Changes to water pressure impacting fire services

This information is provided for hydraulic consultants and building maintenance managers about planned changes to water pressure which may impact properties with a fire service.

We’ve recently advised property owners with a fire connection of a change to the water supply network in their area due to our Pressure Management Program. The change will see a difference to the flow rate to their property, including the fire connection service.

The letter provided an assessment of the available flow rate at the property both before and after the planned change.

The information below is provided to help you interpret the data in the letter and ensure the fire service remains compliant following the changes.

Figures provided to property owners with a fire service:

• The flows provided are calculated using residual pressures.
• Water Corporation has made an assessment of the hydraulic capacity of the water supply network before and after the planned changes.
• The information provided is indicative only and should not be relied upon by itself as a record of actual performance of the network.

The output from the hydraulic modelling is based upon normal operation of the water supply network at the 95th percentile demand using a calibrated hydraulic model for the network.

• Flows in excess of 40L/s are recorded as >40L/s.
• Figures provided have been rounded down to the nearest whole number.

Pressure and flow at properties cannot be guaranteed, varies during the course of the day and changes over time as the water network changes and a growing Perth population demands more water. Therefore the figures provided are indicative only and reflect a single point in time.

Fire services

Fire Services are a non-standard service and are subject to an agreement between Corporation and the customer.

This agreement is consistent with the following points:

• Water Corporation will make available all spare capacity within a water supply scheme to fight a fire. However, we do not provide a guaranteed level of service (pressure or flow) for the purposes of firefighting.
  
  
• We deliver water networks in line with our operating licence of no less than 15 metres head within Perth Metropolitan area and 13 metres head within country urban areas, with a minimum flow rate of 20 litres per minute.
  
  
• (Due to the above) majority of locations across the State will receive a higher pressure and flow rate than this. Therefore, the hydraulic capacity of fire service connections exceeds the minimum standards.
  
  
• The performance of the network can change over time and may be influenced by planned and/or unplanned maintenance and operating activities, and growth in demand.
  Property owners are responsible for regular testing and maintenance of fire service systems beyond the connection point to the Water Corporation’s network.
  
  
• A development’s firefighting needs are determined by the Building Code of Australia.