16.05.420 Dredging and dredge spoil disposal

16.05.420 Dredging and dredge spoil disposal.

(a) Dredging and disposal of dredge spoils shall avoid, then minimize significant ecological impact; impacts that cannot be avoided shall be mitigated to achieve no net loss of ecological processes and functions. Proposals for dredging and dredge disposal shall include details on all feasible mitigation measures to protect aquatic habitats.

(b) Dredging and dredge spoil disposal are prohibited in wetlands, except for the purposes of enhancing valuable wetland functions. A design prepared by a qualified wetland scientist is required prior to allowing dredging and/or disposal of dredge spoils into a wetland.

(c) The City of Covington may impose limitations on dredging activities, such as limited operating hours, time periods, and requirements for buffer strips at the site.

(d) New development siting and design shall avoid the need for new and maintenance dredging.

(a) Dredging may be permitted as a conditional use activity only:

(i) When necessary to support a water-dependent use or navigation;

(ii) For expansion or alteration of public utility facilities or bridges within a public right-of-way, when there is a documented need and where other feasible sites or routes do not exist;

(iii) As part of approved mitigation actions, environmental restoration, and habitat enhancement projects;

(iv) To improve water quality;

(v) To improve water flow or manage flooding when a biological and geomorphological study demonstrates a long-term benefit to hazard reduction and the action is part of a comprehensive flood management solution; or

(vi) To clean up contaminated sediments.

(b) Where dredging is permitted pursuant to subsection (2)(a) of this section, the applicant shall demonstrate that applicable permits of other local, State, and Federal agencies have been obtained, and shall demonstrate using technical information produced by a qualified professional that:

(i) Water circulation, littoral drift, aquatic life, and water quality will not be substantially impaired; and

(ii) Other solutions would result in greater environmental impact.

(c) Dredging to establish, expand, relocate, or reconfigure navigation channels consistent with subsection (2)(a)(i) of this section shall be allowed only where needed to accommodate existing navigational uses, and then only when significant ecological impacts are minimized and when mitigation is provided consistent with required mitigation sequencing.

(d) Maintenance dredging of established navigation channels and basins shall be restricted to maintaining the previously dredged and/or existing authorized location, depth and width.

(e) When dredging is permitted, the extent of dredging shall be the minimum necessary to accommodate the proposed use.

(f) Dredging for the primary purpose of obtaining fill or construction material is prohibited.

(g) Dredging shall be timed so that it does not interfere with aquatic life.

(h) Dredging shall utilize techniques (such as hydraulic dredging instead of agitation dredging) that cause minimal dispersal and broadcast of bottom material.

(i) Dredging landward of the ordinary high water mark is considered excavation and shall be subject to the regulations set forth in CMC 16.05.430.

(a) Disposal of dredge spoils shall be done only in approved sites.

(b) Dredging material that will not subsequently cause violation of State Water Quality Standards may be used in permitted landfill projects.

(c) Individual disposal operations shall comply with Department of Natural Resources leasing practices, the Department of Ecology Water Quality Certification process, and the permit requirements of the State Department of Fish and Wildlife and the U.S. Army Corps of Engineers.

(d) Dredge spoil disposal waterward of the ordinary high water mark may be allowed only by conditional use permit for one or more of the following circumstances:

(i) For wildlife habitat improvement;

(ii) To correct problems of material distribution adversely affecting fish;

(iii) For permitted beach enhancement;

(iv) When the alternative of depositing material on land is demonstrated to be more detrimental to shoreline resources than depositing in water areas; or

(v) In approved open-water disposal sites as identified by appropriate agencies.

(e) If suitable alternatives for land disposal are not available or are infeasible consistent with subsection (3)(d)(iv) of this section, water disposal sites shall be identified consistent with the following criteria:

(i) Sites shall not interfere with geohydrologic processes;

(ii) Dredge spoils have been analyzed by qualified personnel and found to be nonpolluting;

(iv) Aquatic life will not be adversely affected; and

(v) The sites and method of disposal shall meet all requirements of applicable regulatory agencies.

(f) Dredge disposal within the channel migration zone of Jenkins Creek, Big Soos Creek or any other stream is prohibited, unless part of an approved fish habitat improvement project and studies indicate it is consistent with the criteria in subsection (3)(e) of this section.

(g) Any significant placement of materials from off site (other than surcharge or pre-load), or the substantial creation or raising of dry upland shall be considered fill and shall also comply with the fill provisions of CMC 16.05.430. (Ord. 09-19 § 6 (Exh. C))