WSP07201 - Laserfiche WebLink

Home Browse Search

28 June, 1962 IR2 1. Drawdowns were computed on the assumption that all the water came from storage in the aquifer, or from Fountain Creek where it intersects the aquifer. 2. The first approximation neglected the effect of drawdowns in reducing the cross- sectional areas of the saturated part of the aquifer and was made as a concession to mathematical difficulties. Later, a computation was made with the help of Robert E. Glover, F. ASCE, to evaluate the effect of the shortcomings of the first approximation; the difference was found to be less than 1/2 ft at the plaintiff's well. 3. Additional drawdown caused by the relatively impervious shale bound- aries was computed by the "method of images." 4. Monthly pump age was idealized in making the computations shown in Fig. 5; however, the sum of the idealized monthly pumpage equaled the actual quantity of water withdrawn from the aquifer. 5. None of the water pumped from the aquifer is returned. 6. Drawdown computations were based on the Theis formula. TABLE I.-ANNUAL PUMPAGE IN ACRE FEET 1953 1954 1955 1956 Irrigation (includes Plaintiff's well) 2,400 2,595 1,730 1,075 Industrial - - 140 140 Colorado Springs (defendant) - 1,155 1,805 1,125 Security Village - - 170 720 Total 2,400 3,750 3,845 3,060 Bender well (plaintiff) 200 290 160 200 ,. The computed effects8 on the water level in the plaintiff's well are shown graphically in Fig. 5. Curve" A" shows the effects of the plaintiff'S own pump- ing. Curve "B" shows the effect of the increased pumping for irrigation by a new irrigation well. Curve "C" shows the effects of pumping the defendant's wells. Curve "D" shows the combined effect on the water level at the plain- tiff's well as computed and as observed. Although curve D deviates some from the observed data for the last 2 months of pumping, the curves do show a close relationship. Fig. 5 clearly shows that the chief cause for the lowering of the water level in the plaintiff's well was the pumping of the defendant's wells. Some of the essential facts concerning ground-water technology, as related to this case, can be summarized as follows: r, ~ r. a. The decline and rise in water level in the plaintiff's well coincided with pumping periods of the defendant's wells. b. The yield of the plaintiff's well declined as the water level declined. c. Computations show that the greater part of the lowering of the water level in the plaintiff's well was caused by pumping of the defendant's wells. d. The plaintiff was able to pump as much water during 1954, 1955, and 1956 as he had previously pumped, but it took longer to pump the same volume.