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. The groundwater supply in turn plays an important role in the city's Sustainable Water Master Plan, whereby Santa Monica has set a goal of attaining 100% water independence by 2020. The city has numerous programs designed to promote water conservation among residents, including a rebate of $1.50 per square foot for those who convert water intensive lawns to more local drought-tolerant gardens that require less water.