Spend Less Energy Managing Water

Communities and their residents use a lot of energy treating and moving wastewater, which accounts for an estimated 3 to 4 percent of total U.S. electricity consumption.ⁱ By implementing green infrastructure that reduces rainwater flows into sewer systems, recharges aquifers, and harvests rainwater, communities can decrease municipal and domestic energy use. Green infrastructure can be implemented in tandem with other strategies to decrease energy usage, such as addressing leaks and breaks in collection systems, preventing infiltration and inflows into collection systems, and conserving water. Visit EPA's WaterSense page to learn more about conserving water.

As heavy rainfall events increase with a changing climate, resilient stormwater management becomes all the more important. Explore the sections below to learn about using green infrastructure to manage water more efficiently and find resources for implementation.

On this page:

• Using Green Infrastructure To Spend Less Energy Managing Water
• Resources
• References

Using Green Infrastructure to Spend Less Energy Managing Water

Among other resiliency benefits, green infrastructure can help reduce the energy needed to manage stormwater. To learn about using green infrastructure for storing and conserving water, visit the Prepare for Drought page.

Manage Stormwater More Efficiently

Keeping stormwater out of combined sewer systems can reduce the need for pumping, therefore saving energy on wastewater treatment. Green infrastructure can help with this by controlling stormwater runoff (pdf) through infiltration, evapotranspiration, and rainwater harvesting. It can also recharge aquifers and conserve water, further reducing municipal and domestic energy use.

Communities can widely distribute different types of green infrastructure locally and prioritize locating it in areas for maximum rainwater storage and infiltration. For instance, a community with combined sanitary and stormwater sewers could consider using a free resources available through EPA's Green Infrastructure Modeling Tools page, such as the Storm Water Management Model (SWMM), Watershed Management Optimization Support Tool (WMOST), Community-enabled Lifecycle Analysis of Stormwater Infrastructure Costs (CLASIC), or the Integrated Decision Support Tool (i-DST) to identify ideal combinations of green and gray infrastructure within a given treatment area.

Learn more about using green infrastructure contributions to reduce combined sewer overflows in EPA's Greening CSO Plans: Planning and Modeling Green Infrastructure for Combined Sewer Overflow (CSO) Control (pdf).

Estimate Reduced Pumping Cost Figures

While in the planning process, communities can estimate reduced pumping cost figures to help make the case for green infrastructure investments.

For instance, by using green infrastructure within their combined sewer area, Lancaster, Pennsylvania (pdf), could reduce the volume and rate of runoff entering their sewer systems, which then reduces the storage and treatment required for managing combined sewer overflows. Green infrastructure implementation was estimated to save Lancaster over $600,000 annually in reduced pumping and treatment costs.

Resources

Guides and Fact Sheets:

• Greening CSO Plans: Planning and Modeling Green Infrastructure for Combined Sewer Overflow (pdf) (CSO) Control — An EPA guide on modeling green infrastructure contributions to combined sewer overflow long-term control plans. Includes a case study on how to model reduction in total wastewater flows using dynamic hydrologic and hydraulic modeling.
• UC Davis Energy and Efficiency Institute — Discusses a collaboration between UC Davis and the Los Angeles Department of Water and Power on a landmark energy-water conservation study. Outlines energy requirements to move water and the energy savings associated with conserving water.
• Water – Use it Wisely — A conservation campaign providing information and strategies on practical ways consumers can conserve water.

Reports and Studies:

• Water Efficiency Saves Energy: Reducing Global Warming Pollution through Water Use Strategies (pdf) — This National Resources Defense Council report outlines energy efficiency opportunities relating to water.

Tools:

• AVoided Emissions and reGeneration Tool (AVERT) — EPA's Office of Air and Radiation developed this tool to help estimate the emissions benefits of energy efficiency and renewable energy policies and programs.
• Climate Ready Water Utilities (CRWU) — EPA's CRWU initiative assists the water sector—including drinking water, wastewater, and stormwater utilities—in addressing climate change impacts. By developing practical and easy-to-use tools, practitioners can access clear climate science and adaptation options by translating complex climate projections into accessible formats.
• EPA's Climate Resilience Evaluation and Awareness Tool (CREAT) Climate Scenarios Projection Map — This map provides easy-to-access scenario-based climate change projections drawn from CREAT. The impacts from a changing climate, including extreme heat and more intense storms, present challenges to water, wastewater, and stormwater utilities and the communities they serve. Understanding how climate change may affect a utility's ability to maintain and deliver adequate, reliable, and sustainable water supplies and clean water services is the first step in climate-related planning.
• Water Footprint Calculator — Calculate your household's water footprint and learn how to save water.

References

1. National Renewable Energy Laboratory. (2012). Energy efficiency strategies for municipal wastewater treatment facilities (pdf). Retrieved March 10, 2023.