Cofferdam may aid recovery of rafter’s body
September 29, 2010
CHAFFEE COUNTY – Officials met Friday to discuss constructing a cofferdam to divert Arkansas River flow away from a river hazard thought to still contain the body of Kimberly Appelson, a 23-year-old Breckenridge rafting guide missing since July. A cofferdam is essentially a watertight enclosure pumped to dry to allow construction work below waterline.
Appelson fell out of a raft July 11 near the river’s Frog Rock rapid and has not been seen since. The 23-year-old Breckenridge resident was a first-year raft guide with Arkansas Valley Adventures but was not on duty during the accident. Her body is thought to be trapped in a natural river feature known as a sieve, which works like a narrow tunnel of rocks funneling water and creating high pressures. The feature is located about two miles north of Buena Vista, at Frog Rock rapid. At least six deaths have occurred at the area since 1990.
Stew Pappenfort, senior ranger at the Arkansas Headwaters Recreation Area, said Friday’s meeting was attended by a variety of officials and potential contributors to the effort, including heavy equipment contractors, white-water engineers from Grand Junction, Boulder and Salida, Bureau of Land Management and US Forest Service personnel, search and rescue volunteers and Colorado Division of Wildlife officials.
The goal of the cofferdam is to divert the river’s current from the sieve and thereby slow the velocity of water running through the deadly feature. So far, attempts to recover Appelson’s body have been hindered by the flow of water through that area.
Pappenfort said cofferdams are often used by white-water engineers in Colorado to build play parks. They dry the riverbed so construction can take place. However, Pappenfort said the pool below the Frog Rock sieve may be too deep to dry. He hopes slowing the water will be enough to get under the rock to access the body.
“There’s a lot to do before we actually jump in and do it,” Pappenfort said. “There’s a little red tape to go through.”
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Before anything else, search dogs will again be brought in to reconfirm the body’s location.
There also needs to be some environmental impact analysis of the plan before contacting the Army Corps of Engineers for approval. Because the recovery has been so extensive, funding must be found beyond the normal operation budget. And, either an access road must be built to haul in heavy machinery or a military helicopter will be hired for an airlift. Another piece of the puzzle is managing impact to brown trout, which are in their spawning season.
Officials want to build the dam and attempt the recovery as soon as possible, preferably before the end of October, Pappenfort said.
“There’s no guarantee that there will be a recovery, but we want to exhaust all options,” Pappenfort said. “This I never would have envisioned – a recovery going to these lengths.”
SDN reporter Janice Kurbjun can be contacted at email@example.com or (970) 668-4630.