Title
A RESOLUTION AUTHORIZING THE CITY MANAGER TO ADVERTISE FOR BIDS AND TO ENTER INTO A CONTRACT FOR THE WILLOW LAKE DRAINAGE IMPROVEMENT PROJECT WITH THE LOWEST AND BEST BIDDER; AND DECLARING AND EMERGENCY.
Brief Description: This project involves a short-term solution that involves the removal of tall vegetation, regrading of the existing ditch from Eastham Way towards the Norfolk Southern Railroad tracks to alleviate or eliminate flooding within the drainage ditch at a cost of $100,000, which includes a 10% contingency.
Body
Legislative History
None.
Purpose & Explanation
In late 2022, the City commenced with a storm water hydraulic study of a drainage ditch downstream of properties off Eastham Way and behind properties of the cul-de-sacs of Willow Lake Drive and Chatham Way. The drainage ditch was constructed in the 1970’s with the creation of the Plymouth Village subdivision. The ditch is fed by a 36-inch storm pipe from Eastham Way, through private properties and to a 24-inch pipe under Norfolk Southern’s railroad tracks. The drainage ditch has a very flat slope and is prone to blockages, sediment buildup and flooding of its banks. See Study Area Map attached.
The on-going hydraulic study is evaluating multiple solutions to alleviate or eliminate flooding of the drainage ditch. Solutions being evaluated include regrading of the existing ditch, storm water detention and re-routing of flows to an alternate location. The study is nearly complete and the recommended improvements to address the flooding along the ditch corridor include a short-term solution that includes removal of tall vegetation and re-grading of the existing ditch and a long-term solution of re-routing of the drainage flows entering the ditch from Eastham Way to the City’s Colony Park.
The cost of the long-term solution, re-routing of flows from Eastham Way to Colony Park and introducing additional storm water storage is still being evaluated and is currently estimated at over $750,000.
The cost of the short-term solution that includes removal of vegetation from the drainage ditch and re-grading the ditch including hauling away of surplus material is estimated at $100,000 and includes a 10% contingency.
As this work would take place on private property, staff verified that the scope of work meets the City’s Private Property Storm Water Policy. Staff has confirmed that the following conditions of the policy are met: (1) is a Public Nuisance & Public Benefit, (2) Reduces Flood Risk, (3) Drainage Area is between 5 and 300 acres and (4) Exceeds Resident Capacity to Resolve.
Staff recommends proceeding with designing, bidding and constructing the short-term solution, re-grading the drainage ditch later this summer/fall. The long-term solution’s evaluation will be finalized, and its estimate included in the upcoming capital budget program.
Legal Authority for Proposed Legislation
Pursuant to Charter Section 6.04:
X Competitively bid and advertised for three consecutive weeks
Joint or Cooperative Purchase Program
Professional Services
Other
Fiscal Impact
X Currently Budgeted (504 fund - $285,777)
Supplemental Appropriation Required
Appropriation Not Required.
Does this legislation require use of an emergency clause?
x Yes - In order to meet the construction scheduled for 2023.
No
Recommendation
Suggested Action
Staff recommends that Council approves this authorization for the City Manager to advertise, receive bids and award to the lowest and best bidder for the Willow Lake Drive Drainage Improvement Project.
Submitted by,
Thomas J. Sheridan, City Manager
Bradley S. Kosco, PE, PS, City Engineer
David Rapp, PE, PS, Assistant City Engineer