Summary of UCS Report on Freshwater Use by U.S. Power Plants
To Manage Risk, Government Officials and Power Plant Operators Must Consider Impact of Water Use.
Power plants are stressing freshwater resources around the country, according to a new report by the Energy and Water in a Warming World Initiative, a three-year research collaboration between the Union of Concerned Scientists (UCS) and a team of more than a dozen scientists. The report, “Freshwater Use by U.S. Power Plants: Electricity’s Thirst for a Precious Resource," is the first systematic assessment of how power-plant cooling affects freshwater resources across the United States and of the quality of the data available on power plant water usage.
The UCS-organized analysis looked at different aspects of the implications of power plant water use related to the supply and demand of freshwater and to water quality issues including:
- Water withdrawals by power plants (including fish entrainment and entrapment issues)
- Water consumption by power plants
- Impact of the discharge of hot water on the river
UCS calculated the available water in every major watershed in the U.S. and measured that against the water used by power plants in each watershed. The research found that the Catawba basin – a region commonly viewed as having an abundance of water – is experiencing high water-supply stress. 
Unlike the Southwest, where the majority of power plants have minimized their water use, a large share of water stress in the Southeast is being caused by power plants. The study found that power plants (primarily those owned by Duke Energy) consume between 5 and 19 billion gallons of water per year for cooling from the Catawba River basin. A Duke Energy study concluded that by 2048 water supply in the Catawba River will not be able to meet demand.
To gauge water-supply stress, the analysis examined the balance of local water supply and demand in each major watershed or “sub-basin” in the United States, then factored in the amount of water that power plants are using. The analysis then focused on areas where power plant demands were the largest contributor to water body stress based on the methodology. The Catawba River basin was identified as the fourth most stressed river in the United States from water use by power plants.
The report also studied how power plants are stressing water bodies by discharging water at temperatures harmful to fish and other wildlife. In 2008, 350 power plants across the country reported discharging water at temperatures of over 90 degrees Fahrenheit and some at temperatures over 110 degrees, according to the report. The discharge of heated effluent from powerplants is believed to have contributed to large fish kills on Lake Norman.
In recent years, a number of power plants, including power plants in the Catawba basin, have had to cut back power production because they were unable to stay within water temperature discharge limits, according to the report. Without water-smart energy choices, energy-water collisions may worsen as the population and the corresponding demand for energy and freshwater supplies grows, and as the climate changes. Water-smart technologies include wind and solar photovoltaics, which use essentially no water, and produce no carbon emissions, according to the report.
For more information about the UCS report and related issues, click on one of the links below:
- Overview of the collision between energy and water
- UCS Report on Freshwater Use by U.S. Power Plants
- Report on Energy-Water Collision
- Report on Powerplant Water Use by Electric Power Industry
- Map & Information About Water Withdrawals and Discharges - Interactive Google map of municipal water withdrawals and wastewater discharges along the Catawba River and Wateree River
- Overview of water quantity issues in the Catawba basin
- Videos on improving water efficiency
- Library of documents on water efficiency.
- Library of information about water use.
- Library of documents on drought issues.
