“Riding man-altered rapids?”
Photo from https://chattahoochee.whitewaterexpress.com where our family road the rapids in Columbus, GA. Benji was a great guide.
By Scott Hamilton
Last week I went on a vacation with the family and one of our stops was not only fun, but fascinating. We made the decision to go white water rafting on our way to the beach and stopped in Columbus, Ga., at Whitewater Express. Our guide, Benji, was amazing as he navigated our raft down Cutbait. Cutbait is among one of the largest Class V rapids on the East Coast. I know you are wondering what whitewater and technology have in common; that’s the fascinating part of this particular destination.
The rapids down this stretch of the Chattahoochee River run through the urban area between Phoenix City, Ala., and Columbus, Ga., making them urban rapids. The river was modified by adding concrete barriers, removing large sections of rock, and even creating a set of rapids, the Waveshaper. Yes, you read that correctly, there is a set of man-made, or at the very least man-altered rapids on the Chattahoochee.
This man-made rapid allows the park to control the flow of the river, increasing flow rate and changing the shape of the waves utilizing baffles placed underwater to change the contours of the rock. There are four hydraulic cylinders in Waveshaper modeled after a similar man-made rapid in Boston. The ability to control not only the flow of the river, but also the contour of the waves makes Waveshaper a prime location for kayaking competitions.
The controls consist of a cooperative agreement with the flood control dam and a large pump mechanism utilized to cycle downstream water back through the rapid. The two mechanisms combined allow them to control the flow rate between 4000 cubic feet per second and 12,000 cubic feet per second. During normal tourist runs the flow rate is maintained near the middle of the range, around 9,000 cubic feet per second. This puts the Waveshaper in the class IV category of rapids.
Rapids are rated in levels of intensity based on a few criteria, but it is mainly about how wet you get during the ride and the survivability of the ride. Class I just means that the water is moving, Class II means water will splash over the side of the raft. Class III rapids are “wet and fun,” promising to get you soaked head to toe. Class IV rapids have big drops to get the heart pumping; you run the risk of flipping your raft or being thrown overboard on these rapids. Class V rapids carry a 50/50 chance of staying in the raft through the violent rapids. Class VI rapids are the final classification and are “impassible whitewater,” which means that no one has rafted that section and lived to tell about it.
Prior to this experience, I did not know we were engineering rapids for kayak competitions in the manner of Waveshaper. I would love to take another trip to Columbus, Ga., the week of October 9, to witness the ICF Kayak Freestyle World Championships, where they will turn the level of Waveshaper up to its maximum level for the best paddlers in the world to compete down the man-altered waters of the Chattahoochee. It makes me wonder if the same technology could be used to make Class VI rapids like the ones in Valley Falls, WV passible.
For more information about the various rafting trips down the Chattahoochee check out https://chattahoochee.whitewaterexpress.com/
Until next week, stay safe and learn something new.
Scott Hamilton is an Expert in Emerging Technologies at ATOS and can be reached with questions and comments via email to sh*******@te**********.org or through his website at https://www.techshepherd.org.
