30.62B.140 Geotechnical report requirements

30.62B.140 Geotechnical report requirements.

(1) A geotechnical report will be required for any development activity, action requiring a project permit or clearing proposed within:

(a) An erosion hazard area;

(b) A landslide hazard area;

(d) Two hundred feet of any faults.

(2) The geotechnical report shall be prepared, stamped, and signed by a licensed engineer or geologist and contain the following information relevant to the geologically hazardous area:

(a) The topography at contour intervals of five feet unless the underlying project permit requires a lesser interval;

(b) Significant geologic contacts, landslides, or downslope soil movement on and within 200 feet of the site;

(d) Impervious surfaces, wells, drain fields, drain field reserve areas, roads, easements, and utilities on the site;

(e) The location or evidence of any springs, seeps, or other surface expressions of groundwater;

(f) The location or evidence of any surface waters;

(g) Identification of all existing fill areas;

(h) The location and extent of all proposed development activity;

(i) A discussion of the geological condition of the site including:

(i) a description of the soils in accordance with the Natural Resource Conservation Service indicating the potential for erosion;

(ii) engineering properties of the soils, sediments, and rocks on the subject property and adjacent properties and their effect on the stability of the slope;

(iii) a description of the slope in percent gradient;

(iv) the location or evidence of seismic faults and soil conditions indicating the potential for liquefaction; and

(v) a hazard analysis and finding of risks associated with geologic hazards and the potential impacts to public safety, the hazard area and the subject property;

(j) The proposed method of drainage and locations of all existing and proposed surface and subsurface drainage facilities and patterns, and the locations and methods for erosion control;

(k) The extent and type of existing vegetative cover;

(l) A vegetation management and restoration plan prepared by persons experienced in vegetation management and restoration plans such as botanists, landscape architects and certified arborist, or other means for maintaining long-term stability of slopes;

(m) Analysis of erosion rates, slope recession rates and potential impacts to existing or proposed development from wave cutting, stream meandering, or other erosional forces to determine the recommended solution for bank or shoreline stabilization or flood protection in conformance with SCC 30.62B.320(2);

(n) Analysis of soil borings when the geology of an area is uncertain; and

(o) Any other information determined by the department to be necessary to determine compliance with this chapter including but not limited to the use of LIDAR, technical reports, studies or documents related to geologic hazards and models for estimating how far landslide materials will travel.

(3) The geotechnical report shall include a summary or abstract of the report for the property where the development activity is proposed. The abstract shall at a minimum include the type of hazard, extent of the hazard, hazard analysis and geologic conditions. (Added 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).