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(i.e., the period when the water table would be at its lowest point). Similarly, soil moisture Itrofile data for the same cross-section (see Appendix III) were collected during October. The conclusion that can be drawn from [Iris data is that the hay meadow is not subirrigated in October. In order to make a statement about subirrigation conditions in this hay meadow during the rest of the growing season it was assumed that the same capillary rise (i.e., 2.5 - 3 feet from the soil moisture data of Appendix III) would occur above the water table as it fluctuated through the growing season. To determine the water level Fluctuations representative of the cross-sections through the growing season the location of the Pittsburg and Midway Coal Mining Company's well FI-4 (Water, Waste and Land, Brown and Caldwell, 1981) was located on the cross-section (see Figure 3), and the water level data for the growing season was taken into account (Table 3). Witlt the water table information and an average capillary rise of 2.5 - 3 feet, it can be seen that the plant roots are deriving some benefit from shallow groundwater's during May, June, and part of July (see Figure 3). During the rest of the growing season, the plants are not capable of taking up water supplied from the water table. Therefore, the lower hay meadow, previously described, is marginally subirrigated though the growing season. Summary of Subirrieation Conditions Kaman Tempo installed seven test pits on Fish Creek (see Map 4), in order to evaluate subirrigation conditions on [he portion of the valley floor meeting the AVF geomorphic criteria (see Map 2), Data from these test pits are provided in Appendix 1. lit summary, depth to groundwater on the T2 terrace ([Ire most significant valley landfonn) ranged from about three feet in May, to six feet in June, to seven feet in July, and to about 7.7 feet during the remainder of [he growing season. The average capillary rise noted for all of these test pits in the Fish Creek valley was about 32 inches. The average rooting depth (excluding the few fine roots) for agriculturally useful native species was about 25 inches while the average rooting depth for hay crops, (i.e., smooth brome) was about 37 inches. The few find roots that extend deeper ion every pit are not considered important to meet the plants' overall moisture requirements. This rooting depth for the smooth brome, using the common fine root classification, agrees with SCS information that smooth brome is only capable of uptaking moisture, which will be of significant benefit to the plants' growth, from a depth of 36 inches (Tom Steitz, for SCS, Steamboat Springs, Colorado, Personal Communication, October, 1982). Using the data described above, the TI terrace, which is approximately four feet above Fish Creek with native vegetation, is subirrigated through most of the growing season. The T2 terrace, which is approximately 8.5 feet above the level of the stream, is clearly subirrigated in May for both native grasses and improved hay meadows. However, in June, only the Itay meadows are subirrigated since the capillary fringe is 1.25 feet below the roots of native grasses. In July, the separation between the roots and the capillary fringe increases to 2.25 and 1.25 feet for the native grasses and hay grasses, respectively. The capillary fringe remains at or below the roots by the same amount during the remainder of the summer with a maximum separation of roots and capillary water in September of 2.95 and 1.95 feet for native and Itay grasses, respectively. According to the Colorado irrigation Guide (USDA-SCS, 1960, revised 1982), the total growing season water deficit for pasture grasses in the study area is 14 inches of water. If grasses on the T2 terrace are fully capable of deriving their water needs during May and a small part of the I:environ\tracy\document/ExhibTA 8 01/16/98 ~,~f ~~l~i! JUN 2 0 2000