This chapter is adopted under the authority of Article XI, Section 11 of the Washington State Constitution, Chapter 36.70 RCW, which empowers a county to enact a critical area ordinance and provide for its administration, enforcement and amendment, and Chapter 36.70A RCW, the Growth Management Act. [Ord. 5-20 § 2 (Appx. A)]

The purpose of this chapter is to adopt development regulations that protect critical areas that are required to be designated under RCW 36.70A.170, part of the Growth Management Act (Chapter 36.70A RCW). [Ord. 5-20 § 2 (Appx. A)]

The intent of this chapter is to comply with the requirements for critical areas in the Growth Management Act (Chapter 36.70A RCW), the Growth Management Act implementing regulations (Chapter 365-190 WAC), and the Jefferson County Comprehensive Plan. The provisions of this chapter and all proceedings under it shall be liberally construed with a view to affect its purpose and intent. [Ord. 5-20 § 2 (Appx. A)]

Article II. Administrative Provisions

(1) This chapter applies to any land disturbing activity, development, or activity undertaken on land located within or containing a critical area or a critical area buffer in Jefferson County. All persons within Jefferson County shall comply with this chapter.

(2) Jefferson County shall not grant any permit or other approval to alter a critical area or a critical area buffer without ensuring compliance with this chapter.

(3) No land disturbing activity, development, or activity on land located within or containing a critical area or a critical area buffer in Jefferson County shall be authorized without full compliance with the terms of this chapter.

(4) Areas characterized by a particular critical area may also be subject to other regulations established by this chapter due to the overlap or multiple functions of some critical areas. When one critical area adjoins or overlaps another, the more restrictive standards shall apply.

(5) Uses, development, and activities in critical areas or critical area buffers for which no permit or approval is required by any other provision of the Jefferson County Code nevertheless are subject to the requirements of this chapter.

(6) When any provision of this chapter is in conflict with any other section of the Jefferson County Code, the provision that provides most protection to the critical area shall apply, except that any critical area occurring within the jurisdiction of the Shoreline Management Act also shall follow the policies and regulations in Chapter 18.25 JCC.

(7) Compliance with these regulations does not remove an applicant from the obligation to comply with all other applicable federal, state, or local regulations.

(8) Any action taken in a critical area or a critical area buffer designated by this chapter that is in violation of the standards and conditions contained in this chapter is expressly prohibited.

(9) The requirements of this chapter shall apply concurrently with review conducted under the State Environmental Policy Act (SEPA) (Chapter 43.21C RCW), as locally adopted (Chapter 18.40 JCC). Any conditions required pursuant to this chapter shall be coordinated with the SEPA review and threshold determination.

(10) This chapter applies to all forest practices over which Jefferson County has jurisdiction under Chapter 76.09 RCW and WAC Title 222. [Ord. 5-20 § 2 (Appx. A)]

(1) The approximate location and extent of critical areas within the county are displayed on various inventory maps available on the Jefferson County geographic information system (GIS) web site.

(2) The critical areas maps are provided only as a general guide to alert the viewer to the possible location and extent of critical areas. These maps shall not be relied upon exclusively to establish the existence/absence or boundaries of a critical area, or to establish whether all of the elements necessary to identify an area as a critical area actually exist.

(3) The type, extent and boundaries may be determined in the field by a geotechnical professional, wetland specialist, wildlife biologist or staff person according to the requirements of this chapter. In the event of a conflict between a critical area location shown on the county’s maps and that of an on-site determination, the on-site determination will apply.

(4) To the extent practicable, the county shall ensure that its critical area maps are updated as inventories are completed in compliance with the requirements of the Growth Management Act (Chapter 36.70A RCW). [Ord. 5-20 § 2 (Appx. A)]

(1) All applicants for new development are encouraged have a customer assistance meeting with the department prior to applying for a permit. Fees for a customer assistance meeting may be applied towards the application fee for the same project. The purpose of this customer assistance meeting is to discuss zoning and applicable critical area requirements, to review any conceptual site plans prepared by the applicant and to identify potential impacts and mitigation measures. Such conference shall be for the convenience of the applicant, and any recommendations shall not be binding on the applicant or the county.

(2) The department shall perform a critical area review for any application submitted for a regulated activity. Reviews for multiple critical areas shall occur concurrently. For critical areas within shoreline jurisdiction, critical area review shall occur as part of the shoreline review process.

(3) The department shall, to the extent reasonable, consolidate the processing of related aspects of other county regulatory programs which affect activities in regulated critical areas, such as subdivision or site development, with the approval process established in this chapter so as to provide a timely and coordinated review process.

(4) As part of the review of all development or building-related approvals or permit applications, the department shall review the information submitted by the applicant to:

(a) Confirm the nature and type of the critical area and evaluate any required assessments, reports, or studies;

(b) Determine whether the development proposal is consistent with this chapter;

(c) Determine whether any proposed alterations to the site containing critical areas are necessary; and

(d) Determine if the mitigation and monitoring plans proposed by the applicant are sufficient to protect the public health, safety, and welfare consistent with the goals, purposes, objectives, and requirements of this chapter.

(5) If a proposal has the potential to impact a critical area or a buffer, the administrator may require a special report pursuant to this chapter. When required, critical area special reports are subject to the following requirements:

(a) The applicant is required to submit a critical area report prepared by a qualified professional based on the report requirements of this chapter;

(b) The report will be evaluated to determine if all potential impacts to the critical area or buffer have been addressed in the critical area report;

(c) Any impacts of the proposed development will be reviewed for compliance with mitigation requirements (as defined in JCC 18.10.130) and determine if the mitigation plan sufficiently addresses the potential impacts; and

(d) Ensure that the submittal for critical areas is consistent with other documents submitted as part of the application and that the submittal is consistent with the requirements for a complete application in Chapter 18.40 JCC.

(6) At every stage of the application process, the burden of demonstrating that a proposal is consistent with this chapter is upon the applicant. [Ord. 5-20 § 2 (Appx. A)]

(1) The activities listed in subsection (4) of this section are exempt from the requirements of this chapter, assuming the proposed activity complies with all provisions of the exemption.

(2) The administrator may determine that an activity is closely allied or similar to any activity in this list even if the proposed activity does not meet the precise terms of a listed exempt activity. The administrator is authorized to determine through a Type I permit process whether or not a development should be classified as an exempt activity and that such an activity does not impact the functions and values of any critical area or a critical area buffer.

(3) It is the responsibility of the applicant to provide sufficient information for the administrator to determine that one of the exemptions listed in subsection (4) of this section applies.

(4) The following activities in critical areas or critical area buffers are exempt from the requirements of this chapter:

(a) Agriculture, as defined in JCC 18.10.010, may continue in substantively the same manner; provided, the activity does not result in adverse impacts to a critical area or a critical area buffer. This exemption shall include maintenance and repair of lawfully established structures, infrastructure, drainage and irrigation ditches, and farm ponds; provided, maintenance work does not expand further into a critical area.

