WATER ENERGY

Strategies

The state’s water-energy stakeholders identified several high priority water-energy strategies.  In addition to substantially reducing use of potable water for non-potable uses, one of the most important is to reduce the energy intensity of the state’s water resources.  Within this context, strategies include: 

  • Changing the portfolio of the state’s water resources
  • Displacing reliance on high energy intensity resources with lower energy intensity resources
  • Changing water systems and operations to reduce energy use by the water sector itself
  • Identifying new technologies that can substantially reduce the energy intensity of important new drought-proof water supply options such as seawater desalination

The Water-Energy subgroup of the Governor’s Climate Action Team (WET-CAT) is investigating the establishment of a water resources loading order in which lower energy intensive supplies are prioritized over higher energy intensive supplies.  The following diagram illustrates the relative energy intensity of various water supply resources in Southern California.  Energy intensity will likely become a component of the methodology to determine a statewide water resource loading order. 

Figure courtesy of Professor Robert Wilkinson, Bren School, University of California, Santa Barbara.

Note: Light Blue – Recycled Water; Green – Groundwater; Red – Imported Water; Orange – Desalination

Other state agencies are also playing a role in California’s water future. Following recent findings regarding the benefits of recycled water, the State Water Resources Control Board developed aggressive goals to add 2 million acre-feet of new recycled water supply by 2030. This would more than triple the current statewide capacity and is equivalent to 23% of the state’s current urban water demand.

The Alliance Water‐Energy Advisory Committee agreed recycled water is likely the supply with the lowest energy intensity and is the next best resource after water conservation.  Consequentially, in May 2008, the Alliance released a study estimating the potential energy and carbon benefits of accelerating and increasing the development and use of recycled water in Southern California.

email this page to a friend  print this page

Water Treatment Plant Operator holding a sample of recycled water
Water Treatment Plant Operator holding a sample of recycled water
Recycled Water Study

In the U.S., many non-potable uses are served by potable water that has been treated to safe drinking water standards established by the federal Environmental Protection Agency and state and local agencies charged with protecting public health and safety.  Recycled water can be used to safely displace use of potable water for these types of non-potable uses such as toilet flushing, landscape irrigation, commercial car washing, and fire protection. 

Recycled water is produced by treating municipal wastewater.  California treated about 5 million acre-feet of municipal wastewater in 2002.  About half of that amount was recoverable as recycled water.  However, as much as 70% is discharged without beneficial use to natural waterways and to the ocean every year, representing a viable, untapped resource – a lost opportunity.

Recycled water could be used to enhance potable supplies after undergoing highly advanced treatment. Several water agencies in Southern California are taking advantage of advanced technologies to produce recycled water that exceeds California drinking water standards.  These agencies are using this recycled water to protect and replenish groundwater aquifers that serve as a major potable supply to the region. 

In May 2008, the Alliance released a study titled The Role of Recycled Water in Energy Efficiency and Greenhouse Gas Reduction that estimated the potential energy and carbon benefits of accelerating and increasing the development and use of recycled water in Southern California.

Results of the study show up to 580,000 acre-feet of existing recycled water supply in Southern California is currently being released to streams and the ocean without benefit.  This supply could meet all of Southern California’s projected increase in water use through 20301 . According to the study, every gallon of recycled water that is not used to offset potable water use is a missed opportunity for California to increase water and energy supplies and to reduce carbon emissions.

Download the full report for more information.  See the appendices for profiles of each of the participating water agencies.

1As projected by the Department of Water Resources under a Business As Usual scenario

Water Energy Video

Water-Energy Nexus

Water related energy use accounts for nearly 20% of all electricity consumed in California. Below, Cynthia Truelove, Senior Water Policy Analyst, California Public Utilities Commission, discusses the water-energy nexus and how water can be conserved and used more efficiently to decrease energy usage. As part of California's Climate Action Team focused on water and energy, Cynthia discusses six measures identified as principle targets to reduce GHGs in addition to those required under AB32.

Showcase Water Agencies

In the last two years, the Alliance recognized two water agencies as leaders in sustainability: Inland Empire Utilities Agency and Sonoma County Water Authority. The Alliance celebrates their success and the excellent work they are doing to improve sustainability and provides important information to other organizations about the strategies that these water agencies have used to achieve their goals.

Inland Empire Utilities Agency is a leader in best-in-class projects and initiatives that range from green buildings and energy efficient systems and operations, to innovative environmental and resource management strategies. The Agency has become the leader in recycled water production in California as it accelerated development of its infrastructure so that all recycled water produced through its wastewater treatment activities can be beneficially used.

IEUA Headquarters
Inland Empire Utilities Agency's LEED headquarters.

Sonoma County Water Agency pledged to eliminate its carbon footprint by 2015 through its Carbon Free Water effort. The Agency has taken several steps towards its goal including: improving energy efficiency, using hybrid vehicles into its fleet, installing three solar projects, conducting ongoing studies of alternative energy generation options, and co-founding a county-wide financing mechanism to spur investment in efficiency and renewable energy for existing homes and buildings.

SCWA Solar
Sonoma County Water Agency’s solar panels.