First Central Plains Water sustainability report released
28 April 2017
FIRST CENTRAL PLAINS SUSTAINABILITY REPORT RELEASED
The Central Plains Water Trust holds the resource consents for the Central Plains Water Scheme. Central Plains Water Limited (the Company) owns and operates the infrastructure of the Scheme and contracts the supply of water for irrigation in the Scheme area to the farmers who are shareholders. The Trust licences the use of the consents to the Company for the taking and supply of the water, but does so with agreed conditions over and above those imposed by the resource consents. The Trust’s conditions relate to the environmental performance of the Scheme, and require that the Company impose environmental requirements on the users, set out in individual Farm Plans. Another one of the conditions is for the supply of data to the Trust on an annual basis so that the Trustees can have the data analised independently for use in publishing an Annual Sustainability Report on the environmental performance of the Scheme.
The attached report was published today on the Trust’s website: www.cpw.org.nz
The Report is the first produced and published by the Trust, and covers the irrigation season for the 2015-16 year (15.9.15 to 16.4.16), which was in respect of Stage 1 of the Scheme. Stage 2 construction began this month.
The salient features of the Report are that:
During the season the Scheme supplied 91 million cubic metres of clean alpine water for irrigation, including 67 million cubic metres taken from the Rakaia River during high flow periods, and another 24 million cubic metres from storage in Lake Coleridge.
This meant 100% reliability of water for the participating farmers throughout the dry irrigation season.
Because no water was taken from the river during mid to low flow periods, the take of water for the Scheme had no effect on the natural character of the river nor on its ecology.
The Scheme is integral to the achievement of the outcomes set for the Selwyn Waihora Zone of the Canterbury Water Management Strategy.
The Trust requires the careful management of nutrients, and this will over time reduce the leaching of nitrates and phosphorous into the ground water and will therefore also reduce the pollution of Te Waihora, however it is likely to take up to 30 years before the water in the system before the Scheme opened, will be fully flushed away, and up to 70 years before the full positive effects are seen in Te Waihora.
During the season 20% (19 million cubic metres) of the total Ecan ground water allocation held by farmers in the Scheme area, was switched off in favour of Scheme water. This is equivalent to the volume of the water in two Wellington Harbours.
Of the remaining allocation, 73% (60 million cubic metres) was unused.
This reduction in groundwater takes will steadily increase over the next few years as the Scheme swings into full operation, ultimately resulting in half of the water currently actually taken from the Central Plains aquifers being replaced with clean alpine water delivered by the Scheme. This means a huge improvement in the water levels in the aquifers as well as more water for the lowland rivers and streams in the Scheme area.
It also means that the water quality in Te Waihora will begin to improve, although ground water levels in the land around the lake will also rise.
The Central Plains Scheme is already demonstrating a win-win for both farmers needing 100% reliable water, and for the Central Plains environment.