OAR 350-081-0560
General Management Area Wetland Review Criteria
(1)
Wetlands Boundaries and Site Plans for Review Uses in Wetlands(a)
If the proposed use is within a wetland or wetlands buffer zone, the applicant shall be responsible for determining the exact location of the wetland boundary.(A)
The approximate location and extent of wetlands in the Scenic Area is shown on the National Wetlands Inventory (U.S. Department of the Interior 1987). In addition, the list of hydric soils and the soil survey maps shall be used as an indicator of wetlands. Wetlands boundaries shall be delineated using the procedures specified in the Corps of Engineers Wetlands Delineation Manual (Wetlands Research Program Technical Report Y-87-1, on-line edition, updated through March 21, 1997).(B)
All wetlands delineations shall be conducted by a professional which has been trained to use the federal delineation process, such as a soil scientist, botanist, or wetlands ecologist.(C)
The Executive Director may verify the accuracy of, and may render adjustments to, a wetlands boundary delineation. In the event the adjusted boundary delineation is contested by the applicant, the Executive Director shall, at the applicant’s expense, obtain professional services to render a final delineation.(b)
In addition to the information required in all site plans, site plans for proposed uses in wetlands or wetlands buffer zones shall include:(A)
A site plan map prepared at a scale of 1 inch equals 100 feet (1:1,200), or a scale providing greater detail;(B)
The exact boundary of the wetland and the wetlands buffer zone; and(C)
A description of actions that would alter or destroy the wetland.(2)
Commission Rule 350-081-0560 (General Management Area Wetland Review Criteria) shall not apply to proposed uses that would occur in the main stem of the Columbia River. The main stem of the Columbia River is depicted on the map titled “Boundary Map, Columbia River Gorge National Scenic Area,” numbered NSA-001 and dated September 1986. (This map is available at county planning departments and Commission and Forest Service offices.) The boundaries of the main stem appear as a heavy black line that generally follows the shoreline. For Commission Rule 350-81, backwaters and isolated water bodies created by roads and railroads are not part of the main stem of the Columbia River.(3)
The following uses may be allowed in wetlands and wetlands buffer zones when approved pursuant to the provisions in 350-081-0560 (General Management Area Wetland Review Criteria)(5), and reviewed under the applicable provisions of 350-081-0520 (General Management Area Scenic Review Criteria) through 350-081-0620 (Special Management Area Recreation Resource Review Criteria). Proposed uses in wetlands and wetland buffer zones shall be evaluated for adverse effects, including cumulative effects, and adverse effects shall be prohibited.(a)
The modification, expansion, replacement, or reconstruction of serviceable structures, if such actions would not:(A)
Increase the size of an existing structure by more than 100 percent,(B)
Result in a loss of wetlands acreage or functions, and(C)
Intrude further into a wetland or wetlands buffer zone. New structures shall be considered intruding further into a wetland or wetlands buffer zone if any portion of the structure is located closer to the wetland or wetlands buffer zone than the existing structure.(b)
The construction of minor water-related recreation structures that are available for public use. Structures in this category shall be limited to boardwalks; trails and paths, provided their surface is not constructed of impervious materials; observation decks; and interpretative aids, such as kiosks and signs.(c)
The construction of minor water-dependent structures that are placed on pilings, if the pilings allow unobstructed flow of water and are not placed so close together that they effectively convert an aquatic area to dry land. Structures in this category shall be limited to public and private docks and boat houses, and fish and wildlife management structures that are constructed by federal, state, or tribal resource agencies.(4)
Uses not listed in 350-081-0560 (General Management Area Wetland Review Criteria)(2) and (3) may be allowed in wetlands and wetlands buffer zones, when approved pursuant to 350-081-0560 (General Management Area Wetland Review Criteria)(6) and reviewed under the applicable provisions of 350-081-0520 (General Management Area Scenic Review Criteria) through 350-081-0620 (Special Management Area Recreation Resource Review Criteria).(5)
Applications for modifications to serviceable structures and minor water-dependent and water-related structures in wetlands shall demonstrate that:(a)
Practicable alternatives to locating the structure outside of the wetlands or wetland buffer zone and/or minimizing the impacts of the structure do not exist;(b)
All reasonable measures have been applied to ensure that the structure will result in the minimum feasible alteration or destruction of the wetlands, existing contour, functions, vegetation, fish and wildlife resources, and hydrology;(c)
The structure will be constructed using best management practices;(d)
Areas disturbed during construction of the structure will be rehabilitated to the maximum extent practicable; and(e)
The structure complies with all applicable federal, state, and county laws.(6)
Applications for all other Review Uses in wetlands shall demonstrate that:(a)
The proposed use is water-dependent, or is not water-dependent but has no practicable alternative considering all of the following:(A)
The basic purpose of the use cannot be reasonably accomplished using one or more other sites in the vicinity that would avoid or result in less adverse effects on wetlands;(B)
The basic purpose of the use cannot be reasonably accomplished by reducing its size, scope, configuration, or density as proposed, or by changing the design of the use in a way that would avoid or result in less adverse effects on wetlands; and(C)
Reasonable attempts have been made to remove or accommodate constraints that caused a project applicant to reject alternatives to the use as proposed. Such constraints include inadequate infrastructure, parcel size, and zone designations. If a land designation or recreation intensity class is a constraint, an applicant must request a Management Plan amendment to demonstrate that practicable alternatives do not exist. An alternative site for a proposed use shall be considered practicable if it is available and the proposed use can be undertaken on that site after taking into consideration cost, technology, logistics, and overall project purposes.(b)
The proposed use is in the public interest. The following factors shall be considered when determining if a proposed use is in the public interest:(A)
The extent of public need for the proposed use.(B)
The extent and permanence of beneficial or detrimental effects that the proposed use may have on the public and private uses for which the property is suited.(C)
The functions and size of the wetland that may be affected.(D)
The economic value of the proposed use to the general area.(E)
The ecological value of the wetland and probable effect on public health and safety, fish, plants, and wildlife.(c)
Measures will be applied to ensure that the proposed use results in the minimum feasible alteration or destruction of the wetland’s functions, existing contour, vegetation, fish and wildlife resources, and hydrology.(d)
Groundwater and surface-water quality will not be degraded by the proposed use.(e)
Those portions of a proposed use that are not water-dependent or have a practicable alternative will not be located in wetlands or wetlands buffer zones.(f)
The proposed use complies with all applicable federal, state, and county laws.(g)
Areas that are disturbed during construction will be rehabilitated to the maximum extent practicable.(h)
Unavoidable impacts to wetlands will be offset through restoration, creation, or enhancement of wetlands. Wetlands restoration, creation, and enhancement are not alternatives to the guidelines listed above; they shall be used only as a last resort to offset unavoidable wetlands impacts. The following wetlands restoration, creation, and enhancement guidelines shall apply:(A)
Impacts to wetlands shall be offset by restoring or creating new wetlands or by enhancing degraded wetlands. Wetlands restoration shall be the preferred alternative.(B)
Wetlands restoration, creation, and enhancement projects shall be conducted in accordance with a wetlands compensation plan.(C)
Wetlands restoration, creation, and enhancement projects shall use native vegetation.(D)
The size of replacement wetlands shall equal or exceed the following ratios (the first number specifies the required acreage of replacement wetlands and the second number specifies the acreage of wetlands altered or destroyed):(i)
Restoration: 2:1(ii)
Creation: 3:1(iii)
Enhancement: 4:1(E)
Replacement wetlands shall replicate the functions of the wetland that will be altered or destroyed such that no net loss of wetlands functions occurs.(F)
Replacement wetlands should replicate the type of wetland that will be altered or destroyed. If this guideline is not feasible or practical due to technical constraints, a wetland type of equal or greater benefit may be substituted, provided that no net loss of wetlands functions occurs.(G)
Wetlands restoration, creation, or enhancement should occur within 1,000 feet of the affected wetland. If this is not practicable due to physical or technical constraints, replacement shall occur within the same watershed and as close to the altered or destroyed wetland as practicable.(H)
Wetlands restoration, creation, and enhancement efforts should be completed before a wetland is altered or destroyed. If it is not practicable to complete all restoration, creation, and enhancement efforts before the wetland is altered or destroyed, these efforts shall be completed before the new use is occupied or used.(I)
Five years after a wetland is restored, created, or enhanced at least 75 percent of the replacement vegetation must survive. The owner shall monitor the hydrology and vegetation of the replacement wetland and shall take corrective measures to ensure that it conforms with the approved wetlands compensation plan and this guideline.(7)
Wetlands Buffer Zones(a)
The width of wetlands buffer zones shall be based on the dominant vegetation community that exists in a buffer zone.(b)
The dominant vegetation community in a buffer zone is the vegetation community that covers the most surface area of that portion of the buffer zone that lies between the proposed activity and the affected wetland. Vegetation communities are classified as forest, shrub, or herbaceous.(A)
A forest vegetation community is characterized by trees with an average height equal to or greater than 20 feet, accompanied by a shrub layer; trees must form a canopy cover of at least 40 percent and shrubs must form a canopy cover of at least 40 percent. A forest community without a shrub component that forms a canopy cover of at least 40 percent shall be considered a shrub vegetation community.(B)
A shrub vegetation community is characterized by shrubs and trees that are greater than 3 feet tall and form a canopy cover of at least 40 percent.(C)
A herbaceous vegetation community is characterized by the presence of herbs, including grass and grasslike plants, forbs, ferns, and nonwoody vines.(c)
Buffer zones shall be measured outward from a wetlands boundary on a horizontal scale that is perpendicular to the wetlands boundary. The following buffer zone widths shall be required:(A)
Forest communities: 75 feet(B)
Shrub communities: 100 feet(C)
Herbaceous communities: 150 feet(d)
Except as otherwise allowed, wetlands buffer zones shall be retained in their natural condition. When a buffer zone is disturbed by a new use, it shall be replanted with native plant species.(8)
Wetlands Compensation Plans Wetlands compensation plans shall be prepared when a project applicant is required to restore, create or enhance wetlands. They shall satisfy the following guidelines:(a)
Wetlands compensation plans shall be prepared by a qualified professional hired by a project applicant. They shall provide for land acquisition, construction, maintenance, and monitoring of replacement wetlands.(b)
Wetlands compensation plans shall include an ecological assessment of the wetland that will be altered or destroyed and the wetland that will be restored, created, or enhanced. The assessment shall include information on flora, fauna, hydrology, and wetlands functions.(c)
Compensation plans shall also assess the suitability of the proposed site for establishing a replacement wetland, including a description of the water source and drainage patterns, topography, wildlife habitat opportunities, and value of the existing area to be converted.(d)
Plan view and cross-sectional, scaled drawings; topographic survey data, including elevations at contour intervals no greater than 1 foot, slope percentages, and final grade elevations; and other technical information shall be provided in sufficient detail to explain and illustrate:(A)
Soil and substrata conditions, grading, and erosion and sediment control needed for wetland construction and long-term survival.(B)
Planting plans that specify native plant species, quantities, size, spacing, or density; source of plant materials or seeds; timing, season, water, and nutrient requirements for planting; and where appropriate, measures to protect plants from predation.(C)
Water-quality parameters, water source, water depths, water-control structures, and water-level maintenance practices needed to achieve the necessary hydrologic conditions.(e)
A 5-year monitoring, maintenance, and replacement program shall be included in all plans. At a minimum, a project applicant shall provide an annual report that documents milestones, successes, problems, and contingency actions. Photographic monitoring stations shall be established and photographs shall be used to monitor the replacement wetland.(f)
A project applicant shall demonstrate sufficient fiscal, technical, and administrative competence to successfully execute a wetlands compensation plan.
Source:
Rule 350-081-0560 — General Management Area Wetland Review Criteria, https://secure.sos.state.or.us/oard/view.action?ruleNumber=350-081-0560.