Taupo-Nui-A-Tia Environment

How Clean is the Lake?

Environment Waikato tests the water from both the Lake’s edge and a deep water site. Check out its monitoring results that show that Lake Taupo continues to have high quality, clear water that is safe to swim in.

However, since the mid 1970s, nitrogen has built up in the bottom waters of Lake Taupo. This could lead to reduced water clarity, blooms and scums of algae and could affect the amount of dissolved oxygen needed by the plants and animals that live in the Lake.

Find out about the importance of dissolved oxygen in the EW glossary.

Ecosystems at Risk

Lake Taupo is home to many native plant species, at least 31 species of aquatic birds and a number of native and introduced fish, including:

•  koaro
•  the common bully
•  the common smelt
•  rainbow trout
•  brown trout.

Catfish have been recorded in the Lake since 1985. Catfish are a pest because they feed on freshwater snails, koura, bullies and smelt. They have been known to attack juvenile trout.

Native plant species don’t compete well with introduced aquatic weeds. Oxygen weed, pondweed and hornwort are a growing problem in the Lake. These water weeds spread rapidly. Waternet is present in Kinloch marina, but low nutrient levels in the Lake mean it is not likely to become a problem weed.

Keeping the Lake clean and weed free

Everyone can help look after Lake Taupo’s water quality by being careful about what they put into the stormwater drains. Stormwater is not treated and drains straight into the Lake, or into rivers and streams that flow into the Lake. Taupo District Council aims to reduce pollutants going into the Lake, local rivers and streams through stormwater drains.

Landowners living around the Lake can help by planting and fencing stream banks. Plants help to filter out nutrients and sediment in runoff, as well as providing shade and habitat for wildlife. Fencing streams prevents stock from:

•  muddying the water

•  depositing waste in streams

•  causing bank erosion.

Boat–owners also need to carefully wash down boat keels, motors and trailers before putting boats into Lake Taupo. This reduces the chances of introducing water weeds.

If boats have seam leaks or loose stern glands, oily bilge water often dribbles into the Lake. Automatic bilge pumps can release dirty water directly into the Lake. To prevent these problems, boaties need to keep boat bilges clean and dry and ensure they dispose of rubbish and sewage on–shore.