north vancouver water model assessment and audit

Water Street Engineering Ltd. completed an assessment of the City of North Vancouver's water system hydraulic model to develop a model updating plan.  WSE reviewed the existing H20net model against the CIty's record drawings, source flow records, and facility information.  Model update recommendations included:

  • Updating and improving the accuracy of the model boundary conditions (supply sources), 
  • Improve control valve station modelling,
  • Use of actual pipe inside diameters (as opposed to nominal diameters),
  • C-factor calibration for cast iron piping,
  • Re-scaling and GIS assignment of the model demands to better reflect seasonal irrigation,
  • Addition of diurnal patterns to allow for extended-period simulation,
  • Review of potential inter-zone leakage. 

WSE also completed a water audit following AWWA M36 methodology.  This component of the work included:

  • Review of existing water loss / unaccounted for water information,
  • Review of source flows including night-time flows,
  • Summation of billed metered authorized consumption (from industrial, commercial, and institutional meter data),
  • Developing estimates of billed un-metered authorized consumption (residential un-metered demands),
  • Estimates of unmilled unlettered usage and apparent losses (un-authorized consumption, metering inaccuracies),
  • Calculation of non-revenue water
  • Compiling system data for calculation of the City's Infrastructure Leakage Index (ILI),
  • Assessing and recommending components for a water loss management program to improve current understanding of water usage and build on the results of the audit.  

As a result of the audit the following recommendations were made.

  • Setting ILI targets,
  • Source flow metering improvements,
  • District metering,
  • Survey of top-ICI users,
  • Expansion of trial residential metering,
  • Night-time flow step-testing,
  • Purchase of leak detection equipment, and
  • Yearly water audits.  

 

Client: City of North Vancouver

Client Contact: David Matsubara, P.Eng. ; dmatsubara@cnv.org