GRAND ISLAND, Nebraska - The Central Platte Natural Resources District’s (CPNRD) updated Groundwater Management Plan will become effective on July 1, 2023.  Changes were implemented by the CPNRD Board of Directors to address continuing groundwater level declines and increased nitrate levels in some areas of the District. 

Luke Zakrzewski, GIS Image Analyst, said the spring 2023 static groundwater levels showed declines in all 24 Ground Water Management Areas (GWMA) compared to groundwater levels in 1982. The 1982 levels were established as the standard for the NRD’s Groundwater Management Plan with maximum acceptable declines and a margin of safety calculated for each of the District’s 24 GWMAs. Below are the substantial changes from the original Plan implemented in 1987:

New Quantity Triggers & Controls

Phase I:    Trigger ranges from 0-25% of the maximum acceptable decline.

                 Management Plan Control:  No changes

Phase II:   Any area with declines greater than 25% of the Maximum Acceptable Decline. 

                Management Plan Control:  Limitations on transfers and supplemental wells

Phase III:  50% decline in water levels relative to the Maximum Acceptable Decline.

                Management Plan Control:  Measurement devices are required on active irrigation wells in the GWMA, and the
                owner/operator of active wells will be required to report annual water usage on each to the CPNRD

Phase IV:  Area where water levels continued to decline and reach 75% of the Maximum Acceptable Decline

                Management Plan Control:  Groundwater use will be allocated to prevent the management area from reaching the                    Maximum Acceptable Decline. 

Phase V:   Area where Maximum Acceptable Decline is 100% reached or exceeded.

                Management Plan Control:  Reduction of the Phase IV allocation

Subdivision of Groundwater Management Areas

Ground Water Management Areas 7 and 9 were subdivided due to differences in irrigation development that have occurred.

New Quality Triggers

The Quality Management triggers address increasing high concentrations of large areas of nitrate-nitrogen in the groundwater and vadose zones (areas between the root zone and the top of the water table). CPNRD adopted rules, regulations, boundaries, and controls to be included in the original Groundwater Management Plan, with lesser restrictions in areas with lower nitrates and added regulations applied to areas with higher nitrate concentrations in the groundwater.  

Because the phases are by area, individual wells in a Phase Area may be higher or lower than the designated range of nitrate concentrations.  Other factors, including proximity to a municipal water supply and vadose zone nitrates, are also used in determining the phase areas.  

Phase I:    0 - 7.5 ppm

Phase II:   7.6 - 10.0 ppm  

Phase III:  10.1 ppm and above

Phase IV:   An area where nitrate concentrations are not decreasing

The updated Groundwater Management Plan and subsequent maps are available at www.cpnrd.org or can be requested by calling (308) 385-6282.