Chapter 21.40
CRITICAL AREAS

Sections:

21.40.010    Purpose.

21.40.020    Wetlands.

21.40.030    Fish and wildlife habitat conservation areas.

21.40.040    Adjustment of habitat buffer areas.

21.40.050    Geologically hazardous areas.

21.40.060    Critical aquifer recharge areas.

21.40.070    Reasonable use determination.

21.40.010 Purpose.

WAC 365-195-410 requires that critical areas be designated and that regulations to protect them be adopted. Critical areas include wetlands, areas of critical recharging effect on aquifers used for potable water; fish and wildlife habitat conservation areas, frequently flooded areas; and geologically hazardous areas. (Ord. 07-015 § 4, 2007).

21.40.020 Wetlands.

A. Wetland Classification and Rating. Wetland areas mean areas that are inundated or saturated by surface water or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands do not include those artificial wetlands intentionally created from non-wetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands may include those artificial wetlands intentionally created from non-wetland areas created to mitigate conversion of wetlands (RCW 36.70A.030(21)).

Wetlands areas are identified in Chapter 8 of the Spokane Valley Comprehensive Plan in conformance with the Washington State Wetlands Identification and Delineation Manual (Ecology Publication No. 96-94), March 1997, as it may be amended from time to time, which classifies wetlands. Wetland scoring is based on the Washington State Wetland Rating System for Eastern Washington (Ecology Publication No. 04-06-15, or as amended).

1. Category I wetlands are those that represent a unique or rare wetland type; are more sensitive to disturbance than most wetlands; are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or provide a high level of function.

a. Alkali wetlands;

b. Wetlands that are identified by scientists of the Washington Natural Heritage Program/DNR as high quality wetlands;

c. Bogs;

d. Mature and old-growth forested wetlands over one-quarter acre with slow-growing trees;

e. Forests with stands of aspen; and

f. Wetlands that perform many functions very well (scores of 70 points or more).

2. Category II wetlands are difficult, though not impossible, to replace, and provide high levels of some functions and include:

a. Forested wetlands in the floodplains of rivers;

b. Mature and old-growth forested wetlands over one-quarter acre with fast-growing trees;

c. Vernal pools; and

d. Wetlands that perform functions well (scores between 51 to 69 points).

3. Category III wetlands include:

a. Vernal pools that are isolated; and

b. Wetlands with a moderate level of functions (scores between 30 to 50 points).

4. Category IV wetlands have the lowest level of functions and are often heavily disturbed. These wetlands may provide important functions and shall be replaced or restored.

B. Wetland Buffer Areas.

1. Exemptions.

a. Wetlands less than 1,000 square feet in area where the area is not associated with a riparian corridor; is not a vernal pool, an alkali wetland, part of a wetland mosaic, or does not contain habitat identified as essential for local populations of priority species.

b. Category III and IV wetlands of less than 4,000 square feet in area where the area is not associated with a riparian corridor; is not a vernal pool, an alkali wetland, part of a wetland mosaic, does not contain habitat identified as essential for local populations of priority species scoring less than 20 points or less on the Eastern Washington Rating System and is not required for biofiltration of stormwater.

c. An exemption under this section does not relieve the proponent for providing full mitigation through restoration or replacement.

2. Buffers.

a. Wetland buffer areas shall be required for all regulated uses and activities adjacent to wetlands. Any wetland created, restored or enhanced as compensation for approved wetland alterations shall also include the standard buffer required for the category of the created, restored, or enhanced wetland. All buffers shall be measured from the wetland boundary as determined in the field.

b. The width of wetland buffers shall be established by one of the following methods:

i. Alternative 1. Width based only on wetland category.

Table 21.40-1 – Wetland Buffer Width

Wetland Category	Minimum Buffer Width (in feet)
I	250
II	200
III	150
IV	50

ii. Alternative 2. Width based on wetland category and the intensity of impacts from proposed changes in land use. Land use intensity shall be determined as follows:

Table 21.40-2 – Wetland Impact

Impact from Proposed Change in Land Use	Types of Land Use Based on Common Zoning Designations *
High	Commercial, industrial and institutional
	Residential (more than 1 unit/acre)
	High-intensity recreation (golf courses, ball fields, etc.)
Moderate	Residential (1 unit/acre or less)
	Moderate-intensity active open space (parks with biking, jogging, etc.)
	Paved trails
	Utility corridor with access/maintenance road
Low	Passive open space (hiking, bird-watching, etc.)
	Unpaved trails
	Utility corridor without road or vegetation management

Table 21.40-3 – Wetland Intensity Impact Buffer

Wetland Category	Minimum Buffer Width (in feet)
	Low Impact	Moderate Impact	High Impact
I	125	190	250
II	100	150	200
III	75	110	150
IV	25	40	50

iii. Alternative 3. Width based on wetland category, intensity of impacts, and wetland functions or special characteristics. This alternative has two options for determining the widths of buffers when they are based on the score for habitat. Alternative 3 provides three buffer widths based on habitat scores. Where more than one width applies based on score for function or based on special characteristics, the calculation providing the widest buffer shall be used.

