Clause 3.8: Identifying FMUs and special sites and features

FMUs must be identified, as a prerequisite to all other steps in the NOF. An FMU (or part of it) is the primary unit in which activities are managed and monitored under the NPS-FM.

Councils must determine how to define their FMUs, and the location of their monitoring and primary contact sites, provided these are representative of the FMU or relevant part of it. In practice, this allows for significant variation from place to place. The council must actively involve tangata whenua and engage with communities when doing this, and they must collaborate with tangata whenua to determine monitoring sites relating to Māori freshwater values.

Identification method

The NPS-FM does not mandate a single correct or preferred way to identify FMUs. Each FMU should reflect the unique circumstances of each region. These will dictate what target attributes, freshwater environmental objectives, limits and flows to set. The definition of FMUs is intentionally flexible, so councils can determine the spatial scale best suited to their region. The FMUs (one or more) in a region must include all freshwater bodies.

Scale

The FMUs in a region will determine the scale at which to set a vision, or environmental outcome, for an attribute. For example, for periphyton (the slime and algae on the beds of streams and rivers), councils must set an environmental objective, and instream nutrient concentrations to achieve these objectives, for all FMUs.

A long-term vision or limit can be set at the FMU scale or part of an FMU (a catchment or subset of catchments). They cannot be set at a larger scale than one FMU. All other steps of the NOF are similarly set at an FMU or part of an FMU scale.

It might be that in any given FMU an attribute, such as deposited fine sediment, provides for more than one value (eg, human contact and mahinga kai). In this case, it is the most stringent TAS relevant for either of these values that must be achieved. If a less stringent TAS is applied, the plan cannot reach all community values and objectives.

Monitoring sites

Each FMU should have one or more monitoring sites. Councils are required to monitor and report on the achievement of long-term visions and TASs, so will need monitoring sites to do this. The sites must be representative of all or part of the FMU. If the FMU has primary contact sites, at least one representative monitoring site must be identified for that value.

FMUs and monitoring sites provide data and information to help set baseline states and TASs. They will influence limits on resources, and setting flows and levels.

Monitoring sites for Māori freshwater values (including mahinga kai values) do not have the same requirements. They differ in two main ways:

1. they do not need to be representative of all or part of the FMU
2. they do not need to be representative of a primary contact site.

Monitoring sites for Māori freshwater values must be determined in collaboration with tangata whenua.

Managing freshwater is inherently linked to managing the land that feeds into the freshwater body, or the catchment, that supplies it. The NPS-FM requires councils to manage freshwater and land use in an integrated and sustainable way (ki uta ki tai). Councils should consider the surrounding land use and its effect on freshwater bodies, when identifying FMUs. A catchment or sub-catchment is a good scale to begin assessing FMU boundaries.

When setting FMU boundaries, councils should work with tangata whenua and the community to consider:

1. the hydrological, geographical, social, political and cultural characteristics of the region, including the cultural connections of tangata whenua and communities to place
2. practical issues with managing freshwater to give effect to the NPS-FM, which may result in sub-dividing or grouping the units further, after considering these characteristics.

Factors to consider when determining FMU boundaries may include*:

• intensive pastoral development
• prominent geophysical features, such as being prone to erosion
• location of aquifers and connection to groundwater and surface water
• urban issues affecting water quality
• a current or historic mahinga kai site or other cultural areas of significance
• degraded freshwater bodies that may need specific management methods
• hapū or iwi rohe boundaries, which reflect relationships between tangata whenua and place, and may aid discussions about the transfer of powers or other mechanisms under clause 3.4(3).

This approach allows councils to tailor the limits and management methods to the values and outcomes for each FMU.

*See the guide to freshwater management units [PDF, 656 KB]

Coastal water

The NPS-FM does not require councils to include coastal water in FMUs, or to set freshwater objectives and limits for it. However, it requires that, when setting freshwater objectives and limits, councils take a ki uta ki tai approach and have regard to connections between freshwater and coastal water. This may mean decisions about managing freshwater will be driven in part by intended outcomes in coastal water (eg, to provide for mahinga kai).

When identifying FMUs, councils should consider any connections between freshwater bodies and coastal water. For example, where several rivers meet in an estuary, a council may decide to group the rivers together in one FMU, so that any management decisions for the FMU align with the outcomes for the estuary.

Scale for target attribute states and limits

The scale for setting TASs and limits does not have to be synched with whole FMUs. TASs and limits can apply to part of an FMU, or the same TAS or limit may be set for multiple FMUs.

Each FMU will have a bundle of TASs applied to it, at least one for each relevant attribute.

Determining the area for a TAS will depend more on the characteristics of the water bodies than for the land type. A tributary that has a different ecosystem and land use from other tributaries and mainstem of a river system might have different requirements for a TAS.

Limits and/or action plans may need to be more granular at the sub-catchment scale, because catchments have many different areas with varied land characteristics. A catchment may have forest-covered hill slopes, then plains with clay soil and other areas with stony, free-draining soil. Councils should tailor the intervention to these varied features.