30.91L.040 Landslide hazard areas.
"Landslide hazard areas" means areas potentially subject to mass earth movement based on a combination of geologic, topographic, and hydrologic factors, with a vertical height of 10 feet or more. These include the following:
(1) Areas of historic landslides as evidenced by landslide deposits, avalanche tracks, and areas susceptible to basal undercutting by streams, rivers or waves;
(2) Areas with slopes steeper than 33 percent which intersect geologic contacts with a relatively permeable sediment overlying a relatively impermeable sediment or bedrock, and which contain springs or ground water seeps;
(3) Areas located in a canyon or an active alluvial fan, susceptible to inundation by debris flows or catastrophic flooding.
For subsections (1), (2), and (3) of this section, the landslide hazard area also includes lands within a distance from the top of the slope equal to the height of the slope or within a distance of the toe of the slope equal to two times the height of the slope. The director may expand the boundary of a landslide hazard area pursuant to SCC 30.62B.390. (Added by Amended Ord. 02-064, Dec. 9, 2002, Eff date Feb. 1, 2003; Amended by Amended Ord. 06-061, Aug. 1, 2007, Eff date Oct. 1, 2007; Amended by Amended Ord. 15-034, Sept. 2, 2015, Eff date Nov. 1, 2015).