Delridge Natural Drainage Solutions

Combined sewer overflows cause water quality problems in Longfellow Creek. Herrera helped fix this problem by designing green stormwater infrastructure (GSI) retrofits for thirteen blocks of right-of-way to improve water quality and reduce stormwater volumes discharging to the creek. Bioretention facilities, intersection bioretention bulb-outs, and permeable pavement sidewalks integrate with sidewalk and ramp reconfigurations to achieve these improvements and ADA compliance. Underdrains collect and convey treated stormwater from the planters to a simplified injection well (drilled drain) for deep infiltration. Herrera designed the project in partnership with a neighborhood greenway project in the Delridge neighborhood. Together, the projects enhance pedestrian mobility, increase traffic safety and improve water quality.