Energy and Water Nexus

Energy and Water Supplies Are Linked

In the West, our energy and water supplies are inextricably linked – water supplies are often pumped from deep aquifers or over hundreds of miles, and large thermoelectric coal and nuclear plants consume large amounts of water each year. Population growth and climate change further compound the challenge.

Water is needed to produce electricity, though the water intensity of electricity generation varies considerably depending on the fuel source and the technology used. Fossil-fueled power plants use a tremendous volume of water in the Intermountain West. In the Colorado River basin alone, power plants consume over 167,000 acre-feet (AF) of water each year. Scores of other plants rely on groundwater or surface supplies in other watersheds. In contrast, many renewable sources of energy like wind, solar photovoltaic, geothermal, and certain types of concentrating solar power consume negligible amounts of water.

Electrical power generation is one of the biggest consumers of water, so every decision to build a new power plant places additional burdens on already tight water supplies. In contrast, clean, renewable sources of energy are far less water intensive and can even create ‘new’ water supplies when they replace traditional power plants. Nowhere do these types of energy planning decisions have greater consequence than in the dry American West.

Power Plants Compete for Water with Agriculture, Cities and the Environment

Most electric utilities and state and federal regulators do not adequately consider the value of the large volumes of water power plants consume. Electric utilities typically appropriate or purchase water rights for new thermoelectric power plants, but the cost of these water rights does not reflect the opportunity cost of water use over the life of the power plant — 40 to 50 years or longer. And increasingly, existing and proposed power plants compete directly with water demands for growing food, providing for growing urban areas, and sustaining the West’s rivers and streams.

Energy needs also come into play in trying to meet water demands. Western states have long depended on major water transfer projects to fill the gap on demand. Most of these projects, such as the Central Arizona Project (CAP), the San Juan-Chama Project, and the California Aqueduct, to name a few, tap the Colorado River or its tributaries. But to move these vast volumes of water, these projects also consume tremendous amounts of energy. For example, CAP is the single biggest consumer of energy in the state of Arizona.

Almost every western state has proposed a new water supply project in recent years—projects like the Flaming Gorge Pipeline that would move 225,000 AF of water up to 500 miles from Flaming Gorge Reservoir to the Front Range of Colorado. This project would lift water over the Continental Divide, and if powered by electricity, have greenhouse gas emissions equivalent to burning 48 million gallons of gasoline each year. Most new water supplies will be increasingly energy-intensive, with notable exceptions: water conservation, recycled water, and flexible, compensated water leasing agreements between existing users.

Energy Planning Must Account For and Value Water

As water in the West becomes scarcer, its value will undoubtedly rise. Today, most electric utilities do not adequately value water when they create their future resource plans. And although most regulators in western states have the authority to value water in evaluating utilities’ resource plans, most do not. WRA evaluated the prices cities, farmers, electric utilities, and environmental interests are willing to pay for water in the West. Understanding the value of water is an important step toward better integration of water issues in electric resource planning. In Every Drop Counts, Western Resource Advocates highlights the opportunities for utilities and regulators throughout the region to better integrate water into resource planning processes.

New Water Projects Should Minimize Energy Needs

The large energy needs for new water projects need to be a factor in decision-making when considering the West’s current and future water needs. As growing western cities seek to expand water supplies, they often must tap deeper groundwater aquifers, pump water over greater distances, and treat degraded water supplies. Water utilities’ proposed development projects will, in most cases, use more energy than existing water supplies – further increasing greenhouse gas emissions and the impacts of climate change. Water conservation and water recycling are common-sense solutions to meeting current and future demands. Water conservation also saves energy and money for utilities and customers. In fact, for many utilities, energy is their second biggest cost (second only to staff salaries). And on average, heating water represents 14 – 25% of a household’s energy use. For the household, low-flow showerheads and efficient clothes washers and faucets represent the biggest opportunities for saving energy through water conservation.

