(Ord. 48-93; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
(Ord. 48-93; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
The following activities which occur within a wetland and its associated buffer, or outside a wetland or buffer, but affecting the wetland or buffer, shall be regulated pursuant to the standards of this chapter:
A.
Removing, excavating, disturbing or dredging soil, sand, gravel, minerals, organic matter or materials of any kind;
B.
Dumping, discharging or filling with any material;
C.
Draining, flooding or disturbing the water level or water table;
D.
Driving, piling or placing obstructions;
E.
Constructing, reconstructing, demolishing or altering any structure or infrastructure if the activity results in greater impervious surface coverage;
F.
Destroying or altering vegetation including through clearing, harvesting, intentional burning, shading or planting vegetation that would alter the character of wetland;
H.
Alteration of natural drainage patterns or any activity that results in a discharge of stormwater runoff into a wetland; and
I.
Any other activities affecting a wetland or wetland buffer not otherwise exempt from the provisions of this section.
(Ord. 48-93; Ord. 23-01; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
B.
Wetlands. The following wetlands are exempt from the buffer provisions contained in this chapter and may be filled if impacts are fully mitigated based on provisions in RMC § 22.10.120, Wetland alteration and mitigation. In order to verify the following conditions, a critical area report for wetlands must be submitted.
1.
All isolated Category III and IV wetlands less than 1,000 square feet that:
a.
Are not associated with riparian areas or buffer.
b.
Are not part of a wetland mosaic.
c.
Do not contain habitat identified as essential for local populations of priority species identified by Washington Department of Fish and Wildlife or species of local importance.
d.
Are not a vernal pool.
e.
Are not an alkali wetland.
f.
Do not contain aspen stands.
C.
Activities Allowed in Wetlands. The activities listed below are allowed in wetlands. These activities do not require submission of a critical area report, except where such activities result in a loss of the functions and values of a wetland or wetland buffer. These activities include:
1.
Conservation or preservation of soil, water, vegetation, fish, shellfish, and/or other wildlife that does not entail changing the structure or functions of the existing wetland.
2.
The harvesting of wild crops in a manner that is not injurious to natural reproduction of such crops and provided the harvesting does not require tilling of soil, planting of crops, chemical applications, or alteration of the wetland by changing existing topography, water conditions, or water sources.
3.
Agricultural activities that are existing and ongoing; provided, that they implement applicable best management practices (BMPs) contained in the latest editions of the USDA Natural Resources Conservation Service's Field Office Technical Guide; or develop a farm conservation plan in coordination with the local conservation district. BMPs and/or farm plans should address potential impacts to wetlands from livestock, nutrient and farm chemicals, soil erosion and sediment control and agricultural drainage infrastructure. BMPs and/or farm plans should ensure that ongoing agricultural activities minimize their effects on water quality, riparian ecology, salmonid populations and wildlife habitat.
4.
Drilling for utilities/utility corridors under a wetland, with entrance/exit portals located completely outside of the wetland buffer; provided, that the drilling does not interrupt the ground water connection to the wetland or percolation of surface water down through the soil column. Specific studies by a hydrologist are necessary to determine whether the ground water connection to the wetland or percolation of surface water down through the soil column will be disturbed.
5.
Enhancement of a wetland through the removal of nonnative invasive plant species. Removal of invasive plant species shall be restricted to hand removal unless permits from the appropriate regulatory agencies have been obtained for approved biological or chemical treatments. All removed plant material shall be taken away from the site and appropriately disposed of. Plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species. Revegetation with appropriate native species at natural densities shall occur in conjunction with removal of invasive plant species.
6.
Educational and scientific research activities.
7.
Normal and routine maintenance and repair of any existing public or private facilities within an existing right-of-way; provided, that the maintenance or repair does not expand the footprint or use of the facility or right-of-way.
D.
Notwithstanding the exemptions provided by this chapter, any otherwise exempt activities occurring in or near wetlands shall comply with the intent of these standards and shall consider on-site alternatives that achieve no net loss of ecological wetland functions.
(Ord. 48-93; Ord. 45-00; Ord. 23-01; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
The approximate location and extent of wetlands within the city of Richland's planning area are shown on the critical areas maps adopted as part of this section. These maps shall be used only as a general guide for the assistance of property owners and the public, as the boundaries are generalized. The actual type, extent and boundaries of wetlands shall be determined in the field by a qualified professional according to the procedures, definitions and criteria established by this chapter. In the event of any conflict between the wetland location or designation shown on the city of Richland's maps and the criteria or standards of this chapter, the results of applying the criteria and standards during the field investigation shall control.
Additional guidance may be obtained from a Department of Ecology publication "Focus on Irrigation Influenced Wetlands, Publication No. 10-06-015."
(Ord. 48-93; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
Wetlands shall be designated Category I, Category II, Category III, or Category IV according to the following:
As set forth in the Washington State Department of Ecology's Wetland Rating System for Eastern Washington, Publication No. 14-06-030, as may be amended in the future (hereinafter referred to as the Ecology Wetlands Rating System).
