Chapter 18.305


18.305.010    Purpose.

18.305.020    Applicability.

18.305.030    Hydrologic study.

18.305.040    Development standards.

18.305.050    Application, review, and hearing.

18.305.060    Property maintenance agreements.

18.305.010 Purpose.

This chapter provides standards for the protection, maintenance, enhancement, and restoration of creeks, streams, and waterways in a manner that preserves their ecological integrity, function, and value, as follows:

A. Establish adequate buffer areas along waterways to avoid flood hazards and maintain or expand storage capacity for flood waters;

B. Protect water quality and in-stream habitat;

C. Preserve, enhance, and restore riparian habitat, adjacent wetlands, and upland buffers;

D. Provide for continuous wildlife migration corridors that connect habitat areas; and

E. Allow development that is compatible with the important physical, habitat, aesthetic, and recreation functions of waterways, while ensuring that these functions and values are protected in perpetuity. [Ord. 12-4. DC 2012 § 122-799].

18.305.020 Applicability.

The provisions of this chapter apply to any subdivision or proposed development, with the exception of public projects, as follows:

A. On any site adjacent to or crossed by a watercourse that is shown as a creek or stream channel on the city’s general plan map or as a blue line on the most recent United States Geological Survey (USGS) 7.5-minute topographic quadrangle map; or

B. On any site within the floodplain as defined in CMC 15.75.050. [Ord. 12-4. DC 2012 § 122-800].

18.305.030 Hydrologic study.

A design and site development permit shall be required for improvements to any applicable property in addition to any other permit (subdivision, use permit, design review, etc.) required by the development code. All applications for a site development permit shall include:

A. A site-specific hydrologic study prepared by a hydrologist, civil engineer, or other qualified professional, approved by the city, to identify the precise locations of the waterway centerline, the boundary/top of bank of the waterway, and the boundary of the 100-year floodplain. This requirement may be waived if the city engineer determines that the project, because of its size, location, or design, will not have a significant impact on the waterway, or that sufficient information already exists and further analysis is not necessary. This study shall include all information and materials as required by the city engineer; and

B. Grading and improvements plans shall be submitted along with the hydrologic study. [Ord. 12-4. DC 2012 § 122-801].

18.305.040 Development standards.

A. Structure Setbacks for Unimproved Channels.

1. “Unimproved channel” means a watercourse, which has been left as much as possible in its natural state.

2. “Watercourse” means any natural or manmade channel for transporting water, including the stream bed and the banks, whether continuously flowing or intermittent.

3. “Structure setback line” means the line separating the structure setback area from the remainder of the lot. For unimproved earth channels, a structure setback line shall be shown on all plans submitted with any development application as follows: The thalweg of the channel shall be shown as accurately as possible on the plan, and a dashed line shall indicate the appropriate setback with a note describing the method used to determine the top of bank, selected from those set forth herein.

4. “Top of bank” means the point where a line with a slope of two-and-one-half horizontal to one vertical extending from the toe of the channel intersects the existing ground, whichever point is the greatest vertical distance above the channel invert. A separate top of bank shall be determined for each side of the channel. (See Figure 18.305.040.)

Figure 18.305.040

B. The structure setback line for unimproved channels shall be determined by measuring the following horizontal distance away from the top of bank on each side of the watercourse as shown in Table 18.305.040. Where significant riparian vegetation exists beyond these setbacks, additional setbacks may be required by the review authority to preserve the existing vegetation.

Table 18.305.040

Structure Setbacks for Unimproved Channels

Height of Top of Bank Above Channel Invert

Horizontal Distance Between Top of Bank and Setback

less than 20 feet

30 feet

20 feet – 29.99 feet

35 feet

30 feet – 39.99 feet

40 feet

40 feet – 49.99 feet

45 feet

50 feet and greater

50 feet

C. Trails. Paths or trails may be located within a structure setback; however, no road, parking area, parking space, or paved area shall be constructed within the setback area.

D. Alteration of Natural Features. No grading or filling, planting of exotic/nonnative or nonriparian plant species, or removal of native vegetation shall occur within structure setback area, except where authorized for flood control purposes with the proper permits issued by the California State Department of Fish and Game, and all other applicable state and federal agencies.

E. Design of Drainage Improvements. Where drainage improvements are required, they shall be placed in the least visible locations and designed with natural materials through the use of river rock, earth-tone concrete, and landscaping with native plant materials.

F. Use of Permeable Surfaces. The proposed project should incorporate permeable surfaces (for example, wood plank decks, sand-joined bricks, and stone walkways) where feasible, to minimize off-site flows and facilitate the absorption of water into the ground.

G. Creek Bank Stabilization. Development projects or land use changes that increase impervious surfaces or sedimentation may result in channel erosion. This may require measures to stabilize the banks.

1. Creek rehabilitation is the preferred method of stabilization, with the objective of maintaining the natural character of the creek 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/or 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 measures other than rehabilitation or vegetative methods, hand-placed stone or rock riprap are the preferred methods (as specified in subsection (F) of this section).

H. Physical and Visual Access. The provision of multi-purpose creekside trails and public open space is encouraged. Open space areas should include planting for riparian enhancement with native shrubs and trees. Paths and trails, lighting, benches, exercise courses/stations, and trash receptacles may also be provided, outside of the riparian habitat area, where appropriate. [Ord. 12-4. DC 2012 § 122-802].

18.305.050 Application, review, and hearing.

A design and site review permit shall be required for all improvements to all applicable properties. The site review permit shall be processed, reviewed, and approved or disapproved in accordance with the provisions in Chapter 18.415 CDC (Design and Site Review) and all approvals shall meet the development standards in CDC 18.305.040. [Amended during 2014 recodification; Ord. 12-4. DC 2012 § 122-803].

18.305.060 Property maintenance agreements.

A. Property owners with a creek on their property or fronting on a creek shall maintain the creek and abutting vegetation, including removal of any trash accumulated by the creek.

B. Any permit approval shall require the property owner to enter into a city-approved agreement to ensure the improvements are maintained continuously in compliance with the conditions of approval imposed by the review authority, in accordance with Chapter 18.520 CDC (Performance Guarantees and Property Maintenance). [Ord. 12-4. DC 2012 § 122-804].