Chapter 17.50

WATERCOURSE AND RIPARIAN RESOURCE PROTECTION

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.

(A (part), 2004; Ord. 766 § 2 Exh)

The provisions of this chapter apply to proposed development on any site adjacent to or crossed by Copeland, Cotati, or Washoe Creeks, and/or Laguna de Santa Rosa (see Figure 5-1).

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Figure 5-1. Watercourses Where Standards of Chapter 17.50 Apply

(A (part), 2004; Ord. 766 § 2 Exh)

Each planning permit application for a project that is subject to this chapter shall include a site-specific streambed 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 streambed analysis shall include all information and materials required by the department. (A (part), 2004; Ord. 766 § 2 Exh)

• A. Watercourse Setback Requirement. Each proposed structure shall be set back from the top of the bank of a watercourse by a minimum distance of two and one-half times the height of the bank or thirty feet, whichever is greater.

  1. Additional setbacks may be required to preserve existing vegetation or other significant environmental resources along the watercourse.

  2. The review authority may grant an exception to this setback requirement:

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City of Cotati, CA

COTATI CODE

§ 17.50.040

§ 17.50.040

• a. Where a watercourse has been previously channelized; or

• b. In the NU, CD, SPD, and CE zones, where an existing structure is being replaced and is not in an area subject to flooding, and/or where the setback would be inconsistent with the urbanized character of the site and adjacent parcels.

3. A watercourse setback adjacent to a path or open spaces shall be measured from the outside boundary of the path or open space.

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Figure 5-2. Watercourse Setback Requirement

• B. Top of Bank Defined. The "top of bank" means the upper elevation of land, having a slope not exceeding ten percent, which confines the channel waters flowing in the watercourse in their normal winter flow.

• C. Use of Required Setback. A path or trail may be within a watercourse setback; however, no other structure, road, parking access or space, paved area, or swimming pool shall be constructed within a watercourse or watercourse setback.

• 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 a watercourse or watercourse setback area, except:

  1. The review authority may grant an exception where the work is authorized for flood control purposes by permits issued by the California State Department of Fish and Game, and/or all other applicable local, state, and federal agencies having authority over the creek; and

  2. As otherwise provided by this section.

• E. 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, earthtone concrete, and landscaping with native plant materials.

• F. Bank Stabilization. Development or land use changes that increase impervious surfaces or sedimentation may result in channel erosion. Therefore, the city engineer may require measures to stabilize watercourse banks.

  1. Rehabilitation is the preferred method of stabilization, with the objective of maintaining 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-

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City of Cotati, CA § 17.50.040

LAND USE

§ 17.50.040

placed stone or rock rip-rap are the preferred methods.

• G. Physical and Visual Access. Proposed subdivisions and other development shall provide public access to watercourses as follows, and as required by the review authority.

  1. Map Act Requirements. A proposed subdivision shall comply with the public access requirements of Map Act Chapter 4, Article 3.5 (Public Access to Public Resources).

  2. Streets. A proposed subdivision shall provide public access and visibility to watercourses through the use of single-loaded frontage roads adjacent to creeks, but outside of the watercourse setback. Where a single-loaded street is not possible, frequent access to trails along the watercourse and public open space should be provided at least every three hundred feet, and may occur at the end of dead-end streets.

  3. Trails. The review authority may require subdivisions and other proposed development to provide multipurpose creekside trails.

• H. Open Space Areas.

  1. Open space areas within watercourse setbacks shall include planting for riparian enhancement with native shrubs and trees.

  2. Open space areas outside of watercourse setbacks may include paths and trails, lighting, benches, play and exercise equipment, and trash receptacles, where appropriate.

• (A (part), 2004; Ord. 766 § 2 Exh; C (part), 2009; Ord. 823 § 2(C) Exh)

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City of Cotati, CA