(Ord. 48-93; Ord. 45-00; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
A.
The establishment of wetland buffer areas shall be required for all development proposals and activities adjacent to wetlands to protect the integrity, function and value of the wetland. Buffers shall consist of an undisturbed area of vegetation established to protect the functions and values of the wetland. The standard buffer widths assume that the buffer is vegetated with a native plant community appropriate for the ecoregion. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer should either be planted to create the appropriate plant community or the buffer should be widened to ensure that adequate functions of the buffer are provided. Buffers shall be determined in conjunction with considerations of wetland type and quality, approved wetland alterations, and required mitigation measures. Buffers are not intended to be established or to function independently of the wetland they are established to protect; the establishment of a buffer shall not operate to prevent a use or activity that would otherwise be permitted in the wetland subject to mitigation.
B.
Buffers shall be measured from the wetland edge as delineated using the 1987 Army Corps of Engineers Wetlands Delineation Manual and the Arid West Regional Supplement, as may be amended. Buffers shall be marked in the field. Required buffer widths shall be determined according to the proposed land use (Table 22.10.110(C) below) and the wetland category in Table 22.10.110(D).
C.
The following table describes the types of land use:
Table 22.10.110(C) – Types of Land Uses | |
|---|---|
Level of Impact from Proposed Change in Land Use | Types of Land Use Based on Common Zoning Designations |
High | • Commercial • Urban • Industrial • Institutional • Retail sales • Residential (more than 1 unit/acre) • High-intensity recreation (golf courses, ball fields, etc.) • Conversion to high-intensity agriculture (dairies, nurseries, greenhouses, growing and harvesting crops requiring annual tilling and raising and maintaining animals, etc.) • Hobby farms |
Moderate | • Residential (1 unit/acre or less) • Moderate-intensity open space (parks with biking, jogging, etc.) • Paved driveways and gravel driveways serving 3 or more residences • Paved trails • Conversion to moderate-intensity agriculture (orchards, hay fields, etc.) • Utility corridor or right-of-way shared by several utilities and including access/maintenance road |
Low | • Low-intensity open space (hiking, bird-watching, preservation of natural resources, etc.) • Timber management (cutting of trees only) • Gravel driveways serving 2 or fewer residences • Unpaved trails • Utility corridor without a maintenance road and little or no vegetation management |
D.
The following buffer widths are established:
Table 22.10.110(D) – Buffer Widths | ||
|---|---|---|
Wetland Characteristics | Buffer Width by Impact of Proposed Land Use | Other Measures Recommended for Protection |
Category IV Wetlands (For wetlands scoring less than 16 points for all functions) | ||
Score for all 3 basic functions is less than 16 points | Low – 25 ft. Moderate – 40 ft. High – 50 ft. | None |
Category III Wetlands (For wetlands scoring 16 – 18 points for all functions) | ||
Moderate level of function for habitat (score for habitat 5 – 7 points) | Low – 75 ft. Moderate – 110 ft. High – 150 ft. | None |
Score for habitat 3 – 4 points | Low – 40 ft. Moderate – 60 ft. High – 80 ft. | None |
Category II Wetlands (For wetlands that score 19 – 21 points or more for all functions or having the "special characteristics" identified in the rating system) | ||
High level of function for habitat (score for habitat 8 – 9 points) | Low – 100 ft. Moderate – 150 ft. High – 200 ft. | Maintain connections to other habitat areas |
Moderate level of function for habitat (score for habitat 5 – 7 points) | Low – 75 ft. Moderate – 110 ft. High – 150 ft. | None |
High level of function for water quality improvement and low for habitat (score for water quality 8 – 9 points; habitat less than 5 points) | Low – 50 ft. Moderate – 75 ft. High – 100 ft. | No additional surface discharges of untreated runoff |
Vernal pool | 200 ft. | None |
Riparian forest | Low – 75 ft. Moderate – 110 ft. High – 150 ft. | Riparian forest wetlands need to be protected at a watershed or subbasin scale Other protection based on needs to protect habitat and/or water quality functions |
Not meeting above characteristic | Low – 50 ft. Moderate – 75 ft. High – 100 ft. | None |
Category I Wetlands (For wetlands that score 22 points or more for all functions or having the "special characteristics" identified in the rating system) | ||
Wetlands of high conservation value | Low – 125 ft. Moderate – 190 ft. High – 250 ft. | No additional surface discharges to wetland or its tributaries No septic systems within 300 ft. of wetland Restore degraded parts of buffer |
High level of function for habitat (score for habitat 8 – 9 points) | Low – 100 ft. Moderate – 150 ft. High – 200 ft. | Restore degraded parts of buffer Maintain connections to other habitat areas |
Moderate level of function for habitat (score for habitat 5 – 7 points) | Low – 75 ft. Moderate – 110 ft. High – 150 ft. | None |
High level of function for water quality improvement (8 – 9 points) and low for habitat (less than 5 points) | Low – 50 ft. Moderate – 75 ft. High – 100 ft. | No additional surface discharges of untreated runoff |
Not meeting above characteristics | Low – 50 ft. Moderate – 75 ft. High – 100 ft. | None |
(Ord. 48-93; Ord. 45-00; Ord. 28-05 § 1.08; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
A.
