If you look at a map of New Zealand, you'll see an intricate network of waterways across the country. It's like a circulatory system, carrying water from the mountains and hills to farms and businesses, towns and cities, supporting life and prosperity.
Like our own bloodstream, its easy to take this system of aquifers, lakes, rivers, streams and wetlands for granted - until something goes wrong, sending off warning signals. If you ignore these symptoms, it can be fatal.
That is what's happening in New Zealand at present. Across the country, streams and rivers are being choked with sediment and slash, buried by developers, emptied by irrigators and poisoned by pollutants. Although the scientists are warning us about the dangers, we're not listening.
Farmers - even those who ought to know better - put their stock in lakes and rivers; foresters harvest and send flows of sediment and slash downstream; irrigators deplete rivers and aquifers; while businesses and individuals pour chemicals and other pollutants down drains, which then flow out to sea.
The costs to our economy and lifestyles are incalculable. Once a waterway has been choked or becomes so polluted that its ecosystems no longer work, it may be impossible to restore it. At the very least, it is extremely expensive, as we are discovering with the Rotorua lakes.