(b) Forest Practices. Classes I, II, III, and IV special (not Class IV general) forest practices regulated and conducted in accordance with the provisions of Chapter 76.09 RCW and forest practice regulations, WAC Title 222, except where the lands have been or are proposed to be converted to a use other than commercial forest product production.

(c) Maintenance – Transportation. Maintenance or reconstruction of existing public or private roads, paths, bicycle ways, trails, and bridges; provided, that the maintenance or reconstruction complies with the additional requirements in subsection (5) of this section.

(d) Maintenance or Reconstruction – On-Site Sewage Systems. Maintenance or reconstruction of on-site sewage systems; provided, the maintenance or reconstruction complies with the additional requirements in subsection (5) of this section.

(e) Maintenance – Drainage. Maintenance and repair of existing drainage facilities or systems and flood control structures, including, but not limited to, ditches that do not meet the criteria for being considered a fish and wildlife habitat conservation area, culverts, catch basins, levees, reservoirs, and outfalls; provided, the maintenance or repair complies with the additional requirements in subsection (5) of this section.

(f) Utility Activities. This exemption is limited to the utility activities listed below; provided, the utility activities comply with the additional requirements in subsection (5) of this section:

(i) Normal and routine maintenance or repair of existing utility facilities or rights-of-way; or

(ii) Installation, construction, relocation and replacement, operation, repair, or alteration of all utility lines, equipment, or appurtenances, not including substations, in improved road rights-of-way.

(g) Reconstruction, Remodeling, or Maintenance – Structures. This exemption is limited to reconstruction, remodeling, or maintenance of existing structures within the footprint of an existing lawfully established structure provided the maintenance complies with the additional requirements in subsection (5) of this section, work areas are minimized to the fullest extent possible, work areas are restored to previous conditions as soon as construction is complete, and staging areas are located outside of all critical areas and critical area buffers. This exemption shall not apply if the activity creates or continues a circumstance where personal or property damage is likely due to conditions of the critical area or if there is further intrusion into a critical area or a critical area buffer.

(h) Site Investigative Work. Site investigative work in wetlands, landslide hazard areas, riverine and coastal erosion hazard areas, or fish and wildlife habitat conservation areas, or their critical area buffers that is necessary for land use application submittals or permit compliance, including but not limited to groundwater monitoring wells, sediment sampling, surveys, soil borings, shallow soil test pits, and percolation tests involving no fill or use of heavy equipment; provided, the site investigative work complies with the additional requirements in subsection (5) of this section and excavation for soil logs or percolation tests are filled.

(i) Emergency Action. Action that is taken which is necessary to resolve or prevent imminent threat or danger to public health or safety, or to public or private property, or serious environmental degradation; provided, the emergency action complies with the additional requirements in subsection (5) of this section. If the nature of the emergency requires immediate action within a time period too short to allow full compliance with this chapter, the department, as well as any federal or state agencies with jurisdiction (e.g., the U.S. Army Corps of Engineers), must be notified of the emergency action within one working day of the initiation of the emergency action. Any person or agency undertaking emergency action using this exemption must submit a complete application to department for review and approval within 30 days of abatement of the emergency, and the “after-the-fact” application must show compliance with all requirements of this chapter. Any impacts to critical areas or critical area buffers that are not mitigated within one year of issuance of an “after-the-fact” permit shall be in violation of this exemption and may be subject to enforcement actions by the department.

(j) Artificial Wetlands and Artificial Ponds. Artificial wetlands and artificial ponds, provided:

(i) The artificial wetland or pond does not meet the definition of wetland or fish and wildlife habitat conservation area; and

(ii) The artificial wetland or pond was not historically constructed from a wetland or fish and wildlife habitat conservation area (without receiving all applicable permits to modify the critical area).

(k) Irrigation. Operation, maintenance and repair of dikes, ditches, reservoirs, ponds and other irrigation structures and facilities that do not require a state hydraulic permit and do not meet the criteria for being designated a fish and wildlife habitat conservation area; provided, the maintenance or repair complies with subsection (5) of this section.

(l) Passive Recreation. Passive recreation, when the activity does not cause adverse impacts. Examples include, but are not limited to, such recreational uses as swimming, canoeing/kayaking, hunting, and fishing (pursuant to state law), bird watching, hiking, and bicycling.

(m) Existing Residential Landscaping. Planting, irrigating, mowing, pruning, and maintenance and repair of landscaping structures; provided, these activities are part of existing normal residential landscaping activities and no building permit is required and the landscaping complies with subsection (5) of this section. This exemption does not allow any additional intrusion, expansion, or introduction of nonnative species into a critical area or a critical area buffer.

(n) Noxious Weed Control. Removal or eradication of noxious weeds listed in Chapter 16-750 WAC. Such activity is the responsibility of the landowner; provided, the following conditions are met:

(i) The removal or control of noxious weeds shall follow guidelines issued by the Jefferson County noxious weed control board. The Jefferson County noxious weed control board shall coordinate with the department of planning and community development for the control of noxious weeds in wetlands.

(ii) All herbicide applications in aquatic environments shall conform to the rules of the Washington Department of Ecology, Washington Department of Agriculture and Washington Department of Natural Resources, pursuant to Chapters 16-228, 173-201a, and 222-38 WAC.

(o) Harvesting of Wild Crops. The harvesting of wild crops; provided, that the harvesting:

(i) Is not injurious to natural reproduction of such crops;

(ii) Does not require tilling soil, planting crops, or changing existing topography, water conditions, or water sources; and

(iii) Does not have any adverse impacts on protection of the critical area or a critical area buffer.

(p) Planting Native Vegetation. The enhancement of a critical area buffer by planting native vegetation.

(q) New Trails. The construction of new, unpaved, nonmotorized trails when located in the outer 25 percent of a wetland or a fish and wildlife habitat conservation area or their critical area buffers; provided, the new trail is no wider than five feet. This exemption shall not apply within a frequently flooded area or its critical area buffer, where development must follow FEMA requirements, or within a geologically hazardous area or its critical area buffer if the new trail will be for public use.

(r) Navigation Aids and Boundary Markers. Installation of navigation aids and boundary markers; provided, they are installed in accordance with applicable state and federal laws or the installation of mooring buoys in accordance with the Washington Department of Fish and Wildlife design guidelines and the Jefferson County shoreline management program (Chapter 18.25 JCC).

(s) Beaver Dam Alterations with a Hydraulic Project Approval Pursuant to Chapter 77.55 RCW and Chapter 220-660 WAC. Beaver dam alteration in stream channels when undertaken with a hydraulic project approval issued by the Washington Department of Fish and Wildlife pursuant to Chapter 77.55 RCW and Chapter 220-660 WAC.

(5) Additional Protection and Restoration Requirements. Where compliance with this section is required by a subsection above, all of the following requirements must be met:

(a) Prior to the start of the activity for which an exemption is sought, the applicant must submit to the department a written description of the activity that includes at least the following information:

(i) Type, timing, frequency, and sequence of the activity to be conducted;

(ii) Type of equipment to be used (hand or mechanical);

(iii) Manner in which the equipment will be used; and

(iv) The best management practices to be used.

