Lafayette Municipal Code Art. 5 Creek Setback Requirements

(a) As defined by Section 6-312 and Section 6-355, buildings and structures shall be set back from an unimproved creek channel as follows:

(1) Channel Depth of Zero through 21 Feet. If the side slopes of the channel are steeper than 2:1 (horizontal:vertical), the width of the setback is determined by a line measured from the toe of the slope a distance of twice the channel depth plus the appropriate top-of-bank setback as follows:

If the side slopes of the channel are flatter than 2:1 (horizontal:vertical) the setback is as indicated in the table above, measured from the top of the bank.

(2) Channel Depth Exceeding 21 Feet. If the depth of a channel exceeds 21 feet, the width of the setback is determined by measuring from the toe of the slope a distance of three times the channel depth.

(b) If a parcel is subject to subdivision easements or setback requirements under Contra Costa County Ordinance Code Sections 914-14.002 through 14.014 which are inconsistent with Section 6-1841(a), those subdivision requirements control.

(c) No structure other than fences, pervious surfaces, public access paths, trails, bioretention basins, bioswales, and drainage and erosion protection improvements may be constructed within the setback area. Landscaping (including trees and shrubs) is permitted within the setback area.

(d) When California Government Code Title 7, Chapter 12 ceases to apply pursuant to Government Code Section 66301, "unimproved creek channel" in subsection (a) shall be replaced with "creek channel."

(Ord. No. 684, § 2(Exh. 2), 4-10-2023)

(a) The city engineer may approve exceptions to the requirements of Section 6-1841 to allow construction of structures within the setback area if:

(1) The submitted materials under Section 6-1842(c) are complete and adequate; and

(2) The property owner agrees to enter into and record an agreement holding the city and other public agencies harmless in the event of flood or erosion damage. The agreement shall bind successors in interest and be in a form acceptable to the city attorney, and

(3) If applicable, the property owner agrees to implement any conditions imposed under Section 6-1842(b) and 6-1843.

(b) In approving an exception, the city engineer may impose conditions deemed necessary for erosion protection and on-site drainage, and for compliance with applicable laws, regulations, plans and guidelines. For parcels located in one of the four downtown commercial zoning districts, and in compliance with the downtown specific plan, downtown design guidelines, and downtown creeks preservation, restoration and development plan, the city engineer may consider additional conditions that include public access paths, trails, platforms or other improvements to allow viewsheds into a channel.

(c) A person requesting an exception under this section shall submit to the city engineer:

(1) A topographical survey of the lot precisely showing the creek bottom, sides, top of bank and proposed and existing structures or other development;

(2) A soils report prepared by a licensed geotechnical engineer which describes the soils condition for the proposed structure and analyzes and makes recommendations as to the creek bank stability and erosion hazard; and

(3) Certification signed by the geotechnical engineer who prepares the soils report that, in the professional opinion of the geotechnical engineer, there is no likelihood of a hazard to persons or property resulting from the proposed construction.

(d) The decision of the city engineer may be appealed to the city council as provided in Section 6-1852(b).

(Ord. No. 684, § 2(Exh. 2), 4-10-2023)

(a) If a parcel has received an exception pursuant to Section 6-1842, is located in one of the four downtown commercial zoning districts and contains invasive plant species within the setback area, the invasive plants shall be removed from the setback area and the area revegetated as follows:

(1) Vegetation removal shall be principally by hand and not by mechanized equipment;

(2) Disturbed or bare areas shall be planted pursuant to a planting plan prepared by a licensed landscape architect, or certified professional landscape designer and submitted to the city engineer. The planting plan shall use native riparian plants spaced to provide 90 percent coverage of disturbed or bare areas 12 months after installation; and

(3) Landscaping shall be maintained pursuant to a landscape maintenance agreement using a form provided by the city, signed and notarized by the property owner and recorded against the property. The agreement will require the property owner to preserve the vegetation shown in the plan, provide irrigation as needed and keep the setback area free of non-native vegetation and litter.

(Ord. No. 684, § 2(Exh. 2), 4-10-2023)