Connecting the Community to the Creek: Smart Growth and Green Streets in a Dense Urban Area of San Diego County
The City of National City, a community just south of downtown San Diego, is retrofitting a highly urbanized 49-acre area using green infrastructure. The project incorporates elements of Smart Growth design and Low Impact Development into a low to moderate income area of the City’s downtown urban area, providing education, beautification, better water quality, and environmental justice benefits for the community. The project includes bioretention, rainwater harvesting and reuse, and infiltration. An educational pedestrian pathway with storm water themed murals and design elements, augmented with curb extensions and other improvements to improve walkability, will run through the project area. These pedestrian improvements link dense urban residential areas and a recently revitalized commercial corridor with mass transit and a major City park, which also provides access to the main water body in the City, Paradise Creek. Due to the high pedestrian foot traffic to these downtown destinations, there is a significant educational opportunity to teach the community how urban runoff connects them to their creek as it flows through bioretention planters down the street, across the park, and into Paradise Creek. As an additional educational feature, runoff captured in a 30,000 gallon cistern will be used to water a new community garden.
The presentation will discuss how the project addressed widely varying infiltration rates throughout the project area, the need to preserve protected historical areas, utility conflicts, and community concerns. BMP design strategies to maximize effectiveness within the constraints of an urbanized area and maximize other benefits, including aesthetic improvements and pedestrian safety, will also be discussed. The presenation will also describe how the City used simple modeling techniques to compare the relative levels of volume reduction and water quality treatment in different designs. Finally, the details the City’s effectiveness assessment program, including flow measurement, composite storm water sampling, and community surveys will be discussed. Recognizing that green infrastructure retrofits are being considered in many areas across the state, to comply with permits or TMDLs, each portion of the talk will identify key lessons learned that can be applied to other urban retrofit projects.
Note that this project is funded in part by a State Water Resources Control Board Proposition 84 grant.