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<br />problems. It's not going to be easy for Colorado. We have issues before us that are going to be costly. It will require <br />changes in operations and farming practices and we will need to look for opportunities for innovative solutions. We at <br />the Conservation Board have worked hard over the last year, along with the State Engineer's Office and water users <br />through the Arkansas River Coordinating Committee, to look for solutions. We're also proposing legislation to give <br />some assistance to the basin. With that, I will close and take time for some questions. <br /> <br />Q. Inaudible (Question about changes in farming practices) <br /> <br />A. What I am suggesting is that because pumping ground water is quite expensive, it will be expensive to purchase <br />augmentation water and also pay the electric bill for pumping groundwater. You're going to have to look at crop <br />types that will be served by groundwater. You're going to have to look at how your pumps operate, and in some <br />cases yes, you're probably going to want to pump less water to avoid over-application -- in other words, just <br />pumping it out and c)'Cling it around to prevent waste. At the same time, we're also going to have to stay within our <br />apportionment, our historic use of the water system. <br /> <br />Q. Inaudible (Question regarding groundwater not tributary to the Arkansas River.) <br /> <br />A. You're,changing subjects on me. Basically, the Ogallala Aquifer is also utilized in Kansas, but the Ogallala Aquifer <br />and the use of designated groundwater, as we call it, is controlled by the Colorado Ground Water Commission. It is <br />handled under a procedure developed in the 1950s and '60s to try to do something about the problem. The <br />Arkansas River groundwater pumping is principally from the tributary alluvium which is on both sides of the river <br />and terrace gravel on the mesas. Here's how the river actually operates: basically, the large irrigation canals take <br />water out of the river and recharge the groundwater tables; then they pump the conjunctively used groundwater if <br />there wasn't surface water available. Under the recent Supreme Court decision Colorado will have to cut back on <br />utilizing those irrigation wells in order to meet the obligations to Kansas, We have to be able to, in effect, deal with <br />the depletion caused by the wells' pumping, This is tributary groundwater, a renewable resource, and it comes <br />back every year. As the river flows and as we irrigate, we recharge the groundwater. Many people start thinking in <br />terms of conservation -- that is, if you would apply it more efficiently, there will be more water, You have to think of <br />what actually happens to every drop of water that you use. When you divert water from a stream, and with flood <br />irrigating in particular, there is some leakage off the bottom of the canal which recharges the groundwater table, <br />You spread it on a field and a percentage of that water is consumed by the crop, through evapotranspiration. <br />Particularly in the Arkansas Basin, a large amount of that water is returned to the basin through groundwater <br />recharge. Groundwater recharge seeps back to the river later in time, The time it takes to come back depends on <br />how far you are away from the river. As it soaks into the gravel it changes the time it gets back to the river; there is <br />a delayed effect when you intersect the groundwater system and change this timing with pumps. Say you pump 4 <br />acre-feet per acre -- if you are flood irrigating maybe your crops are only consuming 2 acre-feet for every acre you <br />irrigate. The rest is returned because the plants don't use it all. If you change practices, you have to be very careful <br />not to enlarge upon consumption of the water. In other words, if you can pump more efficiently and pump less <br />water you still can grow the same crop, but with reduced energy costs. You haven't necessarily saved water, <br /> <br />Q. Inaudible <br /> <br />A. That's what I was trying to talk about earlier. If you look at the Arkansas River Basin you have a valley that is 5'.10 <br />miles wide, primarily carved out of shale, that has been filled over time through deposition with gravel and sand. <br />Those are the valley fill aquifers. Additionally there were some glacier deposits up on the mesas as a result of <br />glaciation and those are still tributaries. lets think about the Bessemer Ditch, for example. It takes water out high <br />up above Pueblo and it takes it out onto the St. Charles Mesa. That mesa has a large gravel layer, it irrigates that <br />mesa, and recharges that aquifer. With the tributaries of the Arkansas where the streams have eroded the mesa you <br />see springs cropping out, and there are return flows out of that aquifer back to the river. They are physically <br />COIUlected through recharge and return flows. <br /> <br />Q. Inaudible (Question about useable flows) <br /> <br />Arkansas River Basin Water Forum <br /> <br />12 <br /> <br />"A River of Dreams and Realities" <br />