The Upper Arkansas Basin covers 10,300 square miles of
west-central Kansas. The basin includes all or parts of 20
counties. There were an estimated 128,500 residents in the
basin in the year 2000, and the population is projected to grow
to nearly 157,000 by the year 2040. The Pawnee River and Walnut
Creek are the two major tributaries of the Arkansas River in
this basin. Whitewoman Creek and James Draw drain a portion of
the basin but end in depressions. Remaining areas of the basin
are drained by numerous small direct tributaries of the Arkansas
River. The topography of the area varies from a generally flat
plain in the western half to a more rolling topography in the
eastern half.
The economy of the basin is based primarily on agriculture and
petroleum. The major crops are wheat, grain sorghum, corn and
alfalfa with a sizable portion of this acreage being irrigated.
Irrigation has helped stabilize the agricultural economy in this
area of marginal precipitation. Oil and gas production
contributes significantly to the economy of the area. There are
four natural gas refineries, one helium plant and one oil
refinery located in the basin.
Ground water was the source for just over 97 percent of reported
uses in 1997, excluding ditch water; 90 percent if accounting
for ditch irrigation water. Approximately 93 percent of all the
reported surface and ground water used is for irrigation. The
remaining is used almost equally for industrial, municipal, and
recreational uses, and one percent on stockwater.
The average annual precipitation for the basin is 19 inches but
varies from 26 inches at the eastern end to approximately 16
inches at the western end. The annual quantities are subject to
wide fluctuation.
Groundwater Management Districts Nos. 1 & 3 are major water
management entities in the basin.