17.130.080 Allowed permitted activities in streams and buffers – SMP.
(1) See SMC 17.114.140 for allowed activities. In addition to the provisions of that section, the following apply:
(a) Public and Private Pedestrian Trails (in Buffers Only). In addition to the provisions of SMC 17.114.140(4)(e), trails proposed in stream buffers shall be located in the outer 25 percent of the buffer area, the farthest distance from the stream, and shall be constructed of pervious materials.
(2) Conservation, Preservation, Restoration and/or Enhancement. Restoration and/or enhancement of wetlands or their buffers; provided, that actions do not alter the location, dimensions or size of the buffer; that actions do not alter or disturb existing native vegetation or wildlife habitat attributes; that actions improve and do not reduce the existing functions of the stream or buffer; and that actions are implemented according to a restoration and/or enhancement plan that has been approved by the city of Stanwood.
(3) Disturbance of Soils. When disturbance of soils is necessary in stream buffers as part of an authorized, permitted activity or as otherwise allowed in these standards, the following shall apply:
(a) Grading is allowed only during the dry season, which is typically regarded as beginning on May 1st and ending on October 1st of each year; provided, that the city of Stanwood may extend or shorten the dry season on a case-by-case basis, based on actual weather conditions.
(b) The soil duff layer in ungraded areas shall remain undisturbed to the maximum extent possible. Where feasible, any soil disturbed shall be redistributed to other nonwetland and stream areas of the project site.
(c) The moisture-holding capacity of the topsoil layer shall be maintained by minimizing soil compaction or reestablishing natural soil structure and infiltrative capacity on all areas of the project area not covered by impervious surfaces.
(d) Erosion and sediment control that meets or exceeds the standards set forth in the city of Stanwood’s stormwater regulations (Chapter 17.140 SMC) shall be provided.
(4) Public and Private Roadway Crossings, Bridges, and Culverts. Construction of public and private roadway crossings and bridges less than or equal to 30 feet wide and culverts less than or equal to 30 feet long, subject to the following standards:
(a) There is no other feasible alternative route with less impact on the stream or buffer;
(b) Stream crossings minimize interruption of downstream movement of wood and gravel;
(c) Mitigation for impacts is provided pursuant to an approved mitigation plan; and
(d) Stream bridges and culverts are designed according to the Washington Department of Fish and Wildlife “Fish Passage Design at Road Culverts,” March 1999, or the National Marine Fisheries Service “Guidelines for Salmonid Passage at Stream Crossings,” 2000.
(5) Utility Lines. New utility lines may be permitted to cross wetlands and their buffers if they comply with the following standards:
(a) Critical areas and their buffers shall be avoided to the maximum extent feasible;
(b) Installation across a stream shall be accomplished by boring beneath the scour depth and hyporheic zone of the water body and channel migration zone, unless it is not feasible due to engineering constraints;
(c) Installation under a wetland shall be accomplished when feasible by boring beneath the wetland at a depth sufficient to prevent adverse hydrology impacts;
(d) Mitigation for impacts is provided by the city of Stanwood;
(e) The utilities shall cross at an angle between 60 and 90 degrees to the centerline of the channel in streams or perpendicular to the channel centerline whenever boring under the channel is not feasible due to engineering constraints;
(f) Crossings shall be contained within the footprint of an existing street, driveway, or utility crossing where possible;
(g) The utility route shall avoid paralleling the stream or following a down-valley course near the channel; and
(h) The utility installation shall not increase or decrease the natural rate of shore migration or channel migration.
(6) Streambank Stabilization.
(a) Streambank stabilization to protect new structures from future channel migration is not permitted except when such stabilization is achieved through bioengineering or soft armoring techniques in accordance with an approved critical area report. All actions must comply with the appropriate state and federal guidelines and obtain any required state and federal permits.
(b) Streambank stabilization to protect existing structures from channel migration is permitted in accordance with an approved critical area report. All actions must comply with the appropriate state and federal guidelines and obtain any required state and federal permits.
(c) Maintenance of existing streambank stabilization features is allowed under the following conditions:
(i) No power tools shall be used within the stream and stream buffer. Only hand equipment shall be utilized;
(ii) No clearing of vegetation within the stream or stream buffer;
(iii) Maintenance actions shall be restricted to May 1st through October 1st or as modified by appropriate state and federal timing restrictions.
(7) All actions must comply with the appropriate state and federal guidelines and obtain any required state and federal permits.
(8) Modification of Existing Structures. No existing structure may be modified to increase impervious surface in the stream or stream buffer. (Ord. 1373 § 44, 2014; Ord. 1164 § 4, 2004; Ord. 929 Ch. 10(H)(3), 1995. Formerly 17.130.030).