Static Groundwater Level Monitoring

The Little Blue NRD maintains an observation well network to monitor the rises and declines of static groundwater levels.  Static level is the depth to water from ground surface while the aquifer is not being influenced by pumping.  There are 343 sites that are checked each spring and fall by dropping a steel measuring tape down the space between the well casing and pump column.  The end of the tape is rubbed with chalk, if the tape is dropped to 100 feet and the chalk is wet to two feet, it is 98 feet to water in that well.   The date is recorded and the spring levels compared year to year.  The District has been keeping this data since 1975 and tracking long term trends of the static water level.

Looking at the township map first, the average water level across the District rose +1.19 feet.  Every township measured recorded a rise, and areas which have a history of sudden or long term declines rose as well.

On the 2009 Spring Levels colored map, you can see the general rise of the water table by the large areas of dark and medium blue.  This indicates positive gains in almost all areas of the District.  The dark blue areas, one by Daykin and the other, north of Kenesaw, saw average rises in the recorder wells of l.5 feet.  The area by Daykin can be directly attributed to groundwater re-charge from recent completion of Dam Site 40, as five wells measured sites within 1.5 miles of the reservoir met or exceeded that three feet rise.

Stay on Irrigation Acres Issued in Quantity Sub-Area 8

On March 17, 2006 the Little Blue NRD issued a stay on drilling wells, or a series of wells, that are designed to pump 50 gallons per minute or more and a stay on expansion of irrigated acres in an area titled Quantity Sub-Area 8.  This action was taken because the observation network indicated the area is experiencing an average water table decline in monitored wells.  This decline is not consistent with data collected from the District as a whole.  During the time span from the 1992 to 2000 the area showed difficulty in recording a rise in monitored wells, the average rise was around two feet.  However, other units across the District recorded rises of seven feet and more.  Initial results from a study, not yet completed, by the University of Nebraska's Institute of Agriculture and Natural Resources validates the District's decline data from their observation network.  It also raises questions on potential ionic degradation of the High Plains Aquifer from surrounding Dakota aged geologic material.