Water pollution Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water ...

Canterbury Canterbury (, ) is a City status in the United Kingdom, cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour, Kent, River Stour. ...

, New Zealand has become a major

environmental issue Environmental issues are effects of human activity on the biophysical environment, most often of which are harmful effects that cause environmental degradation. Environmental protection is the practice of protecting the natural environment on th ...

, largely due to pollution from agricultural sources, but also industrial and urban sources. Water resources are under the jurisdiction of the Canterbury Regional Council (Environment Canterbury) under the

Resource Management Act The Resource Management Act (RMA) passed in 1991 in New Zealand is a significant, and at times, controversial Act of Parliament. The RMA promotes the sustainable management of natural and physical resources such as land, air and water. New Zea ...

(RMA); water abstraction and use for irrigation purposes requires a

resource consent A resource consent is the authorisation given to certain activities or uses of natural and physical resources required under the New Zealand Resource Management Act (the "RMA"). Some activities may either be specifically authorised by the RMA or ...

. The municipal water supply for Christchurch is sourced from the

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...

s beneath the city.

Background

Due to the rain shadow effect of the Southern Alps the rainfall in Canterbury is lower than many other parts of the country at 500–700 mm per year. Water from melting snow and ice and from rainfall drain into the predominantly

braided river A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, ''aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment l ...

s on the Canterbury Plains. The rivers recharge the aquifers beneath the plains. The Canterbury Region was traditionally arable and livestock farming but there have been a large number of dairy conversions in the region. In recent years there has been a huge expansion in

dairy farming Dairy farming is a class of agriculture for long-term production of milk, which is processed (either on the farm or at a dairy plant, either of which may be called a dairy A dairy is a business enterprise established for the harvesting or ...

throughout the South Island. Dairy farming requires the intensive use of water and it is placing a high demand on water resources in the Canterbury Region.

Issues

Water pollution sign on the Waimakariri River

The rivers and

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

are being polluted with

nitrates Nitrate is a polyatomic ion with the chemical formula . Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble ...

and ''

E. coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

''. Nitrate concentrations in the groundwater are above the drinking water standards in around 7% of monitored wells according to 2017 data from Environment Canterbury. According to Environment Canterbury's
017 progress report on the Canterbury Water Management Strategy
71% of the 224 wells sampled in 2015 showed no increasing or decreasing nitrate trend, 25% of wells showed an increase nitrate trend and 4% showed a decreasing nitrate trend. According to th
Ministry for the Environment
77% of Canterbury rivers and lakes are graded excellent or good for swimming and 4% are graded as poor. Inorganic nutrients, an indication of water quality, are considered to be low but increase closer to the coast. For 2000-2001 28% of tested sites were classed as "alert" due to the presence of organic pollutants. Water pollution of the two rivers flowing through the city of

Christchurch Christchurch ( ; mi, Ōtautahi) is the largest city in the South Island of New Zealand and the seat of the Canterbury Region. Christchurch lies on the South Island's east coast, just north of Banks Peninsula on Pegasus Bay. The Avon River / ...

, the Avon and the Heathcote, is of concern. Untreated sewage can flow into the rivers during times of high rainfall. The estuary where the two rivers discharge had received treated water from the

sewerage treatment Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding envir ...

plant that processed the city's sewage. However, a pipeline was constructed to discharge the water into

Pegasus Bay Pegasus Bay, earlier known as Cook's Mistake, is a bay on the east coast of the South Island of New Zealand, to the north of Banks Peninsula. Toponymy Pegasus Bay takes its name from the brig ''Pegasus'', a sealing ship that was sailing fro ...

. It became operational in 2010. The

Central Plains Water Central Plains Water, or, more fully, the Central Plains Water Enhancement Scheme, is a large-scale proposal for water diversion, damming, reticulation and irrigation for the Central Plains of Canterbury, New Zealand. Construction started on the ...

scheme is a large-scale proposal for water diversion, damming, reticulation and irrigation over an area of 60,000 ha. A large number of resource consent applications for intensive dairy farming in the Mackenzie Basin attracted opposition due in part to the potential effects on water quality. The resource consents were called in under the RMA by the Minister for the Environment Nick Smith. Cheviot has been on a boil water notice since October 2004.

Mitigation

The

Dairying and Clean Streams Accord The Dairying and Clean Streams Accord is an agreement signed in 2003 in New Zealand between Fonterra, Ministry for the Environment, Ministry of Agriculture and Forestry and regional councils. The Accord was prompted by the high-profile "dirty dai ...

was set up by

Fonterra Fonterra Co-operative Group Limited is a New Zealand multinational publicly traded dairy co-operative owned by around 9,000 New Zealand farmers. The company is responsible for approximately 30% of the world's dairy exports and with revenue exce ...

and a number of government agencies as a means of reducing

nonpoint source pollution Nonpoint source (NPS) pollution refers to diffuse contamination (or pollution) of water or air that does not originate from a single discrete source. This type of pollution is often the cumulative effect of small amounts of contaminants gathered ...

. The Accord is criticised for not achieving its goals. In recent years, Environment Canterbury has introduced stricter environmental requirements for farms with most farms now required to have Farm Environment Plans as well as many farms having nutrient discharge limits on nitrogen losses. Farm Environment Plans require farms to plan and demonstrate they are actively managing environmental practices such as nutrient application, erosion risk, irrigation, dairy effluent and waterway protection (through fencing off waterways in intensively stocked areas and riparian planting). Recent assessments of water quality in Canterbury have indicated that the introduction of these new requirements i
helping to improve water quality
Nitrogen, phosphorus, sediment and e.coli are all now improving at more monitored sites than are worsening. Turbidity is the only measure which showed more sites worsening.

Prosecutions

In recent years prosecutions have been made for causing water pollution: *2009 – Philip Curry was fined $5,000 after pleading guilty to discharging effluent onto land that may have resulted in contaminants entering nearby Barry's Bay Stream. *2009 – Corlette Holdings was fined $10,000 after pleading guilty to two charges of discharging effluent from an irrigator resulted in ponding and a second charge of effluent being discharged, which may have resulted in contaminated water. *2010 – A prosecution against Brook Farms and Mosbro Farms in Ashburton was withdrawn after they agreed to mitigate the effects of the effluent discharge. * In 2012, Springston dairy farm company, White Gold Ltd, was fined a record $90,000 after illegally discharging 45,000 litres of diluted dairy effluent over a three-day period in 2010. The public reported the dairy effluent flowing into waterways that flowed into

Lake Ellesmere Lake Ellesmere / Te Waihora is a broad, shallow coastal lake or waituna, in the Canterbury region of the South Island of New Zealand. It is directly to the west of Banks Peninsula, separated from the Pacific Ocean by the long, narrow, sandy K ...

References

External links

Water quality and quantity page
at the

Environment Canterbury Environment Canterbury, frequently abbreviated to ECan. is the promotional name for the Canterbury Regional Council. It is the regional council for Canterbury, the largest region in the South Island of New Zealand. It is part of New Zealand's s ...

Canterbury Water Management StrategyWaterways, wetlands and drainage guide
at the Christchurch City Council
Water Rights TrustOur Water Our Vote
lobby group Environment of Canterbury, New Zealand