McHenry County's regional drought might be over, but groundwater concerns linger
The end of an almost two-year drought in McHenry County hasn't dampened concerns about municipalities' drawing down of groundwater.
While planners at the county and local level are aware of the need for sustainable yields from aquifers, some believe conservation and efficiency measures may not be enough to avoid alternative options for water in the long term, such as Lake Michigan.
County water analysts said the prospect of future droughts may not be the primary cause of concern.
In fact, the region's long-term forecast calls for above-average precipitation, said Wes Cattoor, acting chief of engineering studies for the Illinois Department of Natural Resources.
Although a statewide drought in 2012 caused significant crop failure, Scott Kuykendall, water resource specialist with the McHenry County Department of Planning and Development, said he asked National Oceanic and Atmospheric Administration scientists why McHenry County had experienced a localized drought.
Their explanation? Bad luck.
When a drought does occur, as was the case for almost two years up until this spring, inputs into the shallow aquifer system such as surface water in streams are significantly less, Cattoor said.
There are 37 active monitoring wells in McHenry County that transmit data to U.S. Geological Survey satellites, Kuykendall said, adding that the federal agency, in turn, maintains the data for them.
The challenges for McHenry County's groundwater resources have to do with continued population growth projections, as well as differences in underground geology and hydrology from one municipality to the next, Kuykendall said.
For example, Lake in the Hills has had a much quicker recovery because of sand and gravel in that area, Kuykendall said, while Huntley's water, which comes from a deep-water aquifer, could take longer to recover.
"There's a certain amount of sustainability as long as we don't draw it out faster than it's being recharged," Kuykendall said. "These [water] tables can rise and fall."
Groundwater aquifers, Kuykendall said, are less like underground lakes and more like uneven layers of rock and sediment within which water can fill. How much water can be contained within layers depends on the type of rock and the material between the aquifers, known as aquitards.
Those layers also determine how easily water can penetrate or replenish, Kuykendall said. Sand and gravel, being composed of smaller particles, provide a layer where water can replenish easily. With limestone -- a hard rigid rock that is significantly less porous -- water can fill cracks and fissures, but those fissures then also determine when and how the water can flow within that layer.
Private wells within the county tap into the shallower sand and gravel aquifer or in the layer of limestone directly underneath, where water and snowmelt can infiltrate into the ground and fill the spaces in between.
The deep bedrock aquifer within McHenry County -- part of the Ironton-Galesville Aquifer that spans several states -- is 1,300 feet below the surface in a layer of sandstone, where ancient sands have been pressed into stone but maintain pour spaces, Kuykendall said, adding that sandstone layers often cover a massive area underground.
The benefit of the deep water wells is that they are not susceptible to short-term fluctuations in water levels. Unfortunately, that also means they recharge on very slow time scales.
Recharge for the deepwater aquifer comes from north-central Wisconsin, Kuykendall said.
"It can take thousands of years for water to make the trip," Kuykendall said. "As soon as we start pumping water out, we are drawing the water table down. That aquifer is basically being run dry."
In addition, during drought conditions, municipalities rely on the deepwater sources more heavily, drawing down even faster.
Although the aquifer won't run out anytime soon, Kuykendall said, he warned that we are "robbing from future generations."
Crystal Lake uses a combination of various aquifer layers, while Huntley and Harvard use only the deep bedrock aquifer.
In addition, both Huntley and Crystal Lake are planning to drill new deepwater wells this year, officials in those municipalities said.
Huntley Public Works Director Tim Farrell said the county's uneven geology is partly due to the movement of glaciers thousands of years ago. Those glaciers shaped the region's valleys and upper bedrock layers on a localized level.
"The glaciers advanced and retreated and left behind gravel bedrock that we use for shallow aquifers," Farrell said. "For whatever reason, those glaciers missed Huntley."
All municipalities in the county rely on groundwater for drinking supplies, while the western region depends on wells for agriculture, Kuykendall said.
Kuykendall described state laws restricting groundwater use as "very weak," noting that municipalities are self-governing in that area.
