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DRAFT DRAFT DRAFT <br />during rain storms. During the driest year the flow-by volume was only 22% of the <br />total run-off volume compared to 81 % on the wettest year and 63% on an average <br />year. <br />While MVIC agricultural diversions were out of the Dolores basin, this period saw <br />the introduction of agricultural practices and livestock grazing on public and private <br />land within the Dolores River corridor. There is extensive literature on the effects <br />of grazing on riparian vegetation and river habitat, that generally concludes that <br />historic grazing practices destabilized riparian ecosystems throughout the western <br />U.S. However, specific details of how the introduction of livestock affected riparian <br />and river health on the Dolores is speculative; literature on the effects of livestock <br />region-wide can only be generally applied. It is important to recognize the effects <br />that poor grazing management can have on riparian health, which can be <br />especially detrimental to alluvial reaches where livestock can destabilize the fairly <br />delicate balance of stream flow, sediment flux, and vegetation. Addressing <br />grazing management within the Dolores River watershed, including significant <br />sediment contributors such as Disappointment Creek, will require the participation <br />of public land managers and private property owners responsible for managing <br />lands within the watershed. <br />C. Dolores Project (1986 to 2005) Hydrology and Downstream Ecology <br />Dolores Project (1986-2005) -Hydrology <br />The Dolores Project was designed to supply an average annual of 90,900 of for <br />irrigation, 8,700 of for M&I use, and 25,400 of for downstream fish and wildlife <br />purposes. The Project will provide irrigation water for 61,600 acres of land, <br />including full-service irrigation water for 27,920 acres in the Dove Creek area and <br />7,500 acres on the Ute Mountain Ute Indian Reservation, and supplemental <br />irrigation water for 26,300 acres served by the MVIC. <br />The original operating criteria for McPhee Reservoir were specified in the Final <br />Environmental Statement (FES) and Definite Plan Report (DPR), published in <br />1977. Based upon records from 1928 to 1974, the FES/DPR indicated that an <br />average of 25,400 of/yr of storage was available to supply flows for a trout fishery <br />downstream of McPhee Dam. It was anticipated that the downstream releases <br />from Project supplies and supplemental spill water would create a recreational <br />fishery, to be enhanced by stocking and fishing regulation (e.g., catch and <br />release). Releases from McPhee Dam were determined each year based upon <br />how much water was in storage in McPhee Reservoir and how much snow pack <br />was available in the watershed. Based upon these two indexes, the year was <br />declared `dry', `normal', or `wet' on March 1 of each year. If the water year was <br />declared dry, for the next 365 days, 20 cfs would be released to support the <br />downstream fishery. In a normal year, 50 cfs would be released and in wet years, <br />78 cfs. <br />9/5/06 22 <br />