The quality of sediment on the bed of waterways is monitored by the Christchurch City Council every year. Monitoring is undertaken in a different catchment per year, on a five-yearly rotating catchment basis.

Sediment is typically analysed for the following parameters:

  • Particle size distribution
  • Total recoverable copper, lead and zinc
  • Total organic carbon
  • Total phosphorus
  • Polycyclic aromatic hydrocarbons
  • Semi-volatile organic compounds.

These results are presented in annual reports that determine sites and parameters of concern, based on comparisons to guideline levels and any changes over time.