Upper San Gabriel Valley Municipal Water District
Where Solutions Flow
602 E. Huntington Drive, Suite B., Monrovia, CA, 91016 | (626) 443-2297

Local Water

Local Groundwater


Local water supplies are harnessed in increasingly sophisticated ways.

Flood Control District logo

The Los Angeles County Flood Control District captures over 95% of all precipitation that falls within the San Gabriel River Watershed to recharge the local groundwater basins.  The Flood Control District encompasses more than 3,000 square miles, 85 cities and approximately 2.1 million land parcels. It includes the vast majority of drainage infrastructure within incorporated and unincorporated areas in every watershed, including 500 miles of open channel, 2,800 miles of underground storm drain, and an estimated 120,000 catch basins.

Besides local groundwater that comes courtesy of snow melt in the San Gabriel Mountains and rain that flows through the San Gabriel River, water recycling and watershed protection are key components helping our groundwater basins meet local demands.

Measuring Local Water Supply

Local water supply conditions are measured in a number of ways including local rainfall (see Graph 1, below) and the Baldwin Park Key Well, which measures the groundwater elevation of the Main San Gabriel Basin (see Graph 2, below).

Graph 1

Graph 2