City of Roslyn, WA Article IV Wetlands

§ 18.90.270 Wetland identification and rating.

A. Identification and Delineation. Wetlands shall be identified and delineated by a qualified wetland professional in accordance with the Washington State Wetlands Identification and Delineation Manual (Washington Department of Ecology Publication No. 96-94, or as revised and approved by Ecology), using the criteria in the definition of wetland in Chapter 18.20 RMC. Such wetland delineations are valid for three years; after such date the city shall determine if a revision or additional assessment is necessary.

B. Rating. Wetlands shall be rated according to the Washington Department of Ecology wetland rating system, as set forth in the Washington State Wetland Rating System for Eastern Washington (Ecology Publication No. 04-06-015, or as revised and approved by Ecology), which contains the definitions and methods for determining if the criteria below are met.

1. Category I wetlands include:

a. Wetlands identified by scientists of the Washington Department of Natural Resources Natural Heritage Program as high quality wetlands;

b. Bogs larger than one-half acre;

c. Mature forested wetlands larger than one acre; or

d. Wetlands that perform many functions well (scoring at least 70 points under the Department of Ecology's rating system).

2. Category II wetlands include:

a. Wetlands identified by the Washington State Department of Natural Resources as containing sensitive plant species;

b. Bogs between one-fourth and one-half acre in size; or

c. Wetlands with a moderately high level of functions (scoring between 51 and 69 points under the Department of Ecology's rating system).

3. Category III wetlands have a moderate level of functions (scoring between 30 and 50 points under the Department of Ecology's rating system).

4. Category IV wetlands have a relatively low level of functions (scoring less than 30 points under the Department of Ecology's rating system).

C. Illegal Modifications. Wetland rating categories shall not change due to illegal modifications made by the applicant or with the applicant's knowledge.

(Ord. 1059 § 2 (Exh. A (12.90.270)), 2010; Ord. 1060 §§ 5, 6, 2010; Ord. 1192 § 1 (Exh. A), 2022)

§ 18.90.280 Wetland exemptions.

All isolated Category IV wetlands less than 500 square feet that are not associated with riparian areas or buffers, not part of a wetland mosaic, and do not contain habitat identified as essential for local populations of priority species identified by the Washington Department of Fish and Wildlife or species of local importance identified in RMC § 18.90.210 are exempt from provisions contained in this article. All such wetlands between 500 and 1,000 square feet are exempt from the normal mitigation sequencing process (i.e., can be filled), if impacts are fully mitigated based on provisions in RMC § 18.90.310.

(Ord. 1059 § 2 (Exh. A (12.90.280)), 2010; Ord. 1060 §§ 5, 6, 2010)

§ 18.90.290 Wetland buffers.

A. Standard Buffer Widths. Wetland buffers shall be measured perpendicular from the wetland boundary as surveyed in the field, with the following standard widths:

1. Category I and II Wetlands. Buffer widths for Category I and Category II wetlands are based on habitat function scores (derived from the Washington State Wetland Rating System for Eastern Washington (Ecology Publication No. 04-06-015, or as revised and approved by Ecology)), in accordance with the following graduated scale:

Points for Habitat from Wetland Rating Form	≤  21	22	23	24	25	26	27	28	29	30	≥ 31
Wetland Buffer Width	100	120	140	160	180	200	220	240	260	280	300

2. Category III. Wetland buffer widths for Category III wetlands are based on habitat function scores (derived from the 2004 Wetland Rating System for Eastern Washington) in accordance with the following graduated scale:

Points for Habitat from Wetland Rating Form	≤  21	22	23	24	25	≥ 26
Wetland Buffer Width	100	120	140	160	180	200

3. Category IV. The wetland buffer width for Category IV wetlands shall be 70 feet.

B. Increased Buffer Widths. When a larger buffer is necessary to protect wetland or other critical area functions and values based on site-specific characteristics, the planning official shall require increased buffer widths in accordance with the recommendations of a qualified professional. Examples include when a wetland buffer provides habitat for a species protected under RMC § 18.90.210 or 18.90.220, or if the buffer or adjacent uplands are susceptible to erosion and standard erosion control measures may not prevent adverse impacts to the wetland.

