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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 4
Agricultural Conservation Measures
Efficient application that minimizes runoff, deep percolation, and evaporation
losses
^ hlclusion of forage crops in rotation
^ Skip row, lower plant population, reduced crop canopy coverage
Optimum Irrigation Scheduling
Irrigation scheduling has long been advocated as a way to obtain greater water use
efficiency by applying the right amount of water at the right time to optimize net
returns. This management practice may or may not result in reduced consumptive use
but implies that:
^ The objective is to maximize crop production with the minimum amount of water
^ The objective is optimum economic returns, rather than simply maximizing yields
^ Optimum irrigation may also involve deficit irrigation
Reducing CU comes with a cost and most often a reduction in crop yield, increased
management costs, and increased climate-based risk. Additional insect, disease and
weed problems are another hazard that must be managed under limited irrigation. As
irrigators manage reduced water amounts closer to the yield margin, higher levels of
management and labor are required to maintain profitability.
Agricultural water conservation measures have
been implemented in a number of specific
situations in Colorado. Examples include:
The federally funded salinity management
program on the West Slope where water
conservation measures, improved irrigation
and canal lining were implemented to reduce
deep percolation.
^ In 2005 and 2006 some San Luis Valley
irrigators voluntarily shut off center pivot end
guns to reduce CU by an estimated 8 percent.
^ Growers over High Plains Aquifer where groundwater levels are declining have
adopted cropping patterns that include increasing acreage of cool season crops
such as wheat.
^ Also on the Eastern Plains, the use of deficit irrigation has been employed where
well capacity cannot meet ET (wells with capacity of less than 5 gpm/acre are
usually unable to meet full ET requirements during mid-summer).
^ In the Arkansas Valley, to address impacts of an agricultural water transfer, drip
systems were cost-shared by a large municipality to reduce evaporative losses.
DRAFT 4-4