The written description shall be valid for five years; provided, there is no significant change in the type or extent of the activity.

(b) The activity cannot further alter, impact, or encroach upon critical areas or critical area buffers and no reasonable or practicable alternative exists.

(c) The activity cannot further affect the functions of a critical area or a critical area buffer, and no reasonable or practicable alternative exists.

(d) Best management practices must be implemented to minimize impacts to critical areas and critical area buffers during the activity.

(e) Disturbed critical areas and critical area buffers must be restored immediately after the activity is complete.

(f) Any impacts of the activity to a critical area or a critical area buffer must be mitigated, as approved by the administrator.

(6) The administrator has the authority to:

(a) Request information from an applicant to ensure compliance with exemption requirements;

(b) Determine whether or not an application meets the exemptions listed; and

(c) Take enforcement action for any land disturbing activity, development, or action undertaken on land located within or containing a critical area or a critical area buffer in Jefferson County that does not meet exemption requirements. [Ord. 5-20 § 2 (Appx. A)]

(1) Any legal use or legal structure in existence on the effective date of this chapter that does not meet the critical area or critical area buffer requirements of this chapter for any designated critical area shall be considered a legal nonconforming use.

(2) Any use or structure for which an application has vested or for which a permit has been obtained prior to the effective date of this chapter, that does not meet the critical area buffer requirements of this chapter for any designated critical area, shall be considered a legal nonconforming use.

(3) A legal nonconforming use or structure may be maintained or repaired as allowed by this chapter and the nonconforming provisions of JCC 18.20.260. [Ord. 5-20 § 2 (Appx. A)]

(1) Requests for relief from the dimensional or performance standards of this chapter shall require a critical areas variance which shall be processed as a Type III permit; provided:

(2) The hearing examiner in accordance with Chapter 2.30 JCC shall have the authority to grant a variance from the requirements of this chapter when, in the opinion of the hearing examiner, all of the following criteria have been met:

(a) There are special circumstances applicable to the subject property or to the intended use such as shape, topography, location, or surroundings that do not apply generally to surrounding properties or that make it impossible to redesign the project to preclude the need for a variance;

(b) The applicant has avoided impacts and provided mitigation to the maximum practical extent;

(c) The critical area buffer reduction proposed through the variance is the minimum necessary to accommodate the permitted use;

(d) Granting the variance will not be materially detrimental to the public welfare or injurious to the property or improvement;

(e) Granting the variance is necessary to ensure consistency with the Comprehensive Plan and any attendant public service obligations; and

(f) No other practicable or reasonable alternative exists.

(3) In lieu of the criteria in subsections (2)(a) through (f) of this section, an applicant may pursue a critical area variance through proof of all of the following criteria:

(a) The applicant has avoided impacts and provided mitigation, in accordance with this chapter, to the maximum practical extent;

(b) The variance will not adversely impact receiving water quality or quantity;

(c) The variance will not adversely impact any functional attribute of the critical area;

(d) The variance will not jeopardize the continued existence of species listed by the federal government or the state as endangered, threatened, sensitive, or documented priority species or priority habitats; and

(e) The variance is based on the criteria and standards referenced in this chapter. [Ord. 5-20 § 2 (Appx. A)]

(1) Permit applicants for a property so encumbered by critical areas or buffers that application of this chapter, including buffer averaging, buffer reduction, or other mechanism, would deny all reasonable economic use may seek approval pursuant to the reasonable economic use standards and procedures provided in this section.

(2) Nothing in this chapter is intended to preclude all reasonable economic use of property. If the application of this chapter would deny all reasonable economic use of the subject property, including agricultural use, use or development shall be allowed if it is consistent with the zoning code and the purposes of this chapter.

(3) To qualify as a reasonable economic use, the technical administrator or hearing examiner, as appropriate, must find that the proposal is consistent with all of the following criteria:

(a) There is no portion of the site where the provisions of this chapter allow reasonable economic use, including agricultural use or continuation of legal nonconforming uses;

(b) There is no feasible alternative to the proposed activities that will provide reasonable economic use with less adverse impact on critical areas or buffers;

(c) Activities will be located as far as possible from critical areas and the project employs all reasonable methods to avoid adverse effects on critical area functions and values, including maintaining existing vegetation, topography, and hydrology. Where both critical areas and buffer areas are located on a parcel, buffer areas shall be disturbed in preference to the critical area;

(d) The proposed activities will not result in adverse effects on endangered or threatened species as listed by the federal government or the state of Washington, or be inconsistent with an adopted recovery plan;

(e) Measures shall be taken to ensure the proposed activities will not cause degradation of groundwater or surface water quality, or adversely affect drinking water supply;

(f) The proposed activities comply with all state, local and federal laws, including those related to erosion and sediment control, pollution control, floodplain restrictions, and on-site wastewater disposal;

(g) The proposed activities will not cause damage to other properties;

(h) The proposed activities will not increase risk to the health or safety of people on or off the site;

(i) The inability to derive reasonable economic use of the property is not the result of segregating or dividing the property or creating the condition of lack of use; and

(j) The project includes mitigation for unavoidable critical area and buffer impacts in accordance with the mitigation requirements of this chapter. [Ord. 5-20 § 2 (Appx. A)]

(1) Exclusion for Functionally Isolated Critical Areas Buffers. Subject to the limitations in subsection (2) of this section, critical areas buffers that are both physically separated and functionally isolated from a critical area and do not protect the critical area from adverse impacts shall be excluded from critical area buffers otherwise required by this chapter. Functional isolation can occur due to existing public roads, structures, vertical separating, or any other relevant physical characteristic.

(2) Limitations on Functional Isolation.

(a) Functional isolation shall be limited to wetland buffers and fish and wildlife habitat conservation area buffers only.

(b) Functional isolation shall not be used in geologically hazardous areas, critical aquifer recharge areas or frequently flooded areas.

(3) Special Report May Be Required. The administrator may require a special report to determine whether a critical area buffer is functionally isolated. [Ord. 5-20 § 2 (Appx. A)]

Adaptive management relies on scientific methods to evaluate how well regulatory and nonregulatory actions achieve their objectives and adjusts those programs. Management, policy, and regulatory actions are treated as experiments that are purposefully monitored and evaluated to determine whether they are effective and, if not, how they should be improved to increase their effectiveness. An adaptive management program is a formal and deliberate scientific approach to taking action and obtaining information in the face of uncertainty. To effectively implement an adaptive management program, Jefferson County, in support of this chapter, will:

(1) Address funding for the research component of the adaptive management program;

(2) Change course based on the results and interpretation of new information that resolves uncertainties; and

(3) Commit to the appropriate time frame and scale necessary to reliably evaluate regulatory and nonregulatory actions affecting critical areas protection and anadromous fisheries. [Ord. 5-20 § 2 (Appx. A)]

Article III. Critical Aquifer Recharge Areas

Potable water is an essential life-sustaining element for humans and many other species. Much of Jefferson County’s drinking water comes from groundwater supplies. Critical aquifer recharge areas are important to ensure the quality and quantity of groundwater in aquifers. Preventing contamination from land uses that may contaminate groundwater is necessary to protect water supplies and avoid exorbitant costs, hardships and physical harm to people and ecosystems. It is the purpose of this article to identify and classify aquifer recharge areas in accordance with WAC 365-190-100 and balance competing needs for land uses and clean water supplies and preserve essential natural functions and processes, especially for maintaining critical fish and wildlife habitat conservation areas. [Ord. 5-20 § 2 (Appx. A)]

Critical aquifer recharge areas are areas with a critical recharging effect on aquifers used for potable water, including areas where an aquifer that is a source of drinking water is vulnerable to contamination that would affect the potability of the water, or is susceptible to reduced recharge. Critical aquifer recharge area maps shall be periodically revised, modified, and updated to reflect current information.