C. Buffer Reductions Incentives. Standard buffer widths may be reduced under the following conditions; provided, that functions of the post-project wetland are equal or greater after use of these incentives:

1. Lower Impact Land Uses. Except in the urban forest and watershed zones, standard buffer widths may be reduced up to 15 percent in conjunction with the approval of measures that will result in no net loss or a net gain in ecological function. This may include application of measures to minimize the impacts of the land use adjacent to the wetlands such as infiltration of storm water, retention of native vegetation and soils, direction of noise and light away from the wetland, and other measures that may be suggested by a qualified wetlands professional. The development of these measures and their review by the city, which may include referral to independent qualified professionals, shall be at the applicant's expense. If proposed future land uses are more intense, they are not eligible to maintain this reduction.

2. Restoration. Buffer widths may be reduced up to 35 percent if the buffer is restored or enhanced from a preproject condition that is disturbed (e.g., dominated by invasive species), so that functions of the post-project wetland and buffer are equal or greater. The restoration plan must meet requirements in RMC § 18.90.100 for a mitigation plan and RMC § 18.90.300 for a critical area report.

3. Combined Reductions. Buffer width reductions allowed under subsections (B)(1) and (2) of this section may be added. However, the total reduction may be no more than 25 percent when the planning official determines that the soils or other conditions of a wetland are particularly sensitive to nutrient or pollutant loading.

D. Buffer Averaging. Except in the urban forest and watershed zones, the planning official shall have the authority to average buffer widths on a case-by-case basis, where a qualified wetlands professional demonstrates, as part of a critical area report, that all of the following criteria are met:

1. The total area contained in the buffer after averaging is no less than that contained within the buffer prior to averaging;

2. Decreases in width are generally located where wetland functions may be less sensitive to adjacent land uses and increases are generally located where wetland functions may be more sensitive to adjacent land uses, to achieve no net loss or a net gain in functions; and

3. The averaged buffer, at its narrowest point, shall not result in a width less than 75 percent of that allowed under other provisions of this section; provided, that minimum buffer widths shall never be less than 50 feet for Category I, Category II and Category III wetlands and 25 feet for Category IV wetlands.

4. Effect of Mitigation. If wetland mitigation occurs such that the rating of the wetland changes, the requirements for the category of the wetland after mitigation shall apply.

E. Signage. Signs shall identify post-project wetland buffers as critical areas or native growth protection areas, in accordance with RMC § 18.90.140(B).

F. Allowed Uses. The following uses may be permitted within a wetland buffer, provided they are not prohibited by any other applicable law and they are conducted in a manner so as to minimize negative impacts to the buffer and adjacent wetland:

1. Conservation or restoration activities aimed at protecting the soil, water, vegetation, or wildlife.

2. Passive recreation facilities designed and in accordance with an approved critical area report, including:

a. Wildlife viewing structures; and

b. Walkways and trails, provided pathways minimize adverse impacts on water quality. They should generally be parallel to the perimeter of the wetland, located in the outer 25 percent of the wetland buffer area, and avoid removal of significant trees. They must be limited to pervious surfaces no more than four feet in width. Raised boardwalks utilizing nontreated pilings may be acceptable.

3. Storm water management facilities, limited to storm water dispersion outfalls and bioswales, may be allowed within the outer 25 percent of the buffer of Category III or IV wetlands only; provided, that:

a. No other location is feasible; and

b. Their location, with mitigation, will not degrade the functions or values of the wetland.

(Ord. 1059 § 2 (Exh. A (12.90.290)), 2010; Ord. 1060 §§ 5, 6, 2010)

§ 18.90.300 Wetland critical area reports.

