Water Energy Nexus

Water and energy are often managed separately, despite the important links between the two. Water is used in the production of nearly every major energy source. Likewise, energy is used in multiple ways and at multiple steps in water delivery and treatment systems, as well as wastewater collection and treatment.

Meeting the resource challenges of the 21st century will require a more integrated approach to managing water and energy. The first step to greater integration is to improve our understanding of how these resources are linked and the degree to which they depend on each other.  

How does energy relate to water use?

About 12 percent of California’s total energy use is related to water. Energy is required for the following water activities:

  • Pumping water from underground aquifers
  • Moving water from one location to another (water conveyance)
  • Treating water to make it drinkable
  • Heating and cooling water

The sources of energy used to power these water activities is directly tied to the volume of greenhouse gases we emit into the atmosphere. To mitigate our climate impact, we are committed to identifying and using renewable sources of energy at our State Water Project (SWP) facilities.

The SWP, owned and operated by DWR, delivers water to 27 million Californians and 750,000 acres of irrigated farmland. Transporting water requires a large amount of electricity. In fact, the SWP is one of the largest single consumers of electricity in the state. The SWP also generates a large amount of electricity at its reservoirs and generating stations. Hydropower is a renewable energy source that reduces the greenhouse gas (GHG) emissions of generating power.

Reducing GHG emissions is a priority for us. Our Climate Action Plan targets GHG reduction of 50 percent below 1990 levels by the year 2020, and 100 percent below by 2045. As of 2014, DWR has already reduced its emissions to 42 percent below 1990 levels.