HEMET, Calif. — An area in Hemet offers a spot for people to get a little relief from triple-digit heat by cruising in their boats around a giant body of water.

However, Diamond Valley Lake also plays an important role when it comes to Southern California’s water supply. It is especially vital because Gov. Gavin Newsom has asked Californians to cut their water usage by 15% as the state drought continues to intensify.

Five things you need to know:

  1. Diamond Valley Lake is Southern California’s largest drinking water reservoir.
  2. The lake is 4.5 miles long and more than two miles wide.
  3. It can hold approximately 810,00 acre-feet or 264 billion gallons of water.
  4. Currently, about 10 to 15% of the lake's water has been allocated to Mills Treatment plant to serve Riverside, as supplies from the State Water Project have been declining.
  5. The Metropolitan Water District of Southern California has said that during an emergency, the lake could serve 19,000,000 people for six months.