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Article for River Management Society NewsBy John Haugh, Wilderness & Rivers Program Mgr., Salmon-Challis N.F. A complex river management issue presented itself to the Salmon-Challis National Forest this past July. A large logjam entirely blocked the Middle Fork of the Salmon River during peak float boating season. The logjam was the result of a high intensity localized rain event. These rain events are fairly common during the summer months in this area. Approximately 190 people launch from the Boundary Creek launch site daily in July. July 24, 2006 was no exception. The forest employees now had to determine what management action to take factoring in a Wilderness and a Wild & Scenic River setting, over 350 people stranded and natural resource concerns including endangered Chinook salmon. Here is what happened: That evening we camped at Big Bend, a day’s float from Indian Creek. During the night we had a spectacular lightning show and a little rain from passing thunderstorms. We broke camp early in the morning on July 24 and proceeded downstream for our scheduled rendezvous at Indian Creek. At about 10 am two-way radio traffic announced that there had been a “blow out” near Lake Creek and that there was a blockage at Pistol Creek Rapids. We established radio communication with the Middle Fork Ranger District Office in Challis and were asked to assess the situation. We dispatched two river rangers in the kayaks down to the reported blockage as quickly as possible. The rangers arrived at the blockage around noon and radioed back that there was a huge, impassable logjam at Pistol Creek Rapids. The remainder of the party floated down arriving about 1 hour later. After assessing the situation we radioed the district office to have them stop all launches until further notice. We estimated there were approximately 350 persons on the river upstream of the logjam at this time, with more scheduled to launch today and tomorrow. The site is within the Frank Church – River of No Return Wilderness and the Middle Fork River is designated as “wild” under the National Wild & Scenic Rivers Act of 1968 (The Middle Fork was one of the original eight rivers to be designated by the Act). Later that day we learned that a debris flow, triggered by localized heavy rains in the upper Middle Fork of the Salmon River canyon, had traveled down Lake Creek and across the Middle Fork of the Salmon River. The debris flow temporarily blocked the river then released mud and woody debris (trees) that floated downstream. The debris traveled approximately 1/3 mile down to Pistol Creek Rapids and created a logjam of several hundred logs. Our rafting party coincidentally included all the right players for assessing a situation such as this: Randy Welsh, Region 4 Special Areas Manager for Wilderness and Wild & Scenic Rivers, Ken Wotring, Frank Church – River of No Return Wilderness Coordinator and John Haugh, Wilderness & Rivers Program Manager for the Salmon-Challis NF. Having this mix of qualified personnel on-site at the log jam was an incredibly lucky situation. Additionally, I am a certified blaster for the Forest Service. After we assessed the situation, I was asked if it would be possible to blast the logjam to free it. I determined that with the proper amount and type of explosives and adequate personnel it could be safely done. Before initiating the blasting the group (including the Regional and Forest experts) discussed the various laws and regulations under which Wild & Scenic Rivers and Wilderness areas are managed. We agreed there was no language in the 1964 Wilderness Act, the 1981 Central Idaho Wilderness Act or the 1968 National Wild & Scenic Rivers Act that prohibited the use of explosives. Since it was physically possible and there were no prohibitions for use of explosives in the Acts that govern management of the river and the wilderness area, our recommendation was to commence with a blasting plan. We also took into consideration the number of people above the logjam at the time. We radioed our recommendation to clear the logjam with explosives to the Salmon-Challis National Forest Supervisor, Bill Wood. Supervisor Wood consulted with the Middle Fork and North Fork District Rangers, Tom Montoya and Steve Kimball who came up with three alternatives:
Forest Supervisor Wood selected Alternative 2. He made this decision based the human health and safety issue of approximately 350 persons stranded, that the explosives could be detonated in a manner that would have negligible long-term environmental effects, that blasting was allowed under the wilderness and rivers management acts and that blasting here would be compliant with Endangered Species Act issues. While he fully recognized that in a Wilderness situation natural processes should be allowed to continue without interference from humans, he determined this to be unacceptable given the health and safety needs of those stranded on-site. His decision was radioed to us with the required Regional Forester authorization for the use of motorized equipment should it be needed. Alternative 1 – natural processes -- was not chosen because of a combination of reasons including the fact that the logjam would likely not clear by natural forces until the spring of 2007 or later and approximately 350 people were stranded upstream of the jam and would need to get around the jam and either continue their trip, or leave the wilderness. Either choice forced considerable intrusion to the wilderness in the form of packing around the jam and flying out from the Pistol Creek or Indian Creek airstrips. These airstrips have many limiting factors including airstrip length, not flying beyond 10:00 am due to summer temperature limitations, and weight restrictions limiting the number of passengers on a plane at a time. Alternative 3 – helicopter removal of logs -- was discounted from serious consideration because of safety concerns and the intrusion into the wilderness with helicopters. The logs were intertwined with each other making a hazard to both the aerial resource of helicopter pilot and crew, but also to the ground crews that would be needed to install cables around the logs. In order to commence with the blasting alternative we needed additional resources on site. I requested another blaster from the forest to be flown into Pistol Creek with 150 pounds of explosives and a second blaster from the Boise NF with rigging equipment. While we were waiting for the blasters and equipment we worked on the downstream side of the logjam using mechanical advantage and were successful in freeing about 25 percent of the logjam. Early in the morning of July 26th we began building the explosive charges. It was decided that we would attempt one blast to dislodge the entire logjam at once rather than multiple small blasts because of the anticipated instability after blasting. The blasters were belayed onto the logjam from above and beside the logjam to set the charges. Safety devices such as rescue kayakers with rope throwbags were in position in addition to the blasters wearing body harnesses to be able to retreive them if the jam were to break apart unexpectedly. A total of 39 pounds of explosive were strategically placed on the three largest and longest logs and dropped into six locations on the southwest corner of the logjam. The blasting occurred at 12:50 pm and was 95 percent effective . Four large logs remained blocking the rapids which we dislodged by cutting them with crosscut saws and axes and pulling apart with ropes. The logjam was cleared and the rapids free running by 4:00 pm. A river ranger was sent by kayak downstream to confirm if there was clear passage to the Indian Creek Guard Station. At 5:00 pm, with reports of clear passage from the kayaker, we notified Forest Supervisor Wood that the Middle Fork of the Salmon River was again running free and could be opened. After the logjam was cleared the site was monitored and evaluated by a fisheries biologist. The river channel where the explosives were used was primarily bedrock. Subsequently, little, if any, modifications were made to fish habitat by the explosives and the bedrock was not damaged or changed by the explosives. He determined that impacts to fish and fish habitat appeared to be minor because of several factors:
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