Buffer averaging to improve wetland protection may be permitted when all of the following conditions are met:
1.
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.
2.
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 as demonstrated by a critical areas report from a qualified wetland professional.
3.
The total area of the buffer after averaging is equal to the area required without averaging.
4.
The buffer at its narrowest point is never less than either three-quarters of the required width or 75 feet for Categories I and II, 50 feet for Category III, and 25 feet for Category IV, whichever is greater.
B.
Averaging to allow reasonable use may be allowed when all of the following are met:
1.
There are no feasible alternatives to the site design that could be accomplished without buffer averaging.
2.
The averaged buffer will not result in degradation of the wetland's functions and values as demonstrated by a critical areas report from a qualified wetland professional.
3.
The total buffer area after averaging is equal to the area required without averaging.
4.
The buffer at its narrowest point is never less than either three-quarters of the required width or 75 feet for Categories I and II, 50 feet for Category III, and 25 feet for Category IV, whichever is greater.
C.
Reduction in Buffer Width Based on Reducing the Intensity of Impacts from Proposed Land Uses.
1.
The buffer widths recommended for proposed land uses with high-intensity impacts to wetlands can be reduced to those recommended for moderate-intensity impacts under the following conditions:
a.
For wetlands that score moderate or high for habitat (five points or more for the habitat functions), the width of the buffer can be reduced if all three of the following criteria are met:
i.
A relatively undisturbed, vegetated corridor at least 100 feet wide is protected between the wetland and any other priority habitats as defined by the Washington State Department of Fish and Wildlife ("relatively undisturbed" and "vegetated corridor" are defined in the Washington State Wetland Rating System for Eastern Washington – 2014 Update, or latest update). Priority habitats in Eastern Washington include:
ii.
The corridor must be protected for the entire distance between the wetland and the priority habitat by some type of legal protection such as a conservation easement.
iii.
Measures to minimize the impacts of different land uses on wetlands, as applicable in Table 22.10.110(D), are applied.
b.
For wetlands that score fewer than five points for habitat, the buffer width can be reduced to that required for moderate land-use impacts by applying applicable measures to minimize the impacts of the proposed land uses (see examples in Table 22.10.115(D)).
D.
Required Mitigation to Minimize Impacts to Wetlands from Changes in Land Uses with High Impacts.
Table 22.10.115(D) | ||
|---|---|---|
Types of Disturbance | Examples of Activities and Uses That Cause Disturbances | Required Mitigation |
Lights | • Parking lots • Warehouses • Manufacturing • Residential areas | • Direct lights away from wetland |
Noise | • Manufacturing • Residential areas | • Locate activity that generates noise away from wetland • If warranted, enhance existing buffer with native vegetation plantings adjacent to noise source • For activities that generate relatively continuous, potentially disruptive noise, such as certain heavy industry or mining, establish an additional 10-ft. heavily vegetated buffer strip immediately adjacent to the outer wetland buffer |
Toxic runoff* | • Parking lots • Roads • Manufacturing • Residential areas • Application of agricultural pesticides • Landscaping | • Route all new, untreated runoff away from wetland while ensuring wetland is not dewatered • Establish covenants limiting use of pesticides within 150 ft. of wetland • Apply integrated pest management |
Stormwater runoff | • Parking lots • Roads • Manufacturing • Residential areas • Commercial • Landscaping | • Retrofit stormwater detention and treatment for roads and existing adjacent development • Prevent channelized flow from lawns that directly enters the buffer • Use low-intensity development techniques |
Change in water regime | • Impermeable surfaces • Lawns • Tilling | • Infiltrate or treat, detain, and disperse into buffer new runoff from impervious surfaces and new lawns |
Pets and human disturbance | • Residential areas | • Use privacy fencing; plant dense vegetation to delineate buffer edge and to discourage disturbance using vegetation appropriate for the ecoregion; place wetland and its buffer in a separate tract |
Dust | • Tilled fields | • Use BMPs to control dust |
Notes: |
|---|
* These examples are not necessarily adequate for minimizing toxic runoff if sensitive, threatened or endangered species are present at the site. |
E.
The minimum buffer width stated in Table 22.10.110(D), Buffer Widths, shall be increased when the qualified professional determines, based upon a site-specific wetland analysis, that impacts on the wetland from a proposed development can only be mitigated by a greater buffer width. The standard wetland buffer width shall be increased:
1.
When the adjacent land is susceptible to severe erosion and erosion control measures will not effectively prevent adverse wetland impacts; or
2.
