HAZELTON - Any other year, water in the North Side Canal Co. system would be long gone by now, sucked up by southern Idaho farmers.

This year, the water still flows - part of a first-ever attempt to recharge the depleted Eastern Snake Plain Aquifer, the Magic Valley's primary source of drinking water, after the end of irrigation season.

The recharge effort is part of a deal between groundwater pumpers and surface-water users who say the pumpers have depleted surface water that emerges from the aquifer at Thousand Springs.

Pumpers hope the recharge water will move through the aquifer and emerge at the springs.

Idaho Department of Water Resources hydrologists began measuring the project's success Tuesday, using a $20,000 device that gauges flow. Early indications show the recharge is working, but officials worry about an early hard frost.

"If this water freezes, it could end the whole project," said Cindy Yenter, an IDWR water manager.

Here's why:

As water trickles out of the reservoir at Milner, it seeps into the North Side's web of canals. Officials hope the water will seep through leaky or porous spots and into the aquifer. The water must be released slowly to take advantage of the leaks.

But if the water moves through the system too slowly and freezes, officials will have to call off the project because the ice could damage canal hydroelectric projects.

Then, the nearly $500,000 pumpers paid to buy the water could be for nothing - and surface water users would go another year without water they're entitled to under the law and the agreement.

It's a race against winter - one cubic foot per second at a time.

The water released at Milner at about 500 cfs fell by about 50 cfs by the time it reached the last station east of Hazelton.

The canal company usually runs about 2,000 cfs out of Milner, said Ted Diehl, NSCC manager.

Officials say the water that trickles into the aquifer could show up at Thousand Springs within six months. But models show that it can take as long as two years to move through the aquifer.

So for now, hydrologists and water users can only hope the water disappearing from the canal system finds its way to the aquifer - and eventually to the springs.

Matt Christensen may be reached at 735-3243 and at matt.christensen@lee.net.