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-13- Using current Federal Office of Surface Mining guidelines, the Division identified three areas that are sufficient in size to support agricultural activities. Since there is sufficient water available to support at least a portion of these areas, they all qualify as alluvial valley floors. The first area identified as an alluvial valley floor is the alluvial fan 14 acres in size at the confluence of Yank, Sand, and North Thompson Creeks (see Map D-3-7). Its size barely qualifies it as an alluvial valley floor. In addition, subirrigation is restricted to the immediate strearnbanks and water may not be available to flood irrigate this area, since it is in the upper reach of the North Thompson Creek drainage. However, without more information on water availability, the Division must assume this area is capable of supporting agriculture. The essential hydrologic function of this area is flood irrigation potential. This will not be impacted by the Snowmass Coal Company operation. The site is 2.3 miles upstream from any mine facility and one mile west of the maximum anticipated life-of-mine for the operation. The operator has not identified any actual or potential impact that might extend to this area. The second alluvial valley floor body identified by the Division is a 15-acre tract located in Willow Park along Middle Thompson Creek. This area has the potential to be flood irrigated and is of sufficient size to support agricultural activities. With the exception of an existing mine vent fan, no surface disturbance is planned by the operator within the Middle Thompson Creek drainage. However, mine workings will extend under a small portion of this watershed. The alluvial valley floor, however, will not be undermined. Both the Willow Park and above-mentioned Sand/Yank Creek alluvial valley floors are currently undeveloped rangeland which are not significant for farming. The essential hydrologic functions of these areas will be preserved. Surface and ground water monitoring at the mine will continue to verify the applicant's predictions. Une final body is being identified as an alluvial valley floor by the Division. The area adjacent to the confluence of Thompson Creek and the Crystal River is an alluvial valley floor. This area is currently being used as irrigated pastureland and may be significant to agriculture. This body, althouyh included within the applicant's study area, is located over five miles downstream from the mine and will not be physically disturbed by the operation. Based on the information presented in the application, no impacts to this area are predicted. Therefore, its essential hydrologic functions will be preserved. monitoring at the mine site will verify the applicant's predictions.