2017-04-05_GENERAL DOCUMENTS - C1982057

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XVII. Operations on Alluvial Valley Floors As part of PR -1, the applicant submitted adequate information for the Division to make the required alluvial valley floor (AVF) determination and findings in accordance with Section 2.06.8 of the Regulations. Additional information was submitted during the review of PR -2, PR -3, and TR -50. All information on alluvial valley floors is provided in Tabs 16 and 17 of the application. AVF Determination SP conducted an extensive alluvial valley floor investigation of the permit and adjacent area. This study included the use of aerial photos, alluvial completion wells, stream gaging stations, and consultation with consulting firms and Federal agencies. The study identified areas along Hubberson Gulch, Dry Creek and Sage Creek which meet the criteria for designation as alluvial valley floors (AVF). Based on information available at this time, the Division considers all lands mapped as Qa and Qvf on Exhibit 16-2 to be alluvial valley floors with the exception of lands in upper Hubberson Creek, and with the further exception of the small area of subirrigated meadow and wetland vegetation types along Dry Creek in Section 9, TSN, R88W, immediately upstream of the old J.C. Temple Reservoir #2 and adjacent to the former Olson Ranch buildings. The subirrigated meadow and native wetland types are delineated on the "Map 1" Attachment to Exhibit 16-3, Sheet 2, which was submitted with TR -50 (Map 1 certification date 11/4/05). Upper Hubberson Gulch Exclusion During the review of PR -2, three areas mapped as Qa and Qvf in upper Hubberson Gulch were further investigated to determine their designation as AVF's. The first two areas are located in Section 34 and the third is located in Section 21, TSN, R88W. The first area is southeast of Pond 017; the second area is northwest of the proposed Pond 017; and the third area is south of two irrigated hay fields. All three fields are long, narrow bands of alluvial deposits covering less than one acre total. These areas were determined not to be AVF's. The areas are in narrow reaches of the canyon with a sinuous, incised channel. Flood irrigation and farm production would not be economically feasible in these areas. Dry Creek Exclusion The small area of alluvium on Dry Creek in Section 9 was originally determined by the Division to be an alluvial valley floor. However, based on amended vegetation mapping and narrative presented in TR -50 (amended Tab 17 pages 129 through 129c, and new Map 1 Attachment to Exhibit 16-3, Sht. 2), the Division has revised its original determination. Based on the information presented in TR -50, the Division finds that the subirrigated parcels on Dry Creek in Section 9 do not meet AVF criteria. Native wetlands dominated by species that are not agriculturally useful comprise the major portion of the northern W.