SWSIWaterConservationAndEfficiencyTRTWhitePaper

• Technical Roundtable: Water Efficiency
• Title: SWSI - Water Conservation and Efficiency White Paper
• SWSI II - Doc Type: White Papers

SWSI Phase 2 Technical Roundtable
Water Conservation and Efficiency
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site-specif ic basis, as some irrigated f ields may require periodic f lushing of salts
and minerals that accumulate in the soils in order to remain productive. The
benefits of these improvements accrue to many, and programs like the Colorado
River Salinity Control Program exist to encourage these types of improvements.
There are a number of potential issues and conflicts that must be evaluated for the
potential implementation of agricultural efficiency measures.
Historical agricultural return flows are a vital part of the f lows in all basins and
downstream surface water diverters and downstream states have relied on these
return flows.
These return flows, in addition to satisfying downstream water rights, also create
delayed f lows that can have instream and riparian environmental benef its and
maintain aquifers for domestic and irrigation wells.
^ Typically, any water that is saved by efficiency measures such as canal lining or the
conversion of irrigation practices and technology from f looding to gated pipe,
center pivot circle, and center pivot with corner can only be used on lands f or
which the appropriation was originally made. Selling or delivering "saved" water
to other users would constitute an improper expansion of use.
^ The above considerations assume the existing water rights system (laws, rules, etc.)
does not change. It may not be likely but not impossible that some parts of the
system could be modified to a small extent if the potential savings is significant.
6. Control of Phreatophytes
A basinwide or focused-area program for the removal and control of non-native
phreatophytes that consume water could benefit other basin users: agricultural, M&I,
recreational, or environmental. Non-native phreatophytes are invasive plant species
that consume water. Of particular concern in Colorado are tamarisk trees. Methods of
removal include: mechanical removal, prescribed burning, biological control, and
herbicide application. While state and federal programs are beginning to evaluate
phreatophyte control options in more depth, the costs and benef its (e. g., yields) of
phreatophyte control programs are largely unknown at this time. Demonstration
projects are planned in the Rio Grande and Arkansas basins, and U.S. Geological
Survey is updating estimates of potential water savings.
Native phreatophytes, such as cottonwoods, may be consuming significant volumes
of water along river corridors, such as the South Platte mainstem downstream of
Denver to the state line.
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