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• Postmine herbaceous canopy cover, herbaceous production, and woody stem density <br />were evaluated in reconstructed drainage areas in 1988 and 1989 and compared to <br />sample data from undisturbed premine drainage areas. (Sampling was conducted on <br />drainageways reconstructed in 1987.) Various postmine drainage treatments were <br />incorporated to evaluate vegetation response on topsoiled, non-topsoiled, irrigated, and <br />non-irrigated drainage segments (Table 1). Treatments on undisturbed areas were irri- <br />gated and non-irrigated drainage segments (Table 1). Generally, vegetation measure- <br />ments were lower in reconstructed drainageways than in undisturbed drainage sites. <br />This is understandable due to the short duration of vegetation re-establishment. How- <br />ever, considerable vegetation growth was reported in all reconstructed drainages after <br />the initial growing season and during the second growing season. <br />Vegetation response was the best on topsoiled and irrigated treatments and was signifi- <br />cantly higher when comparing topsoiled versus non-topsoiled areas without irrigation. <br />The overall herbaceous canopy cover for all reconstructed drainage treatments in 1988 <br />(measure of initial growing season) was 39% compared to 71% on undisturbed <br />drainage segments. In 1989, herbaceous canopy cover had increased to 60% in recon- <br />structed drainages and decreased on undisturbed drainage segments to 69% cover. <br />Herbaceous primary production averaged 876 lbs/acre in reconstructed drainages and <br />1943 ]bs/acre on undisturbed sites in 1988. In 1989, herbaceous primary production <br />• decreased to 420 lbs/acres on reconstructed drainages and 521 lbs/acre on undisturbed <br />drainage segments. The reduction in production in 1989 compared to 1988 was a result <br />of severe drought conditions in the area during 1989. <br />Woody stem densities on undismrbed drainage areas averaged 4888 stems/acres for <br />both years compared to 471 stems/acre in 1988 and 897 stems/acre in 1989 on recon- <br />structed drainage areas. <br />Tables 2 and 3 list all plant species encountered in reclaimed drainages and undis- <br />turbed drainage segments respectively. Sixty-three species were identified in reclaimed <br />drainages and 21 in undisturbed drainages. <br />Flow rates have been significantly reduced following the installation of stock tanks and <br />dozer basins on reclaim and spoil areas, respectively. Discharge readings were <br />recorded from a 10-year, 24-hour parshall flume (with Stevens Water Level Recorder) <br />located in the north end of the Coyote Gulch reconstructed drainage channel. The <br />peak flow in 1987 (22.24 cfs) occurred as a result of a high intensity thunderstorm in <br />June (.74" ppt) and caused severe erosion within the newly regraded drainage channel. <br />In 1988, following drainage reconstruction and water retention strategies, the peak flow <br />rate associated with a .53" precipitation event (June) registered .04 cfs of discharge <br />water. Similarly, a high intensity thunderstorm in July 1989 (.75" ppt) resulted in a dis- <br />charge of 1.23 cfs. In addition to assisting in runoff control, the proper frequenty and <br />distribution of livestock ponds has aided in evenly spreading big game animal use over <br />the entire reclaimed area, thus reducing their impact on vegetation establishment. <br />• Table 4 provides monthly peak flows for Coyote drainage in 1989. <br />