The following classifications define critical aquifer recharge areas:

(1) Susceptible Aquifer Recharge Areas. Susceptible aquifer recharge areas are those with geologic and hydrologic conditions that promote rapid infiltration of recharge waters to groundwater aquifers. For the purposes of this article, unless otherwise determined by preparation of an aquifer recharge area report authorized under this article, the following geologic units, as identified from available Washington Department of Natural Resources geologic mapping, define susceptible aquifer recharge areas for east Jefferson County:

(a) Alluvial fans (Ha);

(b) Artificial fill (Hx);

(c) Beach sand and gravel (Hb);

(d) Dune sand (Hd);

(e) Floodplain alluvium (Hf);

(f) Vashon recessional outwash in deltas and alluvial fans (Vrd);

(g) Vashon recessional outwash in melt water channels (Vro);

(h) Vashon ice contact stratified drift (Vi);

(i) Vashon ablation till (Vat);

(j) Vashon advance outwash (Vao);

(k) Whidbey formation (Pw); and

(l) Pre-Vashon stratified drift (Py).

(2) Special Aquifer Recharge Protection Areas. Special aquifer recharge protection areas include:

(a) Sole-source aquifers designated by the U.S. Environmental Protection Agency in accordance with the Safe Drinking Water Act of 1974 (42 U.S.C. 300f et seq.), such as Marrowstone Island;

(b) Special protection areas designated by the Washington Department of Ecology under Chapter 173-200 WAC;

(c) Wellhead protection areas determined in accordance with delineation methodologies specified by the Washington Department of Health under authority of Chapter 246-290 WAC;

(d) Groundwater management areas designated by the Washington Department of Ecology in cooperation with local government under Chapter 173-100 WAC.

(3) Seawater Intrusion Protection Zones (SIPZ).

(a) Seawater intrusion protection zones are:

(i) Aquifers and land overlying aquifers with some degree of vulnerability to seawater intrusion. SIPZ are defined either by proximity to marine shoreline or by proximity to groundwater sources that have demonstrated high chloride readings.

(ii) All islands and land area within one-quarter mile of marine shorelines and associated aquifers together compose the coastal SIPZ.

(b) High Risk SIPZ.

(i) Existing individual groundwater sources with a history of chloride analyses above 200 mg/L are categorized as a high risk SIPZ for development proposed under this code.

(ii) Areas within 1,000 feet of a groundwater source with a history of chloride analyses above 200 milligrams per liter (mg/L) are categorized as a high risk SIPZ for development proposed under this code.

(c) At Risk SIPZ. Areas within 1,000 feet of a groundwater source with a history of chloride analyses above 100 milligrams per liter (mg/L) are categorized as at risk SIPZ for development proposed under this code.

(4) Connate Seawater Exception. In some cases, high chloride readings may be indicative of connate seawater (i.e., relic seawater in aquifers as opposed to active seawater intrusion). When best available science or a hydrogeologic evaluation demonstrates that high chloride readings in a particular area are due to connate seawater, the area in question shall not be considered an at risk or high risk SIPZ.

(5) Recommendation from Public Health Department. When the status of an area as either a high risk or an at risk SIPZ is in question, the administrator is responsible for making the determination based upon recommendation from the Jefferson County department of public health. [Ord. 5-20 § 2 (Appx. A)]

This article applies to any development within critical aquifer recharge areas, unless the proposed activity meets any of the exemptions listed in JCC 18.22.230.

(1) Other Activities. The following activities, when proposed in a critical aquifer recharge area shall be subject to the protection standards in this article:

(a) All industrial and commercial land uses with the potential to impact groundwater;

(b) The following rural residential land uses:

(i) Those using a locally managed community sewage system;

(ii) Those using a large on-site sewage system meeting the management requirements of the Washington Department of Health; and

(iii) All planned rural residential developments. [Ord. 5-20 § 2 (Appx. A)]

The following protection standards shall apply to activities; provided, the activity is not prohibited in JCC 18.22.320.

(1) Critical Aquifer Recharge Area High Impact Activities.

(a) High Impact Activities Listed. The activities listed in Table 18.22.330(1) are high impact activities due to the probability or potential magnitude of their adverse effects on groundwater.

(b) High Impact Activities Prohibited in Areas Classified as Both a Susceptible Aquifer Recharge Area and a Special Aquifer Recharge Protection Area. High impact activities shall be prohibited in areas that are classified as both a susceptible aquifer recharge area and a special aquifer recharge protection area.

(c) High Impact Activities Proposed in Areas Classified Solely as a Susceptible Aquifer Recharge Area Require a Critical Aquifer Recharge Area Report. When high impact activities are proposed for a susceptible aquifer recharge area, a critical aquifer recharge area report that meets all the requirements of JCC 18.22.930 shall be submitted to the department for review.

(d) High Impact Activities Proposed in Areas Classified Solely as a Special Aquifer Recharge Protection Area Require a Critical Aquifer Recharge Area Report. When high impact activities are proposed for a special aquifer recharge protection area, a critical aquifer recharge area report that meets all the requirements of JCC 18.22.930 shall be submitted to the department for review.

(2) Seawater Intrusion Protection Zones. New development, redevelopment, and activities on islands and in close proximity to marine shorelines where there is a risk or a high risk of seawater intrusion should be developed in such a manner to maximize aquifer recharge, maintain the saltwater/freshwater balance to the maximum extent possible, and are subject to the antidegradation policy in accordance with WAC 173-200-030 (Antidegradation Policy).

(3) Stormwater Disposal.

(a) Stormwater runoff shall be controlled and treated in accordance with best management practices and facility design standards as identified and defined in the current Stormwater Management Manual for Western Washington and the stormwater provisions contained in Chapter 18.30 JCC. To the extent practicable, stormwater should be managed in a way that facilitates aquifer recharge.

(b) To help prevent seawater from intruding landward into aquifers, all new development activity on Marrowstone Island and within one-quarter mile of any marine shoreline shall be required to infiltrate all stormwater runoff on site, except for those areas within the Port Ludlow Drainage District. The administrator will consider requests for exceptions to this policy on a case-by-case basis; provided a critical aquifer recharge area report that complies with all the requirements of JCC 18.22.930 demonstrates the project does not pose a threat of seawater intruding landward into aquifers.

