Water pollution in the West Coast Region facts for kids
Water pollution is a big problem for the environment on the West Coast of New Zealand. Water is a very important resource, and how it is used and kept clean is managed by a law called the Resource Management Act. The West Coast Regional Council is in charge of making sure these rules are followed in this area.
A report from 2008 looked at the state of the environment. It found some important things:
- Water from old mines, called acid mine drainage, really harms freshwater places like rivers and lakes.
- Most places where people swim (more than 95%) had safe water. They check 17 spots along 600 kilometers of coastline. However, the northern part (150 kilometers) isn't checked at all.
- Pollution coming from one specific place (like a pipe, called point source pollution) has gone down. But pollution that comes from many different places (like farms or roads, called nonpoint source pollution) has gone up.
- Water quality gets worse in the lower parts of some river areas.
- Good news! The quality of water has actually gotten better in some ways.
Contents
Where Water Gets Polluted
Grey River Issues
Sometimes, after a lot of rain, untreated sewage goes into the Grey River. In the past, all sewage and stormwater from towns like Greymouth, Cobden, and Blaketown went straight into the river. Now, the Grey District Council has better systems to separate and treat sewage. But when it rains very heavily, like in spring, the treatment system can't handle all the water, and some untreated sewage still gets into the river.
Acid from Mines
The West Coast has a long history of mining. Because of this, some rivers and streams suffer from acid mine drainage. This happens when acidic water from old mining areas leaks into the waterways, making the water harmful for plants and animals.
Drinking Water Quality
About 82% of the people on the West Coast get their drinking water from a public supply. Only 28% of this water is treated to make it better. However, none of the public water supplies fully meet the official drinking water standards.
Lake Brunner's Health
The water in Lake Brunner has been checked since the 1990s. Its quality has stayed quite good. But there are worries about how much water drains from nearby dairy farms into the lake, which could affect its health.
Ngākawau River Pollution
North of Westport, the Ngākawau River gets polluted. This pollution comes from the Stockton open-cast coal mine.
Mokihinui River Concerns
The Mokihinui River is about 50 kilometers north of Westport. Most of its large catchment area (68,000 hectares) is natural and protected land. There are two small towns and two large farms near the river's lower parts.
One of these farms is a big dairy farm in Seddonville. In 2004, this farm was letting all its dairy waste go straight into the river. Local environmental groups worked hard to get the regional council to make the farm install special ponds for the waste. For many years, these ponds often let waste into the river through a drain, especially during floods. In 2016, after a specific complaint, the regional council made the farm upgrade its ponds and move them to higher ground, away from floods.
In September 2017, milk was found going into the river through the same drain. This happened because a dairy company might have refused the milk due to high levels of a medicine. It seems there isn't a plan for what to do with milk that dairy companies don't accept on the West Coast.
Over the last ten years, this farm has also changed a lot of its land. More than 60 hectares of forest and wet areas have been destroyed to create more pasture for cows. Farm chemicals and fertilizers are used on the pasture. This creates pollution that washes into the river from many places, causing thick, green mats of algae to grow when the water is low. While these have decreased since 2010, there is still room for improvement. The river at the popular swimming spot in Seddonville is cleaner in summer 2019 than it has been in many years.
Another farm, located at the river mouth, also has problems with its waste ponds overflowing into a creek that leads to the lagoon. Thirty years ago, the stones in the lagoon were clean and shiny. Now, they are covered in slime all year round, and the local plants around the outlet are struggling. The regional council has not insisted that the farmer fix their waste system or follow the rules for discharging dairy waste. If the rules were followed, the lagoon would be clean again.
This farm also has its fences right at the edge of the sea, leaving no space for coastal plants or penguin homes. There are also very few trees in the paddocks and along the streams on either farm, which means less shade and protection for the water.