Western Resource Advocates Promotes Smart Energy and Water Policies

Western Resource Advocates works to promote energy policies that protect the region’s valuable water resources and air quality – advocating for energy supplies like wind, solar, and energy efficiency that require no water, and advancing water policies, including conservation, that reduce our energy footprint.

The clean energy policies enacted over the five year period from 2006 – 2010 now save an estimated 6.3 billion gallons of water per year, or enough to meet the annual needs of approximately 78,000 households. And, clean energy decisions and investments since 2010 have almost certainly increased that number. In fact, water use by the electricity sector in the Interior West is now on the decline. For more, see WRA’s 2012 report, A Powerful Thirst.

Western Resource Advocates promotes water conservation across the West as a common-sense and low cost solution to rising water demands and less water availability. By increasing water conservation, many water utilities could delay or eliminate the need to develop new water supplies. This strategy would save both water and energy. Water conservation can help us mitigate and adapt to climate change. Both energy and water utilities should aggressively pursue water conservation.

Meeting new demands will require an integrated approach between energy and water utilities. New water projects should rely on renewable sources of energy; likewise, new energy projects should reduce, or eliminate, their impacts on freshwater resources.  Further, decentralized solutions may offer both energy and water savings. Where possible, utilities and planning authorities should pursue and encourage decentralized solutions like rainwater harvesting.

Other Resources

Water Required for Energy Generation in Colorado is Declining (2014)
New energy policies in Colorado are resulting in less water needed for the energy generation sector. In 2011, coal- and natural-gas-fired power plants in the State of Colorado consumed approximately 64,000 acre-feet (AF) of water. With state policies promoting energy efficiency and renewable energy, and retiring the state’s most carbon- and waterintensive power plants, Colorado’s energy sector likely will use even less water in the future.

Conservation Synergy: The Case for Integrating Water and Energy Efficiency Programs (2013)
This report articulates why and how Western utilities can achieve conservation synergy by integrating water and energy efficiency programs.

A Powerful Thirst: Managing the Electricity Sector’s Water Needs and the Risk of Drought (2012)
Using case studies, this report highlights the close ties among energy, drought, and water use in the Intermountain West; clean energy policies that reduced the energy sector’s water use and exposure to drought; and, finally, recommendations for mitigating the impact of future droughts on the West’s energy sector.

Every Drop Counts: Valuing the Water Used to Generate Electricity (2011)
The enormous amounts of water used to generate electricity aren’t being taken into account when utilities make plans to meet future energy generation needs. This report lays out the facts of energy’s water costs and recommends ways to address them.

A Sustainable Path: Meeting Nevada’s Water and Energy Demands (2008)
The first of a series of three case studies, this report on water and energy in Nevada looks at the impact that growing water demands and water-hungry fossil energy production will have on Nevada’s future water supply. This scenario is contrasted against a future where water and energy efficiency practices are implemented and renewable energy is used to meet new energy demands. While the unsustainability of Nevada’s “business as usual” approach to meeting Nevada’s energy and water demands is no surprise, the urgency necessary to shift away from this unsustainable path is.

Protecting the Lifeline of the West: How Climate and Clean Energy Policies Can Safeguard Water (2010)
This report by Western Resource Advocates and Environmental Defense Fund illustrates why legislation is needed to curtail the risk climate change poses to western water supplies and highlights the water-energy nexus. The report provides detailed measures to include in a well-designed national climate and clean energy policy that will safeguard the West’s water.

Clean Energy Program

Renewable Energy & Energy Efficiency

Healthy Rivers Program

Water Conservation and Efficiency

Related Publications

Water Required for Energy Generation in Colorado is Declining

Conservation Synergy: The Case for Integrating Water and Energy Efficiency Programs

A Powerful Thirst: Managing the Electricity Sector’s Water Needs and the Risk of Drought

Resource Planning by Western Utilities: Steps Towards Integration of Energy and Water


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