Title
An Ordinance to Add Sections 5.14.2 And 5.27 And Amend Sections 5.18.4, 5.18.6.D, 5.23.4, 5.29.1, 5.29.3.F, 5.29.8.C, 5.29.12.D, 5.37.2.B, 5.37.2.C, 5.37.2.F, 5.37.2.L, 5.37.2.N, 5.37.2.M, And 5.37.2.S of Chapter 55 (Unified Development Code) of Title V of the Code of the City of Ann Arbor (Floodplain Management Overlay District and Regulations)
Memorandum
Section 5.24.4 of the Unified Development Code (UDC) currently regulates 100 Year Floodplains. Throughout Ann Arbor, floodplain areas are approximately 10% of the total city land area. This set of proposed amendments is intended to both modify and expand floodplain regulations throughout the City to accomplish the following benefits:
• To improve safety and welfare of both people and property.
• To provide clear permitting and review expectations.
• To apply existing State-level floodplain regulations across all floodplains in the City.
• To lower flood insurance rates for City property owners.
The last benefit is achieved through incorporation of many Community Rating System best practice approaches into the proposed ordinance. There are numerous aspects to the proposed additions and modifications to the Unified Development Code here, including:
• Terminology updates - Shifting from past references in favor of current conventions that refer to risk factors by percentage (e.g. 1% Annual Chance vs. 100-year floodplain, 0.2% Annual Chance vs. 500-year floodplain).
• Extends State-level regulations to areas not currently regulated.
• Modifications to Floodway Development regulations:
• Extends current prohibition of new residential buildings to no new buildings of any use.
• No new parking where depth is greater than two feet.
• Provides some exemption for redevelopment for parcels with existing buildings in a floodway.
• No new accessory structures.
• Modifications to Flood Fringe Development regulations:
• Adds prohibition of Critical Facilities from development in Flood Fringe.
• Prohibits structures without foundations.
• For development in Floodplain, raises lowest floor/floodproofing requirement from one foot above 1% Annual Chance flood elevation to one foot above 0.2% Annual Chance flood elevation. This typically equates to approximately one additional foot of elevation over existing requirements.
• Specifies required permit application materials.
• Adds and defines a series of related terms.
In addition to the regular consideration process at the Planning Commission, two Webinars were held to present the proposed regulations and answer related questions. These webinars are available for viewing at www.a2gov.org/floodplains <http://www.a2gov.org/floodplains>.
The development of Floodplain Zoning Overlay District is supported by City policy documents including the 2004 Natural Features Master Plan:
Floodways and Floodplains: The floodplain is land adjacent to lakes, streams, and rivers which is prone to flooding water levels rise and overflow the normal water channels during a 100-year frequency flood. The floodway is the sub-area of the floodplain needed to convey flood flows.
Implementation Summary: Review and modify City codes and policies to ensure that best management practices are implemented; restore city-owned wetlands; promote stewardship by educating the public on the identification and value of native plants and activities that can benefit floodplains. (p.4-5)
Floodways and Floodplains Implementation Strategies
3. Review City codes to determine whether they reflect current best management practices to help prevent soil erosion and washout from storm events. Revise codes to implement best management practices, where appropriate.
8. Develop a policy that would restrict or prohibit new development within any floodway within the City unless the development is deemed to be of greater public interest than potential flooding hazards and damage. The policy should consider the location of the floodplain, proposed damage to or enhancement of natural features, and impacts to floodplain capacity and value. The policy also should consider ways to actively remove structures in the floodway that do not conform to policy standards. (p. 19)
The City’s regularly updated Flood Mitigation Plans also support these amendments.
The Planning Commission recommended approval of the proposed ordinance on October 20, 2020.
Attachments: Planning Commission Presentation
Planning Commission Minutes - October 20, 2020
Proposed Ordinance
Staff
Prepared by: Jerry Hancock, Stormwater/Floodplain Coordinator
Brett Lenart, Planning Manager
Reviewed by: Derek Delacourt, Community Services Area Administrator
Approved by: Tom Crawford, City Administrator
Body
(See Attached Ordinance)
Sponsored by: Mayor Taylor