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-IZ- Alluvial Vailcy Flooz•s (con't) Creek directly adjacent to the Blue Ribbon hfine operations. Three sediment ponds, a water storage pond, a coal stockpile, portions of the access road, and a water supply well are all located within or on this alluvium. Blue Ribbon Coal Company has estimated the alluvial body to be approximately 24 acres in size. However, based on planim- etered measurements made by the Division, the alluvial body appears to have an area of between 10 and 12 acres. This area, therefore, only marginally meets the OSM size criteria (10 acres or more) for alluvial valley floors. The alluvial body is isolated by narrow canyons located upstream and downstream of the site. There is no evidence of past agricultural use of this alluvial body and due to the small size and isolated nature of the alluvium, no future agricultural use is antici- pated. Due to the small size, isolated location and marginal utility of this alluival deposit, the Division finds that pursuant to Rule 2.06.8(3)(c), the body of alluvium located along Hubbard Creek directly adjacent to the mine is not an alluvial valley floor. The North Fork of the Gunnison River: AZl of the surface water runoff from the mine floras into the North Fork of the Gunnison River via Hubbard Creek. Hubbard Creek joins the North Fork in Section 14, T135, R91w, approximately 2 miles south of the mine. This area of the North Fork Valley has previously been found to be an agriculturally significant alluvial valley floor (AVF) by the Division. This determination was made during review of the ARCO Coal Company (presently Anaconda Minerals) Mt. Gunnison No. 1 Mine permit application (see page 5 of the June 23, 1981 findings document for the Aft. Gunnison No. 1 Mine application). Alluvial Valley Floor Findings 1. Pursuant to Rule 2.06.8 (5)(a)(i)(A)(I), the Division finds that the proposed surface mining operations would not interrupt, discontinue, or preclude farming on the North Fork AVF (Rule 2.06.8(5)). The North Fork AVF is not within the permit area, and will not be physically disturbed by the mining activities. 2. Pursuant to Rule 2.06.8 (5)(a)(1)(A)(II), the Division finds that the pro- posed surface coal mining operations would not materially damage the quantity and quality of water in surface and ground water systems that supply those alluvial valley floors or portions of alluvial valley floors. Portions of the North Fork AVF receive water from the Afajnik and KIein Ditch (see Hydrologic Area A1ap - Exhibit P - of the permit application). This ditch diverts Hubbard Creek water. The potential effects of the Blue Ribbon Mine upon flows in Hubbard Creek include a worst case reduction in water yields of O.I~ and a negligible increase in total dissolved solids. See the Probable Hydrologic Consequences of Mining subsection of Section VIII, "Probable Hydrologic Consequences of Mining and Cumulative Hydrologic Impacts Study", page 36 of this document, for a discussion of these effects.