(4) Golf Courses and Other Turf Cultivation.

(a) Golf courses shall be developed and operated in a manner consistent with the most current edition of “Best Management Practices for Golf Course Development and Operation,” King County department of development and environmental services.

(b) Recreational and institutional facilities (e.g., parks and schools) with extensive areas of cultivated turf shall be operated in a manner consistent with portions of the aforementioned best management practices pertaining to fertilizer and pesticide use, storage, and disposal. In seawater intrusion protection zones, golf courses and other turf cultivation using groundwater for irrigation shall be prohibited, unless the water source is located outside of seawater intrusion protection zones or in an approved public water supply.

(5) Above-Ground and Underground Storage Tanks.

(a) Above-ground and underground storage tanks shall be fabricated, constructed, installed, used and operated in a manner which prevents the release of hazardous substances to the ground or groundwater and is consistent with the Washington Department of Ecology’s standards for construction and installation under Chapter 173-360A WAC.

(b) Above-ground storage tanks intended to hold or store hazardous substances shall be provided with an impervious containment system, enclosing and underlying the tank; or ensure that other measures are undertaken as prescribed by the Uniform Fire Code which provide an equivalent measure of protection.

(c) Underground storage tanks intended to store hazardous substances shall provide an impervious tertiary containment system underlying the tanks or ensure that other measures are undertaken which provide an equivalent measure of protection.

(d) When required under this section, an impervious containment system must be durable, compatible with the substance it is meant to contain, and large enough to contain a volume equal to 10 percent of all containers, or 110 percent of the largest single container, whichever is greater.

(6) Mining and Quarrying. For mining and quarrying, required performance standards with groundwater protection best management practices pertaining to operation, closure, and the operation of gravel screening, gravel crushing, cement concrete batch plants, and asphalt concrete batch plants, where allowed, are contained in Chapters 18.20 and 18.30 JCC.

(7) Hazardous Substances. Activities that generate, handle, store, or use hazardous substances, which are not prohibited outright under this code, and which are conditionally exempt from regulation by the Washington Department of Ecology under WAC 173-303-100 (Dangerous Waste Criteria), or which generate, handle, store or use hazardous substances, shall be required to prepare and submit a hazardous substances management plan that demonstrates that the development will not have an adverse impact on groundwater quality. The hazardous substances management plan shall describe the following:

(a) How hazardous substance(s) will be managed in a manner consistent with Chapter 8.10 JCC and Chapter 173-303 WAC;

(b) Screening of any waste suspected of being a regulated dangerous waste as defined in JCC 8.10.100;

(c) Requirements for labeling of containers holding hazardous substances with the name of the hazardous substance(s) and the applicable material safety data sheets; and

(d) The secondary containment system to be used to prevent releases of hazardous substances to the ground, groundwater, and surface water.

The facility owner must update the hazardous materials management plan annually and provide the updated plan to the department on or before the next January 1st, after the plan is updated.

(8) Well Drilling, Subdivisions, and Building Permits in Seawater Intrusion Protection Zones (SIPZ).

(a) Well Drilling. The Washington Department of Ecology regulates well drilling pursuant to the Water Well Construction Act. Proposed wells, including those exempt from permitting requirements, must be sited at least 100 feet from “known or potential sources of contamination,” which include “sea-salt water intrusion areas” (WAC 173-160-171), unless a variance is obtained from the Washington Department of Ecology per WAC 173-160-106.

(b) Subdivisions. Applications for land division (Chapter 18.35 JCC) in coastal, at risk, and high risk SIPZ must include specific and conclusive proof of adequate supplies of potable water and the applicant must provide a special report that satisfies all the requirements or a hydrogeologic evaluation contained in JCC 18.22.930(2)(b) that demonstrates that the creation of new lots and corresponding use of water will not cause degradation of the aquifer by seawater intrusion. A hydrogeologic evaluation shall not be required when the applicant demonstrates that public water is available for the entire project.

(c) Marrowstone Island. Due to documented seawater intrusion on Marrowstone Island and the existence of undeveloped lots of record, the department, in consultation with Jefferson County environmental public health will only allow land division on the island if public water connections are provided to each lot of a proposed project and all existing wells within the project site are decommissioned. No permit shall be approved if a public water connection to each lot of a proposed project cannot be provided.

(d) Building Permits.

(i) Evidence of potable water may be an individual well, connection to a public water system, or an alternative system. Whatever method is selected, the regulatory and operational standards for that method must be met and the department will work in consultation with the Jefferson County public health department. Identification of well interference problems and impairment to senior rights is the responsibility of the Washington Department of Ecology. If the possibility of a problem is suspected, the local permitting authority should contact the Washington Department of Ecology, as required by RCW 19.27.097.

(ii) All types of building permits that require proof of potable water use, as per RCW 19.27.097, are subject to this article.

(e) Voluntary and mandatory measures of the Jefferson County seawater intrusion policy apply to applications within the coastal, at risk, and high risk SIPZ, and upon Marrowstone Island, in the following manner, in addition to all existing applicable health codes:

(i) Coastal SIPZ.

(A) Voluntary Actions. Voluntary actions may include but are not limited to:

(I) Water conservation measures;

(II) Ongoing well monitoring for chloride concentration; and

(III) Submittal of data to the county.

(B) Mandatory Actions.

(I) For proof of potable water on a building permit application, applicant must utilize DOH-approved public water system if available;

(II) If public water is unavailable, meaning the subject property is not within a current water service area, an individual well may be used as proof of potable water subject to the following requirements:

1. Chloride concentration of a laboratory-certified well water sample submitted with building permit application; and

2. Installation of source-totalizing meter (flow);

(III) If public water is unavailable, a qualifying alternative system may be used as proof of potable water.

(ii) At Risk SIPZ.

(A) Voluntary Actions.

(I) Water conservation measures.

(B) Mandatory Actions.

(I) For proof of potable water on a building permit application, the applicant must utilize a Washington Department of Health-approved public water system if available;

(II) If public water is unavailable, meaning the subject property is not within a current water service area, an individual well may be used as proof of potable water subject to the following requirements:

1. Chloride concentration of a laboratory-certified well water sample submitted with building permit application;

2. Installation of a source-totalizing meter (flow); and

(III) If public water is unavailable, a qualifying alternative system may be used as proof of potable water.

(iii) High Risk SIPZ.

(A) Mandatory Actions.

