The Wood River Valley's waterways are a valued resource, but cities are grappling with the question of how far they should go to protect them without encroaching on private property rights.
In a workshop Thursday, Jan. 12, members of the Ketchum Planning & Zoning Commission asked questions of and received advice from more than a dozen natural-resource experts. The city is planning to revise its floodplain ordinance, which regulates, among other things, how close to a waterway a building can be constructed.
Protection of life and property, as well as protection of sensitive riparian areas, are reasons for the ordinance.
The ordinance, which currently mandates a 25-foot setback, will apply to the Big Wood River and its tributaries that fall within the Ketchum city limits.
"The real issue is habitat," said fish and wildlife biologist Kaz Thea. "Chronic problems along rivers are everywhere. When you encroach on habitat, you lose habitat characteristics that fish require. A 25-foot setback is not enough to maintain a healthy river with a complex habitat."
Chronic issues are not the only ones to consider, said one participant.
"A lot of this discussion should focus on extreme events," said Trish Klahr, watershed program manager with The Nature Conservancy of Idaho. "Chronic issues happen for 99 years. Then there is the 100th year ... We will have another 100-year flood. It's an economic issue and it's an ecological issue. Riparian buffers are one of the most economical means of controlling and absorbing floods and large flows."
When a flood occurs, a river's course can alter significantly, said Scott Van Hoff, state coordinator for the National Flood Insurance Program at the Idaho Department of Water Resources.
"During a flood you can get some dramatic changes," he said. "There are some places where 25 feet is not enough."
Decks that protrude into the 25-foot setback may eventually end up underwater, he said.
"A uniform setback is a good start, but there are some places where it probably needs more, from an engineering and a safety standpoint," he said.
Education about the value of wild areas is a vital tool in the maintenance of healthy fisheries and riparian areas, experts agreed.
But if the city embarks upon an educational campaign, to whom should it be directed?
"When you have part-time residents who have other people doing their landscaping, who are you going to educate?" asked Bruce Smith, a land surveyor and natural hazards consultant. "It's a good idea to bring in the landscapers."
Aquatic biologist Steve Fisher emphasized the importance of including property owners in the dialogue, saying they have a great stake in healthy rivers.
"There's not a landowner in this valley who bought their property to diminish its value," he said. "They all want to maximize it."
Sun Valley City Councilman Nils Ribi attended Thursday's meeting to determine what should be considered when Sun Valley prepares its ordinance.
"I have a much greater respect for Trail Creek and Elkhorn Creek and what we now need to do to protect it," he said. "Based on what I heard today, the idea of a variable setback makes a lot of sense."
Currently, Sun Valley has no riparian setback ordinance, but Ribi said the city plans to initiate an ordinance "in the very near future."
Regulations regarding pesticides, herbicides and other aspects to healthy waterways will be discussed later, he added.
"I hope when Sun Valley gets ready to do its ordinance, we can call on the same group of people to help us," Ribi said. "The greater community is fortunate to have such a resource."
The Ketchum P&Z's public hearing was continued to March 27.