Residents of Golden Valley, Crystal and New Hope, who share a water system, came within minutes of running dry last June through an odd collision of circumstances:

A storm knocked out power to a water tower pump in Crystal, followed about two hours later by a major water main break in Robbinsdale. At the same time, the remaining water supply pipe was offline for upgrades in Golden Valley.

"We came within 30 minutes of losing water," said Golden Valley Mayor Shep Harris.

The narrowly escaped tri-city drought highlighted the lack of a water backup plan. It's an issue that had been discussed for at least five years by the Joint Water Commission that provides water for the three cities.

In January, the cities took action to solve the problem. They agreed on a $4 million plan to drill three backup wells and rehabilitate an old, unused well in New Hope, said Tom Burt, Golden Valley city manager and water commission chairman.

"It's really good to see all three councils unanimously agree on moving forward with it," said New Hope City Manager Kirk McDonald.

The commission, formed in 1963, buys water from Minneapolis for the cities, Burt said. Minneapolis draws water from the Mississippi River near the Camden Bridge. The intake plant purifies, softens, and sends 45 million to 100 million gallons a day to city residents and other customers, said Glen Gerads, director of the Minneapolis water system. Besides Golden Valley, Crystal and New Hope, the river also supplies Columbia Heights, Hilltop, parts of Edina and Bloomington and the Minneapolis-St. Paul International Airport.

Backup source lacking

A glaring problem with the river-based system is that, like the three suburbs, Minneapolis has no backup water source, officials said. That means more than 500,000 residents and commercial users could face a water shortage under several untoward scenarios, such as if a severe drought dropped the river too low or a natural or man-made disaster hit the system.

By late 2015, the three cities plan to have their own backup groundwater wells that could provide more than 6 million gallons a day, Burt said. Such water would be limited to essential uses until the Minneapolis service resumed, he said.

"We thought we needed to shore up the water front," said New Hope Mayor Kathi Hemken.

"We can't wait any longer," added Harris, noting last summer's close call. He also cited the widespread water shortage that occurred in early January around Charleston, W.Va., when the city's water supply, the Elk River, was contaminated by a chemical spill for more than a week.

A tornado that tore through north Minneapolis in 2011 took off part of a water building roof, but didn't affect water treatment or distribution, Gerads said, noting that the treatment system has backup equipment. He said if the Mississippi suffered a chemical spill, river intakes would be closed for a few days until the contamination floated downstream.

Gerads said that Minneapolis has discussed a backup system for decades. About five years ago, the city considered installing a backup connection to the St. Paul water system, which draws from the Mississippi in Fridley and also uses groundwater wells. Officials decided against the idea because it appeared St. Paul lacked enough backup capacity for its own customers as well as Minneapolis, Gerads said.

Wells considered

Historically, hydrologists had thought groundwater pollution in the area around the Camden water plant might contaminate underlying aquifers, Gerads said. But a recent study suggested drilling backup wells into clean aquifers on the west side of the river and piping the water to the Camden plant, he said.

Minneapolis set aside $1.5 million this year to begin developing a backup system that could include at least 20 wells drilled over 10 to 20 years and costing up to $50 million, Gerads said. He said the city is seeking a state funds match, but that doesn't appear likely this legislative session.

Gerads welcomed the three cities' backup plan, which would mean fewer wells for Minneapolis to finance and maintain. "Contingency plans are always good," he said.

How to pay

The remaining issue for the commission cities is how to pay for the $4 million system. Burt said Golden Valley, which has more business water usage than its two neighbors, will pay about $1.6 million, a 40 percent share. Officials will use city fund reserves that will be repaid over time from a surcharge on customer water bills, Burt said. Households in the three cities use an average of 81,000 gallons of water a year, he noted.

Crystal and New Hope will each pay about $1.2 million, likely using internal reserves and water bill surcharges, officials said. New Hope will likely repay an internal loan by adding 20 cents per 1,000 gallons of water used on water bills. That would cost the average household about $12 a year, McDonald estimated.

The cities decided last week to drill two wells near Crystal's 19-million-gallon reservoir, and the third by Golden Valley's 9-million gallon reservoir, said Crystal City Engineer Tom Mathisen. He said New Hope's old well, closed in 1963, will be re-equipped. Mathisen said he expects bids to go out before April for the backup system.

The wells will need state permits from the Department of Health and the Department of Natural Resources. The state likes to see contingency water plans, and permit conditions would ensure that new wells tap a suitable aquifer and aren't too close to existing wells, said Jack Gleason, a DNR hydrologist.

"This is a proactive step," said New Hope's Hemken. "I don't know anybody out there who thinks we don't need water. It's better to be prepared than to find yourself short."

Jim Adams • 612-673-7658