Geomorphic and hazard vulnerability assessment of recent residential developments on landslideprone terrain: The case of the Traverse Mountains, Utah, USA

Abstract

Homeowners who live near or on steep slopes of the Traverse Mountains along the Wasatch front in southern Salt
Lake City, Utah (USA) are at risk where development of “master-planned communities” has been permitted on known
landslide deposits since 2001. Some of the largest landslides in the state of Utah are being modified as road
construction and residential development progresses. This paper reviewed the setting of the landslide-prone areas
and used Geographic Information Systems (GIS) spatial tools to assess the value of local developments built on
mapped slide features. Dataset overlays were compiled to determine the vulnerability of residences, and to quantify
potential monetary loss from a future landslide event. The key elements at risk include property, as well as the
population, economic activities, and public services of a given region. An initial conservative figure calculated for the
vulnerability of residents owning property exceeds $500 million for the Traverse Mountains region of Draper City,
based on 2007 property values recorded at the Salt Lake County Assessors Office. In developing this area, the failure
to consider existing and potential hazards has caused a myriad of tensions among local government officials,
planners, financiers, state regulators, consultants, developers, realtors, and homeowners.