Upper Arkansas River Subbasin
Issues:
- Groundwater depletion related to diversion for irrigation agriculture
- Ongoing evapotranspiration by phreatophytes
- Saltwater intrusion into the groundwater from the Arkansas River
- Channel impairment by reduction in peak flows, changes in flood plain vegetation, and encroachment onto the channel and floodway by land use changes
Goals:
- Extend and conserve the life of the associated aquifers
- Reduce the infestation of phreatophytes
- Reduce the average concentration of total dissolved salts in the Arkansas River entering Kansas, which will in turn lessen the risk of salt entering groundwater
- Manage the water flow of the Arkansas River to be sustainable in the long-term, and improve channel and floodway conditions
Current Activities:
- Promote water rights purchases for stream-aquifer recovery
- Adoption of a ten-year tamarisk control plan
- Target water use reduction where water quality benefits will occur
- Look at potential stretches of the Arkansas River channel to improve to lessen flooding and phreatophyte consumption
Groundwater Flow Model:
- The Kansas Geological Survey is in the beginning stages of constructing the steady state groundwater model, with pre-development calibration. It will then move onto the transient model for Southwest Kansas Groundwater Management District No. 3. The focus of the Southwest Kansas Groundwater Management District No. 3 model is to learn more about aquifer storage and change through time within the Upper Arkansas subbasin. The projected completion date for the model is in 2010.
The Upper Arkansas River subbasin is made up of the Arkansas River and three distinct aquifer systems. They include the Arkansas alluvial aquifer, the Ogallala-High Plains aquifer and the Dakota aquifer. The Arkansas River originates in Colorado. It flows east through Hamilton, Kearny, Finney, Gray and Ford Counties in Kansas. An appreciable quantity of Upper Arkansas River surface water originates from calls for water out of John Martin Reservoir, irrigation canal return flows in eastern Colorado and alluvial bank discharge after high flow events in the system. The Arkansas River recharges the shallow alluvial aquifer and provides irrigation water to a network of ditches and Lake McKinney. It is a temporary holding basin for irrigation.
The Upper Arkansas subbasin consists of 2,528,124 acres. It is located in all or part of 11 counties. The climate is semiarid. The precipitation ranges from 15.8 inches at Syracuse to 21.5 inches at Dodge City. The subbasin lies in the High Plains physiographic region and the dominant economies are agriculture, and oil and natural gas production. Most irrigation in the subbasin obtains groundwater from the Ogallala-High Plains aquifer. There is an extensive network of ditches diverts surface water from the Arkansas River from the Colorado line east to Garden City. The Upper Arkansas working group submitted Recommendations for the Upper Arkansas River Subbasin in 2002 to the chief engineer that address water resource issues in the subbasin. The group consists mainly of ditch service operators.
Both surface water and groundwater supplies are available and used by water rights in this basin. Surface water is governed by a compact between Colorado and Kansas. There is limited surface water generated on tributaries within Kansas. This is especially true in Hamilton, Kearny and Finney Counties. Six irrigation ditches divert most of the surface water. The irrigation districts are between the Colorado state line and Garden City. There are additional ditches which divert downstream of Garden City.
Groundwater use along the entire alluvial corridor is governed by an Intensive Groundwater Use Control Area. Most of the Upper Arkansas subbasin falls under the local jurisdiction of the Southwest Kansas Groundwater Management District No. 3. A small portion is within the Western Kansas Groundwater Management District No. 1. See map above.
Colorado-Kansas Interstate Compact
The Kansas-Colorado Arkansas River Compact was negotiated in 1948 between Kansas and Colorado with participation by the federal government. Its stated purposes are to settle existing disputes and remove causes of future controversy between Colorado and Kansas concerning the waters of the Arkansas River, and to equitably divide and apportion between Colorado and Kansas the waters of the Arkansas River and the benefits arising from John Martin Reservoir.
Additional information on the Compact can be found at:
