40.240.850 General Management Area Stream, Pond, Lake and Riparian Area Review Criteria

A.    Stream, Pond, and Lake Boundaries and Site Plans for Review Uses in Aquatic and Riparian Areas.

1.    If a proposed use would be in a stream, pond, lake or their buffer zones, the project applicant shall be responsible for determining the exact location of the ordinary high water mark or normal pool elevation.

2.    In addition to the information required in all site plans, site plans for proposed uses in streams, ponds, lakes, and their buffer zones shall include:

a.    A site plan map prepared at a scale of one (1) inch equals one hundred (100) feet (1:1,200), or a scale providing greater detail;

b.    The exact boundary of the ordinary high water mark or normal pool elevation and prescribed buffer zone; and

c.    A description of actions that would alter or destroy the stream, pond, lake, or riparian area.

(Amended: Ord. 2018-03-04)

B.    Uses.

Uses allowed outright in streams, ponds, lakes, and their buffer zones are listed in Section 40.240.120.

(Amended: Ord. 2018-03-04)

C.    The following uses may be allowed in streams, ponds, lakes and riparian areas, and their buffer zones, when approved pursuant to Section 40.240.850(E), and reviewed under the applicable provisions of Sections 40.240.800 through 40.240.900; provided, that proposed uses in streams, ponds, lakes, and their buffer zones shall be evaluated for adverse effects, including cumulative effects, and adverse effects shall be prohibited:

1.    The modification, expansion, replacement, or reconstruction of serviceable structures; provided, that such actions would not:

a.    Increase the size of an existing structure by more than one hundred percent (100%);

b.    Result in a loss of water quality, natural drainage, and fish and wildlife habitat; or

c.    Intrude further into a stream, pond, lake, or buffer zone. New structures shall be considered intruding further into a stream, pond, lake, or buffer zone if any portion of the structure is located closer to the stream, pond, lake, or buffer zone than the existing structure.

2.    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.

3.    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.

(Amended: Ord. 2018-03-04)

D.    Uses not listed in Section 40.240.850(B) and (C) may be allowed in streams, ponds, lakes, and riparian areas, when approved pursuant to Section 40.240.850(F) and reviewed under the applicable provisions of Section 40.240.800 through 40.240.900.

E.    1.    Applications for modifications to serviceable structures and minor water-dependent and water-related structures in aquatic and riparian areas shall demonstrate that:

a.    Practicable alternatives to locating the structure outside of the stream, pond, lake, or 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 water quality, natural drainage, and fish and wildlife habitat of streams, ponds, lakes, and riparian areas;

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 local laws.

2.    Applications for all other review uses in wetlands, streams, ponds, and lakes shall demonstrate that:

a.    The proposed use is water-dependent, or is not water-dependent but has no practicable alternative as determined by Section 40.240.840(F)(1), substituting the term “stream,” “pond,” “lake,” or “riparian area” as appropriate.

b.    The proposed use is in the public interest as determined by Section 40.240.840(F)(2), substituting the term “stream,” “pond,” “lake,” or “riparian area” as appropriate.

c.    Measures have been applied to ensure that the proposed use results in minimum feasible impacts to water quality, natural drainage, and fish and wildlife habitat of the affected stream, pond, lake, and/or buffer zone. At a minimum, the following mitigation measures shall be considered when new uses are proposed in streams, ponds, lakes, and buffer zones:

(1)    Construction shall occur during periods when fish and wildlife are least sensitive to disturbance. The Washington Department of Fish and Wildlife shall evaluate specific proposals and specify periods for in water work.

(2)    All natural vegetation shall be retained to the greatest extent practicable, including aquatic and riparian vegetation.

(3)    Nonstructural controls and natural processes shall be used to the greatest extent practicable.

(4)    Bridges, roads, pipeline and utility corridors, and other water crossings shall be minimized and should serve multiple purposes and properties.

(5)    Stream channels should not be placed in culverts unless absolutely necessary for property access. Bridges are preferred for water crossings to reduce disruption to streams, ponds, lakes, and their banks. When culverts are necessary, oversized culverts with open bottoms that maintain the channel’s width and grade should be used.

(6)    Temporary and permanent control measures should be applied to minimize erosion and sedimentation when riparian areas are disturbed, including slope netting, berms and ditches, tree protection, sediment barriers, infiltration systems, and culverts.

