Water quantity allocations

Water is allocated by Greater Wellington via a resource consent in accordance with policies and rules in the Wellington regions’ Natural Resources Plan (NRP). Water is allocated as either ‘core allocation’ or ‘supplementary allocation’.

Core allocation is available at all times except when rivers or aquifers are under stress during dry spells.  Most consents in the region are for core allocation.

Supplementary allocation becomes available (in addition to core allocation) when rivers are at higher flow and is commonly only used for flow harvesting and storage for later use.   

This viewer application provides information about core allocation only. 

The amount of water available for core allocation is defined in the NRP for various catchment management units and aquifers as an allocation amount. For rivers and streams, allocation amounts are defined as instantaneous rates (litres per second) whereas annual volumes (cubic metres per year) are used for groundwater.  

For groundwater takes that are connected to nearby rivers or streams, water is partly allocated from the relevant aquifer management unit and partly from the relevant river or stream catchment management unit. 

In this viewer, the total amount of water allocated to resource consents for any catchment management unit is called the consented core allocation.   

Water take consents have been approved (and allocated) based on information available and allocation amounts identified at the time the consent was processed.  

Over time, information used to establish allocation amounts improves and/or the approach to allocating water changes.  This can result in a change to the allocation status of a catchment management unit even though the actual amount of water consented has not changed.  Where an allocation amount has been recently reduced the catchment management unit may now be over allocated (i.e. consented core allocation is now greater than 100% of the allocation amount).  

Specific reasons for catchment management units having consented core allocation that is now greater than 100% of the allocation amount include: 

• The application of standardised default methods to set allocation amounts as proportions of mean annual low flow.  For small stream catchments in particular this has resulted in significant reductions in the available allocation amount; 
• Revision of groundwater catchment management unit boundaries and use of more conservative methods to assess sustainable yield, and therefore allocation amounts; 

• The addition of groundwater allocation to surface water allocation in some management units where there is a strong connection that hasn’t been recognised in the past; this results in an increase in consented allocation on paper. 

In the future, our Natural Resources Plan will address how over-allocation is dealt with in each catchment management unit.