Impacts of the scheme - Local and Wider Impacts

Requiring Authority Status
Central Plains Water Ltd has been granted requiring authority status by the Minister for the Environment, the Hon. David Benson-Pope. Many farmers have stated publicly they will NOT sell their land for this scheme therefore Central Plains Water plan to compulsorily acquire the land they need. The Requiring Authority is the first stage toward using the Public Works Act. Rural landowners are angry and oppose Central Plains Water`s compulsory purchase of private land. They are also angry that a designation is already in place over properties affected by the scheme. (The designations are applied from the time of the lodgement of applications). At present CPW have applied to Selwyn District Council to designate land for the major scheme components i.e. the dam, the reservoir, the intakes and the level headrace canal. Submissions on the designations have closed and will be heard at the same time as submissions for resource consents.

The Malvern Hills area has strong links to local Maori and is historically significant as an area of early Canterbury settlement. Scenic Highway 73 from Woodend to Geraldine passes through the foothills villages of Homebush, Coalgate and Glentunnel. Local rivers such as the Selwyn, Hororata, Hawkins and Waianiwaniwa/ Waireka have been impacted by land intensification with increasing abstraction and pollution of surface waters. With the construction of a 55m high dam and massive canals through the area, the Central Plains Water scheme will destroy community, landscape, historical and environmental values of the area.

The Waianiwaniwa Valley in the Malvern foothills is to be inundated by the proposed Central Plains Water Irrigation scheme.

There are 14 properties in the Waianiwaniwa Valley that would be affected by the reservoir. The Deans family have farmed in this area for over 150 years. The land is fertile and productive and all farmed without irrigation. The valley has higher rainfall than on the plains, providing drought security during the drier summer months. Some farmers, with properties out on the plains bought land in the valley to hedge themselves against drought. Its an irony that new dairy farmers who wish to convert some of the dryest land on the Canterbury Plains to dairying, are demanding the properties of families with long connections to the land. The dam would destroy many of the Valley farms and most of the buildings and productive farmland would be submerged under water. The Valley is an important habitat for the rare and endangered Canterbury mudfish.

Coalgate
The village of Coalgate is situated 100m from the footprint of the dam wall. The dam wall will replace the existing 100 yr old oak and hardwood forest that provides an attractive backdrop to the village with a massive unsightly gravel heap.

The 280 residents would be living in the shadow of this 55 m high dam, with the worry that a dam incident could see them inundated by the 280 million cubic meters of water being held back by the dam.

The CPW Dam Safety Report states that over 5000 people will be living downstream of the dam and may be at risk from a dam burst

There are earthquake fault lines in the valley. The Hororata Fault is downstream of the proposed dam.

A survey of the village indicated that 80% of residents do not want to live under a dam.

Sheffield
It is proposed to bring water from the Waimakariri river to the reservoir via a 10km tunnel and under the Malvern Hills at Sheffield. Sheffield will also be affected by the network canal system. Farms and a successful jetboating business at Kowai Bush will be put in jeopardy by the construction of the Upper Waimakariri Intake and canal.

Central Plains area
500 properties are affected by the network distribution system that will see 450km of canals criss-crossing the Central Plains. Another 100 landowners are affected by the reservoir, the dam, the intake canals and the main level headrace canal which runs between the Waimakariri River and Rakaia River for approx. 60km. The headrace canal is 50m wide i.e. 30m water width and 10m embankment on either side.

If you think you are an affected landowner you should contact Selwyn District Council and view the maps of the canal networks. SDC also has a list of affected landowners.

Selwyn District Council website

WIDER IMPACTS

Nitrates
The CPW proposal would be one of New Zealand`s largest irrigation schemes. The associated land use intensification will lead to a major expansion in dairying. If the scheme proceeds Central Plains Water plans to double the area of land converted to dairying from 22,000 hectares to 46,000 ha.

Land intensification will further degrade drinking water quality. Nitrate contamination of drinking water wells is increasing across Canterbury. Rising levels of nitrates are a public health issue. Nitrates and pathogens leaching into lowland springs, rivers and streams is degrading ecological values. Many lowland rivers are now unsafe for swimming. The proposed CPW irrigation scheme will exacerbate these problems.

The Waimakariri and Rakaia Rivers are internationally recognised braided rivers. They support an abundance of flora and fauna, some unique to these regions. A 40 cumec water take from both rivers and construction works in the beds and on banks of the rivers, will degrade ecological and recreational values and destroy the intrinsic beauty of these important river systems.

The scheme will also have an adverse impact on groundwater quality/quantity in lowland rivers, springs and streams and on Te Waihora/Lake Ellesmere.

A 40cumec abstraction from the Waimakariri River may affect the river`s capacity to recharge aquifers that supply Christchurch City`s groundwater.