Projects funded to prevent tons of salt from entering Colorado River each year
The U.S. Bureau of Land Management recently awarded $20.9 million for six projects along the Colorado River aimed at reducing the costly amount of salt in its water. Five of the projects are in Colorado.
In a Feb. 12 press release, the BLM estimated economic damages currently caused by excess salinity in the Colorado River water at about $332 million per year. That economic damage mostly comes from the inability to plant certain types of crops which need the river's water for irrigation, as well as costs associated with treating the river's water for residential and commercial usage, according to a BLM report released six years ago.
"This funding will prevent approximately 11,661 tons of salt each year from entering the Colorado River," the BLM announced in its press release.
One way salt enters the Colorado River naturally is through erosion. Ash-filled sediment that washes downhill after wildfires is an exaggerated example.
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The shelf of Mancos Shale underneath most of Colorado's Western Slope keeps a steady supply of salt concentrated below the surface, too. The areas with underlying sedimentary rock which receive less than eight inches of rain a year tend to register the highest concentrations, according to the BLM.
Some of the underground salinity comes to the surface through geothermal activity, including hot springs.
But recent research indicates man-made activities contribute considerably to the river's salinity levels: runoff from irrigation, road management, timber production, and water flowing from mining or drilling operations or off-road vehicle areas are among those named by the BLM.
The six projects are focused on delivery systems to agricultural irrigation. Canals and dirt ditches will be lined with a type of concrete in several cases. Pipelines will be inserted in others.
The Colorado River begins as snowmelt and streamwater originated in the Never Summer Range on the west side of Rocky Mountain National Park. It travels 1,400 miles through seven states and into Mexico.
It was the impact to water at the border that prompted U.S. action. In 1961, water was diverted behind the nearly completed Glen Canyon Dam to fill Lake Powell. Also, the Bureau of Reclamation launched operations at its Gila Project in southwestern Arizona which drained saline-rich water into the Colorado prior to its crossing into Mexico.
Salinity levels in water delivered to Mexico jumped from 800ppm (parts per million) in 1960 to more than 2,000ppm in 1962 (the Gila Project's output was measured at 6,000ppm).
The impact to farm land in Mexico was significant. Mexican authorities protested and the U.S. negotiated water treatment actions.
Legislation signed into law in 1974 created the Colorado River Basin Salinity Program. That law was amended with additional federal support last year when congressional representatives from the seven states pushed for assistance in the effort to reduce salinity in the river.
Last week, following a competitive bidding process, the Bureau of Reclamation announced the six projects receiving funding:
- Lower Bench Canal Salinity Control Project, Utah: This project is to fund the Uintah Indian Irrigation Project O&M Company for salinity control by eliminating seepage losses via piping of 13.97 miles of the unlined open Bench Canal.
- Hartland Ditch Improvement Project, Delta, Colorado: This project will provide resources to the Hartland Ditch Company to line the upper Hartland Ditch (currently an earthen ditch) with shotcrete along the existing alignment, including new turnouts for all headgates. It will also replace various spill structures and turnouts and install other various infrastructure to enable lining and piping.
- North Delta Canal Salinity Control Project, Delta, Colorado: This project will provide resources to the North Delta Irrigation Company to provide salinity control improvements to the North Delta Canal. This project will install approximately 4,945 ft of pipe and 6,820 ft of shotcrete liner along the canal. It will also provide for headgate structure, gate replacement, and siphon installation; all with remote controls to allow the ditch company to operate headgates remotely.
- Bostwick Park Hairpin Lateral Piping/Salinity Reduction Project, Montrose, Colorado: The proposed Hairpin Lateral Piping/Salinity Reduction Project will install a pressurized irrigation water inverted siphon approximately 4,625 feet (ft) long across Hairpin Draw, which will allow water to bypass approximately 20,490 ft of open ditch.
- Fire Mountain Canal Phase 2 Salinity Project, Hotchkiss, Colorado: The Fire Mountain Canal & Reservoir Company will install 1044 ft of pipeline as an inverted siphon across Short Draw Creek and abandonment of 8,659 ft of open earthen canal. A valve and necessary accessories will be installed at the bottom of the siphon to allow draining of the pipeline.
- Grand Valley Irrigation Company Phase 6 Lining Project, Grand Junction, Colorado: Three sections of canal will be lined with an impermeable membrane liner system and coated in shotcrete conforming to U.S. Bureau of Reclamation specifications. Old headgates within each section will be replaced with new concrete structures complete with trash screens and sacrificial anodes. The canal will be re-graded and shaped using a combination of imported materials and suitable on-site materials prior to installation of liner materials.
" It is estimated," the Bureau of Reclamation stated in its press release, "that damages would increase to $631 million per year without the Colorado River Basin Salinity Control Program."
