Carlsbad Caverns National Park, New Mexico
Size & Type of Project:
14.8 acres, Open space - Park
Former Land Use:
Notable sustainable features on the project include 100% of plant materials from local genetic stock, no supplemental irrigation once plant materials are established, the use of salvaged materials and plants, and the use of local materials. In addition, the preservation of a historic structure within the site and the elimination of pollution sources are also notable sustainable contributions.
The great diversity of plant materials in Carlsbad Caverns National Park is not widely available in the commercial plant industry and the site conditions in this semiarid National Park are harsh. These situations supported the National Park Service policy to use local genetic stock wherever possible. In this case, using local genetic stock ensured that the plant materials would be best-adapted to the harsh site conditions and that rare or commercially-unavailable plant material would be available for revegetation efforts on this site.
The project team then created a handbook on propagating and establishing Chihuahuan Desert plants for revegetation and restoration purposes. This project was one of several parks around the country used as a model for developing monitoring standards for revegetation in the National Park Service. Seed and plant materials were collected from within the park from local genetic stock or from salvaged plant material where possible.
The massive collaboration from a multidisciplinary team during the project inception proved to be very successful and allowed for a more comprehensive and thoughtful project. Other successful strategies for achieving SITES credits were to make the best use of local materials by using rock, soil, and plant material that were salvaged during the construction process, and importing materials from as near to the site as possible. A temporary high efficiency drip irrigation system is being used to irrigate plants until they are successfully established, and the irrigation system uses solar-powered irrigation controllers.
The NEPA process required an Environmental Assessment be written as well as compliance with Section 106 and SHPO concurrence with the work being performed in and around historic structures. All of the NEPA and SHPO requirements influenced the project's successful outcome, and as more people became involved in the efforts to comply with the requirements, more thought was put into the planning stages.
The integrated design team worked together throughout the comprehensive NEPA process as well as developing a five year strategy to develop plant material and plan for project inception. Regular team meetings were held throughout the design process and during construction to ensure that project goals were continually in focus and on-track for being implemented. Constant cross-division communication occurred. Consistent, thorough communication resulted in a project that met its over-arching goals and objectives.
The primary goal of the project was to remove the source of contaminants that were seeping into the cave pools below the park and to replace them with native vegetation characteristic of the Chihuahuan desert ecosystem. It was important to create a landscape that blended with the natural surroundings in this isolated National Park, and that could survive without supplemental irrigation once the plant materials were established.
Revegetation efforts using plant materials from 100% local genetic stock have been extremely successful. The project revegetated the entire greyfield site, reduced the amount of paving over the caverns, and controlled the stormwater runoff by directing it to oil and grit separators. The project also maintained the integrity of the existing historic stone walls on site, made use of salvaged materials and plants, and used regional materials.
The National Park Service strives to exceed in sustainable practices and this project showcased many of the ways NPS perform those practices outside in the landscape. Motivation to pursue SITES certification did not directly influence the project details, since most of these were completed prior to acceptance into the pilot program. There was, however, a tremendous amount of effort put into the documentation of previous efforts.
There has been a tremendous amount of knowledge gained from the experience of this project that can be applied to other National Park Service projects. For example, the multi-year collaborative effort proved to be a very successful approach.
Acquiring clean topsoil was particularly challenging and despite efforts made by those involved, the topsoil specifications written needed to be more specific. Weed seed brought in by a source, like topsoil, can cost a project a significant amount of money in later years. This has become a valuable lesson on this project.