For generations, the Chicago region has relied on Lake Michigan to sustain our communities with safe, clean drinking water, power our economy, shape our identity, and secure our future.

But this seemingly abundant fresh water, one of the largest such systems in the world, is not guaranteed. Threats loom over the next several decades: Demand is rising in many areas, infrastructure is aging, weather patterns are becoming more extreme, and water-intensive industries are expanding — like advanced manufacturing, data centers and other industrial uses.

To address these challenges, the U.S. Environmental Protection Agency estimates Illinois will need substantial water infrastructure investments in the coming decades: roughly $22 billion for drinking water and more than $11 billion for wastewater and stormwater. Nationally, experts estimate that even a single day’s interruption in water service could put $43.5 billion in sales and $22.5 billion in GDP at risk.

Water is more than just a utility, it’s core economic infrastructure.

How does northeastern Illinois make sure this precious resource is carefully managed so it’s resilient to change and shared fairly for generations to come? How do we plan today so that tomorrow we have plentiful, safe, reliable and affordable water?

These are emerging questions as the Chicago Metropolitan Agency for Planning convenes leaders across government, business and civic sectors to develop The Century Plan, which will define priorities and a shared vision for a better, stronger future.

Much like with our economy or transportation, decisions about water in one community affect costs, reliability and infrastructure needs in others. Yet, we largely manage these shared resources through fragmented processes.

Unlike in other Great Lakes states, water oversight in Illinois is dispersed across multiple agencies, each with partial authority and an incomplete view of the whole system. Municipal leaders are working diligently to manage these challenges locally, but risks such as reliability failures, affordability pressures and long-term supply constraints do not stop at municipal boundaries.

The state of Illinois shares a Supreme Court-limited allocation of water from Lake Michigan — essentially a fixed budget. We also share groundwater aquifers, rivers and, in many cases, the same treatment plants and distribution lines that carry lake water across municipal boundaries.

There are growing pressures on these shared water resources. Communities dealing with groundwater quality or supply challenges are increasingly seeking to shift onto Lake Michigan water. At the same time, advanced manufacturing and data centers — facilities that can use millions of gallons of water per day — are expanding in Illinois and across the Midwest.

Water governance — the policies, institutions and practices that determine how water is allocated and sustained — shapes who has access, at what cost and with what long-term reliability. When shared resources are managed through largely fragmented systems, disparities can grow.

Stewarding Lake Michigan for the next century will require greater coordination across existing utilities and jurisdictions, better alignment between water withdrawals and long-term growth, and shared investment in modern infrastructure.

This is not about restricting opportunity. It’s about protecting it.

Northeastern Illinois’ next century of growth — from new housing to next-generation industries — will depend on how deliberately we manage the systems that make that growth possible. Join us in this effort and watch its progress at cmap.is/the-century-plan.

Water abundance is a gift of nature. Stewardship is a shared responsibility. The choices we make today will determine whether future generations inherit a region defined not just by access to water, but by the wisdom to manage it together.

Erin Aleman is executive director of the Chicago Metropolitan Agency for Planning (CMAP), the region’s federally designated metropolitan planning organization and state-authorized regional planning agency. CMAP is a sponsor of Crain’s Forum.