Disappearing Water

Most water in Nebraska does not flow to the stream or into the aquifer.  

Very little of the precipitation has ever made it to the stream.  Most of the precipitation evaporates. No one knows how much evaporates and how much seeps to the aquifer, though many have attempted to guess.  Because the aquifer has declined since ground water pumping began, we know that seepage into the aquifer must be less than the pumping amount.  That means somewhere between 80% and 95% of all precipitation either evaporates or transpires into the atmosphere. The amount transpiring differs little between plant species.  Whether it is corn, beans, trees or grass, water loss to the atmosphere is similar.  Some plant species, however, are of more economic value than others. 

Stream flow declines match the time of development of large scale ground water irrigation.  

As of June 2005, Chase County has about 3,500 acres signed up for CREP.  The small red line between the yellow and blue areas is the increase in stream flow that the DNR predicts will happen because of CREP.

According to the DNR, turning off irrigation would result in an increase in the stream flow.  For Quick Response acres, the increase in flow would be within 3 years.  Shutting off Upland wells (those wells more than 2.5 miles from the stream), it would take much longer for any change to be evident.  For the first 10 years after shutting off every Upland well, there would be very little evidence at the stream.  Even after 40 years, only 10% of the ground water that would have been pumped would arrive at the stream.