Tuesday, April 11, 2017

Water Resources Priority: Aquifer recharge

Water flows to this recharge site outside of Shoshone, water managers are stepping up flows just ahead of irrigation season--Ritter photo

Water managers divert spring runoff overflows to Snake River Aquifer

Pocatello—Following the floods in February and record mountain snow, the Bureau of Reclamation is allowing 15,000 cubic feet per second of water to flow past American Falls Reservoir and Milner Dam to free up reservoir space for spring runoff.

The state has a water right to intentionally recharge up to 1,200 cubic feet per second from the Snake River to recharge the aquifer, they hope to double and triple that number to free up water storage space. We talked to Idaho Water Resource Recharge Manager Wesley Hipke on the 2017 recharge:

This has been a good water/snowpack year, what does this mean for Idaho?
We’ve seen a lot of impacts this year and specifically theres a lot of flooding with higher river flows. From a recharge standpoint this is going to be a great year. Theres a lot of natural recharge going on all over the Snake River plain but theres still a lot of snow in the mountains. We’ll have a lot more runoff and most of that will infiltrate into the aquifer. For our managed recharge, we wouldn't have this kind of year without record snowpack in the mountains. This is going to be a great year given the amount of water thus far. With our irrigation partners we’ve moved a lot of the water into the ground that otherwise we would have flowed down the Snake River.

We visited the recharge site outside of Shoshone in the desert…it looks like an ordinary canal dumping water into a large pond, its far from the green fields of the Magic Valley, whats going on at that site? 
Thats a great area for recharge because its over an old lava bed. That stretch of land is very fractured with busted up lava flows and it’s a perfect site for a drain field. Areas like this typically have deep crevasses that allows water to infiltrate in the ground. That water trickles down more than 200 feet of sand and gravel to the water table.

Is that enough to clean up the surface water?
It is! Thats what our data has shown thus far. All of our recharge sites are heavily monitored for water quality. Of course, all surface water has bacteria, but what we’ve found is that the sand and gravel does a good job cleaning the water. In all our monitored wells is that the water is very good quality and meets the highest ground water standards.

Since 1913, Idaho farmers have irrigated the Snake River plain heavily. In the old days water could seep back into the ground, how much ground water have we lost in the past 100 years? The Aquifer has lost a lot water through the years. Over the past century we’ve seen a lot of irrigation along with industrial and population growth. We lost a lot of water from the Snake River aquifer. We started doing a lot of pumping as pump technology improved. Since the 1950s, due to that pumping and more efficient Ag practices, less water has recharged naturally through the ground. So that and combined with droughts, the aquifer has lost about 200,000 acre feet per year since the 1950s. Lawmakers and the Water Resource board set a goal to put water back in the ground every year.

What’s that number and is there a chance that Idaho can catch up soon?
The number is 200,000 acre feet on average, every year. An acre-foot is the amount of water it takes to cover one acre of land to a depth of one foot. Our goal is to hit capacity and get the program filled out and we’re well on our way. The legislature says that has to happen by 2024 but we’re actually hoping to get there by 2020. As far as turning the water deficit around, this is a huge aquifer and its over 10-thousand square miles. So thats a huge order to stop the decline and turn the aquifer around. So even putting 250,000 acre feet back into the ground is going to get us back to even. From here we can start to build the aquifer back up to historic levels. The Ag community is doing well in terms of reducing consumptive use and helping us divert water back into the aquifer. I think we stand a good chance of stopping this decline and building the aquifer back up in the coming years.

This snowpack is epic and one of the best years in decades for recharge, but is it enough? 
This is a long term thing, its taken us since the 1950s to get to this point. But our recharge program is designed to be a long term program. It’s not like we can say, ‘oh we had a good year and we’re done,’ this is a decades-long solution and it is going to happen every year. How does the “first in time” doctrine come to play in all this? It’s very crucial to all of this. In fact it jump-started the recharge situation a few years ago when we had water calls. It started because the first-in- time people were not getting their water right and thats water they clearly had a right to use. Water users saw clearly then that something had to be done. That could see that a constant draw on the aquifer without replenishing the aquifer, means that Idaho cannot grow. So its in the best interest to use water in the most efficient way and to work on this recharge program. We must add this excess water that would otherwise leave the state and we have to do it every year for our future use.

We did well this year with snowpack but thats no guarantee for next year. Whats in the Department's crystal ball? 
When it comes to weather forecasting, that is— so not my expertise! My crystal ball? When it comes to predicting water years is cracked, its frosty and never clear. The only thing that we can say for sure is that it is really hard to predict whats going to happen in the future. The last few years we’ve had drought conditions and here we have a wet year. What’s predicable is the variability from year to year! So I think recharge management and this artificial recharge program is crucial in the coming years. We must be diversified to handle these changes. When its dry we need to capture as much water as possible and when its wet we must capture as much as possible. So this is going to be a very diverse program, it has to because of the extremes.

 How closely is groundwater tied with economic growth?
With the recharge program the key point is this: if the aquifer is not replenished, it affects the first-in-time users. They have first rights to water. They can cut all current uses. So if we don't fix this problem, the lack of water could cut potential growth in the future. Water impacts everyone and this aquifer accounts for a third of Idaho’s economy. No question about it, Ag is a big economic driver of the economy. Furthermore because of Ag we’ve had a lot of industry come in, which funnels into our cities and allows them to grow. Industry brings in brings in more businesses as they grow. Without water we cannot grow. Its crucial that we handle this problem. We want to make sure that there’s alway water in the aquifer and with that, room to grow.

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