Erosion is a natural process, but people can greatly accelerate the rate of erosion by removing vegetation and using inappropriate land management practices. In the Waikato region, eroded soil often ends up in our waterways, causing poor water quality. Good land management reduces erosion.
Gravity, wind and water can wear away the soil surface and move soil far from where it was formed. This process is called erosion.
The rate of soil erosion depends on the:
Soil scientists classify 43 percent of land in the Waikato region as having high potential for erosion.
People often accelerate the rate of erosion by removing vegetation and having inappropriate land management practices. Sometimes the vegetation is removed intentionally (for example during logging, cultivating or grazing). Sometimes introduced pests remove it for us (possums, goats, rabbits, deer and pigs).
Once the vegetation is removed, the land is very vulnerable to erosion. Large amounts of soil can be lost from cultivated land during storms. In some cases as much as 35 cm of soil has been lost over thirty years.
We lose most eroded soil from the land. Soil particles moved during erosion are often washed and blown into our waterways.
This is bad for our waterways because:
Eventually the water carries the soil particles downstream to the coast, causing increased sediment in our harbours. More sediment in our harbours means:
Forty-three percent of land in the Waikato region has a high potential erosion risk.
The risk of erosion increases if land:
Cultivation also leaves soils vulnerable to erosion. The compacted soils left in wheel tracks often act as channels for water. When it rains, water can then undercut and remove the surrounding soil.
Find out more about:
Common ways to reduce erosion include:
In many communities, groups of people are working together to care for their local environment. One way they are doing this is through local care groups. Another way is the Trees for Survival Trust - check it out under our Resources for Teachers information.
Waikato Regional Council manage soil conservation programmes to minimise erosion and the amount of sediment entering water. We are also designing a land monitoring programme based on soil quality monitoring at key representative sites.
Waikato Regional Council and the Department of Conservation work together to control wild goats under our Regional Pest Management Strategy (RPMS). The RPMS also sets standards for rabbit control. It is the land occupier’s responsibility to ensure these standards are met.