San Diego’s Web-Based Mapping Applications Streamline Data-Driven Stormwater Project Planning
The City of San Diego (City) Storm Water Division has recently completed Water Quality Improvement Plans (WQIPs) tabulating the quantity of structural control measures necessary to achieve water quality requirements. While the WQIPs provide subwatershed-scale schedules of structural best management practice (BMP) footprints and types to create the “recipe of compliance,” the plans lack the street-by-street or parcel-by-parcel resolution necessary to identify, prioritize, and plan individual projects. The difficult near-term milestone schedules with limited funds require that specific, highly efficient BMPs be identified and constructed first to reduce initial capital investments while still yielding the requisite load reductions.
In addition to the WQIP goals, new and redevelopment projects are required to meet separate water quality requirements. While the majority of development projects are expected to implement onsite BMPs, developers have the option to comply via offsite mitigation. The City realized that there is significant opportunity to link this offsite alternative compliance program with the WQIPs to develop synergy and accelerate the overall improvement of water quality across the City. A list of candidate BMP sites was prepared for the WQIP, and ongoing high-resolution watershed master planning is currently identifying additional opportunities at a street-by-street and parcel-by-parcel scale. These efforts have generated substantial quantity of spatial data necessary for data-driven project planning; however, no centralized framework was available to identify, evaluate, and prioritize sites in a universally accessible mapping environment. It was imperative that the output from the various planning and analytical efforts be organized into a spatial database to enable prioritization of candidate projects and avoid inefficiencies.
The City therefore developed customized web-based mapping applications using the ESRI Web App Builder to house watershed planning data and enable smart project selection. The web applications were programmed with specialized—yet user-friendly--widgets to serve a variety of audiences interested in identifying, selecting, and implementing green infrastructure and/or regional projects. Functionality includes search and query tools to identify candidate projects based on the user’s needs. The web applications were also customized to generate standard reports for projects of interest that summarize key project attributes, standard design details, and recommended BMP sizing on the basis of detailed water quality modeling.
One of the immediate purposes of these tools will be to streamline exploration of project opportunities to support the City’s alternative compliance program. The web based applications enable accessibility and ease of navigation by City (and eventually non-City) users and effectively identify and map potential offsite project opportunities. The web applications also provide an efficient data management and transfer structure that enables transparent, comprehensive planning by consolidating data from multiple sources.
By consolidating inter-agency infrastructure data into a centralized framework, the web applications have also been used to initiate analysis of integrated systems that use stormwater as a resource to augment local water supply. Next steps include development of automated drainage area delineation tools within the web-based platform, and adaptation of the web-based platform to receive and export data for reporting and asset management.
This project will provide other municipalities and practitioners with a road map for implementing similar applications to streamline the attainment of their unique stormwater management goals. The web application interface will be explored in real-time to demonstrate the satisfaction of several common project planning use cases. Use of the web applications for strategic BMP operations and maintenance will also be discussed.