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-13- Potential impacts to the source of water supplying these water rights are discussed in detail in the probable hydrologic consequences section of this document, Section VIII, pages 16-19. Upon acceptance of the stipulations contained in Section VIII of this document, the Division finds the proposed operation in compliance with the requirements of this section. VII. Alluvial Valley Floors - Rules 2.06.8 and 4.24 J.F. Sato and Associates developed the Alluvial Valley Floors section of the permit application, through the Small Operators Assistance Program. There are three drainages within the permit and adjacent area that contain map able alluvial deposits: Lewis Gulch, South Oak Creek and Oak Creek (See Figure 2). Lewis Gulch, a narrow, ephemeral tributary to Oak Creek, flows by and beneath the proposed surface facilities. There is insufficient alluvium and/or water to consider Lewis Gulch an alluvial valley floor (A.V.F.). ' South Oak Creek, also an ephemeral tributary to Uak Creek, flows northeast through the permit area and will be undermined. The alluvial deposits along South Oak Creek are discontinuous and are under 10 acres in size. In the eastern portion of the permit area the stream flows through abandoned strip mine pits and during low flow the stream is impounded by the previous mine disturbances. Based on these facts South Oak Creek is not considered to be an alluvial valley floor. Approximately one mile north of the proposed surface facilities is the Oak Creek drainage. The stream is considered to be perennial, however, during the fall season the base flow is diverted into alluvial wells which supply the town of Rockvale with water. The alluvial deposits adjacent to the stream are over 50 feet in width and over 10 acres in size as shown on the General Mine Area Map, TP-1. Flood irrigation has been historically practiced and is practiced today along the Oak Creek Valley. The Division has, therefore, determined that the stream valley of Oak Creek is an alluvial valley floor. Potential impacts to the Oak Creek A.V.F, are minimal. There will be no physical disturbance to the A.V.F in the construction of surface facilities, and it will not be undermined. The only potential impact is from degraded water flowing from the area to be disturbed by Twin Pines Coal Company, Inc. into the adjacent Oak Creek A.V.F. The mine has been designed to mitigate this impact. The drainage from the disturbed area will be adequately controlled during mining and reclamation, as discussed in Section XVII of this document. Once the site is reclaimed, water quality degradation is not expected to exceed background levels contributing to the water supply of the A.V.F. The potential for material damage to the Oak Creek A.V.F. from the Twin Pines No. 2 Mine is, therefore, considered negligible. Based on the information presented in the application the Division makes the following findings: