We know that the Waikawa Stream isn’t as clean as it used to be (The river runs red), and many of us have our suspicions about why that might be, though we lack the data to confirm the sources of the problem.
The article Troubled Waters in the New Zealand Geographic is a long and careful look at contamination in New Zealand rivers and makes many very interesting points. I suggest you set aside half an hour and read it.
The conclusion of the article is particularly interesting and gives us some useful ideas:
Young believes that correct diagnosis coupled with professional support can lead not just to an immediate improvement in river health but long-term benefits in preventive care. In the Sherry River catchment, for example, the shock of landowners and residents at finding their beloved stream was, in fact, a microbial health hazard galvanised the community to form a catchment group.
Cattle crossings were bridged, leading to a 50 per cent improvement in water quality. Five kilometres of waterways were fenced, and 4000 trees, shrubs and grasses planted in riparian margins. Multiple other measures to control run-off and limit soil erosion were implemented, leading to the group receiving environmental awards in 2009 and 2013.
The community’s enthusiasm for their local river had another benefit: they published their story as a case history. Others can now refer to this “medical literature” and learn from the Sherry River experience.
Sometimes now the Waikawa stream is not swimmable. Next we need to know why and then we can start working on the changes needed to get it back to the safe and fun river so many have enjoyed over the years.