Great Lakes system can’t afford so many water withdrawals
The Great Lakes may give the impression they are water-rich but they are like a finite and exhaustible shared bank account that could go bust.
There are plenty of examples of bankrupt water budgets and ecological disasters in regions that once had sufficient and even plentiful water. Why?
No one was there to certify that withdrawals did not exceed deposits. There were no plans to control the insatiable demand for water that grew exponentially to meet the demands of a population that went from 2.5 billion to more than 7 billion in just 61 years.
Water withdrawals from aquifers, lakes, rivers and reservoirs continued to increase but the amount of water did not. Without an accurate bookkeeping system to alert users about how much could safely be removed, depletion occurred before the accounts could be restored. There were no collaborative plans in place to protect the Aral Sea, the Colorado River, the Ogallala Aquifer and other communities that are now water-challenged, such as Waukesha, Wis. A positive balance could have been maintained to protect ecosystem services and future generations but instead, unsustainable withdrawals resulted in depletion and deteriorated water quality. Overpumping, climate change and drought have left communities like Waukesha with depleted aquifers. These communities, which sit just outside the basin, and others farther away see the Great Lakes as the answer to their water woes. But with historic low Great Lakes water levels already damaging ecosystems and threatening shipping, is it wise to grant exceptions to tap the Great Lakes?
The impacts of existing diversions on lake levels may seem minor, but they already alter the natural flow of the Great Lakes. Furthermore water returned from diversions may be of a lesser quality. That’s why in 2008 the eight states and two Canadian provinces that rely on Great Lakes water adopted a legally binding Great Lakes Compact to protect the lakes, rivers, streams and groundwater that feed them. They banned the diversion of water, with some limited exceptions, and set standards for water use and conservation within the basin. What they did not know then is how much warmer the water in the lakes would become or how ice cover would diminish in winter. They didn’t know that evaporation would increase or that precipitation patterns would be altered, with drought more common. They also could not have imagined how alarmingly fast uncontrolled groundwater resources would be depleted to support agriculture, industry and unrestrained development in surrounding communities. Neither did they envision new withdrawals for unconventional gas extraction which are not returned to the system. To defend a sustainable Great Lakes ecosystem, Great Lakes states and Canada must heed the science and maintain strict water budgets. But citizens too need to be involved in taking action to conserve and preserve the Great Lakes.
Contributing writer, Anna McCartney, a communications and education specialist for Pennsylvania Sea Grant, can be reached by e-mail at firstname.lastname@example.org.