WSP04560

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications - Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 2/9/1994
• Author: John Hedlund
• Title: Salt Primer - Water and Salt Budgets
• Water Supply Pro - Doc Type: Report/Study

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TOTAL SALT LOAD REDUCTION

The total salt load reduction from the USDA onfarm program from
installing improved irrigation systems:

Reduction
Reduction
Total

Salt Load Reduction
Ditch Seepage = 11,800 tons/year
Deeo Percolation = 34.600 tons/vear
= 46,400 tons/year

The 38,000 ton salt load reduction shown in the 1983 USDA Onfarrn
Irrigation Improvement salinity control report and the 1989 USDA
Final Ers on the McElmo Creek Unit for salinity control in
Colorado is revised to 46,400 tons/year salt load reduction.
These changes are as follows:

SALT LOAD REDUCTION
USDA Program 1983 & 1989 plan 1993 Plan
ac ft tns/yr ac ft tns/yr
Lining/Pipeline 268 miles 6,000 22,000 2,800 11,800
Onfarm Systems 21,550 acres 3.000 16.000 8.250 34.600
S~ 9,000 38,000 11,050 46,400

Historically, the salt load in McElmo Creek at the state line has
averaged about 119,000 tons per year. The USDA onfarrn irrigation
improvement program will reduce the total salt load about 46,000
tons per year or 24 percent.

The USSR 1989 EIS shows a total salt load pickup for the future
with salinity control project to be 118,000 tons/year (p.41).
USBR estimated salt loading by canal seepage to be 20,000
tons/year (p.S8). This means that 98,000 tons per year would be
picked up by onfarm or local runoff. The salt budget on p.S3,
App.B, shows 107.000 tons of salt loading per year by irrigation;
minus 20,000 tons for canals, leaves 87,000 tons for onfarm.

Another way of looking at the McElmo Creek salt loading is to
look at the historical salt load of 119,000 tons per year at the
USGS state line gage in combination with USBR project. The net
increase in salt loading from the imported water with the Bureau
Dolores project and salinity control features is 18,600 tns/yr
(5-9, 1989 USBR EIS). This totals 137,600 tons/year.
Subtracting the 20,000 ton of salt loading for canal seepage,
leaves 117,600 tons from onfarm and natural sources. There is
very little runoff or salt loading from natural sources and
irrigat~on water is imported from the Dolore~ River.