City of Burlington: An Ordinance in Relation to Comprehensive Development Ordinance-Steep Slopes ZA#22-03

In the Year Two Thousand Twenty-Two
ORDINANCE 6.11Sponsor: Office of City Planning, Planning Commission, Ordinance Committee
Public Hearing Dates: 08/15/22
First reading: 06/27/22
Referred to: Ordinance Committee to Rules suspended and placed in all stages of passage:

Second reading: 08/15/22
Action: adopted
Date: 08/15/22
Signed by Mayor: 08/24/22
Published: 09/28/22
Effective: 10/19/22

It is hereby Ordained by the City Council of the City of Burlington as follows:

That Appendix A, Comprehensive Development Ordinance, of the Code of Ordinances of the City of Burlington be and hereby is amended by amending Section 5.2.4, Buildable Area Calculation, and adding Map 5.2.4-1, Steep Slopes Overlay District, thereof to read as follows:

Sec. 5.2.4 Buildable Area Calculation & Steep Slopes Overlay District The intent of this section is to: To protect sensitive natural features; To prevent overdevelopment of properties that contain sensitive and unbuildable areas, and

To minimize the potential for erosion, slope failure, and contamination of surface waters caused by the adverse effects of development on steep slopes, and

To ensure that new development fits within the existing scale and intensity of the surrounding neighborhood.

(a) Buildable Area Calculation

For any properties two (2) or more acres in size within any RCO, WRM, RM, WRL, or RL zoning district, the maximum building density or lot coverage shall be calculated using the buildable area only. Buildable area shall be deemed to include only those portions of a property that are not inundated at least six months per year by water including streams, ponds, lakes, wetlands and other bodies of water; and lands with a slope in excess of 30%.

The DRB may under conditional use criteria allow up to 50% of the maximum building density or lot coverage to be calculated on lands with a slope between 15-30% if the applicant can demonstrate that the additional density or lot coverage will be compatible within the existing scale and intensity of the surrounding neighborhood, and not have an undue negative impact on sensitive natural features.

(b) Steep Slopes Overlay District

This overlay district consists of all lands delineated in Map 5.2.4-1 – Steep Slopes Overlay District. This overlay district contains expanses of contiguous land with an average slope of 15% or greater over 50-foot intervals and adjacent lands within 50 feet of the top of slope.

***[Attached Map 5.2.4-1 – Steep Slopes Overlay District will be inserted here]

The boundaries shown on the Steep Slopes Overlay Map may be supplemented or modified by examination of one or more of the following sources by the Development Review Board whenever an application is submitted for review.

Contour maps prepared from the most current orthophotography.

On-site survey prepared by a registered professional engineer or surveyor.

The Zoning Administrative Officer or Development Review Board shall determine whether or not the Steep Slope Overlay District has been shown accurately on the application plans. The applicant may be required to revise the steep slope boundaries shown on the application plans. The burden of proving the correct boundary shall be on the applicant, supported by engineering and/or surveying data or mapping.

1.) District Specific Regulations

A. The Steep Slope Overlay District shall be an overlay on all zoning districts. The regulations in the overlay are in addition to those regulations of the underlying zoning district.

B. These regulations apply to applications within the Overlay District that include 400 square feet or more of earth disturbance.

C. Finished slopes of all cuts and fills shall not exceed 30%, unless the applicant can demonstrate that steeper slopes can be stabilized and maintained adequately to the satisfaction of the ZAO or DRB in consultation with the City Engineer.

D. Any fills placed on a steep slope shall be property stabilized and, when necessary, supported by retaining walls or other appropriate measures as approved by the ZAO or DRB in consultation with the City Engineer.

E. Finished grades shall be reasonably safe from slide, collapse, or similar failure as determined by the ZAO or DRB in consultation with the City Engineer.

2. Additional Application Requirements

A. A site plan prepared by a registered professional engineer or surveyor that accurately depicts the proposed development and related land disturbance relative to the Steep Slope Overlay District boundaries, with all pertinent information describing the proposal, and a topographical survey depicting existing and proposed contour lines at no greater than 2-foot intervals. The plan shall depict all proposed cut, fill, and grading.

B. A plan depicting the extent of proposed vegetation clearing.

3. Approval Condition

A. Prior to construction, the applicant shall provide a geotechnical analysis prepared and stamped by a professional geotechnical engineer that determines the suitability of the steep slope for development.

* Material stricken out deleted.

** Material underlined added.

tm/KS: Ordinances 2022/Zoning Amendment – ZA 22-03, Steep Slopes
Sec. 5.2.4, new Map 5.2.4-1
8/10/22
The referenced map, Map 5.2.4-1, Steep Slopes Overlay, for ZA 22-03, Steep Slopes, regarding changes to the Burlington Comprehensive Development Ordinance may be found at: https://go.boarddocs.com/vt/burlingtonvt/Board.nsf/files/CH6Q7D67E787/$file/Map%205.2.4-1%20Steep%20Slopes%20for%20CC.pdf or are available upon request from the Burlington Clerk’s Office.