Environment & Sustainability | Environmentally Critical Areas
stream habitat or inhibit migration of anadromous fish; ii. All crossings are constructed during the summer low flow and are timed to avoid stream disturbance during periods when use is critical to resident or anadromous fish including salmonids; iii. Crossings do not occur over spawning areas used by resident or anadromous fish including salmonids unless the City determines that no other reasonable crossing site exists; iv. Bridge piers or abutments are not placed within the FEMA floodway or the ordinary high water mark;
viii. The number of crossings is minimized and consolidated to serve multiple purposes and properties whenever possible. h. Relocations. Stream relocations may be allowed only for: i. Type F, Np, and Ns streams as part of a public road, trail, or park project for which a public agency and utility exception is granted pursuant to SDC 21.03.020F.; and ii. Type F, Np and Ns streams for the purpose of enhancing resources in the stream if: a) Appropriate floodplain protection measures are used; and b) The relocation occurs on site, except that relocation off site may be allowed if the applicant demonstrates that any on-site relocation is impracticable, the applicant provides all necessary easements and waivers from affected property owners and the off-site location is in the same drainage sub-basin as the original stream. i. For any relocation allowed by this section, the applicant shall demonstrate, based on information provided by qualified professionals, including a civil engineer and a biologist, that:
v. Crossings do not diminish the flood-carrying capacity of the stream;
vi. Underground utility crossings are laterally drilled and located at a depth of four feet below the maximum depth of scour for the base flood predicted by a civil engineer licensed by the state of Washington. Temporary bore pits to perform such crossings may be permitted within the stream buffer established in SDC 21.03.020AA.1. Crossing of Type Ns streams when dry may be made with open cuts; vii. Trail crossings shall use bridges and boardwalks consistent with the design requirements of the Washington Department of Fish and Wildlife (WDFW, 2003, Design of Road Culverts for Fish Passage, as amended); and
i. The equivalent base flood storage volume and function will be maintained;
118 | Title 21: Sammamish Development Code
Effective | January 1, 2022
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