What happens when you want to build that pristine cabin in the mountains you've always dreamed of? Besides static snow loads, when is it necessary to plan for avalanche loads?
The other day a friend came into our office looking for material on the Yodelin slide path, where an avalanche killed 4 people and destroyed 7 cabins in 1971 (see The Avalanche Review, Vol. 3, No. 3, 1985). He was concerned because his purchasing agreement said the property was outside any recognized avalanche danger and he wanted to find out if this was a legally accepted statement. Without any readily available avalanche zoning descriptions, his trail of information led him to our bookshelves, storage hanger, and notes from E.R. LaChapelle, who did a study for some previous property developers in that area.
Is it possible to have a reasonable avalanche zoning plan that does not infringe on the rights of property owners? Ketchum, Idaho thinks so. After the Yodelin accident the State of Washington recognized the "duty to wam" of known hazards. Ketchum city planners saw this as a prime motivation to wam their citizens of avalanche hazards within their city limits.
James Kennedy was kind enough to send us copies of Ordinance #208 which outlines Ketchum's zoning requirements. The following paraphrases Section XVI, "Avalanche Zoning District," as it was revised and updated 9/86.
After studies by Norman Wilson in 1977, and Art Mears in 1978 and 1979, the Avalanche Zone District in Ketchum was established to: a) identify those areas where an avalanche potential exists, b) let the public know where those zones exist, c) give the public an opportunity to review the pertinent avalanche studies mentioned above, d) minimize health and safety hazards, disruption of commerce and extraordinary public expenditures, e) promote health safety and welfare, and f) allow for construction of singlefamily residences by persons informed of potential avalanche danger, while protecting lessees, renters and subtenants.
Essentially an Avalanche Zone District is an "overlay" district. It simply applies additional requirements to uses otherwise permitted in that district. For instance: a) All utilities installed after the effective date of this Ordinance must be installed underground. b) Avalanche defense structures may not be built in a way that will deflect avalanches toward the property of others. c) Prior to building, owners must prove their design will withstand recognized standards for minimum avalanche forces through an approved engineers study. d) Any structure that is built without the above mentioned engineers study cannot be rented or sublet during the winter.
There are also requirements to notify all potential buyers and renters in writing. In addition the City must post signs on public right of way to identify the boundaries of Avalanche Zones.
Residents and tenants are also warned that the City may suspend services during periods of avalanche danger. And the City is not responsible to guarantee that such services, rescue efforts or emergency services will be provided during periods of avalanche danger.
This seems like a .workable plan for Ketchum, which is in the heart of Idaho's popular ski country. Vail, Colorado also has a viable avalanche zoning plan. Both cities feel it is their responsibility to warn and help protect their residents. As our mountain population grows we should expect more and more avalanche zoning ordinances to be developed and issued in towns, cities, and counties.
The Avalanche Review, VOL. 6, NO. 4, MARCH 15, 1988
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