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.

Specific Responses  January to June 2020

Step Champion Action Items Next Steps
1. Continue making asset management decisions based on G.I.S. data, inspection data, the function of the asset, and the ramifications of asset failure Operations Manager, Engineering Manager, Water Production Manager, Water Reclamation Manager, Stormwater Manager WCH WRP:  Monitoring inflow and customer use of reclaimed system. Replaced grit lines and weir supports for Primary Tanks.
RDF WRP: Resurface 3 concrete structures and replace 7 slide gates in September 2020.
2. Begin ramping funding for water mains replacement,                   reaching 3 miles per year by 2030 N/A N/A N/A
3. Increase the inspections and data on corrosion of                         wastewater pipes and manhole covers, and recommend             updated maintenance procedures and increased funding Water Reclamation Manager WCH WRP: Implemented inspection and maintenance programs for belts, blower voltage, pump vibrations, Arc Flash (req'd) and IR inspection of electrical equipment. N/A
4. 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. N/A
5. 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 Manager 1. In Design phase for upgrades/rehab of LMWTP Sedimentation Basins. 30% & 60% plans received, reviewed and modified.                                              
​2. Woody Mountain Sand Clarifier project in site preparations for construction. Equipment on order.                  
1. 90% plans for Sedimentation Basin rehab expected in mid-August.                             2. Woody Mountain Sand Clarifier project in construction by September 2020. 3. RDF WRP: Construction of bypass line at headworks and primary systems in September 2020.
6. Determine the best approach for Inner Basin pipeline                   replacement. N/A N/A N/A