Tauranga Comprehensive Stormwater Consent Monitoring – The First Five Years

Stormwater Conference

Tauranga City Council was granted a comprehensive stormwater consent in 2012 for the discharge of stormwater throughout Tauranga City. Conditions of consent require monitoring of stormwater quality and ecological values of freshwater and marine receiving environments. The aim of the monitoring is to identify sub-catchments with poor stormwater quality and adversely affected receiving environments to focus treatment and/or remediation effort. Contaminant trigger levels are identified within consent conditions including a condition requiring further investigation should trigger levels be exceeded over consecutive sampling events or in the same quarter over consecutive years.

The end of 2017 marked the completion of five years of monitoring which provided sufficient data to identify sub-catchments with stormwater quality and/or receiving environment issues.

Water quality data indicated contaminants exceeding trigger values and requiring further investigation at 25 monitoring sites (from a total of 41 sites) across 16 sub-catchments. Freshwater ecological assessments indicated at least one contaminant above trigger levels at 13 monitoring sites (from a total of 28 sites) and nine sites were categorised as having poor ecological values based on habitat values and macroinvertebrate and fish assemblages. Three marine receiving environment sites (from a total of 49 sites) recorded at least one sediment contaminant above trigger levels and three sites were categorised as having poor ecological values based on benthic invertebrate assemblage.

Sampling results have been used by Tauranga City Council to address sub-catchments with contaminant issues through the following remedial actions:

  • Refine the monitoring programme;
  • Investigative sampling;
  • Pollution prevention audits;
  • Stormwater mitigation (i.e. installation of stormwater treatment devices); and
  • Habitat restoration.

The completion of five years of monitoring comes at an opportune time, coinciding with:

  • Development of Tauranga City Council’s environment strategy that includes focus on water quality and protecting/enhancing the natural environment;
  • Start of a new Long-Term Plan cycle enabling funding for proposed mitigation; and

Water New Zealand’s 2018 Stormwater Conference

  • Ability to collaborate with other programmes such as City Transformation and Parks restoration projects.
Conference Papers

1. Tauranga Comprehensive Stormwater Consent Monitoring - The First Five Years.pdf

pdf
310 KB
25 Jun 2018

1350 - Kieran Miller - TCC_BML_stormwater_presentation.pdf

pdf
4 MB
25 Jun 2018