Frequently Asked Questions (FAQ)

What is a reservoir?

A reservoir is an artificial lake created in a river valley by the construction of a dam. The most critical purpose of reservoirs is flood risk management. Reservoirs collect water during times of high rainfall, reducing flood risk, and then release the water slowly over the following weeks and months. In addition to flood risk management, L.A. County's reservoirs assist with water conservation by providing water to the downstream spreading grounds, which are open areas where surface water can soak down into the subsurface and recharge the aquifers in a groundwater basin.