
projects for each of the City's eight watersheds. This paper describes how the process was used to establish defensible and community endorsed solutions.
On a watershed-by-watershed basis, the process enabled the SFPUC to develop a set of recommended project alternatives that achieve
the collection-system related SSIP goals and levels-of-service through technologically sound watershed projects and programs that maximize overall benefits and improve sustainability. The process places significant energy on engaging the public and disseminating information in order to facilitate
valuable input to the analytical process. The public previously did not think of a “watershed” as a geographic construct or as an organizing principle for where they live, work or play. People understand neighborhoods, blocks, or commercial districts but few people think about
the hydrologic elements of their area. By introducing and educating the public about watersheds, the SFPUC has connected the public, in a more holistic way, to water collection and management issues. This further presents a unique opportunity to capture and galvanize public interest in urban
The public input is invaluable in implementing the socio-environmental-economic considerations of the myriad opportunities for resolving watershed specific surface drainage and collection system challenges in the combined sewer system watersheds. The public input and
trust builds on the performance foundation of solutions to further establish the viability of alternatives and ancillary benefits.
The analytical process included watershed characterization conducted to evaluate the existing watershed conditions and identify challenges for meeting SFPUC's
stated level of service (LOS) goals. The information gathered during the characterization was used to identify synergistic opportunities to address the LOS goals while providing ancillary benefits within the watershed as well as addressing more systemwide challenges (location, frequency, and
volume of combined sewer discharges to the Pacific Ocean and San Francisco Bay).
A triple bottom line (TBL) process and model was used to present value costs and benefits to determine direct, indirect, and induced economic, social, and environmental benefits by alternatives. The TBL process
provided a sustainable return on investment (SROI) metric in addition to a present value benefit to cost ratio analysis. Economic benefits” are the direct and indirect costs and benefits to the SFPUC. Benefits such as employment benefits are incorporated as social benefits rather than
direct economic benefits. This enables the SFPUC to change the weighting based on community input and differentiate the costs to SFPUC versus the other additional realized benefits. Other components of the process included adaptation to the two most relevant effects of climate change, sea
level rise and changing rainfall characteristics. The process also incorporated rigorous assessment of current regulatory permit requirements and anticipated future regulatory mandates.
Proposed projects considered a wide range of collection system improvements including “grey infrastructure”
such as sewer pipes and pump stations, as well as green infrastructure including technologies such as bioretention and rainwater harvesting. The process established what types of solutions are appropriate at what scale and at which locations, and assembled suites of specific projects and programs
into Project Alternatives based on their cumulative ability to meet watershed and systemwide needs/challenges.
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