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• Board Meeting Date: 5/21/2008
• Description: IWMD Section - Presentation of Agricultural Water Conservation Paper
• Board Meetings - Doc Type: Memo

Section 2
Introduction
Reduction in water use associated with agricultural water conservation can be
achieved f rom:
1. Increasing the efficiency of water application.
2. Reducing crop consumptive use.
3. Reducing phreatophytes along ditches and canals.
4. Decreasing delivery losses from the river headgate to the f arm f field in ditches,
canals, and diversion structures.
5. Reducing non-beneficial evaporative losses.
Agricultural water conservation may be helpf ul to f armers, other water users, and the
environment in a number of situations, including:
^ Drought
^ High pumping costs
^ Irrigation system problems
^ Interruption in surf ace water supplies
^ Declining groundwater levels
^ Compact compliance
^ Alluvial well water restrictions
^ Urban water transfers
^ Need f or additional instream f lows
Water conservation measures, however, also have significant limitations. A primary
f actor is that the amount of water that is legally transferable is an irrigator's historical
consumptive use, not the amount of water diverted. Another significant factor is that
downstream water rights holders are entitled to the stream conditions that existed at
the time of their appropriation. When water is diverted from a river or stream, a
significant amount of the water percolates through the soil and eventually flows back
to the river to be used by downstream water users. For agricultural water
conservation measures to be successful, these aspects of water in Colorado must be
taken into consideration.
Implementing agricultural water conservation measures may also result in unf oreseen
effects on stream systems, both negative and positive. Any large scale agricultural
water conservation initiative could have potential effects on an entire river system
including downstream water users, compact delivery requirements, groundwater
aquifers and the users relying upon them, riparian environment, water quality, and
others. Opportunities f or agricultural water conservation exist where the conserved
water is returned to the stream system and is available for instream flows or diversion
DRAFT 2-1