Waitohi Storage

Waitohi is an alternative storage site to the South Branch and Lake Sumner. It  is more expensive but it has been recommended by the Zone Committee as a location that will not cause environmental, cultural or recreational problems. If we can find a way to make Waitohi affordable then it will fast-track water storage for irrigation to the Hurunui Waiau Zone.  

In December 2011, the Waitohi Irrigation Scheme Selection Panel report endorsed HWP's Waitohi scheme over two competing developers. The independent panel was initiated by the Hurunui-Waiau Zone Committee, Hurunui District Council and Environment Canterbury in August 2011 to ensure whichever scheme is developed for the zone is the best possible solution.

HWP's Waitohi scheme ranked the highest against the panel's own criteria including environmental acceptability, consentability, the potential for hydroelectricity to offset costs, the price per hectare and the value of infrastructure, as well as the ability to proceed at the earliest possible opportunity. While all irrigation scheme options using the Waitohi Basin look expensive, HWP has concentrated on keeping capital costs low and reaching an energy-balanced solution that provides some future proofing around power pricing.  

What will it look like?

HWP is proposing to establish a community irrigation scheme with hydro power generation. The proposal involves the abstraction of water from the Waitohi and Hurunui Rivers with storage planned within Waitohi catchment. Water will be pumped from the Hurunui River about 1.5kms below Surveyors Stream up a rising main and through a short tunnel into a large reservoir at Hurricane Gully in the Waitohi catchment. Initial investigations show that this could hold live storage of around 210 Million Cubic Metres. There will be three further dams down the length of the Waitohi Gorge used primarily for re-regulation during power generation, as well as early stage, small scale storage for irrigation. The main intake canal from the Hurunui River will be situated on the plains somewhere between 305RL and 280RL with an upgrade to the Amuri intake. In total the scheme will irrigate approximately 58,500 ha and generate 82Gwh of power. We believe that we've come up with a simple and cost effective scheme which has environmental and economic benefits. The first stage of the scheme will irrigate up to 10,000 hectares within a short time frame, with close to 60,000 hectares of potential irrigation over the long term. 

Staging?

It is HWP's intention to develop the scheme in a staged approach. The first stage will be to build the Seven Hills and Inches Road dams for storage from the Waitohi. Supplemented with run-of-river supply from the lower intake on the Hurunui River, this will irrigate a potential 10,000ha while providing additional reliability for some existing A Block users.

Resource Consent Application?

Environment Canterbury has accepted an application for Take, Use, Divert, Damming and Discharge of water which is the first stage of the consent process for the HWP Waitohi Irrigation and Hydro Scheme. Resource consents related to the construction of the irrigation and hydro power generation scheme, dams and associated infrastructure will be applied for as part of stage two of the consent process. All consents are being applied for a duration of 35 years. HWP's Waitohi resource consent application does not replace our 2009 resource consent application for water storage within the South Branch of the Hurunui River and Lake Sumner. It is a supplementary application. The Waitohi resource consent application will not be processed until April 2012 in accordance with the Environment Canterbury (Temporary Commissioners and Improved Water Management) Act 2010.  

Below are links to the Waitohi resource consent application.  Copies of the specialist reports can be obtained by contacting our office. Oct-2011-HWP-Waitohi-Irrigation--Hydro-Scheme-Application-Part-A.pdf (314KB)
http://ecan.govt.nz/publications/Consent%20Notifications/hwp-waitohi-irrigation-hyrdro-scheme-part-b-aee.pdf