SWSIWaterConservationAndEfficiencyTRTWhitePaper

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SWSI Phase 2 Technical Roundtable Water Conservation and Efficiency ~• ~ 5. Agricultural Conservation (Ef f iciency Improvements) Agricultural conservation or agricultural ef ficiency implementation is a means to create new water supply that must be carefully evaluated since Colorado water law and interstate compacts may limit or preclude the use of this option to increase supply. This option may involve increasing the efficiency of water used for irrigation, so that more of the water that is diverted from streams and rivers or pumped from groundwater meets the direct CU needs for agricultural crops. Typical agricultural efficiency measures include canal lining or the conversion of irrigation practices and technology from flood irrigation to gated pipe or the installation of sprinklers or drip irrigation systems. These measures are designed to reduce the delivery losses that occur as water is diverted from a stream or as groundwater is pumped and delivered to the f arm or ranch or as it is applied to the crops. Table 3 from the SWSI report shows the range of expected application eff iciencies f or diff erent types of irrigation practices and the approximate costs to install these irrigation delivery systems. Table 3 Estimated Efficiencies and Cos ~, 1' 1 ts for Irrigatio ° ~1 .1 ~ ~ ~ n Methods ~ ~ir ~ .~ t - Flood 30-50% - - Furrow 40-60% $37 $30 Gated Pipe ~60% $178 $51 Center Pivot Circle ~85% $433 $64 Center Pivot with Corner ~85% $568 $80 The benefits of agricultural efficiency measures include: ^ No new diversions are required f rom rivers or streams. ^ Permits are not required f or implementation. ^ Increased ability to deliver water to the crops can stretch existing supplies. This benefit would apply to water short irrigators that would benefit if additional water could be delivered to their crops. If the irrigator that has water short crops typically experienced 50 percent losses, reducing those losses will result in an increased delivery to the water short crops and a resulting increase in crop CU. Agricultural efficiency may reduce non-crop CU. Some of the CUs and losses may be due to tailwater from irrigation ponding at the end of fields and evaporating, rather than returning as surface or groundwater return flows. ^ There may be potential water quality benefits. Canal seepage and/ or flood or furrow irrigation may result in the leaching of minerals from the soils that result in impacts to the water quality of the return flows. Lining canals or the installing sprinklers may reduce the leaching of these minerals. This must be examined on a DRAFT 13 S:IMEETINGSITECHNICAL ROUNDTABLEITRT MEETING - SPECIFICIWATER EFFICIENCYISWSI WATER EFFICIENCY TRT BRIEFING.DOC