Groundwater Modeling for Gravel Pits
Gravel pits often intercept groundwater and therefore can require dewatering in order to conduct dry mining of the alluvial materials. Martin and Wood personnel assess the impact of the dewatering and estimate the amount of dewatering necessary.
St. Barbara Gravel Pit
Trans-Colorado Concrete was seeking to develop the St. Barbara gravel mine in the Arkansas River alluvium east of Pueblo and had the potential to impact both neighboring high capacity irrigation wells and an unlined ditch running along the north side of the alluvial valley. Martin and Wood initially carried out an analytical distance-drawdown calculation to make preliminary estimates as to the potential for any impacts on the wells and ditch. Martin and Wood then conceptualized, constructed and ran a numerical groundwater flow simulation of a significant portion of the alluvium that included the mine site, the irrigation wells, and the ditch. The Arkansas River was simulated, as was the local alluvial gradient. The model results indicated that the pit would have essentially no impact at all on the unlined ditch, but that there would be the potential for drawdown impacts to the closest wells resulting from the dewatered mining of the pit over time. This work allowed for formulation of alternate practices that would assist in preventing any negative impacts on the wells.
