Iowa Hill Pumped-Storage Project

SMUD is studying the potential for building a pumped-storage system near Iowa Hill, a few miles from Camino in El Dorado County. This would be an addition to our existing hydroelectric system. It would expand SMUD's production of clean energy in our region, help meet peak demand for power, and allow us to integrate additional supplies of intermittent wind and solar energy, reducing greenhouse-gas emissions.

The pumped-storage project would add 400 megawatts of generating capacity to SMUD's hydroelectric system. It would allow us to reuse water from Slab Creek Reservoir and make more efficient use of existing resources, a critical plus in dry years.

The project would require construction of a new, off-stream reservoir 1,200 feet above Slab Creek Reservoir, a new underground powerhouse, and tunnels connecting the two reservoirs. Construction would take about five years, employing an estimated 235 workers and benefiting the economy of El Dorado County.

Project timeline, maps and diagrams

SMUD has been working with the greater Apple Hill community since 2001 to explain the Iowa Hill proposal, answer questions and listen to feedback. In 2005, we signed a cooperation agreement with El Dorado County.

In addition, El Dorado County agencies, recreational advocates and other stakeholders participated in a collaborative process that led in 2007 to a comprehensive agreement on how SMUD should operate its hydro system in the decades to come, with Iowa Hill as part of the long-term energy solution.

The SMUD Board of Directors is expected to decide by 2017 whether to build the project. In the meantime, SMUD will continue to work closely with the community to address questions and concerns.

Project update

SMUD is delaying the geotechnical exploration activities originally planned for October 2015 until approximately October 2016.
Read more

Road activity and work log

See a 2-week look ahead of project activities, road impacts and more.
July 27 - August 9 (167k PDF)
July 20 - August 2 (190k PDF)

Iowa Hill Simulation

Iowa Hill Pumped Storage project simulation

Watch a short animation showing how it would work.

Watch the video

Contact information

If you have questions regarding the Iowa Hill project, we are eager to hear them. Please get in touch with us at or 916-732-6822.

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