Natural resource condition assessment: Chaco Culture National Historical Park

Wynne, J.

doi:10.36967/nrr-2287402

The Natural Resource Condition Assessment (NRCA) Program, administered by the National Park Service’s (NPS) Washington Support Office, Denver Service Center Planning Division, provides documentation about current conditions of important park natural resources through a spatially explicit, multidisciplinary synthesis of existing scientific data and knowledge. The workshop for Chaco Culture National Historical Park (CHCU) NRCA was held on 28–30 November 2017. Chaco Culture National Historical Park (CHCU or Chaco Canyon) was originally established as a national monument in 1907 by President Theodore Roosevelt. Designated a national historical park in 1980, these lands were recognized as a national park unit because of the impressive Puebloan archaeological ruins built between 850 and 1140 BCE (Lekson 2015). Encompassing over 34,000 acres and containing at least 4,000 archeological sites, 26 southwestern Native American tribes are culturally affiliated with CHCU (NPS 2015a). Because CHCU is a non-urban park, current and future threats are primarily associated with increased oil and gas exploration activities on BLM, Navajo Nation, and private lands adjacent to the park. Additionally, increased visitation and issues associated with growing population centers at considerable distances from the park’s boundary are also contributing to the deteriorating conditions of indicators identified as significant and moderate concern. Acoustic environment was rated as “significant concern”, which is due to aircraft, vehicular traffic, the CHCU Visitor Center generator, other unidentified low frequency humming sounds, and people. As visitation increases, the condition of the acoustic environment will be further eroded – unless efforts are ultimately taken to limit the number of vehicles on park roads. Air quality and night skies will continue to be challenged by the growing population centers of Farmington, Albuquerque, and Santa Fe, New Mexico. Unless these population centers address air and light pollution, improving these conditions at CHCU will be beyond the park’s control. Given that gas and oil exploration activities are on the rise; these activities may also negatively impact these conditions of these resources. Importantly, water quality of the Gallup Sandstone aquifer is considered of moderate concern, but the future quality and human use of this groundwater source is challenged by oil and gas exploration activities within the Mancos Shale and Gallup Sandstone formations. These formations are interbedded, and any directional drilling, hydraulic fracturing, or wellbore stimulations within this formation adjacent to the park boundary could negatively impact CHCU’s sole drinking water source. Eleven natural resources (with 34 indicators) were identified and grouped into three broad categories: landscape-scale, supporting environment (i.e., physical resources), and biological integrity. The latter included chapters on wildlife and vegetation. This NRCA includes an assessment of condition and trend for key resources determined by assessing multiple indicators for each focal resource (Chapter 4). A summary is provided for each resource category below. Most indicators were identified as currently in good condition (13 indicators) or unknown/ data deficient warranting moderate concern (13). The most significantly impacted resources included air quality and the acoustic environment. Ozone effects on vegetation health were of significant concern, yet the trend could not be determined due to lack of long term data; additionally, the condition for “reduction in listening area” is deteriorating due to an increase in anthropogenic activities. Six indicators were identified as “moderate concern”. For trend not determined due to lack of long-term data, these include the geospatial sound model, ozone effects on human health, deposition of wet nitrogen, and aquifer water quality. Additionally, the condition for haze index of air quality was identified

Natural resource condition assessment: Chaco Culture National Historical Park

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