Quantity Rules & Regulations - Level Management Areas
The Lower Platte North NRD measures district groundwater levels twice a year, and in selected areas, has installed dedicated monitoring wells with data loggers that take measurements on a much more frequent basis. (The most recent groundwater level results can be viewed here.)
For monitoring groundwater quantity, the district has been divided into several subareas with similar aquifer conditions (see map below). ‘Level Management Areas’ compare current groundwater levels to the 1987 base year. (The year 1987 is used as a base year since this followed several years of above normal rainfall, which recharged our aquifers to near ‘pre-development’ levels.)
Currently the entire district is in a "Level One" management area. If 50% or more of a subarea reaches or exceeds its trigger level then a Level Two or Level Three ground water management area shall be established.
The trigger level varies depending on the type of aquifer: confined or unconfined. (An aquifer is a underground layer of material, such as sand or gravel, that is saturated with water.)
Unconfined Aquifers
Unconfined aquifers are not sealed off from the ground surface and have the same pressure as the atmosphere. Therefore, the water table (the upper surface of the saturated zone) is free to rise and fall according to groundwater recharge and the amount of water withdrawal through wells. A well drilled into an unconfined aquifer will often show these fluctuations. When water withdrawal exceeds recharge, water levels may fall below the bottom of the well, rendering it dry.
Trigger levels are more lenient for unconfined aquifers, because these aquifers are not prone to land subsidence if too much water is removed.
Confined Aquifers
Confined aquifers are aquifers that are sealed off by a confining layer made up of impermeable material such as clay that prevents or slows water movement into the aquifer. Confined aquifers are under pressure, so when a well is drilled into one, the water will tend to rise in the well casing. In some cases, water could rise all the way to the ground surface. This is referred to as a "flowing artesian well."
If too much water is removed from a confined aquifer, land subsidence (though rare in Nebraska) can sometimes result, creating sinkhole-like conditions. The storage capacity of the aquifer can also be reduced, sometimes permanently.
Rules & Regulations
Condition |
Level 1
|
Level 2
|
Level 3 |
Trigger Level |
None, but water conservation encouraged district-wide | Unconfined Aquifer = 10% decline Confined Aquifer = 7% decline |
Unconfined Aquifer = 15% decline Confined Aquifer = 10% decline |
NRD will certify historically irrigated acres |
Required | Required | Required |
Operators of irrigation, municipal, and industrial well systems attend
education classes and be certified every 4 years |
Required | Required | Required, including some domestic and livestock well owners * |
Well spacing requirements shall be observed (varying depending on aquifer subarea) |
Required | Required | Required |
Water well permits (Class 1, 2, 3, or 4 depends on annual water use or number of irrigated acres) |
Required for all new and replacement high capacity wells | Required for all new and replacement high capacity wells | Required for all new and replacement high capacity wells and some low capacity wells * |
Establish well metering program |
Encouraged for all high-capacity wells | Required for all high capacity wells | Required for all high capacity wells and some low capacity wells * |
Acre-inch allocations per crops planted, dependent on aquifer subarea. |
Encouraged | Required or may be offset by reduction in number of irrigated acres | Required or may be offset by reduction in number of irrigated acres |
Annual water use report made to LPNNRD by January 31st of the following year. |
Encouraged on existing wells, required on new and replacement high capacity wells | Required on existing high capacity wells and on new and replacement high capacity wells | Required on existing, new, and replacement high capacity wells and some low capacity wells * |
Best management practices used. |
Encouraged | Encouraged | Encouraged |
More Information
For more information concerning ground water quantity management, also review Groundwater Quantity Rules and Regulations – Water Development Areas.
The full text of the NRD's GWMA Rules and Regulations is available as a PDF in our Downloads section.
If you have questions or would like more information about the GWMA, please contact Water Resources Manager Larry Angle.