1. The city shall pursue accurate identification and rating of all wetlands in its planning area based on the Washington State Wetlands Identification and Delineation Manual (Washington Department of Ecology Publication No. 96-94, or as amended) and the Washington State Wetlands Rating System for Eastern Washington (or as amended).

2. Until funding is obtained to conduct a comprehensive inventory of wetlands, the National Wetlands Inventory (NWI) maps shall be used as a base designation. The NWI maps, along with other supportive documentation, shall be used to review development proposals, but because the National Wetlands Inventory was done at such a broad scale, local verification according to the criteria in this section shall be part of the standard process for identifying and designating wetlands.

3. If the administrator determines that the site of a proposed development potentially includes, or is adjacent to, a wetland, and a critical areas report is required, wetland identification and, where applicable, rating shall be undertaken using the Washington State Wetlands Identification and Delineation Manual. Identification of wetlands and delineation of their boundaries pursuant to this chapter shall be done in accordance with the approved federal wetland delineation manual and applicable regional supplement. All areas within the city meeting the wetland designation criteria in that procedure are hereby designated critical areas and are subject to the provisions of this chapter. Wetland delineations are valid for five years; after such date the city shall determine whether a revision or additional assessment is necessary.

4. 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 Western Washington: 2014 Update (Ecology Publication No. 14-06-029, or as revised and approved by Ecology). Where federal regulations require use of the U. S. Army Corps of Engineers Arid West Interim Regional Supplement (or as amended) to the 1987 Wetland Delineation Manual, delineation using the Washington State Wetlands Identification and Delineation Manual (Washington Department of Ecology Publication No. 96-94, or as amended) shall also be required.

1. Category I. Category I wetlands are those that:

Generally, these wetlands are not common and make up a small percentage of the wetlands in Eastern Washington. Category I wetlands include alkali wetlands, bogs, natural heritage wetlands, mature and old-growth forested wetlands with slow growing trees, forested wetlands with stands of aspen, and wetlands that perform many functions well, as measured by the rating system.

2. Category II. Category II wetlands are:

These wetlands are difficult, though not impossible, to replace. They provide high levels of some functions. These wetlands occur more commonly than Category I wetlands, but still need a high level of protection.

3. Category III. Category III wetlands are:

These wetlands have generally been disturbed in some manner, and are often smaller, less diverse and/or more isolated in the landscape than Category II wetlands. They may not require as much protection as Category I and II wetlands.

4. Category IV. Category IV wetlands have the lowest levels of functions, as measured by the rating system, and are often heavily disturbed. These are wetlands that we should be able to replace, and in some cases improve. These wetlands do provide some important functions and should be afforded some degree of protection.

1. New or changed activities and uses shall be prohibited from wetlands or wetland buffers unless the applicant can show that the proposed activity will not degrade the functions and values of the wetland or other critical areas, or as otherwise provided in this title.

2. Buffer Widths. The following standard buffer widths have been established in accord with best available science to provide predictability in the regulation of wetlands:

The standard buffer widths shall be applied unless a critical areas report establishes, based on intensity of impacts, wetlands functions, or special characteristics as described in Appendix 8-D of Wetlands in Washington State, Volume 2: Managing and Protecting Wetlands (Department of Ecology Publication No. 05-06-008, or as amended), that a greater or lesser buffer width would serve to protect the functions and values of a particular wetland. The standard buffer widths may be reduced by up to, but not more than, 25 percent for low intensity uses such as open space recreation, unpaved trails, or utility corridors that do not require roads or vegetation management. Greater buffer widths or rehabilitation of an inadequate plant community may be required where necessary to ensure development does not result in adverse impacts to wetlands.

3. Measurement of Wetland Buffers. All buffers shall be measured from the wetland boundary as surveyed in the field. The width of the wetland buffer shall be determined according to the wetland category and the proposed land use. The same buffer widths and measurement criteria shall apply to any wetland created, restored, or enhanced as compensation for approved wetland alterations. Buffers shall be clearly marked on the ground.

4. Wetland Buffer Width Averaging. The administrator may allow averaging of wetland buffer widths in accordance with an approved critical areas report, provided the following conditions are met:

5. Where other critical areas coincide with wetlands, buffers shall be configured so as to protect aggregate functions and values. Particular consideration shall be given to habitat connectivity.

6. Wetland buffer zones shall be retained in their natural condition. Where buffer disturbances are unavoidable during adjacent construction, a detailed mitigation plan shall be required to ensure successful revegetation with native plant materials.

7. The following activities shall be allowed within wetland buffers:

8. Stormwater management facilities shall be allowed within the outer 25 percent of a wetland buffer around Category III or IV wetlands; provided, that no other location is feasible, and that the location of such facilities will not degrade the functions of the wetland or its buffer.

9. As a condition of any permit or authorization pursuant to this chapter, the administrator may require temporary or permanent signs and/or fencing along the perimeter of a wetland or buffer in order to protect the functions and values of the wetland, or to minimize future impacts or encroachment upon the wetland or buffer.

10. Wetland alteration proposals shall be approved only if no alternative is available. If alteration is unavoidable, all adverse impacts shall be mitigated as set forth in an approved critical areas report and mitigation plan.

11. Mitigation shall achieve biological functions equivalent to or greater than existed in the wetland prior to mitigation.

12. When possible, mitigation shall be on site and sufficient to maintain the functions and values of the wetland and buffer areas. If on-site mitigation is not feasible, then the applicant shall demonstrate that the site is the nearest that can reasonably achieve the goals of mitigation with a high likelihood of success.

13. Mitigation actions that require compensation by replacing, enhancing or substitution shall occur in the following order of preference:

14. The following ratios apply to the creation, restoration or preservation of wetlands that is in-kind, on-site, the same category, timed prior to or concurrent with alteration, and has a high probability of success:

These ratios do not apply to remedial actions resulting from unauthorized alterations.

15. The mitigation ratio may be increased if the administrator identifies that:

16. The administrator may decrease the mitigation ratio where:

17. The long or short subdivision of lands that include wetlands is subject to the following:

18. The administrator may allow greater density of development outside of wetland areas and associated buffers as an incentive, provided the ability to ensure a high level of protection for on-site resources is demonstrated in an approved critical areas report and mitigation plan.

1. Vegetation within the riparian buffer shall be maintained as riparian habitat. Noxious weeds in the riparian buffer should be controlled according to best management practices. The Stevens County noxious weed control board should be consulted for recommendations. Where riparian buffer vegetation disturbances have occurred, only revegetation with locally prescribed native vegetation is permitted.

2. All riparian buffers shall be temporarily fenced between the construction activity and the riparian buffer with a highly visible and durable protective barrier, such as filter fencing and straw bales, during construction to prevent access and protect the riparian buffer. The administrator may waive this requirement if an alternative to fencing which achieves the same objective is proposed and approved.

3. Riparian Buffer Widths. Water bodies designated by the shoreline master program use regulations of the city’s environment classifications and water bodies meeting the definition of shorelines of the state per Chapter 90.58 RCW (the Shoreline Management Act) shall have the following required buffer widths: