Zone Name:	Otaio	Current Status:	(Yellow)
Allocation Limit:	4.93 million m3/yr	Valid date:	23 June 2007
Approach:	50% of land-based recharge, 7DMALF (7 day mean annual low flow) deducted from rainfall recharge

Recharge component

Method of estimation

Background notes

The Otaio zone has two main aquifer types, a shallow aquifer immediately adjacent to the Otaio River, and heavily dependent on river recharge, and a deeper aquifer within a marine sequence of Cannington Gravels (60-80 m+). The deeper aquifer will be recharged by rainfall, and may have a component of Otaio River recharge where the Otaio crosses fault lines in the upper valley. The shallow aquifer is within recent river gravels and is very shallow (sometimes less than 1 m thick). This aquifer responds quickly to flow in the river, and in periods of low flow, existing users have problems maintaining supply.

Thorley and Ettema have provided the latest assessment of the groundwater allocations limits for this area, including assessment of the nature of the recharge over loess strata. This has led to an adjustment of the boundary and a revised allocation limit for this zone. This has been incorporated via proposed NRRP Variation 4. New applications to take groundwater that is linked to a surface waterway may be subject to surface water restrictions and/or allocation.

Other available information sources

These reports may be used to provide a full description of groundwater resources in this area. They may include information that will be of use in a consent application, but are not necessarily a comprehensive list.

• Aitchison-Earl, P., Davey, G., Ettema, M., McKerchar, A., Scott, D., Smith, E., and Weeber, J. 'State of the Canterbury Region Water Resource October 2004' (pdf 3.83 MB), U04/101
• Aitchison-Earl, P. L. 2003, 'Pareora-Waihao water use patterns" report on data collected in 2000-2002' Environment Canterbury Unpublished Technical Report U03/84.
• Brown, L. J, 2000, 'Groundwaters of the Canterbury Region' Environment Canterbury Report R00/10.
• Waugh J.,1980. 'Draft Water Resources Investigation: Pareora, Otaio, Makikihi, Hook, Waihao, Waimate' South Canterbury Catchment Board.
• Thorley, M., Ettema, M. Review of water allocation limits for the South Canterbury downlands. Report U07/09. April 2007.

Allocation history

Effective allocation

  3 May 2010

Effective Allocation (million m³): 4.76
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 97%

  6 July 2009

Effective Allocation (million m³): 4.97
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 101%

  2 June 2009

Effective Allocation (million m³): 4.96
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 101%

  2 March 2009

Effective Allocation (million m³): 4.93
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 100%

  9 February 2009

Effective Allocation (million m³): 4.70
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 95%

  3 November 2008

Effective Allocation (million m³): 3.99
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 81%

  13 October 2008

Effective Allocation (million m³): 3.98
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 81%

 4 February 2008

Effective Allocation (million m³): 3.06
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 62%

 23 July 2007

Effective Allocation (million m³): 2.56
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 52%

 18 September 2006

Effective Allocation (million m³): 3.19
Reason for Change: Consents update
Source: Consents database live-read
Proportion Allocated: 31%

 23 January 2004

Effective Allocation (million m³): 2.0
Reason for Change: This is the first estimate made
Source: Report U04/02 (Table 6.2)
Proportion Allocated: 18.69%

 29 June 2005

Effective Allocation (million m³): 3.19
Reason for Change: Effective allocation recalculated using a revised table of irrigation standards to address concerns with Schedule WQN9 of Chapter 5 NRRP, as approved by the Water Allocation Panel
Source: Consents database live-read on 29 June 2005
Proportion Allocated: 31.00%

 24 November 2004

Effective Allocation (million m³): 2.0
Reason for Change: No change
Source:
Proportion Allocated: 19.23%
Proportion Allocated changed due to Allocation Limit change

 23 January 2004

Effective Allocation (million m³): 2.0
Reason for Change: This is the first estimate made
Source: Report U04/02 (Table 6.2)
Proportion Allocated: 18.69%

Allocation Limit

 23 June 2007

Allocation Limit (million m³): 4.93
Reason for Change: Changed boundary and revised estimate of land surface recharge and groundwater contribution to the lower Otaio River 
Source: Proposed NRRP Variation 4, Chapter 5: Water Quantity

 24 November 2004

Allocation Limit (million m³): 10.4
Reason for Change: Implementation of 2nd Order approach as approved by Directorate
Source: Report U04/97

 23 January 2004

Allocation Limit (million m³): 10.7
Reason for Change: This is the first estimate made and includes an additional 2.2 million m³/yr recharge from the Otaio River
Source: Report U04/02 (Table 6.2)