City Council Meeting Date: June 19, 2018
To: Mayor and City Council
City Administrator
From: Sean Simonson, Engineering Manager
David Bennett, Public Works Director/City Engineer
Title
Spring Creek Road Reconstruction Project Discussion
Body
Action Requested:
The Northfield City Council discusses the Spring Creek Road Reconstruction Project and provides direction on a path forward.
Summary Report:
Staff has moved into the final design phase of the Spring Creek Reconstruction Project. The project corridor includes Spring Creek Road from Superior Drive to Huron Court (Attachment 1). City Council approved the Feasibility Report at the January 2, 2018 City Council meeting via Resolution 2018-005. This resolution also directed staff to design a West Side Urban and East Side Rural road section (Attachment 2). This typical section includes a trail, boulevard, 8’ paved shoulder and a 12’ driving lane on the west side “Urban” Section, and a 12’ driving lane, 5’ paved shoulder, and a ditch section on the east “Rural” Section.
As final design was completed for the project, the Consulting Engineers have indicated the project costs have significantly increased from the feasibility report ($1.6 Million to $3.3 Million). A detailed table is shown below in the financial impact section. Understanding this cost increase, staff is reviewing four alternatives to see if we can reduce the costs of the project. The alternative are being developed and will be sent out in a supplemental next week. The majority of the cost increases are tied to a few items:
1. Unit cost for items have been increased to match bids received for the Division and Seventh St. Project
2. Retaining wall costs on the West Side
3. Storm Water Management
4. Earthwork
Staff believes these cost increases and moving forward has to large of an impact on our State Aid Funds and future street improvements.
Alternative Options:
Four alternatives are being developed.
Financial Impacts:
Included in the final design documents are the final project cost estimates. The tables below show the projected project costs and funding sources at the time the Feasibility Report was approved, and what the final project cost estimates are at this time.
Retaining Walls
Due to the significant elevation difference between the proposed road elevation and the already developed residential properties along the western edge of the project corridor, retaining walls are necessary to accommodate the proposed road design. The feasibility report accounted for an estimated $18,772 in retaining wall costs. At final design, that number has risen to $446,080, an additional $427,308.
Earthwork
At the time of feasibility, the earthwork was estimated to be $183,476. At final design that number is now estimated to be $594,365, which equates to an additional $410,889. These additions can be attributed to an added select granular section to the proposed road base due to subgrade, and additional select granular to correctly build the additional proposed retaining walls.
Stormwater Management
At the time of feasibility, it was projected to use the existing stormwater facility located at the intersection of Jefferson Parkway and Spring Creek Road for stormwater treatment. As the final design progressed, it was determined that this storm water facility could not adequately handle the additional stormwater generated by the proposed road project. As a result, a filtration system was added to the south of the project in the Meadows Park area. This filtration system is located where the proposed future wetland area is located according to the approved Meadows Park Master Plan. This additional stormwater management facility is estimated to increase costs by $120,000.
Miscellaneous Costs
The remaining cost increases have been identified across many items of the project since the feasibility report. Most of these costs have to do with the increase in construction costs since the feasibility report was completed. Staff and the Design Engineer used costs from the recently bid Division Street and Seventh Street Reconstruction Project, and feel that these costs are a more accurate depiction of what to expect if the project was bid at this time.
Tentative Timelines:
Staff will develop a project schedule based on direction and information gathered from this discussion.