We’re all doing our best to save power and petrol. Do we really need to worry about our water use as well? Christchurch writer Mike Bradstock tests the depth of New Zealand’s water supply, and finds that trouble is brewing in his hometown
Water is the stuff of life. With rain falling pretty regularly in most parts of the country, surely we’ve got plenty of it? But trouble is brewing—especially in dairy-intensive regions such as Canterbury. Mike Bradstock tests the depth of New Zealand’s water supply, and finds that quantity isn’t much good without quality
It falls from the sky; it gushes from our taps; it disappears down the drain. But managing our water supply is a tricky business. Supply and demand aren’t always in balance, even in a comparatively wet country like New Zealand. In the drought of 1994, even normally rainy Auckland’s reservoirs almost ran dry.
There are 1,260 million trillion litres of water on Earth, exactly the same amount that has always been here, continually moving from sea to sky and back down as rain. We’re right in the middle of that never-ending cycle, each of us using about 200 litres of water a day, with thousands more used to manufacture the products we buy and the food we eat.
It may fall from the sky, but water isn’t free. Getting clean water to our taps costs the country about $1.5 million every single day, and dealing with it once it goes down the drain can cost three times that much.
Plus Why conserving water matters— even in rainy old New Zealand
Before water gets to many New Zealand homes it must first go through a series of industrial processes (see page 39), including chemical treatment, to ensure it’s safe to drink. Considering a billion of the world’s people go thirsty, it seems kind of crazy that the rest of us use this high-quality drinking water to flush our toilets, water our gardens and wash our cars. Once it goes down the drain, our wastewater goes through yet more expensive cleaning processes before being discharged into our waterways or out to sea.
The amount of water on the planet never changes, so we can’t run out of it—but climate change will affect where it falls, and we can make it too dirty to drink. With groundwater becoming more polluted, rainfall less predictable and demand rising along with our population, the load on our existing water treatment facilities looks set to increase. And new infrastructure doesn’t come cheap. New water works cost the country about $755 million a year, according to a Department of Internal Affairs report.
So water’s expensive—but New Zealand’s lucky. Occasional seasonal and regional shortages aside, there seems to be plenty of drinking water to go around.
Does that mean our country is cheerfully free of water worries? The answer is no—if the 2007 Quality of Life Report is anything to go by. Residents of the 12 cities surveyed recognised water supply and quality as key environmental issues. Those on Auckland’s North Shore, in Auckland city and the Hutt Valley were most concerned about water pollution, although the report noted that the Auckland region, Hamilton and Tauranga all have excellent drinking-water quality. Elsewhere, however, it’s another story, and people have good reason to be uneasy.
A surprisingly high number of New Zealanders rely on water supplies that aren’t proven to be safe. It’s hard to know just how many, because about 380,000 people have private water supplies (from bores, river take off or rainwater tanks) that aren’t tested by the Ministry of Health’s annual drinking-water quality survey and that may be unclean.
The last survey, for 2007–08, shows 118,000 people receive water with unacceptable levels of E. coli bacteria. Then there are the other nasties: campylobacter, salmonella, shigella and disease-causing protozoa like cryptosporidium and giardia. Worse, some water suppliers failed to take corrective action when these bugs were found, and 194,000 people are served by suppliers who are not even properly monitoring their water quality.
It’s hard to tell just how many upset tums this is causing. In the same year as the last Ministry of Health survey, 205 cases of water-borne disease were recorded where untreated or contaminated water was a contributing factor—a tiny fraction of the actual numbers affected, estimated to be as many as 35,000 people each year. “People don’t always go to the doctor with diarrhoea, or GPs don’t often notify such cases,” says Ministry of Health principal public health engineer Paul Prendergast.
Murray Rodgers, chair of the Water Rights Trust and author of Canterbury’s Wicked Water, believes intensification of dairying is the key likely cause of a rising incidence of tummy bugs in Canterbury. “There are almost 16,000 reported cases of campylobacter in New Zealand each year. That’s probably just the tip of the iceberg as studies show only about a tenth of affected people seek treatment.”
