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Vegetation response was better on topsoiled and irrigated treatments than on non topsoiled and non <br />irrigated treatments. The average herbaceous cover and production on topsoiled, non irrigated treatments <br />was higher (62% cover increase and 297°,6 production increase) when compared to adjacent non topsoiled, <br />non irrigated treatments. On irrigated treatments, cover and production estimates were again higher when <br />comparing topsoiled (38% cover increase and 333% production increase) to non topsoiled plots. <br />The data strongly indicate significant benefits to topsoiling a drainageway. In fact, topsoiled, non-irrigated <br />drainageway cover and production exceeded that of adjacent non-topsoiled, irrigated treatments. In <br />addRion, herbaceous cover and production values were higher at the lower reaches of drainages compared <br />to the upper and middle segments. Undisturbed drainages experienced the same cover and production rate <br />increases/decreases depending on drainage elevation with woody stem densities increasing at the upper <br />reaches of drainageways. <br />The actual number of plant species encountered during sampling on reconstructed drainages (53) (fable 3) <br />was higher than on adjacent undisturbed plots (29) (fable 4). Perennial species comprised 39% and 97°.G of <br />the vegetation on reconstructed and undisturbed drainages, respectively. <br />Gully formation and sediment loss was reduced significantly in postmine drainageways when compared to <br />pre~rainage reconstruction. In Coyote drainage, for example, an estimated 99,400 cubic yards of sediment <br />was lost to gully erosion and sheet and rill erosion from 1984-1987. Following treatment an estimated 1,360 <br />cu yds of sediment is lost annually to sheet, rill, and gully erosion. This is a reduction in the annual erosion <br />rate of 24 times the pre-treatment erosion rates. Much of the success for the reduction in erosion rates must <br />be attributed to the wide variety of erosion control materials, methods and sediment reducing measures that <br />were used in reconstructing drainageways and adjacent reclaimed sideslopes. <br />As a result of appropriate erosion control treatment in re-established postmine drainageways, Trapper Mine <br />• has reduced sediment pond cleaning by 100°,6 in 1988. Yeady pond cleaning totaled 80% of the total <br />drainage reconstruction and treatment costs. Within two years. approximately $100,000 in savings could be <br />realized as a result of appropriate erosion control treatment. <br />3.8 Discussion <br />As a strategy for soil conservation planning, the promotion of vegetation in combination with natural and/or <br />art'rficial erosion control measures, has much to offer. Vegetation is one factor that can be easily <br />manipulated by careful management. Beyond that, better vegetative growth, by selecting plants that are well <br />adapted to a particular climate or soil, will almost always provide direct economic benefits in terms of <br />vegetation production, stability and reduced soil loss. <br />The proper implementation of erosion control materials and sediment reducing measures on reclaimed <br />sideslopes, drainageways, and on regraded spoils are valuable in reducing peak water [lows and sediment <br />loads into drainages. Dozer basins should continue to be constructed to trap and store sediment on newly <br />stripped topsoil areas and on regraded spoils. Livestock water tanks are valuable as they trap water on <br />reclaimed sideslopes, in drainageways, and reduce peak rates of flow at downstream locations, making <br />available reliable water for wildl'rfe and livestock use. Water harvesting diversions constructed across slopes <br />are important to transport excessive water from areas that need protection to sites where water can be used <br />or disposed of safely. Contour farming is essential to reduce sheet and rill erosion on reclaimed sideslope. <br />When combined with I'rve haul topsoil transport the erosion potential is further reduced. The installation of <br />rock check structure to dissipate the energy of (lowing water and trap sediment and debris is valuable in <br />stabilizing channels and promoting vegetation growth. Finally, the use of geotextiles, erosion blankets and <br />other erosion control fabrics are effective in reducing stream velocities and increasing sedimentation in <br />drainageways. <br />