An urban runoff facility (SMURFF), the first of its kind in the US, catches and treats 3.5 million US gallons (13,000 m3) of water each week that would otherwise flow into the bay via storm-drains and sells it back to end-users within the city for reuse as gray-water, while bio-swales throughout the city allow rainwater to percolate into and replenish the groundwater supply.