How healthy are Great Lakes?

The Grand Rapids Press: The Great Lakes are big.

But they’re not bottomless.

A just-released report from the U.S. Geological Survey underscores both those points. The study affirms what everybody who lives in and around Michigan assumes: The Great Lakes hold a lot of water. The measure is roughly 6 quadrillion gallons, enough to cover North America, South America and Africa with a foot of water.

Yet, the report cautions that water levels in some places have been drawn down by human use and are threatened by global climate change. Advocates and policymakers should view these facts in a context far beyond the sandy shores of Lake Michigan. Water shortages have grown across the country and around the world. Climate change has altered rain and snow patterns leaving some reservoirs empty.

That makes Great Lakes water a substantial enticement — the shimmering blue gold of the young century. An abundance of fresh water could keep this region afloat economically, even as other quarters go dry. The plenitude surely makes the lakes — 90 percent of the fresh water in the United States and 20 percent of the fresh water in the world — a continuing target for people in drought, and in doubt about future reserves.

Water Census project

The five-year study by the U.S. Geological Survey is part of a larger Water Census project that looks at current water resources nationally, identifies trends and tries to forecast the availability of freshwater for human, economic and environmental use. The Great Lakes were the first part of that overview. The methods used here will be adapted for studies in other parts of the country.

As this latest report confirms, the Great Lakes are enormous. We should work to keep them that way.