Researchers at Idaho State University (ISU) and Boise State University (BSU) are investigating new methods to address water storage and energy needs in Idaho. The focus of their research is on subsurface dams, an approach that involves storing excess snowmelt runoff underground by placing barriers in high mountain aquifers.
Bruce Savage, professor and chair of the Department of Civil and Environmental Engineering at ISU, explained the importance of managing water resources: “The majority of Idaho’s water comes from snowmelt either via surface water or groundwater. Consequently, there is a need to wisely manage our water and find ways to increase our water storage, keeping more of our spring run-off for summer use. This need for additional storage is crucial in a state that ranks third in the nation for total water use and second for irrigation withdrawals.”
Savage and James Mahar, senior lecturer at ISU, have formed a team with colleagues from both universities to explore how subsurface dams could capture snowmelt that would otherwise go unused. Subsurface dams function as underground barriers built across natural groundwater flow paths. These structures allow for the collection and controlled release of stored water during summer months, which can help support stream flows needed by fish as well as agricultural and municipal uses.
“Subsurface dams have their own unique advantages: water isn’t lost to evaporation, the land above the water remains usable, and the water is less exposed to contaminants,” said Savage. “Plus, the high mountain subsurface dam can be set up to generate hydroelectric power using the elevation difference.”
Idaho’s topography may be particularly suited for this technique due to its steep mountain basins with permeable soils. Savage noted: “Idaho’s steep mountain basins with their permeable glacial and alluvial soils make several regions strong candidates for subsurface dam exploration. By capturing excess water during periods of high spring flow, these systems could increase aquifer volume and create natural underground storage that is both geographically shielded and climate-resilient, and be an opportunity to store clean, cold water underground without the environmental and social impacts of large new surface reservoirs. Additionally, using Idaho’s natural river systems for delivery would reduce the need to build new infrastructure like canals to get the water to users.”
The research will continue over two years as part of a statewide project called Idaho Community-engaged Resilience for Energy-Water Systems (I-CREWS), funded by the National Science Foundation’s Established Program to Stimulate Competitive Research (EPSCoR). The I-CREWS initiative aims to study how changes in weather patterns, population growth, and technology affect interconnected energy-water systems.
James Mahar emphasized collaboration among disciplines: “With this research team, we’re getting a good start on the engineering feasibility, potential site characteristics, groundwater impacts, ecological implications, and social perceptions associated with subsurface dams.”
Kitty Griswold from ISU added: “I-CREWS support allows researchers to innovate in ways that directly benefit Idaho. Professors Savage and Mahar built a highly capable team at both ISU and BSU that spans engineering, geoscience, and social science ensuring that technical environmentaland community dimensionsofsubsurface damsare all evaluated together.”
Savage summarized their objective: “While subsurface dams if proven viable will not solve Idaho’swater challengeson their own they offer another tool; an opportunityto store cleanwaterunderground without disrupting river systems or significantly alteringthe landscape.Our goalis tounderstand whenand where this tool can supportIdaho’s long-termwaterand energyneeds.”
For further information about civil engineering programs at ISU visit isu.edu/cee.
