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Ground-water Recharge and Discharge
The addition of water to the underground reservoir is cabled recharge and may be effected in several ways. The most important source of recharge is local precipitation. For the shallow upland wells in bedrock local precipitation is the only source of recharge. Lesser amounts are contributed elsewhere by influent seepage from streams and ponds and by subsurface inflow from adjacent areas. Locally, however, influent seepage from streams may contribute important amounts of recharge to adjacent alluvial deposits and to bedrock where streams cut across permeable zones in bedrock.
Recharge is seasonal in the midwest, including Osage County. Generally the water levels of wells have been lowered by natural drainage into streams during the winter, when soil is frozen and precipitation is small. During the spring months precipitation is fairly abundant and transpiration and evaporation demands are low, resulting in considerable recharge. Recharge may occur in other seasons, also, whenever precipitation is sufficient to overcome the soil moisture deficiency built up during the preceding dry period.
Ground water moves through the permeable rocks in accordance with the character and structure of the rocks, from points of higher to points of lower elevation. It may discharge directly into a stream as a spring or seep or may be discharged by evaporation or transpiration where the water table is near the surface. A part of the total ground water is discharged from wells, but in Osage County the amount is very small compared with other means of discharge.
Over a long period of time approximate equilibrium exists between the amount of water that is added annually to ground water storage and the amount that is discharged annually by natural means.
Availability of Ground-water Supplies
The quantity, quality, and availability of ground-water supplies in Osage County depend largely on the geology.
Wells 25 to 40 feet deep constructed in the alluvium and the deposits of the low terraces in the valleys are capable of furnishing excellent stock and domestic supplies, and in the major valleys they furnish small industrial and municipal supplies. Yields of 10 to 50 gallons a minute can be developed in parts of the valleys of the Marais des Cygnes River, Salt Creek, Dragoon Creek, and One Hundred and Ten Mile Creek. Smaller yields can be obtained in the tributary valleys. During prolonged dry periods, the yield of heavily pumped wells in alluvial deposits may be much reduced, and if located in areas of thin alluvial deposits the wells may fail.
Bedrock aquifers yield small to moderate water supplies to wells in two areas of the county. Many wells constructed in the Ireland sandstone member of the Lawrence shale have yields of 1 to 10 gallons a minute. A few wells yield as much as 35 or 40 gallons a minute. These wells range from about 80 to about 350 feet in depth. Because of the large areal extent of the Ireland and consequent large volume of water in storage, water levels in wells obtaining water from it are not noticeably affected by temporary periods of deficient precipitation.
In another bedrock area the White Cloud and Severy shales yield water to many wells at the rate of 1 to 10 gallons a minute. Locally yields may be as much as 20 gallons a minute or as little as 300 gallons a day, however. Wells obtaining water from sandstone beds in these aquifers range in depth from 30 to about 240 feet. The water levels in the deeper wells are little affected by brief periods of deficient precipitation.
Wells that obtain water from other bedrock aquifers develop yields of only a few gallons a day to, in rare instances, as much as 25 gallons a minute. The geographic areas in which the aquifers occur and the range of yields that can be expected are shown on Plate 3 and are discussed in the section describing the ground-water regions.
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Kansas Geological Survey, Geology
Web version April 2002. Original publication date May 1955.
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