Chapter 17.12
STANDARDS FOR PREPARING PLANS AND ASSESSMENTS FOR CRITICAL AREAS

Sections:

17.12.005    Information – Use.

17.12.010    Wetland assessment.

17.12.020    Habitat management plan requirements.

17.12.030    Geotechnical assessments.

17.12.040    Erosion hazard assessments.

17.12.050    Hydrogeologic testing and site evaluation.

17.12.005 Information – Use.

The following information shall be utilized during the preparation of studies and reports by qualified experts. (Ord. 3082 § 2, 2009; Ord. 2821 § 2, 2002).

17.12.010 Wetland assessment.

(1) Wetland Assessment. A wetland assessment shall typically include the following. Technical justification shall be provided where any information is not deemed applicable by the qualified expert.

(a) An on-site wetland delineation performed by a qualified expert. The wetland boundaries shall be staked or flagged.

(b) Vicinity map drawn to scale and including a north arrow, public roads and other known landmarks in the vicinity.

(c) A Natural Resource Conservation Service soil map identifying the soil types on the site.

(d) National Wetlands Inventory Map (U.S. Fish and Wildlife Service).

(e) Site Map. This map must be drawn to a usable scale, one inch equals 100 feet or better, and must include a north arrow and all of the following requirements:

(i) Site boundary/property lines and dimensions;

(ii) Wetland boundaries based upon a wetland specialist’s delineation, and depicting sample points and differing wetland types if any;

(iii) Recommended wetland buffer boundary;

(iv) Internal property lines such as rights-of-way, easements, etc.;

(v) Existing physical features of the site including buildings and other structures, fences, roads, utilities, parking lots, water bodies, etc.;

(vi) Topographical variations.

(f) Report. This document must include each of the following:

(i) Location information (legal description, parcel number, physical address, phone numbers) of both the consultant and applicant;

(ii) Site characteristics including topography, total acreage, delineated wetland acreage, other water bodies, vegetation types, soil types, etc., and distances to and sizes of other off-site wetlands and water bodies within one-quarter mile of the subject wetland;

(iii) Identification of the wetland’s classification as defined in this chapter, including the rationale for selecting the wetland category using the Washington State Department of Ecology wetland rating system found in the Washington State Wetland Rating System for Western Washington (Ecology Publication No. 04-06-025, August 2004), and appropriate wetland rating forms;

(iv) A complete description of the proposed project and any potential impacts to the wetland and, if applicable, adjacent off-site wetlands, including construction impacts;

(v) A wetland buffer recommendation and rationale for the buffer size based on Tables 17.10.110.4.a, 17.10.110.4.b, or 17.10.110.4.c.

(g) Completed wetland data forms from the Army Corps of Engineers Wetlands Delineation Manual (1987) Army Engineer Waterways Experiment Station Technical Report Y-87-1 or the Washington State Wetlands Identification and Delineation Manual, Ecology Publication No. 96-94, March 1997, will be provided to the city. (Ord. 3082 § 2, 2009; Ord. 2821 § 2, 2002).

17.12.020 Habitat management plan requirements.

(1) Habitat Management Plan Requirements. At a minimum, the habitat management plan, prepared by a qualified expert, shall typically contain the following information. Technical justification shall be provided where the qualified expert does not deem any information applicable.

(a) A description of state or federally designated endangered, threatened or sensitive fish or wildlife species, or species of local importance, on site or adjacent to the subject property within a distance typical of the normal range of the species.

(b) Habitat management plans map, will be drawn to scale one inch equals 100 feet, or recent land survey showing the following items:

(i) All lakes, ponds, streams, wetlands, or tidal waters on or within 300 feet of the subject property, including the name (if named), and ordinary high water mark of each, and stream type and wetland category consistent with WAC 222-16-030 and LMC 17.10.110(1).

(ii) The location and description of the fish and wildlife habitat conservation area on the subject property, as well as any potential fish and wildlife conservation areas within 300 feet of the subject property as shown on maps identified in the summary of map sources (LMC 17.10.100) and/or housed within the department.

(iii) The location of any observed evidence of use by critical species.

(c) An analysis of how the proposed development activities will affect fish and wildlife habitat conservation area and any critical species.

(d) Provisions to reduce or eliminate the impact of the proposed development activities on any fish and wildlife habitat conservation area and critical species, and description of replacement of any lost habitat functions.

(e) Prohibition or limitation of development activities within fish and wildlife habitat conservation area.

(f) Establishment of buffers around fish and wildlife habitat conservation area demonstrating rationale for buffer widths consistent with WAC 365-195-900 through 365-195-925.

(g) A detailed description of vegetation on and adjacent to the project area and its associated buffers. Demonstrate how the applicant will retain vegetation or vegetation critically important to threatened and endangered species.

(h) Establishment of monitoring protocol both pre- and post-development to demonstrating provisions including proposed monitoring and maintenance programs of the subject property.

(i) Review and comments by the Washington State Department of Fish and Wildlife, and other appropriate state and federal agencies that review SEPA checklists. (Ord. 3082 § 2, 2009; Ord. 2821 § 2, 2002).

17.12.030 Geotechnical assessments.

A geotechnical assessment is intended to be a limited study of geological hazards (i.e., landslides, liquefaction) at a site, and does not include the collection of any subsurface soil, rock and groundwater data. The scope of services should typically include, at a minimum, a site visit and literature review performed by the qualified geotechnical engineer. If determined to be necessary, the geotechnical engineer will recommend the preparation of a detailed geotechnical report that includes the investigation of subsurface soil, rock and groundwater conditions to better assess the geological site hazards.

(1) The geotechnical assessment shall typically include at a minimum the following:

(a) A discussion of the surface and subsurface geologic conditions of the site.

