Why we are out of compliance
This chart shows the Allocation for the Republican River Basin as compared to the Consumptive Use for the Basin.
As you will notice, the consumptive use has gone down, not up as some people would try to make you believe.
But the water allowance for the Basin has gone down even more.
What controls the allowance?
Precipitation.
The Virgin Water Supply is the total water to be divided to each State. It is made up of two components – run off to the stream and seepage from the aquifer, called baseflow.
The baseflow is calculated as if the aquifer is still at the predevelopment levels. Any lowering of the aquifer is counted as a depletion to the stream after. In other words, if there is a reduction in baseflow it doesn’t reduce the allocation. The allocation is calculated as if there is no baseflow reduction and then the actual reduction is charged against the groundwater irrigator.
What this means is that the reduction in the allocation is not a result of any change in the aquifer because that is calculated later. Instead the reduction in allocation is the direct result of a reduction in the amount of precipitation.
This chart shows the precipitation received at the 19 Nebraska Compact Precipitation Gages. It also graphs the allocation in acre feet on the secondary axis. The allocation tends to follow the precipitation fairly well until 2003 where the allocation fails to rebound as it has in the past. I don’ t know why there is no allocation bounce. Knowing the answer to that would probably be very informative as to what Nebraska needs to do to comply
Notice that if the allocation had bounced up as it normally does, that Nebraska would be in compliance.
The only way to get the answer to this question is to look at the computer simulation in detail. Only the DNR can do that. Persuading the DNR to do that is probably next to impossible but worth a try. Only several hundred million dollars resting on the answer.