To: Honorable Mayor and Members of Town Council
From: Andrew Focht, Project Manager
Title
Resolution Approving the Second Amendment to the Service Agreement for the Plum Creek Parkway Widening and Roundabout Project
Body
________________________________________________________________________________
Executive Summary
The purpose of this memo is to obtain approval of an amendment to the contract between the Town of Castle Rock and Kimley-Horn & Associates (KHA) for design and construction engineering services for the Plum Creek Parkway Widening and Roundabout Project.
The attached resolution (Attachment A) approves the amendment to the contract with KHA (Attachment B). The amendment will allow the remaining design work for Plum Creek Parkway phase 2 (Eaton to Ridge) to be completed. The amendment also addresses Phase 1 (Gilbert to Eaton) design and construction engineering needs required to complete the project. The discussion section that follows provides summary information on the needs that drive this increase request.
History of Past Town Council, Boards & Commissions, or Other Discussions
At the April 3rd, 2018 Town Council meeting a service agreement was approved by Council via resolution 2018-030. An amendment to the service agreement was presented and approved by Town Council on September 18th, 2018 via resolution 2018-014. The proposed second amendment to the service agreement was recommended for approval by the Public Works Commission on July 6th.
Discussion
Under the current contract, additional engineering effort will be required to complete the Plum Creek Parkway Widening and Roundabout project. The known additional engineering work can be categorized into 2 categories: phase 1 construction phase engineering services and phase 2 design engineering services.
Phase 1 Construction Engineering Services
The implementation of roundabouts at Gilbert and Eaton, along with a challenging topography have required additional property acquisitions, storm drainage design adjustments, and roadway design adjustments. These costs are attributed to drainage analysis recommendations and Right-of-Way width restrictions. It also allows the project to utilize engineering services during construction that lead to construction cost/schedule savings, and other opportunities. The following services form the basis of this additional cost:
• Legal descriptions for property acquisitions
• Design for water quality pond
• Offsite drainage design
• Street lighting design
• Design for revised alignments
• Temporary signal design
• Wall redesign to reduce construction cost
• Additional construction services
This effort makes up $128,790 of the increase amount.
Phase 2 Design Engineering Services
Plum Creek Parkway Phase 2 consists of new roadway construction, utility installations and retaining wall implementation from Eaton Street to Ridge Road. There are unique challenges posed to the design of this improvement including; limited ROW, environmental impacts, topography restrictions, new utility investigation requirements and significant off-site drainage considerations. The following services form the basis of this additional cost:
• Additional topographic survey
• Quality level B subsurface engineering
• Roadway cross section revisions
• Additional retaining wall design
• Offsite drainage analysis and conveyance design
• Revised construction plans
• Wetlands investigation and permitting
This effort makes up $165,946 of the increase amount.
Budget Impact
The funds necessary for this contract amendment and a forthcoming construction contract amendment are included in 2nd quarter budget amendment that was unanimously approved by Town Council on July 7th. The budget amendment added $1,017,570 to the project’s budget. The current total budget, with the recent second quarter increase is $10,445,799.
There are sufficient funds in the current budget for the contract amendment. Engineering services for similar projects typically account for 5% and 10% of total construction cost. With this increase the total engineering services will account for approximately 8% of total estimated construction cost.
Original Council Authorized Contract Amount: $565,550
Proposed Council Authorized Contract Amount: $860,286
KHA has proposed to complete engineering effort at an additional cost of $294,736 to complete the project with the additional scope for a new “not-to-exceed” services agreement cost of $860,286. The remaining budget will be $690,576, and will be utilized for construction contract revisions.
Staff Recommendation
Staff recommends Town Council approve the Resolution as introduced by title. The proposed service agreement amendment was also formally recommended for approval by the Public Works Commission on July 6th.
Proposed Motion
“I move to approve the Resolution as introduced by title.”
Attachments
Attachment A: Resolution
Attachment B: Service Agreement