Carryover
The Upper Republican NRD (URNRD) has, for years, encouraged water conservation by allowing something called, “carryover.” The idea is that a farmer will use less water in total if he knows he is rewarded for saving water. The reward is the ability to access that water when it is needed.
For example, you have a budget of 100 units a year. If you lose everything that you don't spend, then you have a strong incentive to use all 100 units, even if you don't need to. If, however, you are permitted to store your savings for a time when you really need them, you will use less in total.
The concept has proven to be very successful at reducing total water usage. Many farmers are very conservative and like to save. Many farmers have worked hard to reduce water usage by rotating crops, by stressing the crop early by giving it less water, by immediately turning off the water when it rains, by using more efficient distribution systems, and by utilizing many other water saving techniques. So, over time, many farmers have used much less than their allocation and built up large carryovers.
Some people look at the large carryovers and see them as a potential liability that must be removed. In reality, their fears are misplaced and more water will probably be used if the carryover mechanism is removed. The carryover concept has allowed the URNRD to use less water, as a percentage of crop need, than any other NRD in the State.
Carryover is an extremely valuable tool that should remain in use. It is not abused for several reasons. One, is because it would be very expensive to do. Two, it isn't responsible. Three, farmers are in this for the long term. Farms usually pass from generation to generation. Having a reserve to call on in droughts is essential.
Because pumping from wells does not have an effect on the stream until many years after the water is pumped, the amount of water pumped in any one year has little relationship to Nebraska’s ability to comply.
The very large amount of carryover water that is on credit in the URNRD is a testimony to how successful farmers have been at using less than their allocation. Very little of that carryover will ever be used. Removing the carryover process will increase the water usage because you have removed one of the most important incentives that farmers have to use less; and he will, instead, be encouraged to use his full allocation each year.
The chart shows the amount of water pumped by groundwater irrigators in the Republican River Basin, according to the DNR. It also shows the depletions to the stream charged to groundwater irrigation, according to the computer simulation that is used to measure Nebraska’s compliance. The depletions are what matters. As can be seen, the amount of water pumped has little relationship to Nebraska’s ability to comply. Thus, allocation reductions are nearly meaningless until many years later. 1993 is the best example. It was a very wet year with little irrigation needed. Even though pumping was dramatically less, the depletions to the stream caused by irrigation were not effected in a way that can be seen for decades. At least that is what the computer simulation says.