When the standard buffer has minimal or degraded vegetative cover that cannot be improved through enhancement; or
3.
When the wetland provides habitat for a species that is particularly sensitive to disturbance (listed by the federal government or the state as endangered, threatened, candidate, monitored or documented priority species or habitat for those species or has unusual nesting or resting sites such as heron rookeries or raptor nesting trees), the width of the buffer should be increased to provide adequate protection for the species based on its particular life-history needs; or
F.
Low impact uses and activities (see Table 22.10.110(C)) that are consistent with the purpose and function of the wetland buffer and do not detract from its integrity may be permitted within the buffer depending on the sensitivity of the wetland. Examples of uses and activities that may be permitted in appropriate cases, based on guidance in Wetlands Guidance for CAO Updates, June 2016, Publication No. 16-06-002 and as amended in the future, include pervious pedestrian trails, viewing platforms, normal and routine maintenance of existing facilities within an existing right-of-way and utility easements. Uses permitted within the buffer shall be located in the outer portion of the buffer as far as possible from the wetland.
G.
A variance from buffer width requirements may be granted by the city of Richland hearing examiner following Type II permit procedures and payment of a fee as set forth in RMC Title 19 upon a demonstration by the applicant that the following criteria are met:
1.
That the strict application of the bulk, dimensional or performance standards set forth in this title preclude, or significantly interfere with, reasonable use of the property;
2.
That the hardship described in subsection (G)(1) of this section is specifically related to the property, and is the result of unique conditions such as irregular lot shape, size, or natural features and the application of this title, and not, for example, from deed restrictions or the applicant's own actions;
3.
That the design of the project is compatible with other authorized uses within the area and with uses planned for the area under the comprehensive plan and applicable development regulations and will not cause adverse impacts to the wetland;
4.
That the variance will not constitute a grant of special privilege not enjoyed by the other properties in the area;
5.
That the variance requested is the minimum necessary to afford relief; and
6.
That the public interest will suffer no substantial detrimental effect.
H.
Signs and Fencing of Wetlands and Buffers.
1.
Temporary Markers. The outer perimeter of the wetland buffer and the clearing limits identified in an approved permit or land use approval shall be marked in the field with temporary "clearing limits" fencing in such a way as to ensure that no unauthorized intrusion will occur. The marking is subject to inspection by the administrator prior to the commencement of permitted activities. Temporary marking shall be maintained throughout completion of all construction activities.
2.
Permanent Signs. As a condition of any permit or land use approval, the administrator may require the applicant to install permanent signs along the boundary of a wetland or its buffer. Permanent signs shall be made of an enamel-coated metal face and attached to a metal post. Signs, when required, shall be posted at an interval of one every 50 feet or one per lot if a lot is less than 50 feet wide and must be maintained by the property owner in perpetuity. Wording of the sign shall note the presence of a protected wetland area and/or wildlife habitat. Specific wording of the sign shall be approved by the administrator.
3.
Fencing.
a.
The applicant shall be required to install a permanent fence around the wetland or its buffer when domestic grazing animals are present or may be introduced on site.
b.
Fencing installed as part of a proposed activity or as required by the administrator shall be designed so as not to interfere with species migration and shall be constructed in a manner that minimizes impacts to the wetland and associated habitat.
(Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 63-19 § 5; Ord. 16-21 § 1)
A.
All adverse impacts to wetland functions and values shall be mitigated. Mitigation actions by an applicant or property owner shall occur in the following priority sequence:
1.
Avoiding the impact by not taking a certain action or parts of actions or moving the action;
2.
Minimizing impacts by limiting the degree or magnitude of the action and its implementation by using appropriate technology and engineering, or by taking affirmative steps to avoid or reduce adverse impacts;
3.
Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;
4.
Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action;
5.
Compensating for the impact by replacing or providing substitute resources or environments. Preference shall be given to measures that replace the impacted functions on site or in the immediate vicinity of the impact. However, alternative compensatory mitigation within the watershed that addresses limiting factors or identifies critical needs based on watershed or comprehensive resource management plans may be authorized;
6.
Monitoring the adverse impact and taking appropriate corrective measures.
B.
Where impacts cannot be avoided, the applicant or property owner shall seek to implement other appropriate mitigation actions in compliance with the intent, standards and criteria of this section. These shall include consideration of alternative site plans and building layouts and/or reduction in the density or scope of the proposal.
C.
Alteration of wetlands and/or their buffers may be permitted by the administrator subject to the following criteria:
1.
Category I Wetlands. Alterations of Type I wetlands shall be avoided.
2.
Category II, III and IV Wetlands.
a.
Any proposed alteration and mitigation shall comply with the requirements of this section through RMC § 22.10.150; and
b.
Where enhancement is proposed, replacement ratios comply with the requirements of RMC § 22.10.130(C); and
c.
No net loss of wetland function and value will occur due to the alteration; and
d.
