(1) In-stream and in-water structures may be permitted in all environmental designations, except the Natural designation where they are prohibited, through a substantial development or conditional use permit as indicated in CCC 35.10.090, Table 2-2, when consistent with this Program and when associated with and necessary for an ecological restoration project, a fish passage project, or a permitted shoreline use/development such as a transportation facility.

(2) In-stream and in-water structures shall not impede upstream or downstream migration of anadromous fish. All new and replacement structures, including culverts, must be made fish passable in accordance with the most recent Washington State Department of Fish and Wildlife requirements or with the National Marine Fisheries Service guidelines for Endangered Species Act-listed species.

(3) All in-water diversion structures shall be designed to permit the natural transport of bedload materials. All debris, overburden, and other waste materials from construction shall be disposed of in such a manner that prevents their entry into a water body.

(4) All in-stream and in-water structures shall be designed and installed by a licensed, professional engineer.

(5) In-stream and in-water structures shall be constructed and maintained in a manner that does not degrade the quality of affected waters.

(6) In-stream structures and their support facilities shall be located and designed to avoid and minimize the need for structural shoreline stabilization.

(7) In-stream and in-water structures shall be located and designed to preserve or enhance aquatic habitat and to minimize impacts on the visual and aesthetic quality of the shoreline.

(8) During construction in stream and in water, all heavy construction equipment and fuel storage, repair, and construction material staging areas shall be located as far landward as necessary to avoid and minimize impacts to shoreline functions.

(9) Natural in-stream and in-water features such as snags, uprooted trees, or stumps should be left in place unless it can be demonstrated that they are not enhancing shoreline function or are a threat to public safety.

(10) In-stream structures such as, but not limited to, high-flow bypasses, and weirs, may be permitted in Type S, F, Np, Ns Waters when they are part of a watershed restoration project or identified in watershed planning documents prepared and adopted under Chapter 90.82 RCW, the salmonid recovery plan or Salmon Recovery Board Habitat Project List, and the County’s shoreline restoration plan and upon acquisition of any required State or federal permits. The structure shall be designed to avoid adverse impacts on stream flow, water quality, or other habitat functions and values.