If required by the planning official in accordance with RMC § 18.90.070(B), a critical area report for wetlands shall meet requirements of this section. The report and its review by the city, which may include referral to independent qualified professionals, shall be at the applicant's expense. The report shall include the following components:

A. The name and contact information of the applicant, a description of the proposal, and identification of the permit requested;

B. A site plan for the project containing the following:

1. Maps (to scale) depicting delineated and surveyed wetlands and required buffers on site, as well as buffers for off-site wetlands that extend onto the project site or that might be impacted by the proposed activity, the proposed development, grading and clearing limits, and areas of proposed impacts to wetlands and/or buffers (including square footage estimates).

2. A depiction of the proposed storm water management facilities and outlets (to scale) for the development, including estimated areas of intrusion into the buffers of any critical areas.

C. A written report for the project containing the following:

1. A vicinity map for the project;

2. Identification of all the local, state, and/or federal wetland-related permit(s) required for the project;

3. The dates, names, and qualifications of the persons preparing the report and documentation of any fieldwork performed on the site, including field data sheets for delineations, function assessments, baseline hydrologic data, etc.;

4. A description of the methodologies used to conduct the wetland delineations, function assessments, or impact analyses, including references and all assumptions made and relied upon;

5. For all wetlands on the subject property and all off-site wetlands that could be impacted by the proposed action (using best available information if adjacent property access is denied) provide the following: hydrogeomorphic and Cowardin classification; characterization of vegetation, soils, and hydrology indicators; wetland rating (RMC § 18.90.270); wetland buffer width (RMC § 18.90.290); and, wetland acreage estimates;

6. Description of the proposed activity and assessment of cumulative impacts to wetlands and buffers from development of the site, including a discussion of the potential impacts to the wetland(s) associated with anticipated hydroperiod and water quality alterations;

7. Evaluation of existing and post-project functions of the wetland and adjacent buffer using a functional assessment method recognized by local or state agency staff (e.g., Methods for Assessing Wetland Functions, Ecology Publication No. 99-115) and including all data sheets and references for the method used; and

8. An analysis of site development alternatives, including a no development alternative.

D. If the proposed development would have significant adverse impacts to wetlands or their buffers, the critical area report must include a mitigation plan consistent with RMC § 18.90.310.

E. Unless otherwise provided, a critical area report may be supplemented by or composed, in whole or in part, of any reports or studies required by other laws and regulations or previously prepared for and applicable to the development proposal site, as approved by the planning official.

(Ord. 1059 § 2 (Exh. A (12.90.300)), 2010; Ord. 1060 §§ 5, 6, 2010)

§ 18.90.310 Wetland compensatory mitigation.

A. All significant adverse impacts to wetlands and buffers as determined by the planning official shall be mitigated in accordance with the standards in RMC § 18.90.090 and 18.90.100 and this section, and with reference to the Department of Ecology's Guidance on Wetland Mitigation in Washington State, Part 2 (Ecology Publication No. 04-06-013B) and Appendix 8-C of the Department of Ecology's Wetlands in Washington – Volume 2: Guidance for Protecting and Managing Wetlands (Ecology Publication No. 05-06-008), or updated guidance by Ecology.

B. If impacts to wetlands are unavoidable, mitigation to achieve compensation for wetland functions shall be approached in the following order of preference:

1. Reestablishment of natural or historic functions to a former wetland, through restoration of physical, chemical or biological processes (e.g., removing fill, plugging ditches, breaking drain tiles, breaching dikes, etc.).

2. Rehabilitation of natural or historic functions of a degraded wetland through restoration of physical, chemical or biological processes (e.g., removing fill, plugging ditches, breaking drain tiles, breaching dikes, etc.).

3. Creation of wetlands on disturbed upland sites, where the post-project hydrologic regime can demonstrably support the proposed wetland plant community.

4. Enhancement of vegetation or other characteristics of a wetland site to improve specific functions, such as filtration of pollutants or wildlife habitat.

5. Preservation or protection of a wetland that would not be adequately accomplished through existing regulations.

C. Mitigation shall be on site, where ecologically appropriate. Where this is infeasible, the applicant shall consult with the city, Yakama Indian Tribe, the Cle Elum district of the Wenatchee National Forest, the Kittitas conservation trust and the Washington State Departments of Ecology and Fish and Wildlife regarding off-site mitigation. Mitigation shall prioritize the preservation and restoration of contiguous wildlife habitat corridors to minimize the isolating effects of development on habitat areas.

