It includes irrigated areas on the North Fork of the Gunnison River and areas north and east of the city of Delta along the Gunnison River. Areas north of Delta and southeast of Hotchkiss contribute large amounts of salt. The total off-farm salt contribution from the North Fork area was estimated to be approximately 148,000 tons per year. Studies of these areas indicate that salt loading occurs when irrigation conveyance system seepage and irrigation return flows pass through highly saline soils and the underlying Mancos Shale Formation. By reducing the amount of groundwater percolating through these saline soils, salt loading to the Colorado River is being reduced.
Reclamation works primarily with the irrigation districts or companies.
The report recommended the construction of irrigation delivery system improvements on the more saline, east side of the Uncompahgre Project area and winter water replacement facilities throughout the project service area. The Salinity Control Act authorized the construction of these facilities. The recommended delivery system improvements involved lining off-farm irrigation canals and laterals. Although authorized for construction, canal lining is not currently competitive with other, lower cost alternatives within the Salinity Control Program. However, a recent re-analysis of the plan found that piping of the irrigation laterals may be competitive.