(I) Water conservation measures;

(II) For proof of potable water on a building permit application, applicant must utilize a Washington Department of Health-approved public water system if available;

(III) If public water is unavailable, meaning the subject property is not within a current water service area, an individual well may only be used as proof of potable water subject to the following requirements:

1. Variance from the WAC Title 173 standards granted by the Washington Department of Ecology per WAC 173-160-106 for a new groundwater well within 100 feet of a sea-salt water intrusion area per WAC 173-160-171 (i.e., within 100 feet of a groundwater source showing chloride concentrations above 200 mg/L or within 100 feet of the marine shoreline) and with the submittal of a hydrogeologic evaluation that satisfies all the requirements or a hydrogeologic evaluation contained in JCC 18.22.930(2)(b);

2. For an existing groundwater well not subject to a Washington Department of Ecology variance, the applicant must provide a hydrogeologic evaluation that satisfies all the requirements or a hydrogeologic evaluation contained in JCC 18.22.930(2)(b), which shall be transmitted to the Washington Department of Ecology for review, demonstrating that use of the well does not cause any detrimental interference with existing water rights and is not detrimental to the public interest;

3. Chloride concentration of a laboratory-certified well water sample submitted with building permit application;

4. If chloride concentration exceeds 250 mg/L in a water sample submitted for a building permit, then the property owner shall be required to record a restrictive covenant that indicates a chloride reading exceeded the U.S. Environmental Protection Agency secondary standard (250 mg/L) under the National Secondary Drinking Water Regulations;

5. Installation of a source-totalizing meter flow;

6. Ongoing well monitoring for chloride concentration; and

7. Submittal of flow and chloride data to the county per monitoring program; and

(IV) If public water is unavailable, a qualifying alternative system may be used as proof of potable water.

(iv) Marrowstone Island. Since Marrowstone Island is a sole source aquifer and a high risk SIPZ, and the island is served by public water, proof of potable water connection to the public water supply will be required for all lots in the project.

(9) Mitigating Conditions. The administrator may require additional mitigating conditions, as needed to provide protection to all critical aquifer recharge areas and to ensure that the subject land or water use action will not pose a risk of significant adverse groundwater quality impacts. The determination of significant adverse groundwater quality impacts will be based on the antidegradation policy included in Chapter 173-200 WAC.

(10) Results of Department’s Review of a Critical Aquifer Recharge Area Report, a Hydrogeologic Evaluation or a Hazardous Substances Management Plan. The department shall review a critical aquifer recharge area report, a hydrogeologic evaluation or a hazardous substances management plan and either:

(a) Accept the critical aquifer recharge area report, the hydrogeologic evaluation or the hazardous substances management plan and approve the application; or

(b) Reject the critical aquifer recharge area report, the hydrogeologic evaluation or the hazardous substances management plan and require revisions or additional information.

(11) Authority for Denial. In all critical aquifer recharge areas, the administrator may deny approval if the protection standards contained in this section or added mitigating conditions cannot prevent significant adverse groundwater quality impacts. [Ord. 5-20 § 2 (Appx. A)]

Article IV. Frequently Flooded Areas

The purpose of this article is to protect the public health, safety and welfare from harm caused by flooding and to establish protection standards for these areas. It is the intent of this article to prevent damage or loss to both public and private property. [Ord. 5-20 § 2 (Appx. A)]

Frequently flooded areas are lands in the floodplain subject to at least a one percent or greater chance of flooding in any given year, or within areas subject to flooding due to high groundwater. These areas include, but are not limited to, streams, rivers, lakes, coastal areas, wetlands, and areas where high groundwater forms ponds on the ground surface. Frequently flooded areas perform important hydrologic functions and may present a risk to persons and property. Flood hazard areas are depicted on the Federal Emergency Management Agency’s Flood Insurance Rate Maps (FIRMs). FIRMs display areas of concern including areas that fall within the 100-year floodplain designations of the Federal Emergency Management Agency and the National Flood Insurance Program. [Ord. 5-20 § 2 (Appx. A)]

These standards apply to any development within frequently flooded areas, unless the proposed activity meets any of the exemptions listed in Chapter 15.15 JCC. The flood damage prevention ordinance (Chapter 15.15 JCC) conforms with the intent of the minimum guidelines (WAC 365-190-110(1)) through directly considering the effects of flooding on human health and safety, together with effects on public facilities and services, through its protection standards. For purposes of this article, “development” is defined as any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, storage of equipment or materials, subdivision of land, removal of more than five percent of the native vegetation on the property, or alteration of natural site characteristics. [Ord. 5-20 § 2 (Appx. A)]

This article incorporates by reference the classification, designation and protection provisions contained in the Jefferson County flood damage prevention ordinance (Chapter 15.15 JCC) with the following additions:

(1) Compliance with FIRMs. The FIRMs identified in the flood damage prevention ordinance (Chapter 15.15 JCC) shall be used to determine flood hazard areas for compliance with the Federal Emergency Management Agency (FEMA) regulatory requirements. Such flood hazard areas shall be subject to the criteria of the flood damage prevention ordinance (Chapter 15.15 JCC).

(2) Compliance with National Marine Fisheries Service Biological Opinion. Development proposed within regulated frequently flooded areas and floodplains shall ensure no impacts to listed fish and wildlife habitat as required by the National Marine Fisheries Service (NMFS) September 22, 2008, final Biological Opinion (BiOp) under the Endangered Species Act (ESA) on the National Flood Insurance Program (NFIP) in Puget Sound (NMFS Tracking No.: 2006-00472 (or as amended by NMFS)).

(3) Habitat Assessment Requirements.

(a) A habitat assessment that meets all the requirements of JCC 18.22.940 shall be submitted to the department for review if any portion of the proposed project occurs within a special flood hazard area (floodplain), as mapped by the Federal Emergency Management Agency (FEMA).

(b) The administrator may request federal assistance in reviewing the submitted habitat assessment.

(c) The administrator may waive the requirement to submit a habitat assessment only if:

(i) The entire proposal meets one of the exemptions listed in Chapter 15.15 JCC and does not require a state hydraulic permit;

(ii) The proposal requires a federal permit that is reviewed by federal agencies responsible for ensuring compliance with the Endangered Species Act (this could include, but is not limited to, project actions covered by separate consultation under Section 4(d), 7, or 10 of the Endangered Species Act);

(iii) A habitat assessment previously has been prepared and the proposed project clearly fits within the nature and scope of that habitat assessment; or

(iv) If FEMA approves an alternate process for Jefferson County to demonstrate compliance with the Biological Opinion (such as a programmatic review), this department may waive the requirement to submit a habitat assessment. [Ord. 5-20 § 2 (Appx. A)]

Article V. Geologically Hazardous Areas

The purpose of this article is to reduce risks to human life and safety and reduce the risk of damage to structures and property from geologic hazards, to allow for natural geologic processes supportive of forming and maintaining fish and wildlife habitat, and to regulate and inform land use and planning decisions. It is recognized that the elimination of all risk from geologic hazards is not feasible to achieve but the purpose of this article is to reduce the risk to acceptable levels. [Ord. 5-20 § 2 (Appx. A)]

Geologically hazardous areas are areas that because of their susceptibility to erosion, sliding, earthquake, or other geological events, are not suited to siting commercial, residential, or industrial development consistent with public health or safety concerns. Unless specifically noted below, principal sources of geologically hazardous areas mapped information are the Washington Department of Natural Resources Geologic Hazard Maps (https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/geologic-hazard-maps).

