Eight generations of cattle farming had taken its toll on the streams at Dean and Carina Elgin’s Mountain Hollow Farm in northern Fauquier County. Historically, “all the cattle had access to the creek. That was our watering system. And that was the norm in that day,” Dean Elgin said. But by 2015, the Elgins wanted to repair the streambank erosion and reduce the water pollution caused by the foot traffic and waste generated by 200 cattle moving in and out of the water repeatedly. But there was a problem.