Water supply
Greater Wellington collects and treats all the drinking water that Wellington, Hutt, Upper Hutt and Porirua city councils supply to consumers. Our water supply costs are not funded from regional rates; they are billed to those councils directly. We have made no change to next year’s bulk water levy.
The quantity of water supplied varies from year to year, depending on summer weather conditions and the amount of garden watering. Annual water supply volumes are gradually increasing in line with population growth. Last year we had only modest demand and little difficulty in maintaining supply. Total supply was 55,000 million litres.
However, the latest population estimate shows growth is near the high end of projections. If this rate doesn’t slow, the existing water assets might not fully meet our customers’ demands as early as 2007. To overcome this, we can either build new capacity or do more to encourage less water use: we’re considering both possibilities.
We have also been working on raising awareness of the need for people to store water in case of a major emergency or disaster. This has included a public display of the issues and solutions for emergency water storage and distribution at an Easter event at Te Papa, and a survey of residential care facilities in Wellington City. A recent survey showed that the majority of households have insufficient water stored for use in an emergency when they might have to cope without a permanent water supply for several weeks.
The process of collecting, treating and distributing drinking water is very complex: from maintaining healthy forests (for example, by pest control); to the exact methodologies and chemicals used to treat water from rivers; to the efficient distribution by a network of pipes, pumps and reservoirs. Over 1300 visitors learnt more about this process by touring our water treatment plants or taking a guided walk in our two catchment areas last year.