Table 21.40-4 – Wetland Buffers by Habitat Score

Wetland Category	Habitat Score	Minimum Buffer Width (in feet)
		Low Impact	Moderate Impact	High Impact
I	29 – 36	100	150	200
	20 – 28	75	110	150
	< 20	50	75	100
II	29 – 36	100	150	200
	20 – 28	75	110	150
	< 20	50	75	100
III	20 – 28	75	110	150
	> 28	40	60	80
IV	N/A	25	40	50

Table 21.40-5 – Wetland Special Characteristic Buffers

Special Characteristic	Low Impact	Moderate Impact	High Impact
Vernal Pool	100	150	200
Vernal Pool with Regional Plan*	40	60	80
Natural Heritage Wetland	125	190	250
Bogs	125	190	250
Alkali	100	150	200
*Develop a regional plan to protect the most important vernal pool complexes.

3. Additional buffer area width may be required by the director if:

a. The wetland includes a plant or animal species listed by the federal government or the state as endangered, threatened, candidate, sensitive, monitored or documented priority species or habitats, or essential or outstanding habitat for those species or has unusual nesting or resting sites such as heron rookeries or raptor nesting trees; or

b. The adjacent land has a slope of 30 percent or more adjacent to the wetland, the buffer area may be increased by 50 percent.

4. Reduction of Standard Wetland Buffer Area Width.

a. The standard wetland buffer area width scored moderate or high for habitat may be reduced if:

i. A relatively undisturbed vegetative corridor of at least 100 feet in width is protected between the wetland and any other priority habitats; and

ii. The protected area is preserved by means of easement, covenant or other measure; and

iii. Measures identified in subsection (B)(4)(b) of this section are taken to minimize the impact of any proposed land use.

b. The standard wetland buffer area width scored less than 20 for habitat may be reduced to that for moderate land use impact where the following mitigation measures are approved by the City:

Table 21.40-6 – Disturbance Buffers

Disturbance	Mitigation Buffers
Light	Light sources are shielded from the wetland
Noise	Wetland is shielded from noise
Stormwater runoff	Biofiltration or other measures prevent introduction of unfiltered stormwater directly into the wetland
Human activity	Visual screening of wetlands is required
Dust/particulates	Parking and driveways are paved

5. Standard Buffer Width Averaging.

a. Standard wetland buffer area width may be averaged if all of the following conditions exist:

i. The wetland has significant differences in characteristics that affect its habitat functions, such as a wetland with a forested component adjacent to a degraded emergent component or a “dual-rated” wetland with a Category I area adjacent to a lower rated area.

ii. The buffer is increased adjacent to the higher-functioning area of habitat or more sensitive portion of the wetland and decreased adjacent to the lower-functioning or less sensitive portion.

iii. The total area of the buffer after averaging is equal to the area required without averaging.

iv. The buffer at its narrowest point is never less than three-quarters of the required width.

b. Averaging may be permitted when all of the following are met:

i. There are no feasible alternatives to the site design that could be accomplished without buffer averaging.

ii. The averaged buffer will not result in degradation of the wetland’s functions and values as demonstrated by a report from a qualified wetland expert.

iii. The total buffer area after averaging is equal to the area required without averaging.

iv. The buffer at its narrowest point is never less than three-quarters of the required width.

6. Wetland Buffer Maintenance. Except as otherwise specified, wetland buffer areas shall be retained in their natural condition. Where buffer disturbances have occurred before or during construction, revegetation with native vegetation shall be required.

C. Wetland Mitigation Plan. When mitigation is required, the applicant shall submit a mitigation plan which shall include:

1. A written report identifying environmental goals and objectives of the compensation proposed, including:

a. A description of the anticipated impacts to the critical areas and the mitigating actions proposed, including the site selection criteria; mitigation goals and objectives, in relation to the functions and values of the impacted critical area; and dates for beginning and completion of mitigation activities;

b. A review of the best available science supporting the proposed mitigation and a description of the report author’s experience to date in restoring or creating the type of critical area proposed; and

c. An analysis of the likelihood of success of the compensation project.

2. Measurable specific criteria for evaluating whether or not the goals and objectives of the mitigation project have been successfully attained and whether or not the requirements of critical area regulations in this chapter have been met.

3. Details of the mitigation shall include:

a. The proposed construction method, sequence, timing, and duration;

b. Grading and excavation details;

c. Erosion and sediment control features;

d. A planting plan specifying plant species, quantities, locations, size, spacing, and density; and

e. Measures to protect and maintain plants until established.

