Water Quality in NZ
By international standards fresh water in New Zealand is abundant and clean, but water quality in New Zealand varies considerably. About 40% of our lakes are in catchments surrounded by pasture and about 2% of lakes are in towns and cities, and these are the lakes that commonly have degraded water quality.
The state of our rivers and streams is certainly not pristine and the big increase in dairying, although great for the economy, doesn’t help with water quality. Fertilizer use has increased more than 600% since 1990 and consequently the effluent produced by dairy cows is rich in phosphorus and nitrogen.
“Nutrient run-off” is the term used to describe these nutrients leaching or running off into our waterways. When this happens algal blooms can result and we find ourselves in the unhappy situation of having about 90% of our native fresh-water species being on the threatened species list.
Wetlands
Wetlands can sometimes be overlooked but are actually incredibly valuable ecologically. Sadly fewer than 10% of NZ’s original wetlands remain, having been drained so the land can be used for other purposes.
Apart from being a home for many birds and animals wetlands also purify water (by reducing erosion and nutrient run-off), replenish groundwater and provide flood control by stabilising shorelines.
Water quality in Nelson
Nelson has high quality water in its conservation estate, including the upper reaches of the Maitai, Wakapuaka and Whangamoa rivers. However, almost all of Nelson's urban streams are physically, chemically and biologically degraded or very degraded, including all of the water bodies in the Stoke area, the Atawhai and Glen streams and the lower reaches of Brook Stream. This means they no longer provide good habitat for the animals and plants reliant on them.
Conserving Water at Home
It’s the bathroom that uses the biggest proportion of your household water (about half). But the garden also accounts for a fifth, so it pays to think of what you can do to minimise your reliance on water in this area too. See the govt Sustainability website for ideas on conserving water use in the home and garden.
How Can I Help?
In Nelson:
• Waimaori Stream Care Project – raises community awareness by way of monitoring waterways. Waimaori provides knowledge and hands-on experience about the freshwater environment, promoting biodiversity and enhancement of freshwater fish habitats.
