by Eugenie Sage
Yesterday’s release of the Board of Inquiry’s final decisions on the regional plan provisions for the Tukituki River and catchment as part of the Ruataniwha dam project confirms that National’s favoured approach to bottom lines for water quality will not help our rivers.
The Board of Inquiry for the Tukituki Catchment Proposal rejected the Government’s favoured model for managing water quality. It decided that limits on polluting nutrients such as nitrogen and phosphorus need to be set at levels which protect the ecological health of rivers, not at levels which are toxic to aquatic life which would have allowed a lot more nutrient pollution.
The Board rejected the Hawke’s Bay Regional Council‘s (HBRC) proposed “one nutrient” approach which set some controls on phosphorus but largely relied on a voluntary approach to controlling nitrogen leaching. The Board confirmed its earlier decision that the regional plan needs to include limits on both nitrogen and phosphorus.
It accepted that a 0.8 mg/l limit on dissolved inorganic nitrogen was needed to protect ecological health. This is much more stringent than the nitrogen limits the Government has included in its proposed changes to the National Policy Statement on Freshwater Management. The Government’s weaker limits allow for more dairying and agricultural intensification and would result in our rivers becoming even more polluted and degraded.
The Government’s proposals also leave out a crucial indicator of ecological health – the Macroinvertebrate Community Index (MCI). It measures the abundance and distribution of aquatic insects which are a crucial part of river food webs. The Board saw the MCI as an important basis for determining the acceptable limits on nitrogen.
In the light of the Board’s decisions the Government needs to rethink its proposed national bottomlines for water quality.
The Board has also signalled that farmers whose land use causes significant nutrient leaching shouldn’t get a free pass because of their existing poor practice. The amended plan will require a Farm Environmental Management Plan for all farms over 4 ha in the Tukituki catchment (or 10 ha if the land use is non-intensive). This is a signal to farmers that land use needs to change to prevent the leaching of polluting nutrients and protect our rivers.
The Board decision runs to three volumes and hundreds of pages. It’s unclear how the nutrient limits the Board has proposed for the regional plan affect the proposed Ruataniwha dam and irrigation scheme. There is some concern that the Board has uncoupled these. While it has limited the amount of nitrogen which can leach from particular land classes and uses it not tied these to upper limits of nitrogen levels in waterways. This potentially gives a lot of leeway to irrigators. There’s definitely more to come as the implications of this decision are more fully digested.
The Board’s decision certainly strengthens the regional plan for the Tukituki River, but there is a large question mark over how effective the Hawke’s Bay Regional Council will implementing it. The HBRC has a major conflict of interest because of its aggressive promotion of the Ruataniwha dam project and its $80 million funding lifeline for the scheme. Regional councils should be independent and objective environmental managers and regulators. They cannot do this if they are also promoting major water abstraction and increased irrigation and intensive agriculture.