Are you interested in learning how to achieve zero-runoff of stormwater from transportation projects? This case study presented by our Founder, Jennifer J. Walker, P.E., D.WRE, CFM, QSD at the Transportation Research Board’s Summer 2015 Workshop “Sustainability in a Time of Resource Scarcity” hosted by Los Angeles Metro encompasses a Low Impact Development (LID) retro-fit of an existing parking lot to infiltrate/evaporate 100% of stormwater from the parking lot reconstruction and solve existing structural flooding issues on the site. The project is located in the arid western U.S. in Riverside County, California. The retro-fit includes the following LID features: porous asphalt, infiltration trenches, vegetated buffers to block low-blowing dust from nearby open space, other dust blocking design features, and extreme event overflow elements into an existing infiltration basin and play field.
The proposed LID features also function as hydromodification management due to the infiltration/evaporation of 100% of stormwater runoff. Long-term continuous simulation modeling using rainfall gauge data from 1970 – 2006 was performed to confirm the operation and performance. Design storm modeling was also performed.
Project phases and lessons learned from all phases of the project, including: planning, modeling, design, landscape design, construction, maintenance, and monitoring are discussed. The project also includes an educational component and interpretive signs. The project included an aggressive schedule to limit loss of use of the parking lot and facilitate installation of solar structures on the site. Challenges and strategies to address design-build items on LID projects are discussed.
