Infrastructure Maintenance

Switzer Canyon Transmission Line
2016-4-15 Little America Meter New Vault install 2_POC

Objective 5: Accelerate Infrastructure Maintenance & Replacement

Relevant Standards

  • Uninterrupted water, wastewater, reclaimed water, and stormwater services
  • Maintain appropriate water system redundancy for both infrastructure and power
  • Investment and rates based on the full cost of service, including long-term investment needs
  • Efficient and cost-effective operations, including applying lifecycle cost analyses
  • Accurate inventory of assets and making data-driven asset management decisions


A critical element of ensuring that water and wastewater pipes, pumps, valves, and treatment plants operate reliably and efficiently is that they are proactively maintained or replaced.


  • Flagstaff has over 470 miles of water lines and the current rate of water line replacement is 2 miles per year. This is appropriate for now, but in the next 10 years, infrastructure that was built in the 1940’s and 1950’s will begin reaching the end of its useful life.
  • Flagstaff’s 270 miles of wastewater pipes and 5,700 manhole covers are experiencing higher rates of corrosion because of water conservation efforts (which increases the concentration of wastewater and corrosive gases in the pipes). The current rate of manhole replacement is only 5 per year.
  • The Lake Mary Water Treatment Plant and Woody Mountain Booster Station are operating with the same sedimentation basins and sand clarifier equipment, respectively, installed in the 1960’s.
  • The North Reservoir Filtration Plant’s filters have not been upgraded in over thirty years.
  • Portions of the pipelines delivering water to these facilities are 100 years old and need replacement. 

Timing Concerns

Infrastructure maintenance and replacement will be an increasing concern over the next 10 years. Planning for this eventually needs to begin in 2020.


Water Services Strategic Plan 2025
Objective 5: Accelerate Infrastructure Maintenance and ReplacementReporting Period:                January-June 2020Reporting Period:    July-December 2020
 Specific ResponsesChampion & TEAMAccomplishmentsAccomplishments Next Steps
Continue making asset management decisions based on G.I.S. data, inspection data, the function of the asset, and the ramifications of asset failureOperations Manager, Engineering Manager, Water Production Manager, Water Reclamation Manager, Stormwater ManagerWCH WRP:  Monitoring inflow and customer use of reclaimed system. Replaced grit lines and weir supports for Primary Tanks.This project was started in December and complete in Mid February 2021.  RDF WRP: Resurface 3 concrete structures and replace 7 slide gates in September 2020.  
Increase the inspections and data on corrosion of wastewater pipes and manhole covers, and recommend updated maintenance procedures and increased fundingWater Reclamation ManagerWCH WRP: Implemented inspection and maintenance programs for belts,  blower voltage, pump vibrations, Arc Flash (req'd)  and IR inspection of electrical equipment.
Continue this work to come up wit a plan for replacement, as we await the CMMS program
Continue developing a more systematic process for capturing data on gas detectors, pumps, and other critical components in water, wastewater, and recycled water treatment plants
WCH WRP:                                          1.  Verifying pump and motor data.  Implemented CMMS in chlorine gas detector calibrations across Water Production.
Continue this work to come up wit a plan for replacement, as we await the CMMS program
Begin concept design to “loop” the recycled water system to increase redundancy and reliability Develop a more comprehensive risk assessment of potable water wells (based on age/condition) Upgrade the Lake Mary Water Treatment Plant sedimentation basins, Woody Mountain Booster Station sand clarifier, and North Reservoir Filtration Plant filters.Water Production Manager1. In Design phase for upgrades/rehab of LMWTP Sedimentaton Basins. 30% & 60% plans received, reviewed and modified.                                               2. Woody Mountain Sand Clarifier project in site preparations for construction. Equipment on order.                                                                      1. Design for Lake Mary Water Treatment Plant Sedimentation Basin Improvement Project was completed.                             2. Woody Mtn. Booster Station Sand Clarifier was rehabilitated with new equipment and coatings as identified in Water Infrastructure Master Plan.                                     3.  RDF WRP: Construction of bypass line at headworks and primary systems in September 2020.Water Production will determine the best means of completing the Lake Mary Water Treatment Plant Sedimentation Basin Improvement Project with available funding/budget.
Maximize the use of GIS to organize data with respect to geographic location

Determine the best approach for Lake Mary Raw Waterline replacement.

Began discussions with Carollo Engineers on the replacement of the Raw Water pipline coming from Lake MaryStart Design