GV expert: Water supply in jeopardy

There are already places in Green Valley and Sahuarita where the ground has settled as much as several inches because the groundwater below it is dwindling, a water expert said Monday.

It will continue to the point where houses are ruined and rendered worthless, said Peggy Bonthron at a special meeting Monday at Bank of America.

Bonthron said, “We the citizens of Arizona are going to have to sue the state,” to save this area from the ravages of overdraft.

Bonthron worked for a water conservation district in California before she and her husband, Green Valley Recreation director Gunnar Bonthron, retired here.

There she saw how cooperation among users big and small brought back one district seemed destined to become desert.

Bonthron’s three rules to preserve and replenish the groundwater are conservation, storm water capture and a Central Arizona Project pipeline to the area.

It will be hard to achieve those, but they’re essential for the survival of Green Valley and Sahuarita as places were people dwell and prosper.

This area’s biggest water users, copper mines, pecan groves and golf courses, will also ultimately benefit she said and they’ll need to join in the efforts, she said.

Bonthron cited figures from Nancy Freeman of the Groundwater Awareness League that this area is withdrawing 40,000 acre-feet of water a year from the aquifer that’s not replenished. It’s called overdraft.

The Santa Cruz Valley is beset with other problems.

Much of the local water is part of the Santa Cruz River, which flow year around from north of Nogales to about Amado before sinking out of sight.

At one time the Santa Cruz flowed year around as far north as Tucson.

Mexico has claim to almost 20 million gallons a day of the water released into the river below an international sewer plant north of border.

But so far, Mexico hasn’t tried to claim that discharge or charge the United States for it.

Bonthron said it sometimes seems like agencies which should be trying to preserve the water pass the problems to other agencies.

One of the big local issues is about building a copper mine east of the Santa Rita Mountains east of Green Valley.

The U.S. Forest Service has been holding a series of public meetings where people can write their objections.

Local water expert Freeman said the way the Forest Service counts the complaints reduces their impact.

The mine, the Rosemont mine, will be built on a private mining claim, but part of the waste will be stored on nearby Forest Service lands.

The Forest Service can’t just say no to the mine. Under the 1872 federal mining act, mining companies have much authority to develop mines in the American West.

Augusta Resource has tested a well east of Sahuarita to pump 60,000 acre-feet of water a year.

An acre-foot of water is a figure hydrologists frequently use, the amount it would take to cover an acre of land with a foot of water—325,851 gallons.

In coming weeks there will be two other similar meetings about local groundwater at the Joyner-Green Valley Library, April 25 and May 30, both from 1 to 3 p.m.

jlamb@gvnews.com | 547-9749