Will the Silurian Aquifer have enough water to support the population that draws from it? Answers to that question are a bit sketchy due to infrequent research into groundwater projections. A 2011 study published by the Iowa Department of Natural Resources had this to say about nearby Coralville, which draws water from the Silurian Aquifer.

The City of Coralville may have to limit its future withdrawal of water from the Silurian aquifer to maintain the sustainability of the resource. Contingency plans should be prepared by the City of Coralville to evaluate alternative water sources.

Groundwater availability modeling of the Silurian Aquifer in East-Central Iowa, November 2011.

Read that quote again and say after me, “Yikes!”

Last summer, water usage on our community’s public water system surged with the drought. We are also on the Silurian Aquifer. So much more water was used during the worst days of drought the well faltered. We instituted voluntary conservation practices and the issue resolved. Usage dropped by 26 percent the following month. The question repeats itself. Will there be enough water in the aquifer?

In 2006 a similar study was published by the U.S. Geological Survey. While I was on the board of health, we reviewed it, and saw it’s conclusion that until 2025, projections indicated there would be enough water to serve the population. That was good enough for the Public Health Department and the Board of Supervisors back then. It may be time for a new survey, and perhaps one of the involved entities has already undertaken it. I hope so. The message was clear in 2011: decrease reliance on the Silurian Aquifer.

Things have shifted. Two of Big Grove Township’s neighboring cities, Tiffin and North Liberty, are among the fastest growing in Iowa. All those people will need water and their public water systems draw from the Silurian Aquifer. Similarly, there has been an exodus of population from rural parts of the state with many moving to urban areas where there are jobs, healthcare, and commerce. This also creates more localized demand for groundwater. Finally, our rivers have been a source of drinking water, as they are in Iowa City. Surface water quality in Iowa continues to get worse with extractive agricultural operations going on in almost every square inch of the state. For how much longer can cities rely on river water for humans to use? Drawing more from the Silurian Aquifer may not be a reasonable alternative when Coralville is being told to make other plans.

My point in this post is ground water is not a limitless resource. We should each be taking steps to minimize household use and if on a public well, use more of our water during off peak hours. The talk about water used for flushing the toilet, watering the lawn, and fixing household leaks is not a liberal conspiracy. Conservation benefits everyone.

We don’t know if there will be enough water for human populations. We cannot live without adequate water and our scientists and governmental organizations should make sure the projected usage models are accurate, and then work on solutions to shortages. If the Silurian Aquifer goes dry we are in for a wake up call. I predict it won’t be pleasant.

Editor’s Note: I checked with the county and, in fact, a new study of the Silurian Aquifer is in progress. Looking forward to reading it when finished.