These written specifications shall be accompanied by detailed site diagrams, scaled cross-sectional drawings, topographic maps showing slope percentage and final grade elevations, and any other drawings appropriate to show construction techniques or anticipated final outcome.

4. A program for monitoring construction of the mitigation project and for assessing the completed project against its goals and objectives.

5. Identification of potential courses of action, and any corrective measures to be taken if monitoring or evaluation indicates project performance standards are not being met.

6. All reasonable efforts to avoid and minimize impacts to critical areas shall be evaluated. When an alteration to a critical area is proposed, such alteration shall be avoided, minimized, or compensated for in the following sequential order of preference:

a. Avoiding the impact altogether by not taking a certain action or parts of an action;

b. Minimizing impacts by limiting the degree or magnitude of the action and its implementation, by using appropriate technology, or by taking affirmative steps, such as project redesign, relocation, or timing, to avoid or reduce impacts;

c. Rectifying the impact to wetlands, critical aquifer recharge areas, frequently flooded areas, and habitat conservation areas by repairing, rehabilitating, or restoring the affected environment to the historical conditions or the conditions existing at the time of the initiation of the project;

d. Minimizing or eliminating a hazard by restoring or stabilizing the hazard area through engineered or other methods;

e. Reducing or eliminating the impact or hazard over time by preservation and maintenance operations during the life of the action;

f. Compensating for the impact to wetlands, critical aquifer recharge areas, frequently flooded areas, and habitat conservation areas by replacing, enhancing, or providing substitute resources or environments; and

g. Monitoring the hazard or other required mitigation and taking remedial action when necessary.

7. If compensatory mitigation is proposed, the mitigation plan shall also include the following:

a. A baseline study that analyzes the existing functions of the wetland and wetland buffer, functions that will be lost, and functions after mitigation;

b. Description of how lost functions will be replaced;

c. Description of when mitigation will occur relative to project construction;

d. Provisions for adequate monitoring to ensure success of the mitigation plan. The monitoring plan shall outline the approach for monitoring construction and assessment of the completed project, and shall include a monitoring schedule. A monitoring report shall be submitted to the City annually for a period of at least five years and shall document successes, problems and contingency actions of the mitigation project. Monitoring activities may include, but are not limited to:

i. Establishing vegetation monitoring plots to track changes in plant species composition and density over time;

ii. Measuring base flow rates and stormwater runoff to model and evaluate hydrologic predictions;

iii. Sampling fish and wildlife populations to determine habitat utilization, species abundance and diversity; and

iv. Sampling surface and subsurface waters to determine pollutant loading, and changes from the natural variability of background conditions;

e. A contingency plan specifying what corrective actions will be taken should the mitigation not be successful.

8. Wetland Mitigation Banks. Credits from a wetland mitigation bank may be approved for use as compensation for unavoidable impacts to wetlands when:

a. The bank is certified under state law;

b. The wetland mitigation bank provides compensation for the authorized impacts; and

c. The proposed use of credits is consistent with the terms and conditions of the bank’s certification.

Replacement ratios for projects using bank credits shall be consistent with replacement ratios specified in the bank’s certification.

D. Wetland Mitigation and Restoration. Any wetland lost or degraded as a result of human activity shall require an approved wetland mitigation plan, prepared by a qualified ecologist and approved by the Washington Department of Ecology, including one or more of the following measures:

1. Wetland acreage replacement and mitigation requirements based on the number of units impacted require replacement/mitigation according to the following table:

Table 21.40-7 – Wetland Replacement and Mitigation Ratios

Impacted Wetland	Replacement	Re‑establishment/Creation (R/C)	Rehabilitation Only	Combined R/C and Rehabilitation	Combined R/C and Enhancement	Enhancement Only
Category I	1:6	1:12	1:8*	1:1 R/C and 1:6 RH*	1:1 R/C and 1:12* E	1:16*
Category II	1:3	1:3	1:6	1:1 R/C and 1:4 RH	1:1 R/C and 1:8 E	1:12
Category III	1:2	1:2	1:4	1:1 R/C and 1:2 RH	1:1 R/C and 1:4 E	1:8
Category IV	1:1.5	1:5	1:3	1:1 R/C and 1:1 RH	1:1 R/C and 1:2 E	1:6
* Based on score for function ----- R/C = Re-establishment/Creation

2. Wetland mitigation¹ may be permitted off-site if:

a. The hydrology and ecosystem of the original wetland and those who benefit from the hydrology and ecosystem will not be substantially damaged by the loss within that primary drainage basin; and

b. On-site mitigation is not scientifically feasible due to problems with hydrology, soils, or other factors such as other potentially adverse impacts from surrounding land uses; or

c. Existing functions off-site are significantly greater than lost wetland functional values; or

d. Established goals for flood storage, flood conveyance, habitat or other wetland functions have been established and strongly justify off-site location of mitigation measures.

