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9) end from four drill holes for i:he stability analyses associated with Pond 10 (Tab 13, • <br />Attachment 13-5). The sample sites ere shown on Exhibit 9-1, Sheet 2 of 2 end Exhibit <br />13-12, Sheet 2 of 2. <br />Zoltay variant clay loam uas the soil type identified at Soil Pit Y39 in Annand Draw (Tab <br />9, Addendum 6). Ground water was not encountered on October 1, 1992 in the backhoe pit <br />which was dug to 7.2 feet. Additionally, soil mottling, an indicator of seasonal <br />fluctuating ground water, was not described at this site. Roots extended to a depth of <br />six feet. <br />Northwest Colorado Consultants drilled and sampled four test holes on April 18, 1994 in <br />the proximity of proposed Pond 10. The ground water ranged from four to six feet at Tes[ <br />Holes 22, 24, and 25. Ground water was not encountered at Test Hole 23. <br />The soil date collected by Nyenhuis in 1992 end Northwest Colorado Consultants in 1994 <br />suggest there is some variability in ground water levels for the Annand Draw alluvium. <br />This variability is also evident on aerial photos from 7/1/88, 7/1/89, 10/10/92, and <br />9/23/93. The photo contrast and tone show three distinct areas of wetter soil conditions, • <br />one being the Pond 10 area. Soil Pit Y39 was not located in the wetter areas. The <br />shading on the photos matches ground water Levels identified at the soil sample sites. <br />The lighter Lanes correspond to areas where the ground water is often too deep for <br />significant subirrigation. Subirrigation does occur in the darker shaded areas as <br />evidenced by higher vegetation production. <br />In summary, the improved pasture-subirrigat ed field in Annand Draw does contain areas with <br />subirrigated species and enhanced productivity. However, a significant portion of the <br />area is not notably more productive than dryland areas nor is the site more agriculturally <br />useful when compared to dryland areas. The field is not typical of alluvial valley floors <br />in the region (topographic position in the drainage system) such as the Yampa River Valley <br />or major tributary systems. The area is not typical of agricultural systems in the Yampa <br />River Valley area and does not have characteristics that would Lend itself to supporting <br />or enhancing agricultural activities based on established regional practices. The Annand <br />alluvial water quality is marginal to poor for use as irrigation water and this likely <br />accounts for the limited productivity of the field. SCC concludes this field is not an <br />AVF and the ueter use of the alluvial aquifer (livestock drinking water) will not be • <br />precluded by pit pumpage or spoil spring discharges (see Tab 17). <br />16 Revised 03/24/95 <br />