A combination of techniques for reconstruction of ephemeral stream channels in Wyoming

This paper offers a stream channel construction technique that was designed by field personnel, based primarily on field measurements, enhanced by simple stream channel construction calculations to promote maximum soil movement and placement by large "dirt-moving" equipment, thereby allowing this method to be an integral part of the mine and reclamation process rather than a "stand-alone" reclamation program. The technique is a combination of simple Mannings flood channel sizing calculations in combination wtih slope, shape and size features from undisturbed, stable drainages in the same area. One of the primary features that was found to be critical for a stable stram channel in the undisturbed areas was a primary channel slope that was 2 percent. In the field, the first construction feature that is built is the Mannings 100 year, 24 hour event channel. Within this channel soil bars are spaced a distance apart that matches the low-flow sinuosity that characterizes the undisturbed stream channel. Soil bar size, location and spacing fit with the cycle route of a small scraper fleet, allowing optimum time for soil pickup and adequate turn and dump cycling. Fitting the stream channel construction approach to the "dirt moving" fleet optimizes material movement and minimizes reclamation costs while insuring construction of a stable stream channel. Numerous channels have been constructed using this technique. Most have been in place for more than 10 years and all remain stable and an integral part of the natural drainage system.