​Keeping an eye on our urban streams

Stream water testing is essential at this time of the year - especially after a heavy rainfall. The stream ecosystems are often seriously affected by stormwater runoff that washes pollutants, nutrients, and sediments into our streams.

Unfortunately, most storm water systems are not designed to handle large amounts of water flowing off imperious surfaces within built up urban areas, which can cause serious problems for stream ecosystems and our health.

The Whau River Catchment Trust frequently get calls from worried people who are concerned about a stream that runs through their property or their local reserve. These concerns often occur after a heavy rainfall, as some of the streams have turned a different colour. Some report that an eel that they saw a year ago has not come back this year. Others describe something in the water they think shouldn’t be there.

The first question they consider is “What is happening up stream?” Is litter being dumped? Are there pollutants? It can be difficult to track down the source, especially in an urban area; even washing a car on the side of the road can be a cause.

Water flows across land before running into the streams, collecting any substances - good or bad - as it moves along its course. Surface water runs into the drains, which flow into streams, then into the river and eventually out to sea.

The Whau River Catchment Trust tests the streams within the Whau Catchment, and the data collected is sent directly to Wai Care who then assess the data and act accordingly.
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If you would like to assist with testing stream water health, come along to one of their regular stream testing days. Or if you are concerned about a stream’s health please contact Justine by email justine@whauriver.org.nz or phone 021-627-864 or the ‘pollution hotline’ 09 377 3107