(1) The following are geologically hazardous areas and subject to the standards of this article when mapped as high or moderate geologically hazardous areas:

(a) Erosion hazard areas (as defined in JCC 18.10.050).

(b) Landslide hazard areas (as defined in JCC 18.10.120). Landslide hazard areas include any areas susceptible to landslide because of any combination of bedrock, soil, slope (gradient), slope aspect, structure, hydrology, or other factors, as follows:

(i) Areas of historic failures, such as:

(A) Areas delineated by United States Department of Agriculture, Natural Resources Conservation Service as having a significant limitation for building site development;

(B) Coastal areas mapped by the Washington Department of Ecology Coastal Atlas as unstable, unstable old slides, and unstable recent slides; or

(C) Areas designated and mapped as quaternary slumps, earthflows, mudflows, lahars, or landslide hazards by the Washington Department of Natural Resources or the United States Geological Survey.

(ii) Areas where all three of the following conditions occur:

(A) Slopes are steeper than 15 percent;

(B) Hillsides intersecting geologic contacts with a relatively permeable sediment overlying a relatively impermeable sediment or bedrock; and

(C) Spring or groundwater seepage.

(iii) Areas that have shown movement during the Holocene epoch (from 10,000 years ago to present) or have been underlain or covered by mass wastage debris of this epoch.

(iv) Areas with slopes that are parallel or subparallel to planes of weakness (such as bedding planes, joint systems, and fault planes) in subsurface materials.

(v) Areas with slopes having gradients steeper than 80 percent subject to rockfall during seismic shaking.

(vi) Areas that are potentially unstable as a result of rapid stream incision, stream bank erosion, and undercutting by wave action, including stream channel migration zones.

(vii) Areas that show evidence of, or are at risk from, snow avalanches.

(viii) Areas located in a canyon or on an active alluvial fan, presently or potentially subject to inundation by debris flows or catastrophic flooding.

(ix) Areas with a slope of 40 percent or steeper and with a vertical relief of 10 or more feet, except areas composed of bedrock.

(c) Seismic hazard areas (as defined in JCC 18.10.190).

(d) Channel migration zones (CMZs) (as defined in JCC 18.10.030).

(e) Seiche and landslide generated wave hazard areas (as defined in JCC 18.10.190).

(f) Tsunami hazard areas (as defined in JCC 18.10.200).

(g) Other geologic events, such as coal mine hazards and volcanic hazards, are not a known risk in Jefferson County, and are therefore not subject to review as part of the permitting process. [Ord. 5-20 § 2 (Appx. A)]

(1) Any development activity or action requiring a project permit or any clearing within an erosion or landslide area shall:

(a) Comply with the requirements in an approved geotechnical report when one is required, including application of the largest buffer or building setback;

(b) Utilize best management practices (BMPs) and all known and available technology appropriate for compliance with this chapter and typical of industry standards;

(c) Prevent collection, concentration or discharge of stormwater or groundwater within an erosion or landslide hazard area and be in compliance with JCC 18.30.070, Stormwater management standards; and

(d) Minimize impervious surfaces and retain vegetation to minimize risk of erosion or landslide hazards.

(2) Any development activity or action requiring a project permit or any clearing within an erosion or landslide area shall not:

(a) Result in increased risk of property damage, death or injury;

(b) Cause or increase erosion or landslide hazard risk;

(c) Increase surface water discharge, sedimentation, slope instability, erosion or landslide potential to adjacent downstream and down-drift properties beyond predevelopment conditions;

(d) Adversely impact wetlands, fish and wildlife habitat conservation areas or their buffers; or

(e) Be identified as a critical facility necessary to protect public health, safety and welfare. This includes, but is not limited to, schools, hospitals, police stations, fire departments and other emergency response facilities, nursing homes, and hazardous material storage or production. [Ord. 5-20 § 2 (Appx. A)]

(1) Clearing, Grading and Vegetation Removal.

(a) Minor pruning of vegetation for view enhancement may be allowed through consultation with the department. The thinning of limbs on individual trees is preferred to topping of trees for view corridors. Total buffer thinning shall not exceed 25 percent and no more than 30 percent of the live tree crowns shall be removed.

(b) Vegetation shall not be removed from a landslide hazard area, except for hazardous trees based on review by a qualified arborist or as otherwise provided for in a vegetation management and restoration plan.

(c) Seasonal Restrictions. Clearing and grading shall be limited to the period between May 1st and October 1st, unless the applicant provides an erosion and sedimentation control plan prepared by a professional engineer licensed in the state of Washington that specifically and realistically identifies methods of erosion control for wet weather conditions.

(d) Only the clearing necessary to install temporary erosion control measures will be allowed prior to clearing for roads and utilities construction.

(e) The faces of cut and fill slopes shall be protected to prevent erosion as required by the engineered erosion and sedimentation control plan.

(f) Clearing for roads and utilities shall be the minimum necessary and shall remain within marked construction limits.

(g) Clearing for overhead power lines shall be the minimum necessary for construction and will provide the required minimum clearances for the serving utility corridor.

(2) Existing Logging Roads. Where existing logging roads occur in geologically hazardous areas, a geological assessment may be required prior to use as a temporary haul road or permanent access road under a conversion or COHP forest practices application.

(3) The department may also require:

(a) Clustering to increase protection to geologically hazardous areas; or

(b) Enhancement of buffer vegetation to increase protection to geologically hazardous areas.

(4) The provisions in this section are in addition to those required in JCC 18.30.060, Grading and excavation standards, and JCC 18.30.070, Stormwater management standards.

(5) If there is a conflict between applicable published standards, the more restrictive protection requirement applies.

(6) Drainage and Erosion Control.

(a) An applicant submitting a project application shall also submit, and have approved, a stormwater site plan that meets all the requirements of JCC 18.30.070(4)(e), when the project application involves either of the following:

(i) The alteration of a high or moderately high geologically hazardous area or its critical area buffer; or

(ii) The creation of a new parcel within a high or moderately high geologically hazardous area; and

(b) Shall discuss, evaluate, and recommend methods to minimize sedimentation of adjacent properties during and after construction.

(c) Surface drainage shall not be directed across the face of a marine bluff that is mapped as high or moderate erodible or susceptible to landslide or debris flow. The applicant must demonstrate that the stormwater discharge cannot be accommodated on site or upland by evidence presented in a geological assessment as required by JCC 18.22.945, unless waived by the administrator. If drainage must be discharged from a bluff to adjacent waters, it shall be collected above the face of the bluff and directed to the water by tight line drain and provided with an energy dissipating device at the shoreline, above ordinary high water mark (OHWM).

(d) The applicant must clearly demonstrate in the geological assessment that stormwater quantity, quality, and flow path post-construction will be comparable to pre-construction conditions.

