CHAMPAIGN, Ill., 1/13/22: When it comes to water supply planning, stakeholders want to know when their community will be at risk for water shortages. Illinois State Water Survey (ISWS) scientists involved in community groundwater modeling are touting the value of engaging those stakeholders to reduce uncertainty and help them understand how the models work.
Groundwater models are like peeking into an imaginary world below the surface and are vital for projecting the viability of the water supply for decision making. But the models are not infallible, said Devin Mannix, ISWS hydrogeologist. Model outcomes are only as good as the data supplied, and many assumptions need to be made.
Some of the uncertainties in modeling are related to a lack of information on the structure of aquifer systems and on future water demand and urban development. Still, the stakeholders—water operators, drillers, and community leaders—want a timetable depicting when wells may no longer be productive. Scientists use different scenarios based on water demand and other factors.
“They ask us, ‘will we run out of water in 2030?’” Mannix said. “We might say, ‘in some scenarios yes, and in other scenarios, perhaps not, and the answer will vary from community to community.’ We try to get on the same page in terms of what the stakeholders are expecting and what the models actually tell us.”
Participatory modeling involving community representatives has been used extensively in environmental modeling and management for decades, but only more recently in groundwater modeling. One goal is for the stakeholders to trust in the process. In this way, all involved can move forward in drawing up plans for the next decade or so.
This type of modeling typically involves discussing groundwater models, the data, and expectations.
“Groundwater modeling for a particular community used to involve completing the model, packaging it up, and calling it a day,” Mannix said. “Now we’re building a living model to some extent. The framework has integrated our database directly, so we can continually update the model. We’re also keeping the communication pathways open with stakeholders and keeping the data flowing.”
Mannix has found that stakeholders’ expectations are as important as the facts. In some cases, newer groundwater models have predicted more dire outcomes than models created years ago. This conflict can cause stakeholders to lose trust in expert knowledge and disengage from the research process, thereby creating more uncertainty.
With time though, scientists’ understanding of a water supply system evolves and more information becomes available that they didn’t have when developing previous models.
The scientists are now looking beyond the scenarios that they’ve developed to predict water supply risk, to what happens if communities switch water sources, in some cases from groundwater to a local river or lake.
The article “Uncertain Waters: Participatory Groundwater Modeling in Chicago’s Suburbs” was published in the journal Geoforum.
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Media contact: Devin Mannix, 217-244-2419, mannix@illinois.edu
news@prairie.illinois.edu