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04. Staff Report-192nd St N Retaining Wall Replacement Staff Report Date of Meeting: 03/06/2024 For: Mayor and City Council From: Charles Fischer – Director of Public Works Subject: 192nd St. N Retaining Wall Replacement Background: The retaining wall on the north side of 192nd St N was reported by Public Works staff to be failing after clearing vegetation below and above the while mowing Right-of-Way. After inspecting the wall Public Works began seeking estimates for replacement. This report is to provide Council estimated costs and request approval to install a new wall system. The final total cost could potentially be higher than the estimates as engineering will need to be provided due to the height of the wall. The engineering costs could range between $1500 and $2,500 depending on what Engineer the contractor chooses for an Engineered Design. Fiscal Impact: The reconstruction of the wall will be funded by the Public Works Road Maintenance General Fund. There is no negative impact to this budget at this time, however, may reduce the number of areas for contracted patch work over the course of the construction season. Issue: Should Council approve to reconstruct the wall through one of the contractors listed in this report. Proposal: Public Works proposes to move forward with reconstructing the wall with Field Stone Boulders based on the current estimates. The boulder style wall is less expensive and can be completed in a shorter time frame than a Segmented Wall (Block Wall). After discussion with our Engineers there is no concern with installing a boulder wall vs. a segmented wall. Each contractor has provided estimates for both systems subject to Engineering Design for final pricing. Although each estimate is similar in price, each estimate has differences accounting for the total estimated cost. A brief breakdown of these estimates is provided below. 1. Nelco Landscaping has provided an estimated cost based on a more complete materials list required for construction of the wall whether boulder or segmented. Material included in the boulder wall, not in the other estimates, is drainage rock placed behind the wall. This material could be required under an engineered design. If not required than the cost could be less than the estimate. An additional cost to this estimate will be the Engineered Design of up to $1,500.00 if completed. Estimated Costs: Boulder Wall = $32,777.50 / Segmented Wall = $41,861.21 2. Outdoor Landscapes has provided an estimated cost but does not include the cost to procure an Engineered Design and also does not account for potential additional material such as drainage rock placed behind the boulder wall. Additional cost over the estimate may be over $4,500.00 Estimated Costs: Boulder Wall = $29,690.16 / Segmented Wall = $34,659.26 3. Peterson Companies Inc. has provided an estimated cost including a budget of $1,500 for an Engineered Design but not the potential for drainage rock material behind the wall. Additional material cost over the estimate could be over $3,000.00. Estimated Costs: Boulder Wall = $31,605.00 / Segmented Wall = $38,120.00 Options: 1. Nelco Landscaping – Boulder Wall estimated cost = $32,777.50 2. Outdoor Landscapes – Boulder Wall estimated cost = $29,690.16 3. Peterson Companies Inc. – Boulder Wall estimated cost = $31,605.00 Recommendation: Option 1. Nelco Landscaping – Boulder Wall estimated cost = $32,777.00 Justification: Although the estimated cost is higher than the other two estimates, the overall cost of the Nelco Landscaping estimate, when adding all the items listed or not listed in each estimate places the recommended option at or near the least expensive option. Boulder Wall Estimate = $29,690.16 Segmented Wall Estimate = $34,659.26 *does not include additional materials