<br />John Wrener, Comments to SWSI., September 2004
<br />
<br />4
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<br />increasing on the South Platte. This substitutevvetted-Iand riparIan habitat is changing again.
<br />Second, the water distribution for irri'gation has created many wetted areas. The extent of this
<br />"created wet-land- is not known. apparently. In case study Q'f B.oulder Creek areast along the
<br />foothills where there are numerous tributaries into the main creek., and the SoulhPlatte, 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 ditchBS (Crifasi 2002, see Wienerl August
<br />comments to SWSJ). The farther from the mountains, th,efewer the tributaries and the more one
<br />would expect the riparian habitat and wetlands to be irrigation d1ep!endent, until the ground-water
<br />tab les are intercepted rath er far eastward
<br />
<br />5. The agricultural issue and rotating faUowidea have some interesting aspects. and should
<br />certainly be further investigated. Someforeseeabl-e problems should be noted. There are
<br />economic and environmental aspects of som!e a.reas, some farm-size, some smaller, some
<br />larger, which warrant taking them out of irrigation asidB from any other goals. These include
<br />those which are inadequately productive and should be in some other management, and would
<br />bet were there no counter-incentives preventing normaJ econo,mic decisions; these may include
<br />base acreage for commodity support payments or other influences. More important to the public
<br />interests, there are areas that should be taken out of Irrigation because O'f their disproportionate
<br />contributions to salinity or other water quality problems~ See Gates et al., 2002, figure 2 and
<br />citation below. It may b:e the case that buy-out .of some areas could be cost-effective aside from
<br />the value of the water that could be moved. ,II is also likely that the water could be made m.ore
<br />productive if moved to an area with un-irrigated good quality soil. which couid support high-
<br />efficiency application technofogy such as subsurface drip irrigation. Second, there are probably
<br />some areas that should not be chang'led, where the cropSt productivity, or other considerations
<br />warrant preservation. Economic efficiency sugg,ests some market considerations should not be
<br />overlooked.
<br />
<br />The problems that SWSl has noted for inte'f'mit1ent irrigation, with water banking, interruptible
<br />supply and other plans} also sU9,gest that effort shouldm.ade to investigate potential for creative
<br />reallocations. Just as some crops are dependent on steady support (orchards, alfalfa, other
<br />perennials)~ some may b-e much more amenabl:e 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. Alsot weed control and potential interactions with invasive species should
<br />be considered; can these problems b!e lessened by chOlces of where and how long to interrupt?
<br />
<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 managem,ent for transfers, including the
<br />presence or absence of adjustabl:H headgates for indIvidual turn-outs and laterals, and the
<br />mana.gement issues resulting from each farm having a mix of perennial and annual crops, and
<br />hydraulic head management probiHms. These are soluble issues but not by arm-waving alone.
<br />
<br />The entire range of novel manage'ment practices and opportunities warrants support for the
<br />traditional means of investigation, which include agricuIturalexperiment stationst 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 b,a unfortunate.
<br />
<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. UHighlightsnt), 73% of
<br />farms made only 50/0 of total saJes)trom 430/0 of Colorado farmland - that's about 13.5 million
<br />acres o'f management not motivated by conventional commercial concerns. And, "ranchettesll
<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'i 25 Nov. 2003 Deinver Post l'Urban getaways spur rural sprawL..,
<br />pA1; and Theobald, D.M.t 2003, Targeting conservation action..., Conservation BioloQY 17(6):
<br />1624-1637 - see W fener August 2004 annotations in comments to SWSI). These lands are not
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