How do wilding pines impact waterways?
Independent analysis suggests wilding pines could have a strong impact on waterways. They reduce the water available within the environment for other species and for other uses. Wilding pines can decrease the amount of water that flows into rivers by 30% to 40%. This is significant enough to be a significant threat to irrigation and hydro-electricity generation.
Why do wilding pines affect water levels?
Wilding pines hold water within the soil and release water into the atmosphere through the trees’ leaves. This reduces the flow of water into rivers and decreases water refilling underground aquifers.
Wilding pines can reduce the amount of water that flows into rivers by 30% to 40%. This reduced water availability negatively impacts irrigation, hydroelectricity and reduces river volumes affecting recreation.
Will the impact on water get worse with climate change?
This impact of wilding pines on waterways is likely to get worse with climate change. In some areas, climate change will increase wilding pine spread as well as lead to hotter drier conditions. This means not only will there be less water entering the environment, but there will be more wilding pines to reduce water into the river systems.
What does the impact of wilding pines on waterways mean for irrigation schemes?
Wilding pines will severely impact New Zealand’s irrigation schemes. According to an independent study prepared for MPI this is because the high country is one of the landscapes most prone to invasion and these areas feed our irrigation rivers.
Studies have shown that wilding pines can use 50% more water than tussock. Once the wilding pines take over there will be less water available for the rivers and therefore less available for irrigation downstream. If we do nothing, the cost to irrigation is likely to be $1.9 billion over 50 years.
How could wilding pines affect hydroelectric generation?
Independent analysis shows wilding pines reduce the water available within the environment. Wilding pines hold water within the soil and release water into the atmosphere through the trees’ leaves. Wilding pines can reduce the amount of water that flows into rivers by 30% to 40%. By removing water from rivers, wilding pines could reduce water within four of New Zealand’s six most significant hydroelectricity catchments; Tongiriro, Waitaki, Clutha and Manapouri.
Failure to control wilding pines would result in a loss of approximately $995 million in relation to hydroelectricity over 50 years and every year we wait, the cost of removing wilding pines rises by 30%.
