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Valley fill deposits located along Rapid Creek have been interpreted as <br /> a mudflow fan deposit which has been modified and reworked by Rapid <br /> Creek to form three terrace levels . The upper terraces (T2 and T3) are <br /> irrigated or have been irrigated with the flow from Rapid Creek. The <br /> lowest terrace (Tl ) is narrow and has not been flood irrigated. The Tl <br /> terrace includes a narrow band of subirrigation along the creek, but <br /> the species present are not agriculturally useful . Subirrigated <br /> species located on the T2 terrace are deep rooted and do not indicate <br /> the general availability of ground water to agriculturally useful <br /> species . The T3 terrace does not have vegetation indicating <br /> subirrigation. <br /> Several minor ephemeral streams also drain the permit area. The stream <br /> valleys are narrow, steep, and contain very little alluvium. None of <br /> these valleys contain deposits meeting the AVF size criteria. <br /> Areas along the Colorado River have been identified as terrace <br /> landforms with existing flood irrigation. The lowest terrace is <br /> marginally subirrigated, but the upper terraces are not subirrigated. <br /> Based on the above information, two areas of alluvial valley floors can <br /> be identified . The two upper terraces (T2 and T3) have been identified <br /> as unconsolidated streamlaid deposits, and have sufficient waters to <br /> support flood irrigated agricultural activities . (Except, two of the <br /> areas designated on Map 1 as have been disturbed by previous unrelated <br /> mining activities and by construction of water treatment facilities and <br /> should not be identified as alluvial valley floors . ) The areas <br /> designated as CRT (Colorado River Terrace) , as well as the lower <br /> terraces and floodplain along the Colorado River, are determined to be <br /> alluvial valley floors . The areas identified as CRT consists of <br /> unconsolidated streamlaid deposits that are currently flood irrigated. <br /> The lower terraces and floodplain are flood irrigated in several areas <br /> (Map 2) , and may be subirrigated in places . <br /> Significance to Agriculture <br /> Since no agricultural information has been provided from any of the <br /> areas designated as alluvial valley floors , all the areas will be <br /> assumed to be agriculturally significant, and all three alluvial valley <br /> floor findings will be made. <br /> Rapid Creek Alluvial Valley Floor - Findings <br /> 1 . The proposed surface coal mining operations would not interrupt , <br /> discontinue, or preclude farming on an alluvial valley floor . <br /> The area designated as alluvial valley floor lies outside of the <br /> permit area, downstream from the proposed operations . As a result, <br /> there would be no surface disturbance within the AVF, and the area <br /> would not be undermined. <br /> 2. The proposed surface coal mining operations would not materially <br /> damage the quantity and quality of water in surface and underground <br /> water systems that supply these alluvial valley floors or portions <br /> of alluvial valley floors . <br /> _a3- <br />