E. Permits Required. A permit shall be required for all development which affects wetlands or wetland buffers. The permit shall specify:

1. The timing and conditions of mitigation, restoration or enhancement;

2. Requirements for title notice, conservation easements or plat dedication;

3. Access limitations and fencing, if required;

4. Temporary and permanent signage; and

5. Requirements for staking of wetland and buffers prior to development; and

6. The application shall be accompanied by a report prepared by a certified biologist specifying the classification, scoring and justification for the selection of method and proposed replacement/creation, rehabilitation, and mitigation proposed. A copy of the report shall be filed with the Washington Department of Ecology. (Ord. 07-015 § 4, 2007).

21.40.030 Fish and wildlife habitat conservation areas.

A. Priority Habitats. Priority habitats within Spokane Valley are illustrated in the Comprehensive Plan, as it may be amended from time to time, and include wetlands, riparian, urban open space, and the habitat of native species, as defined in Appendix A. The status of individual species is included in the Washington Department of Fish and Wildlife Management Recommendations for Priority Species and in Chapter 232-12 WAC. Where differences in regulations exist as a result of overlapping priority habitat, the regulation providing the highest degree of protection shall apply.

B. Wetlands are located on hydric soils, support hydrophytic vegetation and are saturated with water during some portion of the growing season.

C. Riparian fish and wildlife management zones are established pursuant to the classification of streams, lakes and other water bodies by the Washington Department of Natural Resources as follows:

1. “Type S water” means all waters, within their bankable width, as inventoried as “shorelines of the state” under Chapter 90.58 RCW and the rules promulgated pursuant to Chapter 90.58 RCW including periodically inundated areas of their associated wetlands.

2. “Type F water” means segments of natural waters other than Type S waters, which are within the bankfull widths of defined channels and periodically inundated areas of their associated wetlands, or within lakes, ponds, or impoundments having a surface area of one-half acre or greater at seasonal low water and which in any case contain fish habitat or are described by one of the following four categories:

a. Waters, which are diverted for domestic use by more than 10 residential or camping units or by a public accommodation facility licensed to serve more than 10 persons, where such diversion is determined by the department to be a valid appropriation of water and the only practical water source for such users. Such waters shall be considered to be Type F water upstream from the point of such diversion for 1,500 feet or until the drainage area is reduced by 50 percent, whichever is less;

b. Waters, which are diverted for use by federal, state, tribal or private fish hatcheries. Such waters shall be considered Type F water upstream from the point of diversion for 1,500 feet, including tributaries if highly significant for protection of downstream water quality. The department may allow additional harvest beyond the requirements of Type F water designation provided the department determines after a landowner-requested on-site assessment by the Department of Fish and Wildlife, Department of Ecology, the affected tribes and interested parties that:

i. The management practices proposed by the landowner will adequately protect water quality for the fish hatchery; and

ii. Such additional harvest meets the requirements of the water type designation that would apply in the absence of the hatchery;

c. Waters, which are within a federal, state, local, or private campground having more than 10 camping units; provided, that the water shall not be considered to enter a campground until it reaches the boundary of the park lands available for public use and comes within 100 feet of a camping unit, trail or other park improvement;

d. Riverine ponds, wall-based channels, and other channel features that are used by fish for off-channel habitat. These areas are critical to the maintenance of optimum survival of fish. This habitat shall be identified based on the following criteria:

i. The site must be connected to a fish habitat stream and accessible during some period of the year; and

ii. The off-channel water must be accessible to fish.

3. “Type Np water” means all segments of natural waters within the bankfull width of defined channels that are perennial non-fish habitat streams. Perennial streams are waters that do not go dry any time of a year of normal rainfall. However, for the purpose of water typing, Type Np waters include the intermittent dry portions of the perennial channel below the uppermost point of perennial flow. If the uppermost point of perennial flow cannot be identified with simple, nontechnical observations then Type Np waters begin at a point along the channel where the contributing basin area is at least 300 acres.

4. “Type Ns water” means all segments of natural waters within the bankfull width of the defined channels that are not Type S, F, or Np waters. These are seasonal, non-fish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np water. Type Ns waters must be physically connected by an above-ground channel system to Type S, F, or Np waters.

