Essential Freshwater - Canterbury Water Management is an environmental disaster.
Canterbury presently has the highest GDP per capita and worst water pollution of any region in New Zealand, the result of intensive irrigated farming on vulnerable coarse porous soils.
The primary pollutants are nitrates and pathogens from Canterbury’s 1.4 million dairy cows although other forms of intensive farming involving cultivation and the use of urea fertilizers will allow nitrate leaching into groundwater.
Canterbury’s water allocation is managed by the Canterbury Regional Council which has adopted the marketing name Environment Canterbury (Ecan).
Ecan is bound by legislation including the Environment Canterbury Temporary Commissioners and Improved Management Act (2010), (Ean Act), and the Canterbury Water Management Strategy (CWMS).
The Ecan Act (2010)
The Ecan Act was developed by the National government in 2009 with advice from MPI in order to facilitate the massive irrigation development that has occurred in the region over the past decade. The Barrhill Chertsey Irrigation, ( BCI), and Central Plains Water, (CPW), schemes alone can irrigate up to 120,000 hectares using water from the Rakaia River catchment. The Act removed the protections afforded by the region’s National Water Conservation Orders and allowed the government to replace elected regional councillors with its own appointed commissioners. The Act gave statutory authority to the Canterbury Water Management Strategy and removed Cantabrian’s right to appeal to the Environment court.
The CWMS began as a non-statutory plan developed by the Canterbury Mayoral Forum in response to earlier drought conditions. A key architect of the CWMS was Dr Bryan Jenkins, a seven year CEO of Ecan replaced by Dame Margaret Beasley in 2010. Dr Jenkins developed the CWMS as a “living document” that could be amended to manage Canterbury’s water based on a Scandinavian model of community participation. In the Canterbury situation this meant disenfranchising the majority of ratepayers. Ten water zone committees were established composed primarily of water users controlled and directed by Ecan. The CWMS in essence was a plan to scope all available water in Canterbury, identify the water that could be practically harvested, use the water in an integrated and efficient manner to irrigate the maximum area, and largely leave the resilience of the environment to accommodate the large scale water abstraction required.
The Lake Coleridge Project Hearing (2012)
Up to 70 m3 of additional water was needed to supply BCI and CPW. This was achieved by an Ecan Hearing where Trustpower gained consent to store water in Lake Coleridge for sale to CPW and through reductions to the minimum flows proscribed in the Rakaia Rive NWCO (1988).
The legislation above ensured Trustpower’s application would succeed as the fate of a NWCO, the river equivalent of a National Park, could now be determined at a regional council irrigation hearing.
It is unfortunate that the costs of these irrigations schemes are so high that even with NZ$200 million dollars of government subsidy only intensive forms of farming such as irrigated dairy farming might show a profit.
It is also unfortunate that Canterbury’s warm dry climate and free draining soils make it possible to grow highly productive pasture to support high stocking rates of high producing cows. (Around 3.9 cows/hectare with per cow production well over 400 kg MS).
Since at least 1986 the Canterbury Regional Council has known that Canterbury soils do not retain nitrogen and the Ministry of Works, (MOW), models at that time predicted rural residents between Ashburton and Rakaia would eventually be faced with finding alternative sources of drinking water.
Eugenie Sage, an elected Ecan councillor from 2007 to 2010, made a written submission to the Ecan Hearing (2012) stating that it would be reckless to proceed with large scale irrigation schemes when the out of river use had as yet no regulations or known means of managing nitrate pollution, and that future generations would be saddled with a legacy of polluted water with potentially no solution.
A cow urinates 10 – 12 times per day covering an area of approximately 0.7 to 1.0 square meters each time with a urea loading equivalent to 700 to 100kg. At the high stocking rates typical of Canterbury irrigated dairy farms this means about 1/3 of the milking platform would receive these amounts of urea each year.
Environmental farm plans
Nine years on, at the penultimate stage of the appointed Ecan Commissioners era, we are finally seeing land use environment plans being developed. These have yet to pass formal hearing processes and enactment.
A cynic may question how “community consensus” can develop sound environmental plans that are “fit for purpose” rather than scientific method.
The Rakaia River
Living at the Rakaia Huts in the hapua zone of this protected river, I have witnessed the consequences of the Key government’s short term irrigation ambitions: The Internationally and nationally recognized recreational fisheries, protected by the Rakaia NWCO, and native fisheries are in sharp decline. Stokell’s smelt, an endangered regionally restricted species of smelt has all but disappeared from the river. These smelt were until recently so abundant being the largest fishery by mass that NIWA studied them with a view to commercial exploitation in 1992.
Because the smelt have gone, the Black-billed gull colony failed to fledge many chicks this season. These gulls are the most endangered species of gull in the world.
Thanks to constitutionally repugnant legislation and a government’s short term actions to increase GDP, Canterbury is losing its once envied pure groundwater and its aquatic ecosystems are showing significant harm.
The present government has issued a statement of intent to restore water quality.
We will wait and see.
Peter Trolove BVsc MSc MBA (semi-retired) President of the New Zealand Federation of Freshwater Anglers.