MINNEAPOLIS (Reuters) - The Great Lakes region, the world's largest freshwater system, could face local water shortages in the Chicago and Milwaukee areas due to increased demand and environmental changes, the U.S. Geological Survey said on Monday.
Water levels in Chicago and Milwaukee could drop by an additional 100 feet over the next 30 years due to increased demand from pumping of groundwater that has already reduced groundwater levels as much as 1,000 feet, the report found.
"In some areas, the physical quantity of water may be limiting"," said Howard Reeves, USGS scientist and lead author on this assessment.
The Great Lakes water basin has seen relatively little overall impact from groundwater pumping, but water is not distributed evenly throughout the region. This could lead to potential local shortages, according to the assessment, conducted over five years.
The five Great Lakes make up 84 percent of the fresh surface water in North America overall. The study will be used to improve forecasting water supply and demand.
"The Great Lakes are a dynamic system responding primarily to short- and long-term variations in climate," Reeves said. "Understanding the potential for local shortages or conflicts within this dynamic system is important for sound decision making."
(Reporting by David Bailey; Editing by Greg McCune)