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HomeMy WebLinkAbout05-22-2023 Council Work Session PacketCouncil Work Session Monday, May 22, 2023 5:00 P.M. Orono Council Chambers, 2780 Kelley Parkway, Orono, MN 55356 w WORK SESSION AGENDA 1. Retaining Wall Discussion Part II Prepared By: LLO Reviewed By: Approved By: CITY OF ORONO MEMORANDUM DATE: May 22, 2023 TO: City Council Members FROM: Community Development Director and City Engineer RE: Retaining Wall Discussion Continued 1. Purpose Review the current retaining wall regulations and discuss possible text amendments. 2. Background. The City Council processes many retaining wall variances within the lakeshore setback every year. The Council directed staff to bring additional informational regarding retaining walls to explore if any amendments to the City Code are necessary. City Staff presented information at the April 24, 2023 worksession that included general background information, different types of walls, guidance from the Comprehensive Plan, DNR and other lake area communities. The presentation is in included at Exhibit A. Currently the City Code prohibits retaining walls within the lake shore setback. This presents multiple challenges for residents who are working to repair or replace failing walls, address erosion control issues and does not provide any guidance for best practices regarding, material, methods or screening. Staff’s recommendation is to amend the City code to create an administrative and conditional use permit process for allowing retaining walls within the lakeyard with specific conditions. • ADMINISTRATIVE PERMIT (Staff-issued zoning permit) for retaining walls must meet the following:  Replacement Walls: Must be under 4 feet in height, have a documented failure of the existing wall, and the replacement is in the same general location and height of the existing wall.  New Walls: Must be an integral part of an allowed lake yard accessory structure (e.g. lake access stairs) • CONDITIONAL USE PERMIT for any wall not meeting the administrative standards  Demonstratable failure and/or erosion control problem; and/or  Replacement walls 4-feet in height or greater; and/or  Any walls proposed within the defined Bluff slope; and/or  Any new wall proposed that is not part of a lake stair  Additional conditions may be added as necessary by PC, Council, or Staff (e.g. access or method of construction) A retaining wall permit would require site plans, elevation plans, method of construction, and vegetative screening of the walls from the lakeview. COUNCIL ACTION REQUESTED: Provide guidance pertaining to retaining walls within the lakeshore setback. Retaining Walls within the Lakeshore Setback City Council Worksession April 24, 2023 Orono City Code •Shoreland Overlay District •78-1279 (5): Fences, docks, retaining walls.No fence shall be placed within the Shore Setback zone. Portions of dock located landward of the OHWL shall be considered as a landing, subject to the regulations for landings per section 78-1282. Retaining walls shall not be placed within the Shore Setback zone. •Definitions: •78-1 In-kind, when used in the context of replacement of a non-conforming building or structure, means the replacement of a building or structure completely within the limits (location, height, width, and depth) of the previous building or structure. Implementation •New walls and/or expansions are not permitted. •In-Kind replacements are permitted with a zoning or building permit. •Variance must be obtained in order to construct new walls and/or expansions Issues •The City Code prohibits retaining walls within the lakeshore setback. •The ability to reconstruct existing infrastructure is extremely limited. •Best practices for protecting slopes and prevention of erosion control may call for different methods or types of walls. Comprehensive Plan: Chapter 3: Environmental Protect Plan Natural Resource Management Policies: •Protect lake resources to allow reasonable access, use and enjoyment while preventing overcrowding and excessive encroachment. •Lake shorelines will be protected from alteration. •Retention of natural vegetation will limit the impact of urbanization as visible from the lake. Retaining Wall Construction and Impacts •Properly constructed retaining walls require disturbance of the slope being protected •There is more to a retaining wall than what you see from the front or top of a finished wall. Timber Retaining Walls 33 Feet 31 Feet 47 Feet Block Retaining Walls Boulder Retaining Walls DNR Shoreland Regulations •The DNR’s Current Model Shoreland Ordinance (04/28/22) lists retaining walls as permitted within the shore impact zone provided that the walls are: •Used only to correct a documented erosion problem (not aesthetic); •Wall height and length are the minimum necessary to correct the erosion problem (and not higher than 4 feet or longer than 10 feet unless the “zoning administrator” determines the larger wall to be necessary); and •The walls are screened by vegetation to be not visible from the lake. DNR-Higher Standard Alternatives: •Tiered permitting for new walls: •Administrative Permit* walls are at least 50-feet from the OHWL; and less than 3 feet high, less than 25 feet in length; and on a slope less than 12%. •Conditional Use Permit* walls <50 feet from the OHWL; or over 3 feet high & over 25 feet in length; or on slopes greater than 12% •Administrative approval for expansion of non-conforming structures (i.e. walls) not meeting OHWL setbacks, if: •The wall is more than 50 feet from the OHWL; and •Overall site hardcover is met/conforming; and •Property owner agrees to restoration/establishment of a riparian buffer for 80% of shoreline width with a minimum depth of 10 feet to include trees, shrubs, and natural ground cover. •Additional information: •Individual boulders >30” diameter are considered a retaining wall. •Vegetative screening is required for all walls. *Engineered plans may be required. Retaining Wall-Lake Community Input City Are Retaining Walls allowed within Lakeshore? Descriptions Minnetrista Yes, with conditions Allowed within shore setback (75') if 4’ in height or less; Not allowed in steep slope or bluff; Nothing allowed within 10' of OHWL Deephaven/ Woodhaven Yes Allowed in shore setback. Not allowed in Bluff Impact Zone. Greenwood Yes, with conditions Not allowed within the 50' Setback from OHWL, a CUP required for walls within the 50' Shore setback. Retaining walls not allowed in Bluff Impact Zone. Tonka Bay Yes Allowed Minnetonka Beach No Not allowed within 75’ setbacks. Shorewood Yes, with conditions Retaining Walls are allowed only for erosion issues not for accessory improvements (Patios/beaches). Mound Yes Retaining Walls are allowed in shore setback (50’) but are not allowed in bluff. Recommendation •Staff has identified issues with the implementation of the current City Code and its limitations pertaining to the reconstruction of the existing walls. •Additional research is needed to develop best practices to protect the lakeshore from erosion and to align the City Code with DNR standards. Next Steps •Staff will research and develop draft language as a proposed text amendment.