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Jason Richards Environmental Protection Specialist, Carlsbad Caverns National Park, New Mexico
Back to Chapter 6: Restoration Articles Restoration of mountain yellow-legged frogs in Kings Canyon By Harold Werner National Park Service to share science role in Everglades restoration By Thomas Van Lent California condors return to the Colorado Plateau By Elaine Leslie Wolf restoration in Yellowstone successful beyond expectations By Douglas W. Smith, Roger J. Anderson, and Julie Mao Wetland and stream restoration at Elk Meadow in Redwood National Park By James H. Popenoe Other Developments Award-winner Profile - Botanist honored with first professional excellence award Preservation of the Fort Dupont stream Coastal dune restoration at Point Reyes Bonytail restoration continues Maintenance staff help restore native fish at Point Reyes |
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 By Jason M. Richards With the 2001 completion of a new airlock and culvert at its entry, Lechuguilla Cave can finally breathe a sigh of relief. In 1914, Lechuguilla Cave was mined for guano. By 1986, cavers recognized the possibility of an extensive cave system and excavated an opening into the depths of the cave. The need for safe access for scientists and exploration teams through the breakdown rubble of the excavation site led to the installation of a 24-inch-diameter, galvanized road culvert with an interior ladder. Although the culvert solved the problem of safe access, it had a problem of its own. Constant changes in barometric pressure eventually caused the culvert access to deteriorate. In periods of high barometric pressure the interior of the culvert was usually dry owing to the cave inhaling outside desert air. During times of low barometric pressure the cave would exhale the moist air from its interior, creating a very wet environment on the culvert’s interior walls. The extensive size of the cave, which includes 107 miles of mapped passageways, allowed air exchange through the culvert at a rate that sometimes exceeded 60 miles per hour depending upon the outside barometric pressure. Cave Resource Office staff, explorers, and scientists agreed that this substantial air exchange was drying out the upper passages. Although no baseline humidity data were collected before the 1986 excavation, the water level at Lake Lechuguilla in the upper passage was relatively high in the first years of exploration, and now it is almost dry. It is not known whether these drying conditions would have occurred naturally or would have been induced by changes in the rubble pile. The need to resolve the air exchange problem coincided with the need to replace the deteriorating culvert. Adding an airlock to a new stainless-steel culvert seemed to address both problems. This solution also allowed safe access to continue for world-class scientists conducting significant research and secured the cave from unauthorized entry. An environmental assessment was prepared and sent out for review in February 1999. A year later, the process of removing the old culvert began, followed immediately by construction of the new stainless-steel airlock and culvert. Stabilization of the 30-foot-deep, 60-degree-angle shaft created a problem that was solved by the same plastic netting used to stabilize roadsides during construction. The airlock’s two doors, one for entry into the airlock and one that seals the culvert, have virtually eliminated barometric air exchange through the access structure. The significance of Lechuguilla Cave research was another factor in the airlock and culvert installation. Lechuguilla Cave’s microbial ecosystems are in the forefront of cave microbiology. Important studies include Dr. Larry Mallory’s discovery of microbes that may aid in the cure of certain cancers. Dr. Penny Boston and Dr. Diana Northup have discovered sulfur-reducing bacteria and microbes from the archaea family. Speleothems or cave features have been found in Lechuguilla that are found in no other known cave in the world. The construction of the airlock and culvert was a tremendous undertaking that required a little over two years and $79,000 from the Recreational Fee Demonstration Program to complete. Thanks to the efforts of many volunteers and a dedicated staff, the project was a total success.
Restoration of the Lechuguilla Cave entrance entailed lowering sections of stainless-steel culvert into the cave (Left), backfilling around them, and sealing the top with an airlock (middle). The first of its kind, the new entrance prevents air exchange through the artificial cave opening and allows safe access for researchers. |
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This material is from Natural Resource Year in Review--2001, published by the National Park Service, U.S. Department of the Interior, in May 2001 (publication D-2255) /YearInReview/yir/yir2001/06_restoration/06_2_richards.html Last Updated: |
