Ground Water, Continued
Ground-water RechargeRecharge is the addition of water to the underground reservoir and may be accomplished in several ways. All ground water within a practical drilling depth beneath Seward County is derived from water that falls as rain or snow either within the area or within nearby areas to the west and north. Once the water becomes a part of the groundwater body it moves down the slope of the water table, later to be discharged farther downstream. The underground reservoir beneath Seward County is recharged primarily by local precipitation. Other factors affecting recharge in this area are seepage from streams and depressions and sub-surface inflow from areas to the west and north.
Recharge from Precipitation
The average annual precipitation in Seward County is about 19 inches, but only a part of this water reaches the zone of saturation owing to evaporation, transpiration, and surface runoff. The amount of water added to or discharged from the groundwater reservoir is reflected in the fluctuations of the water levels in wells. Periodic measurements of water levels in wells 23, 53, 56, 64, and 158 have been made since August 1940. The fluctuations of the water levels in these wells are shown in Figure 7. Well 53 is a shallow well in Cimarron Valley whereas the other wells are on the upland and have depths to water level ranging from about 96 feet to more than 209 feet. The water levels in all of the observation wells in Seward County were higher at the end of 1944 than they were at the beginning of record. The water level in most wells rose during 1941, 1942, and 1944 which were years of above-normal precipitation, whereas the water level in most wells declined during 1943, a year of below-normal precipitation.
Figure 7--Hydrographs showing the fluctuations of the water levels in five wells in Seward County, the cumulative departure from normal monthly precipitation at Liberal, and the monthly precipitation at Liberal. A larger version of this figure is available.
The fact that the water level in some deep wells fluctuates only slightly does not necessarily mean that there is no recharge, for the water level will rise only when the rate of recharge exceeds the rate of groundwater discharge. The recharge in such areas probably is more or less continuous and is about equal to the natural discharge. Although the annual net rise in water levels in the four deep wells is small, the cumulative rise may be relatively large. The average cumulative rise of water levels in these wells ranged from 0.48 foot in 1943 to 2.00 feet in 1944.
From the beginning of 1941 to the end of 1944 the water levels in three upland wells (56, 64, and 158) rose an average of 0.22 foot a year. If the specific yield of the upper part of the zone of saturation in this area were known, the amount of the annual gain in storage of ground water could be estimated. If it were assumed that the specific yield is 15 percent, then the annual gain in storage would amount to about 0.4 inch and the gain in storage for the four years (1941-1944) would amount to about 1.6 inches. A gain in groundwater storage of 1.6 inches would amount to about 83 acre-feet (27,000,000 gallons) per square mile.
Recharge from Seepage
Some water is contributed to the ground water reservoir by seepage from streams and depressions. Cimarron River is a losing stream in the northwestern part of Seward County. In this part of the course of the Cimarron some of the flood water moves downward to the zone of saturation. This has caused a mound on the water table near the northwest corner of the county (Pl. 1).
Well 23 is located about 0.5 mile from the flood plain of Cimarron River. During a flood in 1941 the floodwater extended from bluff to bluff. It is believed that seepage during this and subsequent floods produced much of the rise shown for well 23 in Figure 7.
Recharge by Subsurface Inflow
Ground water moves into Seward County by subsurface inflow from Stevens County on the west and Haskell County on the north. The water moves across the county in a general southeasterly direction into Meade County, Kansas, and Texas and Beaver Counties, Oklahoma.
Kansas Geological Survey, Seward County Geohydrology|
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Web version Sept. 2001. Original publication date March. 1948.