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3 WatersEnvironment

Managing our lakes, rivers and streams: 3 ways to lift our game

New guidelines for freshwater management are a step in the right direction, says Rebecca Bibby, but we could do so much better.

When the National Policy Statement for Freshwater Management took effect on 1 August 2014 it became the first piece of legislation that solely gives effect to how freshwater bodies are managed in New Zealand. The purpose of the government’s changes to the 2011 National Policy Statement for Freshwater Management (NPSFM) was to incorporate a National Objectives Framework (NOF). This sets environmental bottom lines and provides mandatory guidelines for freshwater plans.
These changes constituted the most important part of the freshwater reform process and were the result of work by more than 60 freshwater scientists from the public, private and academic sectors across New Zealand.
Until the NPS-FM 2011 there had been limited numerical objectives for freshwater management. Arguably, this had to be one of the biggest reasons for the progressive national decline in the water quality of our waterways. There is little doubt that a national framework with numeric national standards was a welcome advance for the better management of our freshwater bodies.
Most people would agree that the NPS-FM is a step in the right direction. However, the NPS-FM (2014) didn’t have a smooth ride into town. There has been plenty of debate, comment and concerns everywhere from scientists to the community alike. Despite being a solid step in the right direction, most would agree that the NOF needs to evolve if we are to improve the overall state of our freshwater bodies.
As a freshwater water quality scientist, I have three primary concerns:
1. The water quality of natural freshwater bodies is a complex business. Water bodies are dynamic systems containing a cocktail of interacting substances which are influenced by physical factors such as climate and flow. With the interplay of so many variables it can be very difficult to predict how a water body will respond to any change to its physicochemical attributes. The NOF provides national bottom lines for nitrogen and ammonium.
These have been set at a level for direct toxic effects. However, nitrogen and ammonium can contribute to significant detrimental effects at much lower levels than the bottom line limits depending on both the cocktail and physical attributes of the water body. Excessive algae growth, for example, can have significant effects on water quality.
However, for excessive algae growth to occur, other conditions such as available phosphorus are required. There are no mandatory phosphorus bottom line limits in streams and rivers. The NOF has not given enough consideration to the
complexities of freshwater systems.

The National Objectives Framework needs to evolve if we are to improve the overall state of our freshwater bodies.

It can be very difficult to predict how a water body will respond to any change to its physicochemical attributes.

2. The focus of the NPS-FM for managing water quality is based on ‘freshwater management units’. This represents a significant move away from the single water approach to freshwater management.
A freshwater management unit (FMU) as defined in the NOF may be an individual water body, part of a water body or multiple water bodies. Management objectives and limits are assigned to each FMU. There are difficulties around setting limits to an aggregate system. For example, freshwater bodies are dynamic systems with generally better water quality in the headwaters and increasing degradation with distance downstream.
The application of a single limit to an FMU may allow decline in some parts of the aggregate and improvements in others. Better guidance is required in terms of how the FMU approach to freshwater management is to be implemented.
3. There are two compulsory national values for fresh water. These are ecosystem health and human health for recreation.
The value for human health supports a new objective in the NPS to safeguard the health of people and communities to a minimum level of wading and boating. Most people agree that this bar is just far too low. In fact, it really is just above the level of wading and boating while wearing a hazmat suit – New Zealand can do better.
The NOF is a good start to the effective management of our freshwater systems. An independent review of its implementation and effectiveness will be conducted before 1 July 2016. Before this time, additional numeric attributes and greater clarity are likely to be proposed which will better serve the purpose NPS-FM. LG

Rebecca Bibby is a senior environmental scientist with engineering, water and environmental consultants Mott MacDonald.

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