(7) Vegetation Retention. The following provisions regarding vegetation retention shall apply:

(a) During clearing for roadways and utilities, all trees and understory vegetation lying outside of approved construction limits shall be retained to the maximum extent practicable;

(b) Clearing limits, as shown on the approved site plan, shall be marked by orange construction barrier fencing to be installed prior to beginning any clearing, grading, or other land-disturbing activities;

(c) Vegetation within identified clearing limits may be removed upon permit issuance. All vegetation within the high or moderate geologically hazardous area or its critical area buffer, but outside the marked clearing limits, shall be retained. Cleared vegetation shall not be placed within a high or moderate geologically hazardous area unless it is used as part of a mitigation plan consistent with other critical area mitigation provisions, is reviewed by the geotechnical professional, and is approved by the administrator; and

(d) Within a high risk CMZ, vegetation removal shall not be allowed. Vegetation removal outside of a high risk CMZ shall not be reviewed under this article. Should this provision conflict with other vegetation retention requirements specified elsewhere within this title, the more restrictive protection requirement applies.

(8) Erosion and Landslide Hazard Development Standards.

(a) Development activities or actions requiring project permits or clearing shall not be allowed in landslide hazard areas unless a geotechnical report demonstrates that building within a landslide hazard area will provide protection commensurate to being located outside the landslide hazard area and meets the requirements of this section. This may include proposed mitigation measures.

(b) Top of Slope Building Setback. All development activities or actions that require project permits or clearing in erosion and landslide hazard areas shall provide native vegetation from the toe of the slope to 25 feet beyond the top of slope, with an additional minimum 15-foot building and impervious surface setback, unless otherwise allowed through a geologic assessment. The minimum building and setback shall be increased from the top of the slope as follows:

(i) For high landslide hazard areas, the setback shall be equal to the height of the slope (1:1 horizontal to vertical) plus the greater of one-third of the vertical slope height or 25 feet.

(ii) For moderate landslide hazard areas, the setback shall be 40 feet from the top of slope.

(9) Geotechnical Report for Toe of Slope Building Setback May Be Required. A geotechnical report may be required based on slope height and stability indicators.

(10) Larger Native Vegetation Width May Be Required. The department may require a larger native vegetation width than the standard buffer distance as determined above if any of the following are identified through the geological assessment process:

(a) The adjacent land is susceptible to severe erosion and erosion control measures will not effectively prevent adverse impacts;

(b) The area has a severe risk of slope failure or downslope stormwater drainage impacts; or

(c) The minimum native vegetation width or building setback requirement may be decreased if a geotechnical report demonstrates that a lesser distance, through design and engineering solutions, will adequately protect both the proposed development and the erosion or landslide hazard area. The department may decrease the setback when such a setback would result in a greater than 1:1 slope setback.

(11) Seismic Hazard Development Standards.

(a) Development activities or actions requiring a project permit occurring within 200 feet of a “high hazard” seismic hazard area may be allowed with an approved geotechnical report that confirms the site is suitable for the proposed development and addresses any fill or grading that has occurred on the subject parcel.

(b) Development activities or actions requiring a project permit within a seismic hazard area shall be in accordance with JCC Title 15.

(12) Reducing Buffer Widths. The administrator may reduce geologically hazardous area buffers as follows:

(a) Buffers may be reduced by up to 25 percent with a geotechnical report prepared by a geotechnical professional with a state stamp; provided, the geotechnical report identifies recommendations for preventing or minimizing risks post-development.

(b) All buffer reductions 25 percent or greater and all development within a high or moderate geologically hazardous area shall require a geotechnical report prepared by a geotechnical professional. The administrator may require a third-party review based on JCC 18.22.930 or the applicant enters into an indemnity and hold harmless agreement with the county that is approved by the county’s risk manager and the prosecuting attorney. If the administrator requires a third-party review of the geotechnical report, the administrator shall be responsible for identifying and transmitting the geotechnical report to the third-party reviewer.

(13) Increasing Buffer Widths. Buffer widths may be increased on a case-by-case basis, as determined by the administrator, to protect the functions and values of a geologically hazardous area and to reduce risks to public safety and welfare. Information that may be used to support this determination, includes but is not limited to:

(a) The landslide area is unstable and active.

(b) The adjacent land is susceptible to severe landslide or erosion, and erosion control measures will not effectively protect the proposed project from the risks posed by the landslide hazard area.

(c) The adjacent land has minimal vegetative cover.

(14) Landslide Hazard Areas – Additional Standards. The following activities may be allowed in active landslide hazard areas when all reasonable measures have been taken to minimize risks and other adverse effects associated with landslide hazards, and when the amount and degree of the alteration are limited to the minimum needed to accomplish the project purpose:

(a) The standards of subsection (1) of this section shall apply.

(b) Developments that will not increase the threat to the health or safety of people and will not increase potential for landslides on or off the site and meet the reasonable economic use exception in JCC 18.22.260.

(c) Utility lines and pipes that are above ground, properly anchored or designed so that they will continue to function in the event of a slope failure or movement of the underlying materials and will not increase the risk or consequences of static or seismic slope instability or result in a risk of mass wasting. Such utility lines may be permitted only when the applicant demonstrates that no other feasible alternative is available to serve the affected population.

(d) Access roads and trails that are engineered and built to standards that minimize the need for major repair or reconstruction beyond that which would be required in nonhazard areas. Access roads and trails may be permitted only if the applicant demonstrates that no other feasible alternative exists, including through the provisions of Chapter 8.24 RCW. If such access through critical areas is granted, exceptions or deviations from technical standards for width or other dimensions and specific construction standards to minimize impacts, including drainage and drainage maintenance plans, may be required.

(e) Stormwater conveyance through a properly designed stormwater pipe when no other stormwater conveyance alternative is available. The pipe shall be located above ground and be properly anchored or designed so that it will continue to function in the event of a slope failure or movement of the underlying materials and will not increase the risk or consequences of static or seismic slope instability or result in increased risk of mass wasting activity.

(15) Seismic Hazard Areas – Standards. Development may be allowed in seismic hazard areas when all of the following apply:

(a) The standards of subsection (1) of this section shall apply.

(b) Structures in seismic hazard areas shall conform to applicable analysis and design criteria of Chapter 18.15 JCC.

(c) Public roads, bridges, utilities, and trails shall be allowed when there are no feasible alternative locations, and geotechnical analysis and design are provided that minimize potential damage to roadway, bridge, and utility structures, and facilities will not be susceptible to damage from seismically induced ground deformation. Mitigation measures shall be designed in accordance with the most recent version of the American Association of State Highway and Transportation Officials (AASHTO) Manual or another appropriate document.

(16) Tsunami Hazard Areas – Standards.

(a) The standards of subsection (1) of this section shall apply.

(b) For development within tsunami hazard areas the proposed development shall be designed to provide protection from the tsunami hazard that meets the projected hazard on the Washington Department of Natural Resources Tsunami Inundation Maps.

(c) For other low-lying coastal areas not included on the inundation maps, development shall be designed to provide protection for debris impact and an inundation as determined by current Washington Department of Natural Resource modeling, unless other measures can be shown to provide equal or greater protection. [Ord. 5-20 § 2 (Appx. A)]