Laserfiche WebLink
<br />------------, - <br />Y //#/fllfY// <br /> <br />" <br /> <br /> <br />. Irrigation water is provided as a continuous flow at each headgate. <br /> <br />· Irrigation tailwater and surplus canal water go directly into deep <br />drain ditches or natural washes. <br /> <br />. Unlined earthen canals lose water by seepage. <br /> <br />. Nonuniform soils require excessively long irrigation sets to <br />adequately wet "tight" areas. <br /> <br />Main Canals & Laterals (A) <br /> <br />c <br />~ <br />'" <br />c <br />e <br />c <br />-u <br />;;U <br />~.. <br /> <br />e: <br /> <br />Colorado <br />River <br /> <br /> <br />t <br /> <br />~ <br /> <br />l.t6ZJO <br /> <br /> <br />The Grand Valley is underlain by the Mancos Shale Formation which contains <br />a large amount of salt. In areas near the river, subsurface gravel deposits are filled <br />with water in contact with this shale. As a result, this ground water is very <br />saline-in fact it is so salty that it is unfit for domestic, stock, or irrigation use. <br /> <br />. Continuous flows (A) result in poor control of water, as it <br />must be accommodated in some manner. Some water moves <br />through the soil (8) to increase the water table height. <br /> <br />. The remainder of the water flows into open drains (0) and <br />combines with surplus canal water (E). This water, flowing <br />toward the river, mixes with the saline water in the aquifer (FJ <br />and carries more salt to the river. <br /> <br />---N <br /> <br />. Seepage from the canals (G) and excessive irrigation (B) <br />increase the height of the water table (e) which displaces the <br />saline ground water into the river (H) and causes salt <br />accumulation in low.lying surface soils (J). <br />