Ålesund Municipality provides water and wastewater services to 60,000 residents. The stormwater and wastewater system comprises more than 12,000 pipes and around 100 pumping stations that convey wastewater to eight treatment plants. The system also includes a large number of overflow structures. When the municipality initiates flow measurement, modelling, and instrumentation, it does so with the objective of:

• Improve understanding of how the pipe network operates.
• Accurate knowledge of actual wastewater volumes within the network and of overflow discharges.
• Improve the quality of the data reported annually to the authorities.
• Use the model to prioritise and implement measures in the right locations.
• Document whether the goals set in the wastewater master plan and rehabilitation plans are actually being achieved.

The model is used to:

• Status analyses by theme:

• • Inflow and infiltration
  • Surcharging, capacity, and flooding
  • Discharge volumes / overflows
  • Adverse events / Emergency preparedness

• Scenario testing with model simulations for:

• • Development / densification
  • Rerouting / separation
  • Interceptor systems
  • Adverse events / Emergency preparedness
  • Climate change

Cross-correlation flow meters have been used for measurement campaigns. A number of zone and overflow meters have been installed using a systematic methodology.