Avoids alterations of wetlands previously enhanced or created as mitigation.
(Ord. 48-93; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
New development within 150 feet of a wetland buffer shall contain stormwater runoff within the developed portions of the site. No stormwater runoff shall drain into the wetland. Deviations from this standard may be approved by the administrator; provided, that a study undertaken by a qualified professional in accordance with the provisions of RMC § 22.10.140 indicates that the potential discharge of stormwater runoff from a development site into a wetland is adequately mitigated to protect the functions and values of the wetland. In the case of a Category III or Category IV wetland, stormwater management facilities may be located within the outer 25 percent of the required wetland buffer; provided, that a determination is made that no other location is feasible and the location of such facilities will not have an adverse impact on the functions and values of the wetland.
Streamflows that are influenced by irrigation practices are not considered stormwater runoff for the purposes of this chapter.
(Ord. 23-01; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
A.
Types of Compensatory Mitigation. Mitigation for lost or diminished wetland and buffer functions shall rely on a type listed below in order of preference. A lower preference form of mitigation shall be used only if the applicant's qualified wetland professional demonstrates to the satisfaction of the administrator that all higher-ranked types of mitigation are not viable, consistent with the criteria in this section.
2.
Creation (Establishment). If a site is not available for wetland restoration to compensate for expected wetland and/or buffer impacts, the administrator may authorize creation of a wetland and buffer upon demonstration by the applicant's qualified wetland professional that:
a.
The hydrology and soil conditions at the proposed mitigation site are conducive for sustaining the proposed wetland and that creation of a wetland at the site will not likely cause hydrologic problems elsewhere;
b.
Adjacent land uses and site conditions do not jeopardize the viability of the proposed wetland and buffer (e.g., due to the presence of invasive plants or noxious weeds, stormwater runoff, noise, light or other impacts); and
c.
The proposed wetland and buffer will eventually be self-sustaining with little or no long-term maintenance.
3.
Enhancement. Applications proposing to enhance wetland or associated buffers shall demonstrate how the proposed enhancement will increase the wetland buffer's functions, how this increase in function will adequately compensate for the impacts, and how existing wetland functions at the mitigation site will be protected.
4.
Protection/Maintenance (Preservation). Permanent protection of a Category I or II wetland and associated buffer at risk of degradation can be used only if:
a.
The administrator determines that the proposed preservation is the best mitigation option;
b.
The proposed preservation site is under threat of undesirable ecological change due to permitted, planned, or likely actions that will not be adequately mitigated under existing regulations;
c.
The area proposed for preservation is of high quality or critical for the health of the watershed or basin due to its location. Some of the following features may be indicative of high-quality sites:
i.
Category I or II wetland rating (using the wetland rating system for Eastern Washington);
ii.
Rare or irreplaceable wetland type or aquatic habitat that is rare or a limited resource in the area;
iii.
The presence of habitat for priority or locally important wildlife species;
iv.
Provides biological and/or hydrological connectivity;
v.
Priority sites in an adopted watershed plan.
d.
Permanent preservation of the wetland and buffer will be provided through a conservation easement or tract held by an appropriate natural land resource manager, such as a land trust;
e.
The administrator may approve other legal and administrative mechanisms in lieu of a conservation easement if determined to be adequate to protect the site;
f.
Ratios for preservation in combination with other forms of mitigation generally range from 10:1 to 20:1, as determined on a case-by-case basis, depending on the quality of the wetlands being impacted and the quality of the wetlands being preserved. Ratios for preservation as the sole means of mitigation generally start at 20:1.
B.
Location and Timing of Mitigation.
1.
Location of Compensatory Mitigation. Compensatory mitigation actions shall be conducted within the same subdrainage basin and on the site of the alteration except when all of subsections (B)(1)(a) through (d) of this section apply. In that case, mitigation may be allowed off site within the subwatershed of the impact site. When considering off-site mitigation, preference should be given to using alternative mitigation, such as a mitigation bank, an in-lieu fee program, or advanced mitigation.
a.
There are no reasonable opportunities on site or within the subdrainage basin (e.g., on-site options would require elimination of high-functioning upland habitat), or opportunities on site or within the subdrainage basin do not have a high likelihood of success based on a determination of the capacity of the site to compensate for the impacts. Considerations should include: anticipated replacement ratios for wetland mitigation, buffer conditions and proposed widths, available water to maintain anticipated hydrogeomorphic classes of wetlands when restored, proposed flood storage capacity, and potential to mitigate riparian fish and wildlife impacts (such as connectivity).
b.
On-site mitigation would require elimination of high-quality upland habitat.
c.
Off-site mitigation has a greater likelihood of providing equal or improved wetland functions than the altered wetland.
d.
Off-site locations shall be in the same subdrainage basin unless:
i.
Established watershed goals for water quality, flood storage or conveyance, habitat, or other wetland functions have been established by the city and strongly justify location of mitigation at another site.
ii.