Troubled water
Why is dairy farming being blamed for tummy bugs? A refresher course in the water cycle might provide some clues. Our water starts in the oceans to our south and west, where water is evaporated by sun and wind. The moist air is swept and squeezed by the prevailing westerly winds up against our long spiny mountain ranges, until rain, and sometimes snow, forms and falls from the sky. This is distilled water, and you can’t get any purer than that.
Some of the water we use falls onto roofs and is stored in tanks, but most soaks into the ground and finds its way into streams. Some is captured behind dams and stored in reservoirs in bush-clad valleys, as in the Waitakere and Hunua Ranges near Auckland. Other water soaks through the ground into underground rivers called aquifers. Most flow slowly under old river flood plains, notably in Canterbury. Water sometimes surges back to the surface in springs, creating rivers and streams; in other places you can bore a well and so-called artesian water comes up under its own pressure. It’s cold, clear and safe to drink without treatment, and it tastes good enough to bottle.
Only 14 percent of New Zealanders with piped water supplies are lucky enough to receive aquifer water, including the people of Christchurch, whose highquality drinking water is a source of much one-eyed pride. Although there’s plenty of artesian water to meet Canterbury’s domestic needs, residents face evergrowing competition for water from dairy farms.
The problem isn’t just that cows drink a lot of water—about a bathtub full every day, according to Fonterra. It’s irrigating the region’s dry plains that uses stupendous amounts of water, while also increasing contamination of groundwater and putting the safety of future water supplies at risk.
Seventy percent of New Zealand’s irrigated land is in Canterbury, where two big irrigated dairy farms can use more water than the whole city of Christchurch.
Rodgers estimates at least 500 litres of water is needed to produce a single litre of milk—possibly much more. Australia’s Commonwealth Scientific and Industrial Research Organisation puts the ‘water footprint’ of a dollar’s worth of milk at 1,470 litres. It takes a quarter of that amount to produce the same value in grain or fruit, says Rodgers. “This doesn’t look like the best use of a resource and, after all, our water belongs to all New Zealanders.”
Then there’s the environmental ‘double whammy’ of irrigation. The trouble is, everything you do with water in one place has an effect somewhere else, says Rodgers. “More irrigation means more grass, more animals, and inevitably more pollution, which ends up in rivers and groundwater. But it also means there’s less water left to dilute that pollution, so the contaminants remain quite concentrated and thus irrigation redoubles its own harmful effects.”
The world’s water
One-third of the people on the planet are affected by water shortages. Over one billion people don’t have enough drinking water, almost half the world lacks access to basic sanitation, and about five million people die every year as a result of poor drinking water, poor sanitation or a dirty living environment. More than two million of them are children.
The planet’s six billion people are using ten times more water than we did a hundred years ago, and the population is expected to increase by 45 percent over the next 30 years. Rivers, lakes and groundwater resources are becoming increasingly polluted. A worldwide water crisis is predicted by 2020, affecting 250 million people in Africa alone.
Some of the worst predicted impacts of climate change are tied to water: flash floods, desertification, melting glaciers, heatwaves, cyclones and water-borne diseases such as cholera. Conflicts over water supplies may also result.
Water shortages in Sudan are thought to be a contributing factor in the Darfur conflict. Over-extraction of aquifers along Israel’s coast has allowed seawater to pollute drinking water, increasing Israel’s reliance on water from the disputed West Bank territory—a Palestinian resource according to international law. Egypt relies on seasonal floods from the Nile River for irrigation, a supply that’s threatened by Ethiopia’s plan to develop the river’s headwaters. Turkey is constructing a series of dams that will reduce flow through the Tigris and Euphrates Rivers, which provide irrigation water to Syria and Iraq. Aquifers are being overpumped in India, increasing salt content in the soil, and in dry Northern China overextraction of aquifers is causing the water table to drop a metre a year, with 300 cities already running short of water.
Closer to home, water theft is on the rise in Australia—and so are are the fines. The penalty for stealing water from South Australia’s Murray River was last year increased by 3,000 percent for corporations (to A$2.2 million) and by 1,900 percent for individuals (to A$700,000).
