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• Board Meeting Date: 11/18/2007
• Description: IWMD Section - Alternative Agricultural Water Transfer Methods - Grant Program
• Board Meetings - Doc Type: Memo

right and furthermore, are waters needed to help meet Colorado's future water needs. The
grant program is intended to further our understanding and potential implementation of
alternative transfer methods and to sustain agricultural areas of the state where they are
deemed to provide high values to our communities and the state as a whole. It is also
hoped that the grant program will improve our understanding of how and when
alternatives to traditional agricultural transfers may present benefits to not only the
parties to the transfer, but other third party beneficiaries.
As a key component to this grant program and to better understand alternatives to
traditional agricultural transfers it is important to establish the fundamental difference
between what some have called "inefficiencies in agriculture" and "reduced consumptive
use". Water that is diverted and applied to a crop generally can be partitioned into three
major components:
1. Consumptive Use (CU) -The quantity of water that is physiologically utilized by the
crop and is viewed as beneficial use of water. Generally speaking and in many instances
CU equates to the crops evapotranspiration (ET).
2. Gross or Total Diversion -The amount of water that is diverted to be delivered to the
crop. If this amount of water is greater then the crop consumptive use there may be
opportunities to reduce the gross diversions and resulting return flows which could in
some cases improve water availability for other uses and/or improve water quality; but in
other cases could cause injury to downstream water rights that rely on the return flow.
3. Nonbeneficial consumptive use - is the quantity of water that is lost from the system
and that is not used by the crop. Examples of nonbeneficial consumptive use include:
~ Evaporation not associated with crop CU
Deep percolation of water diverted from the source or applied to the lands via
irrigation methods that does not eventually return to the stream system as return
flov~-s
Water that consumed by other vegetation including non-native plants (high water
use plants known as phreatophytes are of particular interest).
This grant program focuses on identifying and assisting in the development of
agricultural transfer methods/programs that reduce consumptive use by reducing the
amount/types of crops planted and irrigated. It is this reduced consumptive use, not the
reduction in gross diversions (i.e., changes from flood irrigation to sprinkler irrigation
etc.) that can potentially be transferred to an alternate use. When considering alternative
methods for transferring agricultural water to a new use, one must understand that
someamount of land must be taken out of production and/or the amount and type of crop
be reduced or changed from historic levels. A goal of the alternative transfer is to
minimize the geographic focus of the impact and optimize both the agricultural and
nonagricultural benefits of the remaining lands.
Several types of agricultural transfers have been proposed as potential alternatives to the
traditional agricultural transfers that often result in permanent dry up of all or a large
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Draft
November 3, 2007