Consideration and Approval of Contract:  Design of Lake Mary Raw Waterline Replacement Project, Lake Mary Raw Water Pump Station to the Lake Mary Water Treatment Plant.
 

1. Approve the professional services contract with Ardurra Group, Inc. allowing the Water Services Engineering Team to proceed with the development of a design to replace the aging and failure-prone 1963 raw waterline from the Lake Mary Raw Water Pump Station - located at Lower Lake Mary - to the Lake Mary Water Treatment Plant; and
2. Authorize the City Manager to execute all necessary documents

The 27-inch Lake Mary Raw Waterline was installed in 1963 and is able to deliver up to 8 million gallons of Lake Mary lake water to the Lake Mary Water Treatment Plant for treatment and distribution each day.  This water source represents our largest single source of water for the City of Flagstaff.  At the time of installation, this pipeline had a projected 50-year life expectancy.  Due to the number of years this pipeline has been in service, along with other environmental factors including the surrounding aggressive soil chemistry, abrasion due to the limestone geology where this pipeline is perched, and other factors, the pipeline needs to be replaced at this time.

In the fall of 2025, a solicitation requesting statements of qualifications (RSOQ) was made by the City. Through the RSOQ selection process conducted, Ardurra Group, Inc. was selected as the most qualified design engineering firm to produce a design for the replacement of this critical piece of infrastructure.  Issues with this water pipeline cause slowing and cessation of surface water production at the Lake Mary Water Treatment Plant, removing a large portion of our water production capacity while repairs are made under time-sensitive conditions.  Water Services would like to move forward with this design to begin the process of replacing this pipeline that is critical to meeting our City's water demand.

Project Name:Lake Mary Raw Waterline Replacement Project - Design
Cost: $482,995.00
Account Number Budgeted: 202-08-370-3547-0
FY Budgeted Amount:$550,000.00
Grant Funded:No
Funding Source: Drinking Water Fund

The project is funded by the Council-approved Capital Improvements Budget.

• Approve the contract with Ardurra Group, Inc. in the amount of $482,995.00 for design of the Lake Mary Raw Waterline Replacement Design Project and proceed with this design effort.
• Do not approve the contract with Ardurra Group, Inc. and do not proceed with design work on the Lake Mary Raw Waterline.

Over 5 miles of 27-inch Lake Mary Raw Waterline was designed and installed in 1963 to convey up to 8 million gallons of Lake Mary water from the Lake Mary Raw Water Pump Station to the Lake Mary Water Treatment Plant.  This waterline replaced the previous 12-inch line that had served the City of Flagstaff since 1941.  The 1963 waterline had a projected life expectancy of 50 years and has exceeded that, admirably, by thirteen years.  This pipeline is beginning to show its age however, with more frequent and catastrophic failures as factors such as abrasion and corrosion are taking their toll.  The loss of this crucial water source during these failure events is intolerable as the Lake Mary Water Treatment Plant provides the majority of our daily water production.  Replacement sections of this increasingly rare steel reinforced concrete cylinder pipe, are very expensive and very difficult to source as modern pipe designs have made it all but obsolete.  These new replacement sections must be specially manufactured to specifications and installed by specialists trained in working on this type of exotic and historic pipe material.  Two recent failures of this pipeline this year alone (2025), have totaled roughly $380,000.00 in emergency repair costs and resulted in over 3 weeks of downtime of Lake Mary water production and the closure of Lake Mary Road for roadway repairs.

The Purchasing section posted a Request for Statements of Qualifications (RSOQ) solicitation for design on June 6, 2025, on the PlanetBids website, and advertised it in the Arizona Daily Sun newspaper on June 14 & 21, 2025. There were 2 Statements of Qualifications received by the due date of July 8, 2025. After reviewing of the Statements of Qualifications received from the interested firms, the RSOQ evaluation panel of six (6) professionals in and outside the City selected the highest scoring firm, Ardurra in August 2025 to move forward in negotiations.

This new contract will allow the chosen firm, Ardurra, to design Lake Mary Raw Water Pipeline Project. 

Staff is requesting approval of RSOQ Design Services Contract No.: 2025-11 with Ardurra Engineering for professional engineering services.

• Sustainable and Innovative Infrastructure
• Safe and Healthy Community
• High Performing Governance
• Environmental Stewardship

• Sustainably producing potable water resources
• Implementing Water CIP Projects to address aging infrastructure
• Ensuring water resources are sustainably produced for future generations

This project will serve the Carbon Neutrality Plan through the replacement of existing infrastructure with modern materials with increased longevity and ensuring the continued production of our most energy efficient raw water source to meet the City's growing water demands.

This project will ensure water resources are developed, produced and distributed for continued City growth.

The Water Services Division Capital Improvements Program addresses the replacement of aging infrastructure to meet current and future growth demands.