Annabel McAleer
The region’s current population of over 600,000 dairy cows is spreading the sewage equivalent of eight million humans across the plains, he says. “Some contaminants take decades to seep through aquifers and could result in a future need to treat our artesian water supply. By the time the problem is recognised it may be too late to do anything about it.”
The dairy industry is understandably defensive. Dairy farmers point to the important contribution they make to the economy and say that economically there is no future for farming on the dry Canterbury Plains without irrigation. Some are calling for water harvesting to be allowed, which would let farmers take floodwater from rivers when the flow is high. The industry argues that it has lifted its game in recent years, fencing waterways and improving wastewater management, and Fonterra’s measures of compliance with environmental standards show big improvements. However, ECan’s measures do not: last year it found less than half the region’s dairy farms fully complied with effluent-management rules, even fewer than for the previous year. One in five farms were found to have “strayed significantly”.
It’s true that dairy farming’s not the only form of land use that causes water quality problems, and the Water Rights Trust takes pains to recognise that the rural sector is important to our prosperity. The problem is uncontrolled growth, says Rodgers.
“When the Trust was formed in 2001 we were initially concerned about the drying up of our rivers, caused mainly by rampant growth of water use for irrigation. In some areas Environment Canterbury had over-allocated artesian and river water, and most allocations were for periods as long as 35 years,” says Rodgers. “Many spring creeks had dried up and ECan’s own research showed a history of rapidly declining rural waterways. In 2000, half of our streams were categorised as either ‘poor’ or ‘very poor’, and in 2003 this jumped sharply to 75 percent. Since then the situation has become even worse.”
Back in 2000, New Zealand dairy farms used over one billion cubic metres of water a year, according to a Massey University study. Now that much is allocated for irrigating dairy farms in Canterbury alone, where the number of dairy cows has grown 150 percent, against national growth of 30 percent. The scale and pace of the change are dizzying, regulations are yet to catch up, and local government is struggling to manage the region’s water (see page 36).
A new Canterbury Water Management Strategy has been developed, “but it’s still only a piece of paper, yet to be given legislative authority”, says Rodgers. “For the time being this is the best we have, in the absence of leadership from central government, but it’s still an issue of concern for all New Zealanders.”
Water, water everywhere
Amid all the shouting about who gets to use our water and the effect of dairying on its quality, there’s surprisingly little debate about how much water we’ve actually got. That may not be so strange, considering our low population density and rating as the twelfth-best-endowed country in the world in terms of natural water supplies, says Rodgers. “Overall, our problem isn’t about getting enough, though there are some local issues about equitable sharing and maintaining river flows. The big issue is more about keeping the quality high, and making sure it’s safeguarded for future generations.”
Jim Hodges, chief engineer at Auckland’s Watercare Services, has been in the business for over 30 years and is more positive than ever about the future of water management and supply in the most populous part of the country.
“This is the first region in the world to have an integrated plan for management of water supplies, wastewater and stormwater looking ahead to the year 2100. It’s called the Three Waters Plan and is absolutely fantastic in terms of integrated thinking and proactive management.” But even though Hodges is confident our water supply is secure, he warns that we can’t be complacent about it.
Among the aims of Three Waters is a 15-percent reduction in per capita water demand by 2035, achieved through education and more efficient water use. That’s because, despite our relative abundance of water, the infrastructure necessary to pipe drinking-quality water to our houses, then remove it as wastewater, is expensive to run—and even more expensive to build. The Three Waters infrastructure itself will cost the average Auckland household $29,000. Even if you’re not on a metered water supply, you’re still paying for water treatment facilities through your rates or rent.
New Zealand may be in no danger of running out of water, but using it more efficiently will save us all the expense— and environmental impact—of new dams, reservoirs and treatment plants in future. We can’t keep supplying more water to meet an ever-increasing demand, says Hodges. “In time, people will learn to take it less for granted and water conservation measures like more efficient washing machines and less garden watering will have more effect.”
No matter how much water we conserve around our homes, it’s a drop in the bucket compared with the vast quantities of water embodied in almost everything we buy, eat and drink. Those quantities are much harder to measure and manage, but we’re making progress—and when everyone acts, every drop will count.
Mike Bradstock
