Adopt Resolution #21-300 Ordering Plans and Specifications for Improvement Project #22-02, Autumn Heights Street Reconstructions

Purpose:
The purpose of this case is to adopt Resolution #21-300 Ordering Plans and Specifications for Improvement Project #22-02, Autumn Heights Street Reconstructions.
 
Background:
City Improvement Project 22-02 proposes to reconstruct the streets within the Autumn Heights subdivision, generally located in the northwest region of Ramsey, along either side of Armstrong Boulevard. The streets total approximately 8,500 linear feet (1.61 miles) in length, and are 24 foot wide rural sections. A figure showing the project scope and a street segment summary is attached to this case.
 
On July 13, 2021, the Ramsey City Council ordered the City Engineer to request proposals for Topographic Survey, Geotechnical Evaluations and Utility Testing for proposed 2022 Pavement Management Program (PMP) projects, including IP 22-02. On August 8, 2021, the Ramsey City Council awarded a proposal to Hakanson Anderson for topographic survey, and Haugo Geotechnical Services for a geotechnical report of the project area.
 
Engineering Staff has completed an initial review of the topographic survey and geotechnical report, determining the requirements of the proposals have been met. The initial review of the geotechnical report revealed sub-bas materials consisting primarily of poorly-graded sand and poorly graded sand with silt. These materials are generally well suited for street construction, though silty materials can be susceptible to frost-heave, particularly when the soils are unable to drain. Staff has done field visits of the site and the existing pavement appears not to have been negatively impacted by the silty materials for the majority of the project, though 168^th Lane southeast of 167^th Lane may require some corrections. The geotechnical report revealed groundwater approximately 5 feet below the pavement surface at the time of the soil boring. These wet, less drainable soils are likely a factor in the pavement appearing to rut, which is differential settling across the pavement surface. The report and any proposed improvements will be explored further during project design.
 
The streets within Autumn Heights subdivision were included in the Ground Penetrating Radar (GPR) Pavement Evaluation performed by Braun Intertec. This data provides bituminous and aggregate base thickness information. The GPR data is included in the street segment summary attached to this case.
 
The streets within Autumn Heights are 24 feet wide, rural section streets. These streets are proposed to be reconstructed to the City’s current standard residential street design, with a minimum 4 inches aggregate base and 3.5 inches new bituminous pavement. Due to the underlying soils, Staff is proposing to use the full-depth reclamation process, remove excess reclamation material leaving a minimum of 4 inches to be re-used as aggregate base, and place 3.5 inches of new bituminous pavement on top. The proposed street alignment and profile will generally be unchanged.
 
Municipal sanitary sewer and watermain do not exist within the project area, and are not proposed to be extended with this project. Stormwater runoff is handled through the existing drainage swales along both sides of the streets, with street crossing culverts connecting the ditches. Storm water is generally carried south towards Trott Brook. Staff is unaware of drainage issues or concerns with the existing drainage swales which would require re-grading. Beyond touch up work required due to replacing the street crossing culverts, grade changes to the swales are not proposed, however, this will be reviewed during project design.

This project presents two right of way concerns which will be explored during project design. 169th Avenue west of Rabbit Street terminates without a turn-around. This street segment is 640 lineal feet long, 24-feet wide, and currently lacks enough right of way to build a cul-de-sac or hammer head turn-around. 168th Avenue terminates in a 66 foot diameter cul-de-sac. This cul-de-sac sits within the existing right-of-way, but is below the City standard 100 foot diameter. In both cases any improvements would require additional right of way. Staff is proposing to bring improvement options to a future Public Works Committee meeting for discussion, once impacts can be explored during project design.
 
Estimated project costs per the proposed 2022 – 2031 CIP are $984,000. Estimated costs include 23-percent indirect costs for administrative, engineering, finance and legal costs. Staff proposes to create the plans and specifications in-house as part of their normal duties.
 
The street improvements proposed with this project are identified in the City’s 10-year CIP, and can be funded using a combination of Pavement Management Funds and Storm Water Utility Funds. This project would best be constructed as a stand-alone project and is necessary, feasible, and cost-effective from an engineering standpoint, and can be constructed as proposed herein.
 
The proposed improvements are designated as City Improvement Project #22-02, Autumn Height Street Reconstructions.

Notifications are not required for this case.

Motion to adopt Resolution #21-300 ordering plans and specifications for improvement project #22-02, Autumn Heights Street Reconstructions.

Funding for this improvement is proposed to come from the Pavement Management Fund and Storm Water Utility Fund.
 

• (PMP) Street Project Cost      $895,000
• Storm Sewer Project Cost      $89,000
• Total Estimated Project Cost  $984,000

Staff recommends adopting Resolution #21-300 ordering plans and specifications for improvement project #22-02, Autumn Heights Street Reconstruction.
 
The Ramsey Public Works Committee reviewed this project on October 19, 2021. The committee recommended City Council authorization ordering Staff to prepare plans and specifications.

Adopt Resolution #21-300, ordering plans and specifications for improvement project #22-02, Autumn Heights Street Reconstruction.