Wednesday November 30, 2011
A FISHBIO crew recently installed the anchoring system for a fish counting weir in the Salinas River. Fish counting weirs are designed to withstand a substantial flow, but the Salinas River can be an especially challenging system due to rapid changes in river flows and the sandy substrate. Because of volatile flows in this flashy, rain-fed system, crews are taking extreme measures to reinforce the anchoring system (substrate rail) that holds the weir in place. Crews were driving heavy-duty rebar pins along with large, arrow-shaped anchors 8 feet into the sandy substrate at regular intervals across the width of the river. The creative minds in our FABLAB devised an ingenious way to speed up the process of hammering the stakes deep into the river substrate. They fabricated a sleeve that fits over the end of the stake and attaches to a pneumatic jackhammer driven by an air compressor positioned stream-side. We have posted a video on our YouTube page demonstrating how this system works.