D. Riparian management zones (RMZs) include three zones (measured horizontally in feet from the outer edge of the bankfull width or channel migration zone, whichever is greater) established in the following Tables 21.40-9 and 21.40-10 and zone regulations. Outer zone requirements for S and F stream types are based on DNR Eastern Washington 100-year site index range summarized as follows in Table 21.40-8:

Table 21.40-8 – Outer Zone Requirements for Stream Types

Site Class	100-Year Site Index Range
I	120 +
II	101 – 120
III	81 – 100
IV	61 – 80
V	=< 60

Table 21.40-9 – Riparian Management Zones for Streams Less Than 15 Feet in Width, Bankfull

Site Class1	Core Zone	Inner Zone	Outer Zone	Other	Total Width
	Type S – Shorelines of the state
I	30'	45'	55'	n/a	130'
II	30'	45'	35'	n/a	110'
III	30'	45'	15'	n/a	90'
IV	30'	45'	0'	n/a	75'
V	30'	45'	0'	n/a	75'
	Type F – Natural waters not classified as shorelines of the state with fish
I	30'	45'	55'	n/a	130'
II	30'	45'	35'	n/a	110'
III	30'	45'	15'	n/a	90'
IV	30'	45'	0'	n/a	75'
V	30'	45'	0'	n/a	75'
All	Type Np – Non-fish, perennial			50'	50'
All	Type Ns – Non-fish, seasonal			30'2	30'
1 Washington State Department of Natural Resources State Soil Survey 2 Equipment limitation zone

Table 21.40-10 – Riparian Management Zones for Streams Greater Than 15 feet in Width, Bankfull

Site Class	Core Zone	Inner Zone	Outer Zone	Other	Total Width
	Type S – Shorelines of the state
I	30'	70'	30'	n/a	130'
II	30'	70'	10'	n/a	110'
III	30'	70'	0'	n/a	90'
IV	30'	70'	0'	n/a	75'
V	30'	70'	0'	n/a	75'
	Type F – Natural waters not classified as shorelines of the state with fish
I	30'	70'	30'	n/a	130'
II	30'	70'	10'	n/a	110'
III	30'	70'	0'	n/a	100'
IV	30'	70'	0'	n/a	100'
V	30'	70'	0'	n/a	100'
All	Type Np – Non-fish, perennial			50'	50'
All	Type Ns – Non-fish, seasonal			30'1	30'
1 Equipment limitation zone

If there is more than one site class adjacent to the stream within a proposed RMZ, the landowner has the option of using the highest site class (i.e., most protective) or segmenting out the site classes and managing them separately.

1. Core Zones. The core zone extends 30 feet measured horizontally from the edge of the bankfull width or outer edge of the CMZ, whichever is greater, for all timber habitat types. No harvest or construction is allowed in the core zone except as otherwise provided in WAC 222-30-020. Any trees cut for or damaged by yarding corridors must be left on site. Any trees cut as a result of road construction to cross a stream may be removed from the site unless used as part of a large woody debris replacement strategy.

2. Inner Zones. Width and leaf tree requirements of the inner zone vary by timber habitat type specified in WAC 222-30-020.

3. Outer Zones. This zone has three categories based on timber habitat type: Ponderosa pine, mixed conifer and high elevation. The width of this zone is zero to 55 feet measured horizontally from the outer edge of the inner zone depending on the site class and stream width.

E. The shade requirements in WAC 222-30-040 must be met regardless of harvest opportunities provided in the inner zone RMZ rules.

F. An equipment limitation zone is a 30-foot wide zone measured horizontally from the outer edge of bankfull width of a Type Np or Ns water where equipment is limited. It applies to all perennial and seasonal streams. On-site mitigation shall be required where ground-based equipment, skid trails or stream crossings other than existing roads exposes the soil more than 10 percent of the surface area of the zone. Mitigation must be designed to replace the equivalent of lost functions, especially prevention of sediment delivery. Examples include water bars, grass seeding, mulching, etc.

G. Except as otherwise required to reduce flooding, riparian management zones (RMZ) shall be retained or maintained in accordance with Chapter 222-30 WAC.

H. None of the limitations on harvest in each of the three zones listed below will preclude or limit the construction and maintenance of roads for the purpose of crossing streams in accordance with WAC 222-24-030 and 222-24-050 or the creation and use of yarding corridors in accordance with WAC 222-30-060(1). Roads within riparian buffer areas shall be kept to a minimum and shall not run parallel to the water body. Crossings, where necessary, shall cross riparian areas at as near right angles as possible. If no alternative exists to placement of a roadway within a riparian area, mitigation may be required. Mitigation measures shall be specified in a management plan and may include, but are not limited to:

1. Fencing of riparian buffer area to protect remaining vegetation; and

2. Enhancement of remaining riparian buffer area through planting of native vegetation.

3. Water crossings must be approved by the Washington State Department of Fish and Wildlife (WAC 75-20-100).

I. Proposed equestrian pedestrian/bike trails shall demonstrate though “best available science” that the location and width of the trail minimizes any adverse impacts on habitat, and that measures to reduce effects during construction are implemented.