D. Payment may be accepted in lieu of an off-site mitigation project. At a minimum, such payment shall be equivalent to the cost of implementing an acceptable off-site project, as estimated by a qualified professional approved by the city. The city, in consultation with the Yakama Indian Tribe, the Cle Elum district of the Wenatchee National Forest, and the Kittitas conservation trust, shall use these funds for wetland improvements it believes are in the best interest of the city and provide a greater ecological benefit than the alternative off-site project. Wetland improvements under this section are subject to the following criteria:

1. Fees will be used to find a clearly defined mitigation project;

2. The project being funded will result in an increase in acreage and function that adequately compensates for the permitted impacts;

3. The project being funded is within the same watershed as the impact;

4. There is a clear timeline for completing the mitigation project;

5. There are provisions for long-term protection and management, including mechanisms such as conservation easements, and funding for long-term management of the site; and

6. No approved mitigation bank or other form of compensatory mitigation is environmentally preferable and available.

E. It is preferred that compensatory mitigation projects be completed prior to activities that will disturb wetlands. If that is infeasible, 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.

F. Wetland Replacement Ratios.

1. When an applicant proposes to alter a wetland, the affected wetland acreage shall be replaced through wetland restoration, creation, enhancement or preservation, according to the ratios established in the table below. The ratios apply to mitigation that is on site, timed prior to or concurrent with alteration, having a high probability of success, and in kind (i.e., losses of wetland acreage shall be replaced by creation or restoration of new acreage; degradation of wetland functions shall be replaced by restoration or enhancement of new wetland functions, etc.). Where these conditions do not hold, ratios shall be adjusted accordingly, as determined by the planning official, in consultation with the Washington Department of Ecology, the Washington Department of Fish and Wildlife and the Yakama Indian Tribe.

2. Ratios for remedial actions resulting from unauthorized alterations shall be greater than set forth in the table, as determined by the planning official.

3. Ratios in the table are based on the assumption that the wetland category, based on RMC § 18.90.270(B), and hydrogeomorphic (HGM) class/subclass of the wetland proposed as compensation are the same as the category and HGM class/subclass of the wetland impacted. Ratios for projects in which the wetland category and HGM class/subclass of wetlands proposed as compensation are not the same as that of the wetland impacted will be determined on a case-by-case basis using the recommended ratios as a starting point.

Category and Type of Wetland	Creation or Reestablishment	Rehabilitation	Enhancement	Preservation
Category I – Bog, natural heritage site	Not considered possible	6:1	Case-by-case	10:1
Category I – Mature forested	6:1	12:1	24:1	24:1
Category I – Based on functions	4:1	8:1	16:1	20:1
Category II – Based on functions	3:1	6:1	12:1	20:1
Category III	2:1	4:1	8:1	15:1
Category IV	1.5:1	3:1	6:1	10:1

G. If compensatory mitigation is proposed, the wetlands critical area report must contain a mitigation plan prepared by a qualified wetlands professional, including the following information in addition to that required by RMC § 18.90.100 and 18.90.300:

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

2. Description of how lost functions will be replaced;

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

4. Provisions for adequate monitoring to ensure success of the mitigation plan. The monitoring plan shall outline the approach for monitoring construction of the mitigation project, and for 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 unless a more frequent time period is required by the planning official, and shall document successes, problems and contingency actions of the mitigation project. Monitoring activities may include, but are not limited to:

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

b. Measuring base flow rates and storm water runoff to model and evaluate hydrologic predictions;

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

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

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

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

1. The bank is certified under state law;

2. The planning official determines that the wetland mitigation bank provides appropriate compensation for the authorized impacts; and

3. 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.

(Ord. 1059 § 2 (Exh. A (12.90.310)), 2010; Ord. 1060 §§ 5, 6, 2010)