The design for the compensatory mitigation project needs to be appropriate for its location (i.e., position in the landscape). Therefore, compensatory mitigation should not result in the creation, restoration, or enhancement of an atypical wetland. An atypical wetland refers to a compensation wetland (e.g., created or enhanced) that does not match the type of existing wetland that would be found in the geomorphic setting of the site (i.e., the water source[s] and hydroperiod proposed for the mitigation site are not typical for the geomorphic setting). Likewise, it should not provide exaggerated morphology or require a berm or other engineered structures to hold back water. For example, excavating a permanently inundated pond in an existing seasonally saturated or inundated wetland is one example of an enhancement project that could result in an atypical wetland. Another example would be excavating depressions in an existing wetland on a slope, which would require the construction of berms to hold the water.
2.
Timing of Compensatory Mitigation. It is preferred that compensatory mitigation projects be completed prior to activities that will disturb wetlands. At the least, compensatory mitigation shall be completed immediately following disturbance and prior to use or occupancy of the action or development. Construction of mitigation projects shall be timed to reduce impacts to existing fisheries, wildlife, and flora.
3.
The administrator may authorize a one-time, temporary delay in completing construction or installation of the compensatory mitigation when the applicant provides a written explanation from a qualified wetland professional as to the rationale for the delay. An appropriate rationale would include identification of the environmental conditions that could produce a high probability of failure or significant construction difficulties (e.g., project delay lapses past a fisheries window, or installing plants should be delayed until the dormant season to ensure greater survival of installed materials). The delay shall not create or perpetuate hazardous conditions or environmental damage or degradation, and the delay shall not be injurious to the health, safety, or general welfare of the public. The request for the temporary delay must include a written justification that documents the environmental constraints that preclude implementation of the compensatory mitigation plan. The justification must be verified and approved by the administrator.
C.
Mitigation Performance Standards.
1.
Adverse impacts to wetlands functions and values shall be mitigated. Mitigation actions shall be implemented in the preferred sequence identified in RMC § 22.10.120(A). Proposals which include less preferred and/or compensatory mitigation shall demonstrate that:
a.
All feasible and reasonable measures will be taken to reduce impacts and losses to the original wetland, including a description of how preferred order of wetlands mitigation was followed: (i) restoration (including reestablishment and rehabilitation); (ii) creation (establishment); (iii) enhancement in combination with restoration or creation; and (iv) preservation of high quality, at-risk wetlands;
b.
Compensatory mitigation shall be allowed only after mitigation sequencing is applied and higher priority means of mitigation are determined to be infeasible, and shall achieve equivalent or greater wetland ecological functions;
c.
No overall net loss will occur in wetland functions and values; and
d.
The restored, created or enhanced wetland will be as persistent and sustainable as the wetland it replaces.
D.
Wetland Replacement Ratios.
1.
Where wetlands alterations are permitted by the administrator, the applicant shall restore or create equivalent areas of wetlands in order to compensate for wetland losses. Equivalent areas shall be determined according to acreage, function, type, location, timing factors, and projected success of restoration or creation.
2.
The following acreage replacement ratios shall be applied:
Table 22.10.130(C) Mitigation Ratios for Eastern Washington1 | |||||
|---|---|---|---|---|---|
Category and Type of Wetland Impacts | Reestablishment or Creation | Rehabilitation Only2 | Reestablishment or Creation (R/C) and Rehabilitation (RH)2 | Reestablishment or Creation (R, C) and Enhancement (E)2 | Enhancement Only2 |
All Category IV | 1.5:1 | 3:1 | 1:1 R/C and 1:1 RH | 1:1 R/C and 2:1 E | 6:1 |
All Category III | 2:1 | 4:1 | 1:1 R/C and 2:1 RH | 1:1 R/C and 4:1 E | 8:1 |
Category II | 3:1 | 6:1 | 1:1 R/C and 4:1 RH | 1:1 R/C and 8:1 E | 12:1 |
Category I based on score for functions | 4:1 | 8:1 | 1:1 R/C and 6:1 RH | 1:1 R/C and 12:1 E | 16:1 |
Category I natural heritage site | Not considered possible3 | Case-by-case | R/C not considered possible3 | R/C not considered possible3 | Case-by-case |
Notes: |
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1 Ratios for rehabilitation and enhancement may be reduced when combined with 1:1 replacement through creation or reestablishment. See Table 1b, Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance – Version 1 (Ecology Publication No. 06-06-011a, Olympia, WA, March 2006 or as revised). |
2 These ratios are based on the assumption that the rehabilitation or enhancement actions implemented represent the average degree of improvement possible for the site. Proposals to implement more effective rehabilitation or enhancement actions may result in a lower ratio, while less effective actions may result in a higher ratio. The distinction between rehabilitation and enhancement is not clear-cut. Instead, rehabilitation and enhancement actions span a continuum. Proposals that fall within the gray area between rehabilitation and enhancement will result in a ratio that lies between the ratios for rehabilitation and the ratios for enhancement. |
3 Natural Heritage sites, alkali wetland, and bogs are considered irreplaceable wetlands because they perform some functions that cannot be replaced through compensatory mitigation. Impacts to such wetlands would therefore result in a net loss of some functions no matter what kind of compensation is proposed. |
Reference: Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District, and U.S. Environmental Protection Agency Region 10, March 2006. Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance (Version 1). Washington State Department of Ecology Publication No. 06-06-011a, Olympia, WA. |
3.
