Recharge and discharge of the ground‐water reservoirs on the High Plains in Texas

The High Plains in Texas occupy an area of about 35,000 square miles extending from the northern boundary of the Panhandle southward about 300 miles, and from the New Mexico line eastward an average distance of about 120 miles to a boundary which in most places is sharply defined by a bold escarpment several hundred feet in height.

The region is noted for its abundant supply of ground‐water, most of which is found in the Ogallala formation, a sandy deposit lying at or near the surface throughout most of the region, and reaching a depth of between 200 and 300 feet. The Ogallala formerly extended over a much greater area, but it has been removed by erosion from much of the territory it once occupied. The areas in which it remains are the High Plains, which are bounded by prominent escarpments both on the east and on the west, and are traversed in Texas by the Canadian River, which is deeply entrenched in the older rocks. The water‐bearing sands of the Ogallala in both segments are cut off in all directions from any underground connection, except through the underlying older rocks which contain highly mineralized water unlike the fresh water in the Ogallala. The source of the fresh water, therefore, is within the High Plains themselves, and is from the rain and snow that falls on the surface of the Plains.