Milwaukee, Chicago areas may face water shortages: report

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.

The Great Lakes are a unique and precious resource, providing freshwater for 33 million people who live within the basin and supporting the region's ecosystem and economy. The Great Lakes basin contains nearly 20 percent of the earth's fresh surface water. It is the only freshwater system of its kind in size and ecological diversity and is essential to humans and wildlife alike, providing homes, food, recreation, and economic sustainability. The Great Lakes are critically important to the region. Nearly 11,000 miles of coastline surround the Great Lakes and their connecting channels and islands.

The Great Lakes constitute a vast resource, but each year rainfall and snowmelt replenish only about one percent of the water in the basin, making them vulnerable to depletion and degradation. The other 99 percent is finite and nonrenewable. That fact, coupled with a growing demand for water by domestic users--including utilities, agriculture, manufacturers, and housing--and proposals to export water to other parts of the U.S. and to foreign countries jeopardize the Great Lakes’ future.

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."

Source:
Reuters, "Milwaukee, Chicago areas may face water shortages: report", accessed February 7, 2011
Indiana Wildlife, "Great Lakes Restoration", accessed February 7, 2011

The drying of the West

Standing on the Hoover Dam and looking upstream at Lake Mead, America’s largest reservoir, the visitor notices a wide, white band ringing the cliffs (left). Nicknamed “the bathtub ring”, this discoloration comes from minerals that were once deposited on the volcanic rock by the Colorado River and have become visible as its water level has dropped. It is one sign of a water crisis that threatens America’s south-west.

Other reminders abound. Farther upstream there are dry docks, jutting out ominously into desert, where boats were once moored. In one finger of Lake Mead buildings that were abandoned in the 1930s, as the water of the newly dammed river rose and submerged them, have eerily begun reappearing, like a ghost town.

The main reason why Lake Mead, currently only 40% full, has been getting emptier is a decade-long drought. Whether this is a cyclical and normal event, or an early sign of climate change, is unclear. But even if the drought ends, most scientists think global warming will cause flows on the Colorado River to decrease by 10-30% in the next half century, says Douglas Kenney, the director of a water-policy program at the University of Colorado Law School.

The other reason, says Mr Kenney, is the rapidly increasing demand for the river’s water. The Colorado provides much or most of the water for many cities and farms in seven states—Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California—before it peters out in the sands of Mexico.

In the northern states, its water supports cattle empires. In its southern stretch, especially in California’s Imperial County, the river irrigates deserts to produce America’s winter vegetables. And all along the way, aqueducts branch off to supply cities from Salt Lake City and Denver to Phoenix and Los Angeles. The metropolis closest to Lake Mead, Las Vegas, gets 90% of its water from this one source. (See detailed map at right)

That is why Las Vegas is a canary in the mine shaft, as Pat Mulroy, the boss of the Southern Nevada Water Authority, puts it. The Las Vegas valley gets its water through two long channels drilled through the rock. The first taps the lake at 1,050 feet (320 metres) above sea level, the second at 1,000 feet. Lake Mead’s water level is now near its record low, at 1,086 feet. Within a few years it could leave Las Vegas’s first intake, or even both, dry.

The threat to Sin City is a good example of the four dimensions—physical, legal, political and cultural—of water in the West. For the physical, the standard response is to summon the engineers. Ms Mulroy already has them digging a third intake (left) at 890 feet. Given the weight of the water on top, this is fiendishly difficult and will not be ready until 2014. Ms Mulroy also wants to pipe groundwater from the rural and wetter northern counties of Nevada to Las Vegas, but that has caused a vicious row.

Another response is to call in the lawyers. This was the preferred approach a century ago, in the era of the “water wars”. Starting with the Colorado River Compact of 1922 (right) and continuing with statutes, a treaty with Mexico and case law until the 1960s, a truce was achieved. Called the Law of the River, the resulting regime determines who along the river has what right to how much water.

At least, it does in theory. The problem is that the law took shape after two decades of record water flows, which became the basis for allocation. As a result it apportions more water than there is in the river. For decades that did not matter, since there were so few people. Then the cattle, fruit and people using the river multiplied.

The law’s seniority rules theoretically mean that, for example, the taps to Las Vegas would be shut completely before a single lettuce-grower in California’s Imperial County lost a drop. This “idiocy of who gets cut first and second”, as Ms Mulroy calls it, gives rise to the political dimension. These days, co-operation has supplemented, if not wholly replaced, the old rivalries among agricultural and urban users, and among the seven states. Nevada and Arizona, for example, have a water-banking partnership, whereby Arizona stores excess water in its aquifers so that Nevada could use it in a pinch. In California, the water utility of Los Angeles has bought water rights from farmers in Imperial County. But arguments persist and other options are discussed.

The final dimension is the culture of the West. Does every middle-class house really need a lawn in a desert? Ms Mulroy has already started paying Las Vegans to rip out their turf and opt for desert landscaping, which can be chic. Her own husband put up a fight but lost. So out went that lawn, too, just as the low-flow toilets and taps came in.

Source:
The Economist, "Water Worries: The drying of the West", accessed February 3, 2011