If It's Not Broken… or: Cost-Effective Solutions to Catchment Management

In stormwater management, there are few questions more likely to raise multiple answers than “What’s the problem?”.

To answer the question, do you start with flooding and spend time and money on modelling the “problem”; or with the network upgrading pipes that may just move the “problem” to another area; or building treatment devices in the hope of improving receiving environment quality; or with identifying the real effect the stormwater runoff is having on the environment?

This last approach was taken by Tauranga City Council in preparing its application for comprehensive stormwater discharge and related consents for their stormwater network, with some surprising results.

• Firstly it showed that there wasn’t a widespread contamination problem;
• Secondly it allowed the Project Team of Tauranga City, Beca, Boffa Miskell, and Cathy Bebelman to target specific contaminant issues, locations and management approaches; and
• Thirdly it saved time and money in preparing the consent application and in the future capital works programme.

By knowing what needs to be treated, and where, allows a much more focussed programme of works and the ability for a targeted “top of the cliff” pollution prevention approach – on-site management – rather than expensive end-of-pipe solutions at a cost to all ratepayers.