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percentage of production supplied by these plants is 32.6%. The cover of <br />clover is 5.3% or 6.1% relative cover and production is 2.0%. Using the <br />assumptions presented for Pasture 2, the expected yield decrease might be <br />1.1%. <br />Within the irrigated land of Fish Creek, moderately sensitive species <br />comprise only .5% of the total cover (.7% of relative composition). <br />Concerning the Sagebrush/Meadow vegetation type, moderately sensitive species <br />cover 3.3% (or 3.7% relative composition). <br />Based on site specific data and irrigation practices, Twentymile Coal <br />Company contends a material damage standard of 2000 umhos/cm is applicable <br />for the Foidel Creek Mine. This proposed standard is consistent with the <br />crops and vegetation growing in the area. Moderately sensitive plants do not <br />dominate the area; the current material damage standard appears to be based <br />on that concept. Moderately tolerant species, which are economically <br />important for both hay production and grazing, grow in a greater percentage <br />of the area (21.8%) than do moderately sensitive species (5.8%). <br />At the proposed standard of 2000 umhos/cm, the yield reduction of <br />moderately sensitive plants would not exceed more than 3.1% for grasses <br />(using values for orchard grass) and 6.0% for forbs (using values for <br />clover). For a pasture to experience a yield decrease of even 5%, moderately <br />sensitive grasses would have to provide about 33Yo of the production and <br />moderately sensitive forbs would have to provide the remaining 67%. In such <br />a pasture, the vegetative cover of moderately sensitive species would <br />approach 100%. None of the pastures studied indicate such a situation exists. <br />Additionally, the areas which contribute to the crop productivity of the <br />region are irrigated with waters diverted from Middle, Trout, and Fish <br />Creeks. None of the pastures are irrigated with water diverted from Foidel <br />Creek. The Middle Creek pastures are irrigated with waters diverted either <br />from Middle Creek above the Foidel Creek confluence or Trout Creek above the <br />Middle Creek confluence. The pastures within the Trout Creek region are <br />irrigated with waters diverted from several upstream locations along Trout <br />Creek. Therefore, based on the specific conditions discussed above, <br />Twentymile Coal Company contends a standard of 2000 umhos/cm will not <br />materially damage downstream alluvial valley floors. <br />