Farrell confirmed that Huntley, which has five deepwater wells, was "pumping quite a bit" to meet water demands over the past few drought-stricken years.
He said the extra drawdown was "fine" during that time period, but the wells and treatment plants were at full capacity during the drought due to the lack of rainwater that normally supplements well usage.
Huntley does not have the upper level of sand and gravel that other municipalities can use, Farrell said.
Within 20 or 30 years, Farrell said he anticipates Huntley looking into connecting with Lake Michigan water, which likely would be a regional initiative at that point.
Lake Michigan water service goes as far as Hoffman Estates, which is 20 miles east of Huntley, Farrell said.
"No community can do that alone because of the cost," Farrell said. "It would be too prohibitive. We're 20 years out from that, but it's going to take that long to plan for it and get any pipelines out here anyway."
Crystal Lake Public Works Director Mike Magnuson said city planners are aware of the concern about drawing from the deep well aquifer.
"We are mindful that long term the deepwater aquifer has limited capacity," Magnuson said. "Looking at water options for McHenry (County) is going to have to happen. We can't go on forever if the county keeps growing in population."
Crystal Lake encourages residents to conserve water for uses such as maintaining lawns, and there are restrictions in place for when excessive drought conditions occur, Magnuson said.
Magnuson noted the shallow aquifer was further affected by surface pollutants or chlorides from oversalting roads during the winter. The deepwater aquifer, on the other hand, wasn't affected by that factor.
Farrell also said Huntley came close to having to enact water restrictions but ultimately did not.
"I approached the village board at one point last summer to let them know we were approaching the point where we needed to implement more aggressive water conservation measures," Farrell said.
In the future, the local water agencies want to coordinate with municipalities and state agencies and use better models to gauge the effect of population and infrastructure growth, Kuykendall said.
Several cities in the collar counties already have run into problems with growing too fast or overdrawing on limited water resources.
At the moment, Illinois' allocation of Lake Michigan water affords some amount of future growth, said Joel Brammeier, president of the Alliance for the Great Lakes.
However, municipalities must apply for a permit from the Illinois Department of Natural Resources and fulfill certain conditions, including conservation of their existing water supply, before the state allows a community to move to Lake Michigan water, Brammeier said.
The process can take a long time, and the infrastructure involved requires decades of planning, Brammeier said.
One potential complicating factor, Brammeier said, is that Illinois alone among U.S. states and Canadian provinces is allowed to take Lake Michigan water and transfer it to the Mississippi watershed. That's instead of returning it to the Great Lakes.
While Illinois still is well under its allotment of water, Brammeier said he couldn't envision the state getting a larger allocation of water.
"The last thing we need to be talking about is diverting more water from the Great Lakes," Brammeier said.
Groups such as the Northwest Water Planning Alliance -- an intergovernmental agreement among 80 communities -- and the McHenry County Council of Governments are coordinating on regional issues. Those issues include aquifer drawdown and contamination of water tables from road salts and other contaminants, said Justin Keller, a manager with the Metropolitan Planning Council.
Essential answers must analyze what constitutes sustainable groundwater yields. The solutions must improve planning around surfaces so water re-enters the shallower aquifers, Keller said.
"As we build out further, we put impermeable surfaces on undeveloped land," Keller said. "But a lot of places are planning so they won't just be slapping down concrete willy-nilly."
Today, 6 million residents, or two-thirds of the Chicago metropolitan area, rely on Lake Michigan water. The Chicago Metropolitan Planning Council expects major growth in McHenry County as the region becomes a destination for those leaving the urban core.
But population growth does not have to be tied to excessive water drawdown and "aquifer death," as long as McHenry County planners value sustainability, Kuykendall said.
At the county level, Kuykendall said no planners were considering a potential switch to Lake Michigan because of the distance and cost of such a move. He noted, at present, McHenry County still has ample groundwater resources that, if properly managed, should last well into the future.
"We can have flat water usage," Kuykendall said. "But only if we do good conservation measures. That's the key. What we have here is special, but only if we protect it."