Burlingame, Donnelly Avenue Rain Garden

Stormwater from the parking lot surface now flows into a bio-retention basin, or Rain Garden. This prevents pollutants such as vehicle fluids and trash from flowing into the storm drain and into the San Francisco Bay.

Rocks slow the flow of water as it enters the basin to prevent runoff and erosion. The specially designed soils in the landscape allow stormwater to soak into the ground, removing pollutants and replenishing the groundwater supply.

When it rains, the one-foot thick layer of rock acts as a reservoir that allows water to gradually soak into native soils below. After the rains subside, this water will soak into the ground, get absorbed by plant roots, and evaporate. Within a few days, no standing water will remain.

The green landscaped areas in the parking lot and along the street help treat stormwater by naturally retaining and filtering runoff through the soil and plants.

Stormwater runoff from the street enters a separate area, called a vegetative curb extension. Similar to the rain garden, the plants were chosen for their ability to withstand long periods without any water and survive the short periods of flood during rain events.

Before this project, after significant rain, standing water would accumulate in large puddles on Donnelly Avenue and this adjacent parking lot. The combined rain garden and curb extension solved the problem, and reduces polluted runoff from entering the stormdrains.