One thing Phoenix is not doing, according to the article, is paying residents to rip up their thirsty lawns. Some other Arizona cities do, and Las Vegas may top the lawn-replacement scale with a promise to pay $1.50 a square foot  for grass replaced by landscaping appropriate for dry regions.

And read a Minnpost.com column on the Freshwater lecture last week by U.S. Geological Survey hydrologist Don Rosenberry.

The lecture, sponsored by the Freshwater Society and the University of Minnesota College of Biological Sciences, will be at 7 p.m. in the Student Center theater on the university’s St. Paul campus. Learn more.

If you cannot be with us, watch the lecture in live streaming video.

Some Kansas farmers who have been raising corn are having to switch to less water-intensive, less profitable,  crops like milo and sorghum.

And read a Financial Times article on China’s pressing water problems.

The article describes a region where 10,000 people — known as shengtai yimin, or “ecological migrants” – have left their homes because of water shortages. And the article cites a 2007 World Bank estimate that water problems cost China economic losses of 2.3 per cent of gross domestic product.

Some of the chemicals can interfere with the functioning of hormones in animals and people.

“What these studies really are measuring is the footprint of our society and how we live,” said MPCA Commissioner John Linc Stine. “Our lakes and rivers are reflecting the chemicals we use and put into our bodies. These chemicals have very beneficial uses, but unfortunately they tend to stick around in the environment after their first use.”

The two latest studies provide statistical evidence of just how widespread the chemicals are in Minnesota’s surface waters. In 2010 and 2012, the MPCA sampled lakes and rivers using funds from the state of Minnesota and the U.S. Environmental Protection Agency, part of nationwide EPA surveys to find out what’s in the nation’s waters.

Read an MPCA news release about the two reports. Download the lakes report. Read a Star Tribune article on the lakes report.

Here’s your chance to see how much.

Freshwater has a new quiz – about water, water use and water pollution – on our web site.

It will test your knowledge about how much mercury falls on Minnesota every year, why you really need to worry about silver carp and the contaminants that sometimes afflict private wells.

And, lest you think there is not much fun in a quiz like that, there also is a question about an old Hamm’s beer jingle. And there’s an essay question that involves food coloring and water conservation.

The quiz owes a lot to the U.S. Geological Survey’s Water Science School, which we also borrow heavily from in our web site’s updated Kids’ Page.

Take the quiz, see how you do. Then if you are moved to suggest a question for the quiz, go to our Facebook page and post it. We will send a 2014 Minnesota Weatherguide Environment Calendar to whoever suggests the best new question by the end of May.

The op-ed was written by John A. Vucetich, a population biologist, and Rolf O. Peterson, a wildlife ecologist, both at Michigan Tech University, and Michael P. Nelson, an environmental ethicist at Oregon State University.

A 55-year Michigan Tech study of wolves and moose on Isle Royale is the longest such predator-prey research in the world. Earlier this year, a winter count showed the wolf population – suffering from the long-term effects of inbreeding – appeared to have declined to eight animals.

Researchers believe no wolf pups were born on the island in 2012.

In the New York Times op-ed, the three researchers support either of two options:  introducing new wolves to the existing population, or replacing the existing wolves when the they die out on the island.

The researchers  note that “two of the architects of modern-day thinking about wilderness, the wildlife biologists Aldo Leopold and Adolph Murie, supported the idea of introducing wolves to Isle Royale in the 1940s — to conserve a habitat being overrun by moose — before wolves had arrived on their own.”

The editorial says, in part:

“The vast but finite aquifers are like glasses of water with many drinking straws — perhaps too many — draining their contents. One of the most pressing challenges facing the state is ensuring that increased demand from a growing population and agricultural irrigation doesn’t drain groundwater supplies too rapidly. Instead, this resource must be managed sustainably for future generations.”

The legislation, House File 977, is awaiting action by a House-Senate conference committee.

The editorial cites a Freshwater Society report, Minnesota’s Groundwater: Is our use sustainable?, that estimates total reported groundwater use in the state increased 31 percent from 1988 through 2011.