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• Board Meeting Date: 3/18/2008
• Description: IWMD Section - Presentation of Agricultural Water Conservation Paper
• Board Meetings - Doc Type: Memo

Section 6
Site-Specific Opportunities and
Limitations
The opportunities and limitations for agricultural water conservation measures vary
significantly from basin to basin. In order to calculate volumes and locations of
potentially available water, a basin specific analysis will be necessary, a task that is
beyond the scope of this paper. A few examples of the basin specific limitations and
potential opportunities are noted below. More detailed information on interstate
compact requirements can be found in Section 4 of the SWSI report.
South Platte
^ h1 the South Platte, the compact with Nebraska only requires the delivery of water
to one ditch n1 Nebraska under certain conditions during the irrigation season.
There are no requirements for delivery during the non-irrigation season.
^ The Three States Agreement between Colorado, Nebraska, and Wyoming and the
Department of Interior has certain periodic flow targets and requirements
regarding future depletions.
^ The conversion to center pivot sprinklers in Water Districts 1, 2, 3, and 64 may
result in a reduction of return flows and impacts on alluvial groundwater, which
historically were supplied from flood irrigation.
^ There is a potential for water conservation measures in Water District 64, especially
downstream near the state line if these were implemented in a way that would not
impact any Colorado water rights or endangered species flows.
Arkansas
^ The Arkansas River Compact requires the maintenance of historical streamflow
conditions as of the date of the compact.
^ The Colorado State Engineer has taken the position that agricultural efficiency
improvements in the Arkansas may not result in any reduction of historical return
flows as contemplated in the Arkansas River Compact.
^ Existing irrigation practices have resulted in return flow s that have raised the water
table resulting in non-beneficial CU (as evaporation from the soil surface) and
increasing the salinity of both ground water and surface water. Any measures
addressing these concerns must be in conformance with the Compact.
^ Irrigation of certain lands results in significant impacts to downstream water
quality from leaching of metals and salinity. In addition the return flows from
irrigation of these lands impacts agricultural production on other lands diverting
downstream.
DRAFT 6-1