THE EVOLUTION OF STORMWATER MANAGEMENT PLANS – GIVING EFFECT TO TE MANA O TE WA

S. Dudson & B. Hamilton (WSP), G. Hall & M. Bunt (Timaru District Council), M. Ellis (Pattle Delamore Partners), T. Davidson (Aoraki Consultants Limited)

The industry approach to stormwater management requires a step change in thinking to give effect to Te Mana o te Wai, but there is no specific road map on how this should occur.  The approach taken in the development of Stormwater Management Plans (SMPs) for four urban townships in the Timaru District offers insight to a way that Te Mana o te Wai can be put into practice. A process was established based on adaptive management that can endure beyond both the timeline and geographic limitations of this project. The process has been designed to help foster enduring relationships with mana whenua and achieve Timaru District Council’s vision for stormwater management:

Together we value, protect and restore the mauri/lifeforce of the waterways so that
it enables Mahinga kai, ki uta ki tai (mountains to the sea).

The project started with more of a traditional approach, driven by the need to consent reticulated stormwater networks discharges in TDC’s main urban centres. Initially, the scope was focussed on delivering prioritised management options for stormwater quantity and quality to meet water quality standards and consent conditions.  The need for a new way of thinking evolved out of some early project conflict during mana whenua engagement. Learnings from this experience showed us that:

• Ultimately, we all want the same thing; we all need the same data to understand the extent to which stormwater discharges have impacted the natural environment.
• Having the right advocates to bridge the gap and communicate western science into mana whenua values and vice versa cannot be understated.
• Effort put in upfront into relationships that can endure through generations will pay dividends later in the project, but not too hard too fast; mana whenua needs to be given appropriate time and space to deliberate and respond.
• Te Mana o te Wai is a journey, not a destination and it is the process, not just the outcome that is important to get right.

The new way of thinking led to the development of a process to implement the SMPs based on an adaptive management approach. Projects or management actions are identified and evaluated which consider how well the project or action would progressively improve the management of stormwater, specifically toward achieving the objectives and targets of the SMP which were developed in line with the Te Mana o te Wai hierarchy of obligations. Mana whenua have an integral role in this evaluation process alongside TDC before any projects or actions make it through to the implementation plan. Working within existing funding budgets, the new and existing projects are rescheduled, where projects and actions with
the greatest benefit are prioritised.

Monitoring of environmental parameters (including water/sediment quality, ecological and cultural), and the associated trigger and response plans provides key feedback into the management plan. This monitoring identifies areas that should be targeted for improvement as well as monitoring the performance and progress of management practices that have already been implemented, relative to the specified objectives and targets. New projects are identified that would improve the outcomes of the stormwater system and evaluated, continuing the cycle.

This process demonstrates the next evolution for stormwater management planning in Timaru and provides a tangible example of how giving effect to Te Mana o te Wai can be put into practice.