Lake Rotorua

Lake Rotorua

Why do we need rules

Bay of Plenty Regional Council is responsible for managing water quality in the region. 

The nitrogen reductions needed from rural land and pastoral inputs is well beyond what voluntary adoption of good practice can deliver.  The only way such large nitrogen reductions can be achieved is through rules limiting nitrogen loss from pastoral land.

The community set a water quality target for Lake Rotorua based on a desire for the level of water quality enjoyed in the 1960s.

In 2010 a nitrogen limit was set for Lake Rotorua, allowing only 435 tonnes of nitrogen to go into the lake each year.  Research has indicated that this nitrogen limit will achieve the water quality target.

To meet this limit:

  • The amount of nitrogen going in to the lake needs to be reduced by 320 tonnes per year
  • 50 tonnes can be reduced through urban and engineering options
  • The remaining 270 tonnes needs to be achieved through reductions from rural land.

Existing rules will not meet 270 tonne reduction target

Rules were introduced in 2005 which capped nutrient losses at their 2001-2004 levels.  Known as Rule 11, these rules set a discharge limit called a benchmark for properties in the Rotorua surface water catchment based on each property’s land use between 2001-2004.

Rule 11 didn’t reduce nitrogen levels to the lake, but stopped nitrogen inputs to lake increasing.

When the new nitrogen limiting rules for the Rotorua catchment become operative, Rule 11 will no longer apply to this catchment.

Current actions and engineering solutions not enough

Sewerage reticulation of lakeside communities, upgrades to the wastewater treatment plant and engineering options to reduce geothermal nitrogen sources have been implemented but land use change is still required.

Regional Policy Statement directives

The RPS directs managed reduction by way of regulatory rules.