To: Members of the Castle Rock Water Commission
From: Mark Marlowe, P.E., Director of Castle Rock Water
Mark Henderson. P.E., Assistant Director
Matthew Hayes, P.E., Technical Engineering Manager
David Choi, Water Engineer
Title
Resolution Approving a Services Agreement between the Town of Castle Rock and Dewberry Engineers Inc. for Phase 1 of the Sedalia Gravity Lift Station Collection System Project [Located in Sedalia CO]
Town Council Agenda Date: September 1, 2026
Body
________________________________________________________________________________
Executive Summary
Castle Rock Water (CRW) seeks Town Council approval of a resolution (Attachment A) approving a Services Agreement (Exhibit 1) with Dewberry Engineers Inc. (Dewberry) in the amount of $341,120, plus a 10% contingency of $34,112, for a total authorization amount of $375,232. The agreement includes design and bid support services for Phase 1 of the Sedalia Gravity Collection System project.
The Sedalia Lift Station and Force main that is currently under construction, and that Castle Rock Water will own and operate will make available centralized wastewater service to customers that desire to connect in and around the Town of Sedalia. The proposed project will design the first phase of Sedalia’s gravity sewer collection system to convey future wastewater flows from the CORE Electric Cooperative property to the new Sedalia Lift Station currently under construction. This phase represents the initial segment of the planned gravity collection system and will support future expansion of wastewater service within Sedalia. The project includes an alignment evaluation, detailed design, permitting, survey, geotechnical investigation, easement acquisitions, and preparation of construction drawings and technical specifications.
Design services will begin in September of 2026 and be completed by early summer of 2027, which will allow the Town to advertise the project for construction in the summer or fall. Dewberry’s full scope of services, fees, and project schedule is included in Exhibit 1.
Notification and Outreach Efforts
The project will include coordination with Douglas County, the Sedalia Water and Sanitation District, utility agencies, permitting agencies, affected property owners, and nearby residents throughout the design process. As part of the consultant’s scope of work, Dewberry will conduct a neighborhood meeting to present the project, gather public input, and address community concerns. Additional coordination meetings with stakeholders and permitting agencies will occur as needed throughout design.
History of Past Town Council, Boards & Commissions, or Other Discussions
On December 16, 2025, Town Council unanimously approved a construction contract for the construction of the Sedalia Lift Station and Force Main, which will convey future wastewater flows from the Town of Sedalia to Castle Rock’s wastewater collection system and ultimately to the Plum Creek Water Reclamation Authority (PCWRA). The proposed Sedalia Gravity Collection System is the next phase of the overall wastewater infrastructure improvements necessary to provide sanitary sewer service within Sedalia. The collection system has been planned to integrate with the lift station and force main currently under construction.
Castle Rock Water staff presented the Third Amendment to the IGA with Douglas County for the Highway 85 Wastewater Collection and Treatment System item to the Castle Rock Water Commission that amended the IGA to include County funding for design of the first phase of the Sedalia gravity sewer system at their meeting held on July 22, 2026, and the Castle Rock Water Commission voted unanimously 6 to 0 to recommend Town Council approval of the Resolution as presented.
Town Council unanimously approved the Third Amendment to the IGA with Douglas County for the Highway 85 Wastewater Collection and Treatment System that included County funding for design of the first phase of the Sedalia gravity sewer system at their meeting held on August 18, 2026.
Discussion
The proposed agreement with Dewberry provides engineering design and bid support services for Phase 1 of the Sedalia Gravity Collection System. The project will begin with an alignment evaluation to identify the preferred gravity sewer route between the new Sedalia Lift Station and the CORE Electric Cooperative property (Attachment B). Following selection of the preferred alignment, Dewberry will complete the final design of approximately 1,440 linear feet of 18-inch gravity sewer and 1,700linear feet of 8-inch gravity sewer. The design also includes three trenchless crossings (bores) under Union Pacific Railroad, Burlington North Santa Fe Railroad, and Colorado Department of Transportation.
The scope of work includes topographic survey, geotechnical investigations, subsurface utility engineering (SUE), preparation of easement legal descriptions and exhibits, grading, erosion and sediment control (GESC) plans, technical specifications, construction drawings, engineer's opinions of probable construction cost, public agency and stakeholder coordination, permitting, and bid support services. Design deliverables will be submitted at the 30%, 60%, 90%, and Issued for Bid (IFB) milestones. Upon completion, the Town will have the construction documents, technical specifications, permits, and easement documentation necessary to advertise Phase 1 of the Sedalia Gravity Collection System for construction.
A Request for Qualifications (RFQ) was advertised on Bidnet to procure qualified consultants for the 2026 pre-qualified consultants list for various Castle Rock Water Capital Improvement Projects. A project specific Request for Proposal (RFP) was issued to eight (8) of these pre-qualified consultants for this project from the Wastewater Infrastructure list; responses were received from five (5) firms:
|
Consulting Firm |
Total Cost |
|
Carollo |
No Proposal |
|
Black & Veatch |
$348,816 |
|
Burns & McDonnell |
$467,208 |
|
Dewberry |
$341,120 |
|
Providence Infrastructure |
No Proposal |
|
HDR |
No Proposal |
|
Kimley-Horn |
$349,314 |
|
Consor |
$345,650 |
Dewberry was chosen to perform the design services for this project, and staff has determined the price provided is reasonable and the consultant’s proposal demonstrated the greatest value for this project. Some of the consultants that were invited to propose on this project could not fit this work into their current project loads.
Budget Impact
Dewberry’s fee is $341,120. Staff requests an additional $34,112 (Town-managed 10% contingency) be authorized for a total project authorization of $375,232. The project will be funded from the account shown below. Ultimately, Douglas County will reimburse Castle Rock Water for the design services based on the 3rd Amendment to the IGA for the Highway 85 Wastewater Collection and Treatment System that provides for $375,232 of county funding to be provided for this agreement. The funding from the County reflects the continued partnership between Douglas County and the Town to support centralized wastewater services to residents and businesses in and around the Town of Sedalia.
|
Account Name |
Account Number |
Amount Requested |
Contingency Requested |
2026 Budget |
|
85 Regional Wastewater |
213-4575-445.79-33 |
$341,120 |
$34,112 |
$2,341,292.84 |
Staff Recommendation
Staff recommends Town Council approval of the resolution awarding the Services Agreement for Phase 1 of the Sedalia Gravity Collection System design and bid support services to Dewberry in the amount of $341,120 plus a Town-managed 10% contingency in the amount of $34,112, for a total authorization of $375,232.
Proposed Motion
“I move to recommend to Town Council approval of the Resolution as presented”
Attachments
Attachment A: Resolution (Not Attached)
Exhibit 1: Agreement
Attachment B: Location Map