J. Off-road motorized vehicle use in riparian buffers areas is prohibited.

K. All development proposals shall follow the bald eagle protection rules (RCW 77.12.655 and WAC 232-12-292), as now or hereafter amended, when the proposal is likely to have a direct impact on the habitat of the bald eagle. (Ord. 07-015 § 4, 2007).

21.40.040 Adjustment of habitat buffer areas.

A. Habitat buffer areas may be reduced by the director up to a maximum of 10 percent if a riparian buffer area is enhanced using native plants including trees and shrubs according to a plan prepared in consultation with the Spokane County Soil Conservation District and the Washington State Department of Fish and Wildlife.

B. Habitat buffer areas may be modified by the director if averaging will provide the necessary biological, chemical and physical support necessary to protect the fish and wildlife.

1. The riparian area contains variations in sensitivity due to existing physical characteristics which justify the averaging; or

2. The land uses causing the least disturbance would be located adjacent to areas where the buffer width is reduced and that such land uses are guaranteed in perpetuity by covenant, deed restriction, easement or other legally binding mechanism; and

3. The total area contained within the buffer after averaging is no less than that contained within the standard buffer prior to averaging.

C. Habitat buffer areas may be increased by the director up to a maximum of 25 percent if:

1. The land adjacent to the water is susceptible to severe erosion and other erosion control measures will not prevent adverse impacts.

2. The land adjacent to the water has minimal vegetative cover or slopes greater than 30 percent.

D. This provision does not diminish the 200-foot shoreline jurisdiction applicable to shorelines of the state.

E. Habitat Management Plan Required. A habitat management plan shall be certified by a qualified biologist, reviewed by the Washington State Department of Fish and Wildlife and approved in writing by the director. The plan shall include:

1. A description of the nature, density and intensity of the proposed use or activity in sufficient detail to allow analysis of such land use change upon identified wildlife habitat.

2. An analysis of the effect of the proposed use or activity upon fish and wildlife species and their habitats, identified within the priority habitat and species program.

3. A plan which explains how the applicant will avoid, minimize or mitigate adverse impacts to fish and/or wildlife habitats created by the proposed use or activity.

4. Habitat management recommendations, including potential uses and restrictions of the habitat areas, seasonally sensitive areas and other guidelines necessary for the protection of the species.

5. Proposed provisions for ensuring continued protection of habitat and habitat buffer areas.

6. Conditions established by an approved habitat management plan shall be included as a condition of approval for a permit. (Ord. 07-015 § 4, 2007).

21.40.050 Geologically hazardous areas.

A. Geologically hazardous areas include both erosion and landslide hazard areas where one or more of the following exist:

1. A slope of 30 percent or greater;

2. Soils identified by the Natural Resource Conservation Service as having a severe potential for erosion;

3. Hydraulic factors such as existing on-site surface and groundwater or changes in hydraulic factors, caused by proposals that create a severe potential for erosion or landslide hazard;

4. Areas that historically have been prone to landslide, areas adjacent to lakes, streams, springs, or any one of the following geologic formations: alluvium, landslide deposit, or Latah formation;

5. Areas of uncompacted fill;

6. Areas that are unstable as a result of rapid stream or stream bank erosion.

B. Geo-Hazard Evaluation and Mitigation Plan Required.

1. A geo-hazard mitigation plan, prepared by a qualified geo-technical engineer, shall be prepared for building permits, road construction, utilities and storm drainage facility installations within a geo-hazard area and shall be submitted with any application for preliminary plats, short plats, planned development projects, binding site plans, zone reclassifications, conditional use permits, variances, manufactured home park site plans or top soil removal permits located in geologic hazard areas.

2. The geo-hazard evaluation shall document the extent and nature of the geo-hazard on the subject property and shall provide mitigating measures and an assessment of geo-hazards associated with the proposal.

3. A geo-hazard mitigation plan may be required at the time of building permit application or actual construction approvals. (Ord. 07-015 § 4, 2007).

21.40.060 Critical aquifer recharge areas.

A. Classification of Aquifer Susceptibility. Critical aquifer recharge areas have prevailing geologic conditions associated with infiltration rates that create a high potential for contamination of ground water resources or contribute significantly to the replenishment of ground water.

1. Aquifer recharge areas are rated as having a high, moderate, or low susceptibility based on a scientific analysis of soils, hydraulic conductivity (the ease with which water moves between the surface and aquifers), annual rainfall, the depth to aquifers, the importance of the material between soils and aquifers (vadose zone), and wellhead protection information. The aquifer susceptibility map identifies these areas within Spokane Valley.

2. Designated wellhead protection areas and areas within a 1,000-foot radius of wells without reported plans are additionally treated as high-susceptibility areas. As wellhead protection plans are completed for wells, the 1,000-foot radius placeholder will be replaced by the Washington State Department of Health certified wellhead protection area.

