EVERETT — The Snohomish County Council imposed a six-month ban Wednesday on new construction in the immediate area of the Oso mudslide and areas to the east where flood dangers are thought to have increased.

The emergency ordinances were the county’s first major changes in land-use policy since the March 22 slide, which covered a square mile in dirt and debris, killing 43 people.

The council did not even discuss some of the more controversial ideas, which faced opposition from builders and realtors.

“I prefer a measured approach,” Councilman Terry Ryan said. “I think the starting point is with a moratorium on the slide-impact area.”

The ban on new construction in the slide zone received unanimous support. The flood-area moratorium passed 4-1, with Councilman Ken Klein opposed.

“The flood area is constantly changing out there, so we don’t know what impact this will have,” Klein said.

Council Chairman Dave Somers disagreed with Klein, saying the map for the flood zone is based on best estimates from the Army Corps of Engineers and the Federal Emergency Management Agency.

The emergency ordinances will need to be renewed if the council wants to extend them beyond December. The expiration date happens to coincide with peak flood season.

Other proposed land-use changes did not even get discussed at Wednesday’s hearing. The ideas included recording landslide dangers on property titles to warn future owners of risks, expanding the areas around steep slopes that require a geotechnical study before new construction, and making those engineering studies adhere to more rigorous standards.

Lobbyists for builders and realtors largely opposed the notice requirements in their current form, while conservationists favored them.

“Ultimately, we do want disclosure, but we want it to be uniform,” said Ryan McIrvin, a lobbyist for the Snohomish County-Camano Association of Realtors.

McIrvin said he believed the Legislature will take up a state state-level disclosure law for landslide risk during next year’s session.

Somers, the most forceful advocate on the council for changing land-use rules in light of Oso, was disappointed that most of the proposals didn’t receive a public debate. His motion to talk about the ideas died when none of his colleagues seconded it.

“We know we have hazards that extend beyond what our current code regulates,” Somers said afterward.

Councilman Brian Sullivan said he agreed some of the ideas deserve consideration, such as having property owners sign waivers to acknowledge landslide risks, “but it needs to come back at a later date.”

Noah Haglund: 425-339-3465, nhaglund@heraldnet.com.