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permit application. <br /> 1. Yampa River 2. Williams Fork River <br /> 3. No Name Gulch 4. Johnson Gulch <br /> 5. Pyeatt Gulch 6. Flume Gulch <br /> The above alluvial valleys would meet the regulatory definition of an alluvial valley floor(AVF)if <br /> the valleys had water availability sufficient for flood-irrigated agricultural activities [Section <br /> 1.04(10)], or availability of water sufficient for subirrigated agricultural activities [Section <br /> 1.04(10)]. Flood irrigation is practiced on the valley floors of the Yampa River in the Big Bottom <br /> area and the Williams Fork River near its confluence with the Yampa. Based on the presence of <br /> unconsolidated, stream laid holding streams with water availability sufficient for flood-irrigated <br /> agricultural activities, the following two alluvial valleys have been determined to be alluvial <br /> valley floors: <br /> 1. the Yampa River in the Big Bottom area <br /> 2. the Williams Fork River near its confluence with the Yampa River. <br /> Maps 35 A and Map 52 indicate the location of Alluvial Valley Floors (AVFs), and AVF well sites <br /> respectively. The Coy well, drilled into Flume drainage alluvium functions as a point of <br /> compliance. Four wells are drilled into the Pyeatt alluvium, well Jl is located in the Johnson <br /> drainage alluvium and one of the three GLEV wells in the Deacon drainage reached the alluvium at <br /> the very north east corner of the permit. This GLEV well is located downgradient of any mining to <br /> the east that may occur in the future. These wells constitute an environmental monitoring system <br /> during surface coal mining and reclamation operations continuing until release of all bonds in <br /> accordance with Rule 3 (4.24.4). <br /> Four gulches (No Name, Johnson, Pyeatt, and Flume), are determined not to be alluvial valley <br /> floors based on their absence of water availability sufficient for flood irrigation or sub-irrigation <br /> agricultural activities. <br /> Potential impacts to the Yampa River AVF resulting from the proposed mining operation are <br /> negligible. Generally, the Yampa River AVF receives very little of its water supply (surface and <br /> ground water)from the proposed mine area. The majority of the flow in the river and subsequent <br /> recharge to the alluvial aquifer derive from the headwaters portions of the drainage, far upstream <br /> from Trapper. The applicant states that the contribution of surface water from the Trapper mine is <br /> insignificant as per page 2-533 of the permit application. <br /> This is substantiated by seepage, runoff, and potentiometric studies in Appendix H of the permit <br /> application. Based on the information presented by the applicant, the Division finds that proposed <br /> surface coal mining operations will not interrupt, discontinue, or preclude farming on the Yampa <br /> River AVF, nor materially damage surface or ground water quantity or quality in systems <br /> supplying the Yampa River AVF (4.24.3(1)), (4.24.3(3), and 2.06.8(5)(a)(11)). <br /> The potential for impacts from mining to the Williams Fork AVF is also negligible. The <br /> Williams Fork River is located south of the proposed mining area. Almost exclusively, spring <br /> snowmelt comprises the only surface discharge from sediment ponds in the drainages flowing <br /> 21 <br />