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<br />John Wiener, Comments to SWSI, September 2004
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<br />increasing on the South Platte. This substitute wetted-land riparian habitat is changing again.
<br />Second, the water distribution for irrigation has created many wetted areas. The extent of this
<br />"created wet-land" is not known, apparently. In case study of Boulder Creek areas, along the
<br />foothills where there are numerous tributaries into the main creek, and the South Platte, less than
<br />1 percent of the standing water body surface was not human-created, and 18-20 percent of the
<br />riparian vegetation on the study area was sustained by ditches (Crjfasi 2002, see Wiener, August
<br />comments to SWSI). The farther from the mountains, the fewer the tributaries and the more one
<br />would expect the riparian habitat and wetlands to be irrigation dependent, until the ground-water
<br />tables are intercepted rather far eastward
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<br />5. The agricultural issue and rotating fallow idea have some interesting aspects, and should
<br />certainly be further investigated. Some foreseeable problems should be noted. There are
<br />economic and environmental aspects of some areas, some farm-size, some smaller, some
<br />larger, which warrant taking them out of irrigation aside from any other goals. These include
<br />those which are inadequately productive and should be in some other management, and would
<br />be, were there no counter-incentives preventing normal economic decisions; these may include
<br />base acreage ror commodity support payments or other influences. More important to the public
<br />interests, there are areas that should be taken out of irrigation because of their disproportionate
<br />contributions to salinity or other water quality problems. See Gates et aI., 2002, figure 2 and
<br />citation below. It may be the case that buy-out of some areas could be cost-effective aside from
<br />the value of the water that could be moved. It is also likely that the water could be made more
<br />productive if moved to an area with un-irrigated good quality soil, which could support high-
<br />efficiency application technology such as subsurface drip irrigation. Second, there are probably
<br />some areas that should not be changed, where the crops, productivity, or other considerations
<br />warrant preservation. Economic efficiency suggests some market considerations should not be
<br />overlooked.
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<br />The problems that SWSI has noted for intermittent irrigation, with water banking, interruptible
<br />supply and other plans, also suggest that effort should made to investigate potential for creative
<br />reallocations. Just as some crops are dependent on steady support (orchards, alfalfa, other
<br />perennials), some may be much more amenable to intermittent or interrupted practices. The
<br />optimal rotation should be identified, including turf and nursery crops in the analysis as well as
<br />food and feed crops. Also, weed control and potential interactions with invasive species should
<br />be considered; can these problems be lessened by choices of where and how long to interrupt?
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<br />Research on the Water Bank experiment has also shown that there are serious internal issues for
<br />some but not all ditch companies in accounting and management for transfers, including the
<br />presence or absence of adjustable headgates for individual turn-outs and laterals, and the
<br />management issues resulting from each farm having a mix of perennial and annual crops, and
<br />hydraulic head management problems. These are soluble issues but not by arm-waving alone.
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<br />The entire range of novel management practices and opportunities warrants support for the
<br />traditional means of investigation, which include agricultural experiment stations, cooperating
<br />research partners, demonstration and the techniques of extension. So far, the results from the
<br />Arkansas River Water Bank Pilot Program suggest that failure to use established means of
<br />promotion and exploration of agricultural innovations may be unfortunate.
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<br />Finally, the changing nature of agricultural land ownership and management will interact with
<br />water management. In Colorado as of 1997 (USDA Ag. Census and Co. "Highlights"), 73% of
<br />farms made only 5% of total sales, from 43% of Colorado farmland - that's about 13.5 million
<br />acres of management not motivated by conventional commercial concerns. And, "ranchettes"
<br />now occupy 4 times the area of all incorporated land, and that will probably double in 30-40 years
<br />( in 30-40 years (Olinger, D., 25 Nov. 2003 Denver Post "Urban getaways spur rural sprawl...,
<br />pA 1; and Theobald, D.M., 2003, Targeting conservation action..., Conservation Bioloqy 17(6):
<br />1624-1637 - see Wiener August 2004 annotations in comments to SWSI). These lands are not
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