Chapter 18.52


18.52.010    Purpose

18.52.020    Applicability

18.52.030    Stream Channel Analysis

18.52.040    Limitation on Streambed Alteration

18.52.050    Development Standards

18.52.010 - Purpose

This Chapter provides standards for the protection of watercourse and riparian resources within the City, including provisions for adequate buffer areas between watercourses and adjacent development, to retain the watercourses as valuable natural, scenic, and recreational amenities as appropriate.

18.52.020 - Applicability

The provisions of this Chapter apply to proposed development on any site within the City that is adjacent to or crossed by a watercourse.

18.52.030 - Stream Channel Analysis

Each planning permit application for a project that is subject to this Chapter shall include a site-specific stream channel analysis prepared by a hydrologist, civil engineer, or other qualified professional approved by the City to identify the precise boundary/top of bank of the watercourse. The Director may waive this requirement if it is determined that the project, because of its size, location, or design will have no impact on the watercourse, or that sufficient information already exists and further analysis is not necessary. A required stream channel analysis shall include all information and materials required by the Department.

18.52.040 - Limitation on Streambed Alteration

Channelization, dams or other substantial alteration of stream channels are limited to:

A.    Water supply projects, provided that quantity and quality of water from streams shall be maintained at levels necessary to sustain functional capacity of streams, wetlands, estuaries and lakes;

B.    Flood control projects, where such protection is necessary for public safety or to protect existing commercial or residential structures, when no feasible alternative to streambed alteration is available;

C.    Construction of improvements to fish and wildlife habitat; and

D.    Maintenance of existing flood control channels.

Streambed alterations shall not be conducted unless consistent with all applicable provisions of these regulations and if applicable, permit approval from the California Department of Fish and Game, the U.S. Army Corps of Engineers, and California State Water Resources Control Board.

18.52.050 - Development Standards

A.    Watercourse setback requirement. New development shall be setback a minimum of 50 feet from the top of the creek bank (or the upland edge of riparian vegetation where no top of bank in compliance with Subsection A.3. exists), except as provided in Subsection A.2., and as follows:

1.    Permitted uses within the setback. Permitted uses are limited to passive recreation, educational (interpretive) facilities, utility lines, pipelines, drainage and flood control facilities, bridges, pedestrian and equestrian trails, if the Review Authority first finds that:

a.    Alternative locations and routes are infeasible or more environmentally damaging; and

b.    Adverse environmental effects are mitigated to the maximum extent feasible.

2.    Riparian habitat setback adjustment. Permit approval may include the reduction of a minimum riparian setback if the Review Authority first makes all the following findings, provided that in no case shall a structure be allowed closer than 10 feet from a stream bank.

a.    The adjustment is necessary to allow a principal permitted use of the property, and redesign of the proposed development to comply with the required setback would not allow the use; and

b.    The adjustment is the minimum necessary to accommodate the principal permitted use; and

c.    A biological analysis prepared by a qualified professional approved by the City determines that the lesser setback is sufficient to protect the riparian habitat; or

d.    The required setback would prohibit all reasonable development of the site.

3.    Top of bank defined. The top of bank shall mean the upper elevation of land, having a slope not exceeding 10 percent, which confines the channel waters flowing in the watercourse in their normal winter flow.

B.    Removal or alteration of riparian vegetation. The removal, cutting or alteration of vegetation that protects a riparian habitat is permitted only:

1.    For streambed alterations allowed by Section 18.52.040 above;

2.    Where no feasible alternative exists;

3.    Where an issue of public safety exists;

4.    Where expanding vegetation is encroaching on established agricultural uses;

5.    For minor public works projects, including but not limited to utility lines, pipelines, driveways and roads, where the Director determines no feasible alternative exists; or

6.    To locate a principally permitted use on an existing lot of record where no feasible alternative exists, and the Review Authority first makes all the findings provided in Subsections A.1. and A.2. above.

C.    Bank stabilization. Development or land use changes that increase impervious surfaces or sedimentation may result in channel erosion. Therefore, the Director, Public Works may require measures to stabilize watercourse banks.

1.    Rehabilitation is the preferred method of stabilization to maintain the natural character of the watercourse and riparian area. Rehabilitation may include enlarging the channel at points of obstruction, clearing obstructions at points of constriction, limiting uses in areas of excessive erosion, and restoring riparian vegetation.

2.    Concrete channels and other mechanical stabilization measures shall not be allowed unless no other alternative exists.

3.    If bank stabilization requires other than rehabilitation or vegetative methods, hand-placed stone or rock rip-rap are the preferred methods.

D.    Design of drainage improvements. Where daylighted drainage improvements are approved, they shall be placed in the least visible locations and naturalized through the use of river rock, earth tone concrete, and landscaping with native plant materials.