Each year on 2 February, we celebrate World Wetlands Day and with it the adoption of the Ramsar Convention.
2017's theme, wetlands for disaster risk reduction, was chosen to inform and highlight the value of healthy wetlands and how they can reduce the impact of extreme climate and weather related events.
We can’t stop natural disasters from happening, but in some instances we can reduce their impact. Wetlands can be managed so they act as a natural sponge during flooding, absorbing and storing excess water.
During periods of low rainfall, the stored water helps maintain groundwater levels, delaying the onset of drought. Modelling has shown that during a very heavy flood (a one-in-a-100-year sized event) the Kauaeranga Wetland and spillway area has the capacity to mitigate approximately 46 per cent of the flood waters coming down the river.
This means that at peak flow, this spillway prevents nearly half of the water from reaching and potentially damaging the town. That equates to 10.5 million cubic metres of water or about 4000 Olympic size swimming pools!
Wetlands are permanently or temporarily wet areas that support plants and animals specially adapted to wet conditions.
The types of plants and animals found in wetlands depends on the water - its amount, depth, permanence, temperature, the chemicals found in it, and its source - groundwater, surface water or rainwater.
Fresh water wetlands in the Waikato include:
Wetlands once covered large areas of New Zealand. Now they are some of our rarest and most at-risk ecosystems. Wetlands contain a diverse range of plants and animals and are home to many rare and threatened species.
Wetlands are highly valued by tangata whenua and local communities for their recreational, educational, scientific, aesthetic, spiritual and cultural values.
The conservation and restoration of wetland habitats can make a real difference for wetland species and also benefit us directly.
Wetlands are important storage areas for floodwaters. Think of a wetland as a giant sponge. Wetland plants slow the flow of water off the land, soaking up excess floodwater, and then slowly releasing it to maintain summer water flows.
Wetland plants trap sediment suspended in water, improving water quality. In riparian areas, their roots hold riverbank soil together, reducing erosion. Bacteria living in wetland soils absorb and break down nitrogen from farm run-off and leaching, improving water quality.
Healthy peat wetlands are important sinks for excess carbon, implicated in potential global warming. Find out more about how the drainage of peat releases large amounts of carbon dioxide (CO2).
Wetlands are often in areas that are very desirable for farming. Many wetlands have been drained and turned into pasture. Draining of peat bogs makes them shrink and stops peat formation.
About 90 percent of New Zealand’s freshwater wetlands have been destroyed in the last 150 years. Find out about the change in area of major wetlands in the Waikato region.
The health of a wetland is closely related to the land management practices in its catchment and the quality of water entering it.
Wetlands are also vulnerable to pest damage and stock grazing. Many wetlands have become infested with exotic plants (especially willow). Fire has the potential to destroy smaller wetlands.
Find out more about threats to wetlands.
Waikato Regional Council helps protect wetlands through the Environmental Initiatives Fund.
Many landowners have registered Queen Elizabeth II National Trust(external link) Covenants over their wetlands to protect them in perpetuity. Most areas are smaller than five hectares. The largest area is a 46 ha covenant of manuka wetland surrounding Lake Maratoto, near Hamilton airport.
The National Wetland Trust(external link) was established in 1999 to increase the appreciation of wetlands and their values by all New Zealanders. The Trust plans to build a state-of-the-art wetland interpretation centre near Lake Rotopiko, between Hamilton and Te Awamutu.
World Wetlands Day is held every year on February 2 to celebrate and learn about the value of wetlands. Events in the Waikato have included the launch of our web site factsheet series on wetlands, organising competitions and leading field trips to local wetlands.
Find out about coastal wetlands and estuaries in Our Coasts.
Find out about lakes, including the peat lakes, in Learn about our lakes.
Learn more about Māori and their connection to fresh water.