WSP10582 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I I I I I I I I I I I 3650 irrigated land with 42,000 acres being served by the Grand Valley Project. The valley is carved into the M~ncos Formation (a high salt-bearing Marine shale) by the Colorado~iver and its tributaries. It is esti~ated that the valley con,ributes approximately 580,000 tons of salt annually to th~ Colorado River. These salts are contributqd Erom irrigation return Elow and are primarily attributed to deep percolation Ert,;n conveyance system seepage and irrigation. It is estimated that,410,000 tons of salt could be eliminated from the Colorado River with the ""<0." 0' '.ol.m.'ioo'o O::,::::mC:::::::"OO S'<"'0'\~ p<oq<om". \ The off-farm program of the Bureau of Reclamation iA the Grand Valley area consists of canal and lateral lining. ~h2 program has been divided into two stages: Stage One incluaea the lining of 6.8 miles of the Government Highline Canal and 29 miles of laterals in the western portion of the valley. Stage One will about 24,000 tons of salt from the Colorado River and reduce the salinity level at Imperial Dam by 2.5 mg/l. The Stage One improvements are nearly complete with an estimated cost of about $25 million and cost-effectivenes of about $650,000 per mg/l. Stage Two includes all of the remaining irrigated lands (69,700 acres) in the valley. As in the first stage, the second stage of the Aureau of Reclamation program will concentrate on lining canals and laterals. There are approximately 200 miles of private and Federal canals and 700 laterals with a combined length oE ahout 500 miles that are included in the Stage Two plan. Currently, this phase is in the planning process. The alternative which is undergoing plan formulation would require lining oE the laterals and the west end of the Government Highline Canal. This plan will annually remove about 100,000 tons of salt from the Colorado River and reduce the salinity level at Imperial Dam by about 10 mg/l. The construction cost of -16-