Sunday, June 13, 2010


Went down to Black Rapids to do some survey work on the Delta River. My friend Mike, who moved down to the lower 48 last fall (Last Trip on the Delta…Sep 26, 2009), came back up for a week to get his former project started again. He met me at the site with Tim, who would be taking over the project. The river looked pretty high when we were getting ready, but having surveyed there several times before, we figured we could deal with it. We had no trouble launching the boat or getting the cable strung over the river, but during the survey of the water depth and velocity, one of the vertical stanchions on the cross bar that attaches the boat to the cable broke. It sounded like a gun shot as it went flying off. Almost immediately, the boat began to turn side ways to the current. This was definitely not a good situation, as we were in the biggest standing waves on the river. Mike gunned the motor, which he had kept idling during the survey, and quickly straightened us out. I was able to get the other stanchion released from the cable and then we motored to the shore. We talked about what to do next and decided to try to take a few more readings along the cross section to estimate the unmeasured flow.
After we finished up, the consensus was that high water surveys on this river with the boat tied to a fixed tag line was obviously not the way to go. The high speed of the current and the turbulence in the standing waves put way too much strain on the equipment and we broke the weakest link. There’s a measuring system available that uses GPS for position and an acoustic doppler for depth and velocity, and we’ll try to get one to use next time. It was great to see Mike again and we hope he’ll be back up sometime soon.