3. Regulated Uses. The following uses and activities are regulated as set forth in the following table:

Table 21.40-11 – Uses and Activities Regulated in Critical Aquifer Recharge Areas

	Susceptibility Rating High	Susceptibility Rating Medium	Susceptibility Rating Low
Bio-solids land application		♣	♣
Critical material storage, handling, generating or use	⊗♦	⊗♦	⊗♦ *
Dairy	♣*	♣	♣
Feed lot		♣	♣
Feed mill	♦	♦	•
Floriculture/horticulture	♣	♣	•
Grazing/cultivation	♣	♣	•
Greenhouse/nursery – commercial	♣	♣	•
Large animal raising and/or keeping	♣	♣	•
Orchard/tree farm	♣	♣	•
Poultry raising, commercial		♣	♣
Truck gardening/vineyard	♣	♣	•
• = Permitted without review    _ = Not permitted    * = Hydro-geologic study required
♣ = Agricultural practices not accessory to a residential use that impact critical aquifer recharge areas shall be mitigated by having a conservation plan prepared and the subject property shall be required to comply with approved land management and/or conservation practices that protect groundwater, as set forth in the United States Department of Agriculture Natural Resource Conservation Service (NRCS) Technical Guides, and all local, state and federal regulations and their amendments governing agricultural practices.
♦ Critical materials storage, handling, generating or use requires: 1. All facilities related to the use of critical materials shall be designed so that: a. Any spilled or leaked critical materials are contained on site; b. Any spilled or leaked critical materials cannot infiltrate into the ground; and c. No disposal of any waste containing critical materials shall be allowed on site. 2. Stormwater facilities shall be designed so that: a. Mingling of stormwater and spilled critical materials is prevented; and b. Spill cleanup procedures are enhanced. 3. Surface or subsurface disposal of a critical material is prohibited.
⊗Public sewer services consistent with concurrency requirements set forth in the Spokane County Comprehensive Plan and the Spokane County Zoning Code, or as amended, are required for all new residential and nonresidential uses.

B. If a parcel lies within two or more susceptibility rating designations, the higher susceptibility rating designation shall apply to the whole parcel.

C. When there are low susceptibility areas hydrologically connected to medium and high- susceptibility areas, the regulations for medium or high susceptibility areas apply.

D. Development shall provide for the treatment of stormwater runoff from impervious surfaces in a manner consistent with Spokane Valley requirements and the Stormwater Management Manual for Eastern Washington.