Credit/Debit Method. To more fully protect functions and values, and as an alternative to the mitigation ratios found in the joint guidance "Wetland Mitigation in Washington State Parts I and II" (Ecology Publication No. 06-06-011a-b, Olympia, WA, March 2006, or as revised), the administrator may allow mitigation based on the "credit/debit" method developed by the Department of Ecology in "Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Eastern Washington: Final Report" (Ecology Publication No. 11-06-015, August 2012, or as revised).
(Ord. 48-93; Ord. 45-00; Ord. 23-01; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
Where it is determined by the administrator that compensatory wetland mitigation is required or appropriate, a mitigation plan shall be prepared consistent with the provisions below and shall also meet the minimum requirements contained in the Wetlands Guidance for CAO Updates, June 2016, Publication No. 16-06-002 and as amended in the future). The purpose of the plan is to prescribe mitigation to compensate for impacts to the wetland functions, values and acreage as a result of the proposed action. This plan shall consider the chemical, physical, and biological impacts on the wetland system using a recognized wetlands assessment methodology and/or best professional judgment. The mitigation plan shall be prepared in two phases, a conceptual phase and a detailed phase.
A.
Conceptual Plan – Standards and Criteria. The applicant shall prepare a conceptual mitigation plan for submission to the administrator at a premitigation conference. The conceptual mitigation plan shall include:
1.
General goals of the mitigation plan;
2.
A review of literature or experience to date in restoring or creating the type of wetland proposed;
3.
Location of proposed wetland compensation area;
4.
General hydrologic patterns on the site following construction;
5.
Nature of compensation, including wetland types (in-kind), general plant selection and justification, approximate project sequencing and schedule, and approximate size of the new wetland buffer;
6.
A conceptual maintenance plan; and
7.
Conceptual monitoring and contingency plan.
B.
Detailed Plan – Standards and Criteria. Following acceptance of the conceptual mitigation plan by the administrator, the applicant will prepare a detailed mitigation plan. Each detailed plan shall contain, at a minimum, the following seven components, and shall be consistent with the standards in RMC § 22.10.100 through § 22.10.130:
1.
A clear statement of the objectives of the mitigation. The goals of the mitigation plan should be stated in terms of the new wetland functions and values compared to the functions and values of the original wetland. Objectives should include:
a.
Qualitative and quantitative standards for success of the project, including hydrologic characteristics (water depths, water quality, hydroperiod/hydrocycle characteristics, flood storage capacity); vegetative characteristics (community types, species composition, density, and spacing); faunal characteristics, and final topographic elevations.
b.
An ecological assessment of the wetland values and wetland buffers that will be lost as a result of the activities, and of the replacement wetlands and buffers, including but not limited to the following:
i.
Acreage of project;
ii.
Existing functions and values;
iii.
Sizes of wetlands, wetland buffers, and areas to be altered;
iv.
Vegetative characteristics, including community type, areal coverage, species composition, and density;
v.
Habitat type(s) to be enhanced, restored, or created; and
vi.
Dates for beginning and completion of the mitigation project, and sequence of construction activities.
2.
A statement of the location, elevation, and hydrology of the new site, including the following:
a.
Relationship of the project to the watershed and existing water bodies;
b.
Topography of site using the smallest readily available intervals, preferably one-foot contour intervals but two-foot are acceptable;
c.
Water level data, including depth and duration of seasonally high water table;
d.
Water flow patterns;
e.
Grading, filling and excavation, including a description of imported soils;
f.
Irrigation requirements, if any;
g.
Water pollution mitigation measures during construction;
h.
Areal coverage of planted areas to open water areas (if any open water is to be present); and
i.
Appropriate buffers.
3.
A planting plan, describing what will be planted, and where and when the planting will occur, as follows:
5.
A contingency plan, consistent with these regulations.
6.
A detailed budget for implementation of the mitigation plan, including monitoring, maintenance and contingency phases.
7.
A guarantee, in the form of a bond or other security device in a form and amount acceptable to the city attorney, assuring that the work will be performed as planned and approved, consistent with these regulations, including monitoring, maintenance and contingency.
(Ord. 48-93; amended during 2011 recodification; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
A.
The following performance standards shall be incorporated into mitigation plans submitted to the city of Richland:
1.
Plants should be indigenous to the region (not introduced or foreign species);
2.
Plants should be adaptable to a broad range of water depths;
3.
Plants should be commercially available or available from local sources;
4.
