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AVF Determination <br />Seneca Coal Company conducted an extensive alluvial valley floor investigation of the <br />permit and adjacent area. This study included the use of aerial photos, alluvial <br />completion wells, stream gaging stations, and consultation with consulting firms and <br />Federal agencies. The study identified areas along Hubberson Gulch, Dry Creek and <br />Sage Creek which meet the criteria for designation as alluvial valley floors (AVF). <br />Based on information available at this time, the Division considers all lands mapped as <br />Qa and Qvf on Exhibit 16 -2 to be alluvial valley floors with the exception of lands in <br />upper Hubberson Creek, and with the further exception of the small area of subirrigated <br />meadow and wetland vegetation types along Dry Creek in Section 9, TSN, R88W, <br />immediately upstream of the old J.C. Temple Reservoir #2 and adjacent to the former <br />Olson Ranch buildings. The subirrigated meadow and native wetland types are <br />delineated on the "Map 1" Attachment to Exhibit 16 -3, Sheet 2, which was submitted <br />with TR -50 (Map 1 certification date 11/4/05). <br />Upper Hubberson Gulch Exclusion <br />During the review of PR -2, three areas mapped as Qa and Qvf in upper Hubberson Gulch <br />were further investigated to determine their designation as AVF's. The first two areas <br />are located in Sections 34 and the third is located in Section 21, TSN, R88W. The first <br />area is southeast of proposed Pond 017; the second area is northwest of the proposed <br />Pond 017; and the third area is south of two irrigated hay fields. All three fields are <br />long, narrow bands of alluvial deposits covering less than one acre total. These areas <br />were determined not to be AVF's. The areas are in narrow reaches of the canyon with a <br />sinuous, incised channel. Flood irrigation and farm production would not be <br />economically feasible in these areas. <br />Dry Creek Section 9 Exclusion <br />The small area of alluvium on Dry Creek in Section 9 was originally determined by the <br />Division to be an alluvial valley floor. However, based on amended vegetation mapping <br />and narrative presented in TR -50 (amended Tab 17 pages 129 through 129c, and new <br />Map 1 Attachment to Exhibit 16 -3, Slit. 2) the Division has revised its original <br />determination. <br />Based on the information presented in TR -50, the Division finds that the subirrigated <br />parcels on Dry Creek in Section 9 do not meet AVF criteria. Native wetlands dominated <br />by species that are not agriculturally useful comprise the major portion of the northern <br />parcel in the vicinity of the reservoir embankment. Meadow grass types potentially <br />enhanced by subirrigation occur in the southern parcel, and as a minor type in the <br />northern parcel. The grass meadows may have been managed for hay production in the <br />past, but the report indicates that there is no evidence of management for hay production <br />Seneca II -W Findings Document 54 C- 1982 -057 <br />Permit Revision No. 6 January 6, 2012 <br />