Wood Pond Hills & Chestnut Ridge Street Recon IP 19-03

City Improvement Project No. 19-03 proposes to reconstruct streets within the Wood Pond Hills and Chestnut Ridge neighborhoods including 146th Avenue, Helium Street, and Krypton Street. The streets total approximately 3,310 linear feet (0.63 miles) in length. A map showing the location and scope of the proposed improvements is included as Figure 1 in Appendix A in the linked Feasibility Report.

The streets were constructed between 1992 and 1994 with bituminous pavement, surmountable concrete curb and gutter, and concrete storm sewer. The streets were constructed to a width of 30-feet from face-of-curb to face-of-curb, and are centered within a 60-foot wide right-of-way. 

The existing bituminous pavement section ranges from 1.6 to 5.0 inches thick, with a median thickness of 2.5-inches. The pavement section was built on generally poorly graded sand with silt subgrade material generally considered usable for pavement support with proper conditioning.

City staff evaluates and rates the condition of pavement sections on all City streets on an annual basis using the Pavement Surface Evaluation and Rating (PASER) system. In the summer of 2018, the pavement sections of the above referenced street segments were rated with a PASER rating of 2, with the exception of the south half of Krypton Street receiving a rating of 4. Ratings of 4 and below indicate these streets require complete reconstruction. City Staff patch the streets at least once per year, particularly before winter so the streets can be plowed without further damaging the pavement in the process. Pictures of the streets are located in Appendix A in the Feasibility Report. 

Proposed improvements include removing and replacing all damaged concrete curb and gutter sections, and reconstructing the existing bituminous pavement section using the Full Depth Reclamation (FDR) process. This process would involve reclaiming the entire existing bituminous pavement section, along with the existing aggregate base. This reclaim material would then be spread over the reshaped and compacted subgrade between the curb and gutter, then the top 3 ½ -inches of reclaim material would be removed and hauled off site, after which 3 ½ -inches of new bituminous pavement would be installed over the remaining compacted reclaim material. This would result in a 7-ton pavement design, which is standard for residential streets.

Existing sanitary sewer and watermain infrastructure are in good condition. The existing storm sewer system is also in good condition with only minor work being proposed.

The engineer’s opinion of probable costs for completing the proposed improvements outlined in this report is $372,236.52. Estimated costs include 5-percent contingency costs plus 23-percent indirect costs for administrative, engineering, finance and legal costs. A summary of the engineer’s opinion of probably costs is included in Appendix B in the Feasibility Report. 

A total of 59 assessable parcels have been identified. Staff recommends applying 25-percent of the eligible project costs equally across the 59 assessable properties using the “per lot” assessment method. Eligible project costs include everything except subgrade correction costs. This results in a proposed preliminary assessment rate of $1,303.70 per assessable parcel.

A special benefit consultation report will be completed for this project to verify the proposed assessment amount will not exceed the benefit to the properties.  

This improvement project, which is listed in the City’s current 10-year Capital Improvement Plan, is proposed to be funded using a combination of special assessments to benefiting properties, street reconstruction bond proceeds, and storm sewer funds.

A Public Information Meeting will be held on from 5:00 - 6:00 pm on November 7, 2018 for the purpose of explaining the proposed improvements and assessments in more detail, and to gather public input on the project, including any information which should be explored in more detail during development of plans and specifications. Staff will present this information to the City Council during the Public Hearing on November 13, 2018.

Funding Source:

The Feasibility Report was completed in-house as part of Staff's normal duties. Per the Feasibility Report, the engineer’s opinion of probable project costs is $372,236.52.  Staff proposes to fund the proposed improvements using a combination of special assessments to benefiting properties, street reconstruction bond funds, and stormwater utility funds, as needed.
 
 A total of 59 residential parcels will benefit from the proposed improvements and are preliminarily proposed to be assessed for 25-percent of eligible project costs which totals $76,918.30.  Subgrade correction costs are not eligible for assessments and are paid 100% by the City.  This equates to preliminary assessments of $1,303.70 per parcel. The City will fund the remaining project costs, which totals $295,318.22.  The City’s costs will be funded using Street Reconstruction and Overlay Program bond funds, as well as a small amount of Stormwater Utility Funds.