Our freshwater baseline states

The purpose of the Freshwater Plan is to maintain, or improve where necessary, the state of our freshwater resources and environments - and it is difficult to do that without first knowing what the baseline state is.

The baseline states provide a basis for determining long-term visions, freshwater objectives and setting target attribute states for our freshwater and the time frames to get there. It will also be used along with other information to identify priority areas for any potential rule changes and targeted action plans.

Under the Government’s policy direction (NPS-FM), we’re required to set baseline states for the 22 compulsory freshwater attributes (PDF, 1.1MB), such as water quality, physical habitat, or levels of E.coli, for example. An attribute is essentially something we can measure and monitor and which tells us about the state of a freshwater system.

What are our current baselines states?

In Northland, we have used data from 2015-2019 to determine the baseline state for most of the compulsory river attributes and 2016-2020 for the compulsory lake attributes. We have also included a few extra attributes that we think are important to Northland. There are a few attributes where we have yet to collect enough information to determine the baseline state.

Northland freshwater baseline state evaluation report

This report describes the attributes and associated methodologies used to derive the baseline states for Northland freshwater bodies including rivers, lakes, wetlands and groundwater aquifers where sufficient data available.


Rivers water quality baseline states (2015-2019)
Dissolved phosphorous maximum - baseline state (PDF, 5.2MB) Dissolved phosphorous median - baseline state (PDF, 5.2MB)
E.coli maximum or 95th percentile - baseline state (PDF, 4.3MB) E.coli median - baseline state (PDF, 4.3MB)
E.coli overall - baseline state (PDF, 4.2MB) E.coli - % exceedance > 260/100 ml - baseline state (PDF, 4.3MB)
E.coli - % exceedance > 540/100 ml - baseline state (PDF, 4.3MB) Macroinvertebrates ASPM - baseline state (PDF, 7.9MB) 
Macroinvertebrates MCI - baseline state (PDF, 10MB) Macroinvertebrates QMCI - baseline state (PDF, 7.9MB)
Ammonia toxicity (NH4-N) maximum - baseline state (PDF, 4.2MB) Ammonia toxicity (NH4-N) median - baseline state (PDF, 4.2MB)
Nitrate toxicity maximum - baseline state (PDF, 4.2MB) Nitrate toxicity median - baseline state (PDF, 4.2MB)
Fish index of biotic integrity - baseline state (PDF, 5.32MB) Suspended fine sediment median visual clarity - baseline state (PDF, 4.2MB)
Periphyton - baseline state (PDF, 9.3MB)  


Lakes water quality baseline states (2016-2020)
Trophic Level Index or TLI - Lake WQ baseline state (PDF, 6.0MB) Ammonia toxicity maximum - lake WQ baseline state (PDF, 8.6MB)
Ammonia toxicity median - lake WQ baseline state (PDF, 8.6MB) Lake submerged plant invasive species - baseline state (PDF, 8.6MB)
Lake submerged plant native species - baseline state (PDF, 8.6MB) Phytoplankton maximum - Lakes WQ baseline state (8.6MB)
Phytoplankton median - Lakes WQ baseline state (8.6MB) Total nitrogen median - Lakes WQ baseline state (8.6MB)
Total phosphorus median - Lakes WQ baseline state (8.6MB)  


Wetlands used to cover around 20% of Northland. Today, the remaining wetlands that cover approximately 5% of Northland’s land area, are many (more than c. 1,000) and fragmented. While we have data on some of these wetlands, we don’t have enough to give the full picture on the state of our wetlands. So, we are in the process of developing a wetland monitoring programme to provide us with an assessment of the wetland baseline state across the region.


Groundwater baseline states (2015-2019)
Chloride median - baseline state (PDF, 701KB) Dissolved reactive phosphorus median - baseline state (PDF, 701KB)
Nitrate-nitrogen median - baseline state (PDF, 701KB) E.coli number of exceedances - baseline state (PDF, 624KB)