(b) A site plan of the area delineating all areas of the site subject to landslide geological hazards (i.e., erosion, sliding, earthquake, and other geological events) based on mapping and geotechnical evaluation. Additionally, all geological hazards within 200 lateral feet of the site and all landslide hazards off the property but anticipated to impact the proposed development should be indicated on the site plan.

(c) A contour map of the proposed site, at a reasonable scale (not smaller than one inch equals 100 feet) which clearly delineates slopes for ranges between 15 and 29 percent and 30 percent and greater, and includes figures for area coverage of each slope category on the site.

(d) The seal of the geotechnical engineer.

(2) The geotechnical report shall typically include at a minimum the following:

Technical justification shall be provided where the qualified expert does not deem any information applicable.

(a) A discussion of the surface and subsurface geologic conditions of the site.

(b) A site plan of the area delineating all areas of the site subject to landslide geological hazards (i.e., erosion, sliding, earthquake, and other geological events) based on mapping and geotechnical evaluation. Additionally, all geological hazards within 200 lateral feet of the site and all landslide hazards off the property but anticipated to impact the proposed development should be indicated on the site plan.

(c) A contour map of the proposed site, at a reasonable scale (not smaller than one inch equals 100 feet) which clearly delineates slopes for ranges between 15 and 29 percent and 30 percent and greater, and includes figures for area coverage of each slope category on the site.

(d) The seal of the geotechnical engineer.

(e) Site Geology Information Required.

(i) Topographic data: contour map of proposed site at a scale no greater than one inch equals 100 feet, which clearly delineates the slopes 15 percent and greater, including figures for area coverage of each slope category on the site.

(ii) Subsurface data: logs of borings, test pits and other exploratory methods, soil and rock stratigraphy, groundwater levels including seasonal changes, and laboratory test results.

(iii) Site history: description of any prior grading, soil instability, or slope failure.

(iv) Seismic hazard: data concerning the vulnerability of the site to seismic events.

(f) Geotechnical Engineering Information Required.

(i) Slope stability studies and opinion of slope stability based on a stated factor of safety for static and dynamic slope stability and a minimum horizontal acceleration as established by the current version of the building code;

(ii) Proposed angles of cut and fill slopes and site grading requirements;

(iii) Structural foundation requirements and estimated total and differential foundation settlements, including dynamic settlement in areas determined to be susceptible to soil liquefaction;

(iv) Soil compaction criteria;

(v) Proposed surface and subsurface drainage;

(vi) Lateral earth pressures, including static passive and active earth pressures, as well as dynamic active earth pressures;

(vii) Erosion vulnerability of site;

(viii) Suitability for fill, including the use of on-site soils for use as fill;

(ix) Laboratory data and soil index properties for soil samples; and

(x) Building limitations.

(g) Site Evaluation.

(i) Evaluation of the ability of the site to accommodate the proposed activity. Where a valid geotechnical report has been prepared within the last five years for a specific site, and where the proposed activity and surrounding site conditions are unchanged, said report may be utilized and a new assessment may not be required, at the discretion of the director or the city engineer, and provided the geotechnical report complies with the current building code.

(ii) The report shall bear the seal of the geotechnical engineer. (Ord. 3082 § 2, 2009; Ord. 2821 § 2, 2002).

17.12.040 Erosion hazard assessments.

(1) Erosion Hazard Assessments.

(a) The applicant must submit an erosion hazard assessment prepared by a qualified expert who shall be a geotechnical engineer.

(b) The erosion hazard assessment shall typically include, at a minimum, the following:

(i) An overview of existing channel characteristics and stream hydraulics at the subject property;

(ii) An assessment of the probability for stream induced erosion to occur on the subject property and the estimated extent of the property that would be affected;

(iii) A site map of the property, drawn to scale, delineating the relationship of the stream to the property, and existing erosion areas and/or potential erosion areas, and the proposed development, including structural dimensions;

(iv) A cross-section map, drawn to scale and at two-foot contour intervals from the edge of the river’s surface to the furthest landward boundary of the property, and including the proposed development. (Ord. 3082 § 2, 2009; Ord. 2821 § 2, 2002).

17.12.050 Hydrogeologic testing and site evaluation.

(1) Hydrogeologic Testing and Site Evaluation. If the director determines that hydrogeologic testing and site evaluation are required for development within a CARA, these investigations shall be conducted by a licensed hydrogeologist or qualified expert approved by the city engineer and shall typically include at least the following: Technical justification shall be provided where any information is not deemed applicable based on a case-by-case situation. Applicants are encouraged to use existing studies and resources within the same locality to the fullest extent possible, such as U.S. Soil Conservation Service Data and USGS data, when available, and to select qualified experts with localized knowledge of the Longview area.

(a) A characterization of the site and its relationship to the aquifer and evaluation of the ability of the site to accommodate the proposed activity;

(b) A discussion of the effects of the proposed project on groundwater quality and quantity; and

(c) Recommendations on appropriate mitigation, if any, to assure that there shall be no significant degradation of groundwater quality or quantity.

(2) In addition, the testing and evaluation must include, but not be limited to, an analysis of:

(a) Geologic setting and soils information of site and surrounding area;

(b) Water quality data, including pH, temperature, conductivity, nitrates, and bacteria;

(c) Location of and depth to perched water tables;

(d) Recharge potential of facility site (permeability/transmissivity);

(e) Local groundwater flow, direction, and gradient;

(f) Surface water locations within 1,000 feet of the site;

(g) Data currently available on wells and springs within 1,300 feet of the project area;

(h) Best management practices proposed to be utilized. (Ord. 3082 § 2, 2009; Ord. 2821 § 2, 2002. Formerly 17.12.060).