Zone Name:	Waipara	Current Status:	(Yellow)
Allocation Limit:	10.7 million m3/yr	Valid date:	21 October 2006
Order of Approach:	Second (50% of land-based recharge)

Recharge component

Method of estimation

Background notes

The Waipara groundwater zone comprises the alluvial aquifers within the Waipara basin. The geological nature of the resource is complex and highly variable. Distinct sandstone, mudstone and limestone rock formations form the extremities of the known aquifer system. The aquifer system consists of a series of buried meandering river channels within the gravels that infill the alluvial basin and form the plains of the lower catchment. In some locations, these channels have well defined preferential flow paths (Environment Canterbury Report No U05/87 Revision 1)

The 2nd order limit for the Waipara groundwater zone still applies but the extent of the zone has been adjusted to be consistent with the latest geological information for the area. As a consequence the annual allocation limit has been revised to 10.7 million cubic metres per year.
The methodology and estimates of rainfall and irrigation recharge are described in Groundwater Allocation for the Waipara Groundwater Zone (Environment Canterbury Report No U05/87 Revision 1). The second order approach incorporates estimates of the average annual land surface recharge, estimated to be 15.6 million cubic metres - approximately 52 percent less than the rainfall recharge estimate on which the 1st order limit was based. The detailed analysis of climate and soil data has shown a lower proportion of rainfall recharge than adopted for the 1st order limits.

In addition, there has been a review of the recommendations made in Report U05/87 Revision 1 with respect to the contribution to recharge from the intermittently flowing streams in the zone, as well as further analysis using data from more recent river gauging information that was not available at the time the report was completed. This review has concluded that there is no net-gain from the Waipara River, Weka and Home Creeks, and Omihi Stream to the Waipara groundwater allocation zone. Losses to groundwater from the Waipara River and its tributaries are considered to be mimimal, largely due to the retention of water within the gravels associated with the river, stream and creeks. In fact, there is a large input from Omihi Creek into the Waipara River as a result of contribution from springs in the lower Omihi. This analysis suggests that there is no net recharge of intermittent streams into the Waipara groundwater allocation zone from the Omihi Creek, but rather there is a contribution from groundwater to the Waipara River. Accordingly, no inputs from the Waipara River and its tributaries are included in this 2nd order allocation limit.

Allocation history

Effective allocation

 11 January 2010

Effective Allocation (million m³): 9.91
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 93%

3 November 2009

Effective Allocation (million m³): 9.98
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 93%

3 August 2009

Effective Allocation (million m³): 9.86
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 92%

9 February 2009

Effective Allocation (million m³): 9.28
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 87%

13 October 2008

Effective Allocation (million m³): 9.27
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 87%

8 September 2008

Effective Allocation (million m³): 9.23
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 86%

7 July 2008

Effective Allocation (million m³): 9.26
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 87%

9 June 2008

Effective Allocation (million m³): 9.19
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 86%

12 May 2008

Effective Allocation (million m³): 9.17
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 86%

3 March 2008

Effective Allocation (million m³): 9.04
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 84%

4 February 2008

Effective Allocation (million m³): 8.85
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 83%

3 December 2007

Effective Allocation (million m³): 8.42
Reason for Change: Extent of zone revised
Source: Consents database live-read
Proportion Allocated: 79%

23 July 2007

Effective Allocation (million m³): 7.66
Reason for Change: Extent of zone revised
Source: Consents database live-read
Proportion Allocated: 72%

7 May 2007

Effective Allocation (million m³): 7.64
Reason for Change: Extent of zone revised
Source: Consents database live-read
Proportion Allocated: 71.49%

19 February 2007

Effective Allocation (million m³): 7.42
Reason for Change: Extent of zone revised
Source: Consents database live-read
Proportion Allocated: 69.34%

5 December 2006

Effective Allocation (million m³): 7.38
Reason for Change: Extent of zone revised
Source: Consents database live-read
Proportion Allocated: 68.98%

21 October 2006

Effective Allocation (million m³): 7.45
Reason for Change: Extent of zone revised
Source: Consents database live-read
Proportion Allocated: 69.62%

18 September 2006

Effective Allocation (million m³): 7.45
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 96%

12 July 2006

Effective Allocation (million m³): 7.3
Reason for Change: Second order approach applied
Source: Report U05/87 Revision 1
Proportion Allocated: 93.59%

23 January 2004

Effective Allocation (million m³): 3.8
Reason for Change: This is the first estimate made
Source: Report U04/02 (Table 6.2)
Proportion Allocated: 22.62%

Allocation limit

23 June 2007

Allocation Limit (million m³): 10.7
Reason for Change: Allocation limit remains the same however, the boundary of the zone has been adjusted
Source: Proposed NRRP Variation 4, Chapter 5: Water Quantity

21 October 2006

Allocation Limit (million m³): 10.7
Reason for Change: Extent of zone revised
Source: Aqualinc Research Ltd for Environment Canterbury 2005. Groundwater Allocation for the Waipara Groundwater zone, Revision 1 and Addendum.

12 July 2006

Allocation Limit (million m³): 7.8
Reason for Change: Adoption of a second order approach
Source: Aqualinc Research Ltd for Environment Canterbury 2005. Groundwater Allocation for the Waipara Groundwater zone, Revision 1.

23 January 2004

Allocation Limit (million m³): 16.8
Reason for Change: This is the first estimates made and includes an additional 1.9 million m³/yr recharge from the Waipara River
Source: 1st Order Report U04/02 (Table 6.2)