Laserfiche WebLink
<br />~~~J <br /> <br />is shown in brown, 0 to +2; light blue, +2 to <br />+4; and blue, +4 to +6. The amount of water- <br />table rise in the period May 1 to August 1 in <br />this part of the valley was less than 2 feet. <br /> <br />I <br /> <br />The red dots on the map indicate the loca- <br />tion of irrigation wells. The areas of greatest <br />decline correspond to areas of the greatest <br />concentration of wells and, therefore, the <br />largest withdrawal of ground water. Areas <br />of water table rise are areas where excess <br />surface water was spread. <br /> <br />We will compare these change maps with <br />surface-water application, precipitation, <br />ground-water pumpage, and channel loss and <br />gain studies for these same periods. <br /> <br />I <br /> <br />The results of three recent channel loss <br />and gain studies are shown by these overlays. <br />On these overlays a gaining river is shown <br />in blue and a losing river in red. The points <br />where the measurements were made are shown <br />by black lines. Inflow of surface water and <br />diversions have been eliminated from the calcu- <br />lations, and only ground water inflow to the <br />river or loss from the river is represented. <br />On May 15 the river between Fort Lyon diver- <br />sion dam (near La Junta) and the Las Animas <br />gage showed a slight net gain (less than a <br />second foot). Large losses occurred north and <br />3 miles east of La Junta on that date. However, <br />these losses were balanced in the reach by <br />gains. On July 17 the river between the same <br />points showed a net loss of 22 c.f.s. On that <br />date the river from La Junta to about the Bent- <br />Otero line showed a loss of 47 c.f.s. A part <br />of this loss was balanced by gains east of <br />the Bent-Otero line. The areas of greatest <br />loss show a close correspondence to areas of <br />greatest decline of water level and to areas <br />of greatest pumpage of ground water. On Octo- <br />ber 20, the river from La Junta to Las Animas <br />showed a net loss of 0.5 c.f.s. This measure- <br />ment is almost the same as the May 15 measure- <br />ment. The main cause for the increase in return <br />flow as compared with that of July 17 was the <br />