Plant species high in food and cover value for fish and wildlife are recommended, when possible;
5.
Plants should be mostly perennial species;
6.
Avoid committing significant areas of site to species that have questionable potential for successful establishment;
7.
Plant selection must be approved by wetlands biologist/ecologist;
8.
Water depth is not to exceed six and one-half feet (two meters);
9.
The grade or slope that water flows through the wetland is not to exceed six percent;
10.
Slopes within the wetland basin and the buffer zone should not be steeper than 3:1 (horizontal to vertical);
11.
The substrate should consist of a minimum of one foot, in depth, of clean (uncontaminated with chemicals, or solid/hazardous wastes) inorganic/organic materials;
12.
Planting densities and placement of plants should be determined by a qualified professional and shown on the design plans;
13.
The wetland (excluding the buffer area) should not contain more than 60 percent open water as measured at the seasonal high water mark;
14.
Minimum buffer widths should extend from the wetland boundary in accordance with buffer requirements in Table 22.10.110(D), Buffer Widths, for the proposed category rating of the wetland that will be created;
15.
The planting plan must be approved by the community development administrator or qualified professional acting on behalf of the city;
16.
Stockpiling should be confined to upland areas and contract specifications should limit stockpile durations to less than four weeks. Any area designated as open space shall not be used to stockpile material;
17.
Planting instructions which describe proper placement, diversity, and spacing of seeds, tubers, bulbs, rhizomes, sprigs, plugs, and transplanted stock;
18.
Apply controlled-release fertilizer, if reasonable and prudent, at the time of planting and afterward only as plant conditions warrant (determined during the monitoring process);
19.
Install an irrigation system, if necessary, for initial establishment period; and
20.
Construction specifications and methods must be approved by a qualified professional and the administrator.
B.
On completion of construction, the wetland mitigation project must be signed off by the applicant's qualified professional and the administrator. Signature will indicate that the construction has been completed as planned and all design elements have been fully and correctly implemented. If there have been changes in the implementation of the plan, a written explanation from the qualified professional must be included.
(Ord. 48-93; Ord. 31-03; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)
A.
A monitoring program shall be implemented to determine the success of the mitigation project and any necessary corrective actions. This chapter shall determine if the original goals and objectives are being met.
B.
A contingency plan shall be established for compensation in the event that the mitigation project is inadequate or fails. A performance and maintenance bond or other acceptable security device is required to ensure the applicant's compliance with the terms of the mitigation agreement. The amount of the performance and maintenance bond shall equal 125 percent of the cost of the mitigation project for a period of five years. The administrator may agree to reduce the bond in phases in proportion to work successfully completed over the period of the bond.
1.
During monitoring, scientific procedures for establishing the success or failure of the project must be used and shall be identified in the monitoring plan;
2.
For vegetation determinations, permanent monitoring transects or plots shall be established that adequately represent the compensatory mitigation site;
3.
Vegetative success in the compensatory mitigation wetland will be defined as:
a.
An average density of at least four plants per 100 square feet in the scrub-shrub and forested communities in year one;
b.
A cover of native wetland trees and shrubs combined (planted and volunteer) of at least 10 percent in year three; 25 percent in year five; 40 percent in year seven; 50 percent in year 10;
c.
A cover of native wetland herbaceous plant species (planted and volunteer) of at least 25 percent in year five; 40 percent in year seven and 50 percent in year 10;
d.
Nonnative invasive species must be controlled per site-specific specifications and shall not exceed the maximum amount as identified in the approved monitoring plan;
e.
Buffer vegetation shall be maintained in the amount as identified in the approved monitoring plan;
4.
Submit monitoring reports on the current status of the mitigation project to the administrator. The reports are to be prepared by a qualified professional and reviewed by the administrator and should include monitoring information on wildlife, vegetation, water quality, water flow, stormwater storage and conveyance, and existing or potential degradation, and shall be produced for years one, two, three, four, seven and 10. Monitoring reports shall incorporate hydrology standards to ensure the required wetland habitat and buffer areas are established and functioning and shall detail the minimum number of days during the growing season when soils must remain inundated or saturated to the ground surface;
5.
Monitor for 10 growing seasons. If the mitigation goals are obtained within the initial five-year period, no further monitoring will be required;
6.
If necessary, correct for failures in the mitigation project;
7.
Replace dead or undesirable vegetation with appropriate plantings, based on the approved planting plan or RMC § 22.10.150;
8.
Repair damages caused by erosion, settling, or other geomorphological processes;
9.
Redesign mitigation project (if necessary) and implement the new design;
10.
Correction procedures shall be approved by a qualified professional and the administrator; and
11.
The area where the mitigation occurred and any associated buffer shall be located in a critical area tract, a conservation easement or similar legal instrument as approved by the administrator to ensure the future protection of the mitigation site.
(Ord. 48-93; Ord. 40-17 § 1; Ord. 40-17A § 1; Ord. 16-21 § 1)