Salt Lake County has a new natural hazards ordinance designed to protect developers and buyers from unknowingly building or purchasing structures within known fault, avalanche and liquifaction zones.
Following more than a decade of study and work by planners and geologists, county commissioners Wednesday approved a measure setting specific policies for dealing with development in mapped geologic hazard areas.The ordinance is expected to be a model for other Wasatch Front local governments considering the same type of regulations.
The law requires, in most cases, that developers building within specifically mapped hazard zones conduct a geological study of the building site prior to construction.
A report detailing the site's potential natural hazards identified by that study must be filed with the county and the state Geological and Mineral Survey for review.
If the review determines that the site is subject to risk from natural hazards, the developer must demonstrate the risks can and will be reduced before the County Planning Commission can grant conditional approval for the development.
In addition, the owner of property at risk from natural hazards must record a restrictive covenant with the county disclosing the existence and availability of the report.
The ordinance applies only to mapped fault zones, avalanche zones and areas of potential liquifaction. Liquifaction is the tendency of soils to liquify in the event of an earthquake.
However, other natural hazards, including landslide zones and rock fall zones, will be added to the ordinance as they are mapped. In the case of single-family-dwelling lots, the ordinance requires the disclosure of potential hazards but does not require the site-specific study.
State geologist Genevieve Atwood praised the ordinance as one that doesn't take a simplistic approach of banning construction in hazard areas but shifts the burden of proof to a developers to show a site is buildable.
"We hear about `Utah, a pretty great state,' but we have a pretty hazardous state," she said. "We need to know the geological hazards and respect them. This ordinance defines the hazards and requires disclosure, but doesn't prohibit new construction."
Some parts of Salt Lake County are geologically hazardous because the county sits on a transition zone between the Wasatch Mountains on the east and the easternmost expansion of the Great Basin on the west, Atwood said.
What ordinance will do:
-Require most new developments within mapped geological hazard areas to use techniques to mitigate potential problems.
-Require a report so buyers within those developments can make an informed purchase decision.
-Limit taxpayer liability in the event of an earthquake or avalanche.
What it won't do:
-Will not affect any existing homes or developments.
-Will not prohibit construction within special study areas.
-Will not apply to areas within any Salt Lake Valley city.