Compact Compliance Pipeline

In 1965, the Colorado Legislature passed the Colorado Ground Water Management Act, which allows the Ground Water Commission to determine designated ground water basins. In 1966, the Ground Water Commission established the Northern High Plains Designated Ground Water Basin (the “NHP Basin“), which included Ogallala Aquifer groundwater in the Republican River Basin in Colorado.

At that time and for many years thereafter, no one in Colorado thought that Ogallala Aquifer groundwater was included in the water supply allocated by the Compact. After the NHP Basin was established, several thousand permits to appropriate designated ground water in the Basin were issued and an economy developed relying on groundwater. In 2000, a U.S. Supreme Court Special Master ruled that consumption of groundwater had to be included in compact accounting to the extent that it depleted streamflow.

That ruling had the effect of significantly increasing the beneficial consumptive use charged to Colorado under the Compact. The States then entered into a Final Settlement Stipulation in which they agreed to develop a groundwater model to determine the streamflow depletions caused by well pumping. The good news is that consumption of groundwater has a very small impact on stream flows compared to the amount of groundwater pumped in the NHP Basin. However, the “legacy” effect of past pumping means that shutting down wells in the Basin will not get Colorado within its compact allocations for decades.

The pipeline project delivers groundwater pumped from wells located 8 to 15 miles north of Laird, Colorado, to the North Fork of the Republican River just above the streamflow gage at the Colorado–Nebraska state line. The groundwater will be collected in a storage tank at the upper end of the pipeline, then will be delivered by gravity approximately 12.7 miles to an outfall at the river near the state line. The pipe diameter will be 42” at the upper end of the pipeline, reducing to 30” in the lower section of the pipeline near the river. The pipeline will be capable of delivering up to 25,000 acre feet of water per year. 

GEI Consultants, Inc., of Centennial, Colorado, prepared a feasibility study for the pipeline project with a $50,000 grant from the CWCB and did the engineering design for the project. The project engineering design, which cost $1.2 million and was paid for by the RRWCD Water Activity Enterprise, is complete. GEI assisted in the construction of the pipeline project.

The feasibility study determined that the North Fork of the Republican River was the best location for a pipeline project because the compact streamflow gage is located at the Colorado–Nebraska state line. To minimize transit loss in the river, water delivered by the pipeline needs to be discharged as close as practical above a compact streamflow gage.

Once it was determined that the groundwater should be delivered to the North Fork, the study then focused on areas north and south of the river to determine where the Ogallala Aquifer has the greatest saturated thickness. Also, the wells for the project need to be located at a sufficient distance from the river so that any stream impacts from pumping are minimal.

After it was determined that the area with the greatest saturated thickness was north of the river and a minimum distance from the river was established, wells were identified to minimize pipeline construction costs. The wells under contract for the pipeline project range from 8 to 15 miles north of the river, which ensures a long–term water supply for the pipeline, and are located near the Colorado–Nebraska state line, which minimizes pipeline construction costs. 

The groundwater rights for the pipeline plus easements for well sites, well connector pipelines, the storage tank, a maintenance storage yard, a building with controls for pipeline operations, and the main pipeline alignment for over half of the length of pipeline are under contract with a single landowner. 

The CWCB provided a $50,000 grant to prepare a feasibility study for the pipeline project, and State officials assisted with the preparation of the feasibility study.

The CWCB and the Colorado State Legislature have approved a $60.6 million loan to the RRWCD WAE at the very low interest rate of 2% per year over a twenty year repayment term. This low interest CWCB loan reduced the cost of the pipeline project by approximately $30 million in interest, compared to a loan from a financial institution at a normal commercial interest rate.