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