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Mr. Jim Stark <br />September 23, 2005 <br />Page 4 of 6 <br />(iv) Documentation that areas identified in 2.06.8(3) are, or are not, subirrigated, based on <br />ground water monitoring data, representative water quality, soil moisture <br />measurements, and measurements of rooting depth, soil mottling, and water <br />requirements of vegetation. <br />The locations of monitoring wells completed in the alluvial sediments are presented on <br />Figure 1. Water level data from the wells are presented on Table 1. The depth to <br />groundwater in the alluvial sediments ranges from about 8.5 feet below ground surface <br />(bgs) in the West Fork of Jubb Creek to greater than 47 feet bgs in the lower portion of <br />Little Collom Gulch, near the confluence with Collom Gulch. The depth to water in the <br />valley fill in the vicinity of the monitoring wells appears to be too great to allow for <br />agriculturally significant subirrigation. <br />Deep gullies are present in the Jubb Creek and Collom Gulch valley bottoms, especially <br />in the northern-most portions of those areas shown in Figure 1. The majority of the <br />erosion that created these gullies reportedly occurred in 1983-1984. These gullies are <br />actively eroding and appear to be affecting [he groundwater hydrology of the valley <br />bottoms. Examination of vegetation and soils within the wetland near the Jubb Creek <br />confluence (immediately up the East Fork of Jubb Creek) revealed predominantly <br />hydrophytic vegetation and well-developed soil mottles. However, the soil profile at this <br />location was very dry for a wetland, and a vaziety of upland species appeared to be <br />establishing within the center of the wetland. This site was in close proximity to an active <br />head cut, and the conditions observed may support the conclusion that these gullies are <br />effectively lowering the water table in some portions of the drainages. The 1980 Dames <br />and Moore report noted that the valley floor on the West Fork of Jubb Creek was locally <br />very wet with several small ponds surrounded by common cattail. Because the major <br />erosion of the gullies post-dates the Dames and Moore report, that document does not <br />entirely reflect current conditions. No open water bodies or wet areas capable of <br />supporting cattails are currently present in the area referenced, which is further evidence <br />of the effects of changes in groundwater hydrology. <br />Many of the other wetland features shown on the map (most notably in Collom Gulch <br />and West Fork of Jubb Creek) aze fed by springs and seeps originating immediately <br />adjacent to or within the delineated feature. The presence of springs and seeps suggests <br />that some shallow groundwater is found in the azea. Additionally, examination of seeps <br />in gully walls suggests that some moisture is sporadically and present at inconsistent <br />depths along valley bottoms. Non-wetland soil profiles examined immediately adjacent <br />the drainages reveal very few soils with mottles, shallow rooting depth, or other <br />characteristics that may indicate subirrigation. The vast majority of the vegetation <br />growing in these deposits is similar to that found in upland areas. Notable exceptions to <br />these observations aze wetlands, bottoms of the incised features, and scattered stands of <br />cottonwood and other deciduous trees and shrubs occurring along Collom Gulch. <br />(v) Documentation, based on representative sampling, that areas identified under 2.06.8(3) <br />are, or are not, flood irrigable, based on streamfiow, water quality, water yield, soils <br />measurements, and topographic characteristics. <br />Based on available data, it is reasonable to conclude that alluvial deposits exist within the <br />permit area. However, the topography severely limits the distribution of these deposits <br />and the deposits have not been historically used for flood irrigation. In the vicinity of the <br />"Scientists antl Engineers Committed to Clien[ Satisfaction" <br />