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 be located outside of stream, pond, and lake buffer zones.

f.    The proposed use complies with all applicable federal, state, and county laws.

g.    Unavoidable impacts to aquatic and riparian areas will be offset through rehabilitation and enhancement. Rehabilitation and enhancement shall achieve no net loss of water quality, natural drainage, and fish and wildlife habitat of the affected stream, pond, lake, and/or buffer zone. When a project area has been disturbed in the past, it shall be rehabilitated to its natural condition to the maximum extent practicable. When a project area cannot be completely rehabilitated, such as when a boat launch permanently displaces aquatic and riparian areas, enhancement shall also be required. The following rehabilitation and enhancement guidelines shall apply:

(1)    Rehabilitation and enhancement projects shall be conducted in accordance with a rehabilitation and enhancement plan.

(2)    Natural hydrologic conditions shall be replicated, including current patterns, circulation, velocity, volume, and normal water fluctuation.

(3)    Natural stream channel and shoreline dimensions shall be replicated, including depth, width, length, cross-sectional profile, and gradient.

(4)    The bed of the affected aquatic area shall be rehabilitated with identical or similar materials.

(5)    Riparian areas shall be rehabilitated to their original configuration, including slope and contour.

(6)    Fish and wildlife habitat features shall be replicated, including pool-riffle ratios, substrata, and structures. Structures include large woody debris and boulders.

(7)    Stream channels and banks, shorelines, and riparian areas shall be replanted with native plant species that replicate the original vegetation community.

(8)    Rehabilitation and enhancement efforts shall be completed no later than ninety (90) days after the aquatic area or buffer zone has been altered or destroyed, or as soon thereafter as is practicable.

(9)    Three (3) years after an aquatic area or buffer zone is rehabilitated or enhanced, at least seventy-five percent (75%) of the replacement vegetation must survive. The owner shall monitor the replacement vegetation and take corrective measures to satisfy this guideline.

F.    Stream, Pond, and Lake Buffer Zones.

1.    Buffer zones shall generally be measured landward from the ordinary high water mark on a horizontal scale that is perpendicular to the ordinary high water mark. On the main stem of the Columbia River above Bonneville Dam, buffer zones shall be measured landward from the normal pool elevation of the Columbia River. The following buffer zone widths shall be required:

a.    Streams verified by state or federal resource management agencies as habitat for species recognized to be threatened or endangered by the U.S. Fish and Wildlife Service, Washington Department of Fish and Wildlife, or Washington Department of Natural Resources: one hundred fifty (150) feet.

b.    Streams used by anadromous or resident fish (tributary fish habitat), special streams, intermittent streams that include year-round pools, and perennial streams: one hundred (100) feet.

c.    Intermittent streams; provided, that they are not used by anadromous or resident fish: fifty (50) feet.

d.    Ponds and Lakes. Buffer zone widths shall be based on dominant vegetative community as determined by Section 40.240.840(G)(2), substituting the term “pond” or “lake” as appropriate.

2.    Except as otherwise allowed, buffer zones shall be retained in their natural condition.

3.    When a buffer zone is disturbed by a new use, it shall be replanted with native plant species.

4.    Determining the exact location of the ordinary high water mark or normal pool elevation shall be the responsibility of the project applicant. The responsible official may verify the accuracy of, and may render adjustments to, an ordinary high water mark or normal pool delineation. In the event the adjusted boundary delineation is contested by the applicant, the responsible official shall, at the project applicant’s expense, obtain professional services to render a final delineation.

G.    Rehabilitation and Enhancement Plans.

    Rehabilitation and enhancement plans shall be prepared when a project applicant is required to rehabilitate or enhance a stream, pond, lake and/or buffer area. They shall satisfy the following guidelines:

1.    Rehabilitation and enhancement plans are the responsibility of the project applicant; they shall be prepared by qualified professionals, such as fish or wildlife biologists.

2.    All plans shall include an assessment of the physical characteristics and natural functions of the affected stream, pond, lake, and/or buffer zone. The assessment shall include hydrology, flora, and fauna.

3.    Plan view and cross-sectional, scaled drawings; topographic survey data, including elevations at contour intervals of at least two (2) feet, 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 excavation, and erosion and sediment control needed to successfully rehabilitate and enhance the stream, pond, lake, and buffer zone.

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 predating.

c.    Water-quality parameters, construction techniques, management measures, and design specifications needed to maintain hydrologic conditions and water quality.

4.    A three (3) year monitoring, maintenance, and replacement program shall be included in all rehabilitation and enhancement plans. At a minimum, a project applicant shall prepare an annual report that documents milestones, successes, problems, and contingency actions. Photographic monitoring shall be used to monitor all rehabilitation and enhancement efforts.

5.    A project applicant shall demonstrate sufficient fiscal, administrative, and technical competence to successfully execute and monitor a rehabilitation and enhancement plan.

H.    Wetlands enhancement projects shall be consistent with Section 40.240.840(H).

(Amended: Ord. 2006-05-04)