New approach mooted for urban stormwater discharges

Now that proposed Plan Change 6A to the Otago Water Plan has been publicly notified, the Otago Regional Council (ORC) has started preliminary work on related plan changes, which includes addressing discharges from urban stormwater systems.

ORC chairman Stephen Woodhead said council staff have met city and district council staff as the part of the public consultation on Plan Change 6A, which introduces rules to control rural water pollution from runoff, leaching, and farm drains entering rural waterways.

Cr Woodhead said that while discussing the principles behind ORC’s approach to water quality management, staff had outlined possible implications for discharges from reticulated systems.

Stormwater discharge in Otago is currently a permitted activity in the Water Plan. This means it does not require resource consent, as long as it contains no sewage, and after reasonable mixing does not show conspicuous oil or grease, or change in colour or clarity, or cause objectionable odour or significant effects on aquatic life.

Cr Woodhead said the waterways that act as outlets for these discharges had to be protected from degradation by stormwater discharges.

There were many urban stormwater treatment options available to district councils, with new technologies being developed all the time.

Contaminant standards would eventually be set for stormwater discharge from new and existing sites. System operators could opt for an ‘at-source’ or ‘end-of-pipe’ solution, or a combination of both, to meet the necessary level of treatment, thus ensuring the environment was adequately protected.

Existing sites will also have contaminant standards set, but these will be phased in over time.

Cr Woodhead said it had become apparent during the rural water quality change process so far, that all of Otago, and not just rural water users, needed to commit to a long-term water quality solution.

“Solutions will have to address the need for acceptable water quality while providing a flexible framework which is suitable for Otago, and which will incorporate community expectations and aspirations,” he said.

“The urban water quality strategy complements our rural water quality work and is a clear indication that council is taking an active and responsible approach to ensuring good water quality standards throughout the region for generations to come,” Cr Woodhead said.