A GIS APPROACH TO SITING GROWTH IN SUMMIT COUNTY, COLORADO

Home to the Arapaho, Breckenridge, Copper Mountain, and Keystone ski areas, and Dillon Reservoir, scenic Summit County, Colorado is easily accessible by car from Denver. The county is one of the fastest growing regions in the U.S., with a permanent population of 23,500 in 2000, a number that is projected to be 30,000 by 2010 (U.S. Census). On peak ski and vacation weekends, the county must accommodate more than 100,000 people. About 80 percent of the 620 sq mi (1600 sq km) area of the county is administered by the U.S. Forest Service and the Bureau of Land Management. Also, much of the county is not accessible to emergency services. There are several patented mining claims in Breckenridge and Argentine – Montezuma districts and limited tracts of privately owned land can accommodate some growth through densification and perhaps by vertical expansion, but accommodation of projected increases in permanent and weekend residents is becoming an issue in the county.

Data layers within the GIS include bedrock and surface geology, topographic slope (angle) and aspect (direction), soil types (partial coverage), locations of lineaments, towns and roads, land ownership, and county use zoning. Parcels of land that are the most suitable for development are on south-facing (S, SE, SW) slopes of less than 20 degrees, within four kilometers of existing towns and roads, and owned by towns or individuals. Parcels with favorable topographic and geologic characteristics, but which are on E, NE, N, NW, and W facing slopes are less favored, but still good places to build. Twelve areas ranging from 4 to 9 square kilometers have been identified for future development within the county, to which we have been added the known geology, soil characteristics, and hydrology, plus the locations and orientations of lineaments that could influence the movement of water within the tracts. Negotiation with the U.S. Forest Service may become a significant component in the expected grown of Summit County in the 21st Century.