E. Use, Handling and Storage of Critical Materials.

1. Critical materials, including hazardous material and hazardous wastes, are identified in Appendix 21-G.

Appendix 21-G
 

Hazardous Waste ID Number	CAS #	Substance Name	Critical Concentration µg / L	Critical Quantity kg	DOE Designation	EPA Hazard	Class	Reference
U091	119-90-4	(1,1'-biphenyl)-4-'-diamine,3,3'-dimethoxy-	563	182	DW	D,+	8	V
U236	72-57-1	[(3,3'-dimethyl)-(1,1'-biphenyl)-4,4' diyl)]-bis (azo) bis (5-amino-4-hydroxy)-,tetrasodium salt	3.1	1.00	EHW	H,+	5,8	V
P039	298-04-4	0,0-diethyl S-[2-(ethylthio)ethyl] phosphorodithioate	3.1	1.00	EHW	A	2	V
U087	3288-58-2	0,0-diethyl S-methyl-dithiophosphate	3.1	1.00	EHW	B	2	V
P040	297-97-2	0,0-diethyl-0-pyrazinyl phosphorothioate	3.1	1.00	EHW	A	2	V
P071	298-00-0	0,0-dimethyl 0-nitrophenyl phosphorothioate	3.1	1.00	EHW	A	2	V
P045	39196-18-4	0,0-dimethyl-1-(methylthio)-2-butanone,0-[(methylamino)carbonyl] oxime	3.1	1.00	EHW	B	2	V
P026	5344-82-1	1-(o-chlorophenyl)thiourea	3.1	1.00	EHW	A,H	4	V
U208	630-20-6	1,1,1,2-tetrachloroethane	3.1	1.00	EHW	H	3	V
U226	71-55-6	1,1,1-trichloroethane	1,100	355	EHW	C,H	3	IV
U209	79-34-5	1,1,2,2-tetrachloroethane	1.7	0.549	EHW	H	3	IV
U128	87-68-3	1,1',2,3,4,4' hexachloro-1,3-butadiene	4.47	1.4	EHW	C,H	4	IIa
U227	79-00-5	1,1,2-trichloroethane	6	1.94	EHW	C,H	3	IV
U137	193-39-5	1,10-(1,2-phenylene)pyrene	563	182	DW	+	5	V
U078	75-35-4	1,1-dichloroethane	3.1	1.00	EHW	C,H,+	3	V
U098	57-14-7	1,1-dimethylhydrazine	563	182	DW	I,+	9	V
P060	465-73-6	1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8 endo, endo-dimethanophthalene	3.1	1.00	EHW	B,H	2	V
P004	309-00-2	1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8 endo, exo-dimethanophthalene	3.1	1.00	EHW	B,H	2	V
P051	72-20-8	1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-endo, endo, 1,4,5,8-dimethanophthalene	3.1	1.00	EHW	X,H	2	V
P037	60-57-1	1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-endo, exo, 1,4,5,8-dimethanophthalene	0.00071	0.001	EHW	X,H,+	2	IIa
P081	55-63-0	1,2,3-propanetrio, trinitrate-	3.1	1.00	EHW	R,?	9	V
U207	95-94-3	1,2,4,5-tetrachlorobenzene	3.1	1.00	EHW	D,H	4	V
O003	120-82-1	1,2,4-trichlorobenzene	0.0072	0.002				IIa
U085	1464-53-5	1,2:3,4-diepoxybutane	3.1	1.00	EHW	B,I	13	V
U063	53-70-3	1,2:5,6-dibenzanthracene	0.028	0.01	EHW	P,+	5	IIa
U064	189-55-9	1,2:7,8-dibenzopyrene	0.028	0.01	EHW	P,+	5	IIa
U018	56-55-3	1,2-Benzanthracene	0.028	0.009	EHW	P,+	5	IIa
U094	57-97-6	1,2-Benzanthracene, 7,12-dimethyl-	0.028	0.009	EHW	C,P	5	IIa
U028	117-81-7	1,2-benzenedicarboxylic acid [bis(2-ethyl-hexyl)] ester	563	182	DW	?	4	V
U190	85-44-9	1,2-benzenedicarboxylic acid anhydride	3.1	1.0	EHW	C	4	V
U069	84-74-2	1,2-benzenedicarboxylic acid, dibutyl ester	563	182	DW	D	4	V
U088	84-66-2	1,2-benzenedicarboxylic acid, diethyl ester	563	182	DW	?	4,12	V
U102	131-11-3	1,2-benzenedicarboxylic acid, dimethyl ester	563	182	DW	?	4,12	V
U107	117-84-0	1,2-benzenedicarboxylic acid, di-n-octyl ester	563	182	DW	?	4,12	V
P042	51-43-4	1,2-benzenediol, 4-[1-hydroxy-2-(methylamino)ethyl]-	3.1	1.0	EHW	B	4,9	V
U202	81-07-2	1,2-benzisothiazolin-3-one, 1,1-dioxide and salts	563	182	DW	+		V
U050	218-01-9	1,2-benzphenanthrene	0.028	0.009	EHW	P,+	5	IIa
U066	96-12-8	1,2-dibromo-3-chloropropane	0.05	0.02	EHW	C,H,+	3	IV
U079	156-60-5	1,2-dichloroethane	7	2.26	EHW	D,H	3	IV
U083	78-87-5	1,2-dichloropropane	1.4	0.45	EHW	C,H,I	3	IV
U148	123-33-1	1,2-dihydro-3,6-pyridizinedione	563	182	DW	D	4,9	V
U099	540-73-8	1,2-dimethylhydrazine	3.1	1.00	EHW	C,+,I	9	V
U109	122-66-7	1,2-diphenylhydrazine	0.422	0.14	EHW	C	4,9	11a
U114	111-54-6	1,2-ethanediylbiscarbomothioic acid	3.1	1.00	EHW	B		V
U139	9004-66-4	1,2-oxathiolane, 2,2-dioxide	563	182	DW	+	13	V
P067	75-55-8	1,2-propylenimine	3.1	1.00	EHW	B,+,I	9	V
U182	123-63-7	1,3,5-trioxane, 2,4,5-trimethyl-	563	182	DW	D,I	12	V
U201	108-46-3	1,3-benzendiol	3.1	1.0	EHW	H	4	V
U130	77-47-4	1,3-cyclopentadiene, 1,2,3,4,5,5-hexachloro-	3.1	1.00	EHW	X,H	3	V
U071	541-73-1	1,3-dichlorobenzene	20	6.46	EHW	B,H	4	IV
U186	504-60-9	1,3-pentadiene	563	182	DW	D,I	10	V
U193	1120-71-4	1,3-propane sultone	563	182	DW	+	11	V
U197	106-51-4	1,4-cyclohexadienedione	3.1	1.00	EHW	C	11	V
U074	764-41-0	1,4-dichloro-2-Butene	3.1	1.0	EHW	C,H,I	3	V
U074	764-41-0	1,4-dichloro-2-butene	3.1	1.00	EHW	C,H,I	3	V