Water resources are essential for sustaining economic prosperity, environmental health, and quality of life in the region. The leading sources of water in the region are Lake Michigan, groundwater aquifers, and the Fox and Kankakee Rivers. Access to Lake Michigan water has been critical to regional development and, if well managed, will continue to provide a sustainable supply of water into the future for much of the region. Illinois withdraws, uses, and then diverts Lake Michigan water out of the Great Lakes Basin to the Mississippi River system, a modification which resulted in a U.S. Supreme Court Consent Decree that governs Illinois withdrawal of lake water, which is managed by the IDNR. Over the years, access to Lake Michigan water has been extended, providing a more sustainable drinking water source. That said, there are limits to the amount of water the state can withdraw, which may limit some communities’ ability to access Lake Michigan water.
CMAP is updating the regional water demand forecast of Water 2050, which examined how population and employment, development patterns, climate dynamics, and conservation and efficiency efforts could affect future water usage. Per capita usage has been declining due in part to conservation and efficiency gains, and continued improvements will be necessary to manage the region’s water demand. However, the total demand for water is anticipated to increase with population growth and climate change. The location of future water demand will significantly influence whether the region can maintain a sustainable water supply.
[GRAPHIC TO COME: Map of water use by community, with per capita consumption for 2013 and 2050.]
Population growth and industrial development, particularly in the collar counties, has led to increasing withdrawals from constrained groundwater resources. Continued use of groundwater sources will require coordinated management throughout the region in the future, especially during droughts. In some areas, groundwater is being withdrawn at a rate that exceeds the recharge rate, resulting in decreasing yields, increasing pumping demands, increasing salinity, and the search for alternative water sources, all of which increase the cost of providing water. For example, increasing withdrawals from community water suppliers as well as industrial users in western Will County and northern Kendall County are posing significant risks to the existing quantity and quality of water supply as portions of the aquifer become desaturated. Similarly, shallow aquifer withdrawals in northeastern Kane County and southeastern McHenry County are exceeding the recharge rate, which may result in neighboring wells competing for less water and impacts to nearby streams and rivers dependent on groundwater flows. Land use and transportation decisions affect the amount of water that's available to replenish shallow aquifers as well as the quality of the water that enters our groundwater reservoirs. For example, roads and conventional road and parking lot salting practices are linked to rapidly rising chloride levels in some parts of the region. Water supply management will help to maintain water supplies, support community livability, and mitigate potential conflicts arising from water shortages.
Community water suppliers -- consisting of municipalities, sub-regional authorities, and private companies -- provide an essential service and are key to the region's economic success. They must maintain safe, efficient infrastructure at affordable prices while also managing water use to ensure a long-term supply. This challenging task is often exacerbated by aging infrastructure and strained financial capacity. Mounting infrastructure repair can result in high levels of water loss and delays in replacing lead and copper infrastructure. Some suppliers must also address large shifts in demand, such as new development or the closing of major industries, while others make long-term decisions in the face of near-term supply uncertainties. In addition, local elected officials and residents can be unfamiliar with the complexity of our water supply and the day-to-day challenges faced in continuing to provide clean, safe and reliable water. Low income residents, people of color, and the elderly may be disproportionately affected by deferred maintenance and service costs, which are eventually passed on to consumers. To maintain our quality of life and economic competitiveness, the region should pursue strategies that maintain and improve drinking water infrastructure and protect water sources.
The following subsection describes strategies and actions to implement this recommendation.