Chemical analyses of water samples were made by the Division of Environment of the Kansas Department of Health and Environment.

consolidating benthal deposits-30

In this system, the first set of digits of a well number indicates the township; the second set, the range east or west of the sixth principal meridian; and the third set, the section. For readers interested in the metric system, the English units of measurement given ill this report are listed below in equivalent metric units using the following abbreviations and conversion factors: The land surface of the report area is an undulating plain with little relief.

The first letter after the section number denotes the quarter section or the 160-acre tract; the second, the quarter-quarter section or the 40-acre tract; and the third, the quarter-quarter-quarter section or the 10-acre tract. The topography grades southward from sand dunes along the Arkansas River to a loess-covered upland that is terminated on the south and southeast by deeply eroded valleys.

Annual withdrawals of ground water by wells increased from about 5,000 acre-feet in 1940 to about 140,000 acre-feet in 1974.

The steadily increasing withdrawal rate has not produced long-term declines of water levels that may be distinguished from the effects of climatic changes.

Significant additional development for irrigation that could cause ground-water withdrawal to exceed longterm recharge and result in water-level declines is anticipated in some areas.

The average annual recharge rate to ground water from precipitation is estimated to be about 2 inches.

The chemical quality of ground water from unconsolidated deposits in the western half of the area is generally suitable for most uses.

The chemical quality of water in the eastern half may be unsuitable locally for most purposes as a result of upward leakage of highly mineralized water from underlying Permian rocks.

Unconsolidated deposits of Pliocene and Pleistocene age comprise the principal aquifer in the Great Bend Prairie.

Forty-five million acre-feet of ground water are estimated to be in storage in these deposits.

These tracts are designated a, b, c, and d in a counterclockwise direction beginning in the northeast quadrant. The land surface is poorly drained and traversed by relatively few streams.