Keep Our Waterways Clean

Every month, the Marlborough District Council is testing water quality at 34 sites on the rivers of the region. Half the sites consistently show excellent quality water. About a fifth of sites have poor quality water, especially after heavy rain.

Nitrate levels are watched carefully – they’re always highest in winter and spring. Excess nitrate can lead to increased algae growth. Suspended solids, bacteria and heavy metal concentrations are also highest during heavy rainfall.

The level of pollutants getting into the waterways during wet weather depends on the surrounding land use. Where there is intensive agriculture or high urban density, water quality tends to be at the lower end of the scale.

More information about water quality, and the sites that are monitored, is available on the River Water Quality section of the website.

You can help keep our waterways clean by following these steps:

• Don’t pour household cleaners, paint, herbicides or pesticides or any other chemicals down household drains. They lead directly into our waterways.
• Don’t use herbicides or pesticide sprays in wet weather or if rain is forecast.
• Maintain riparian strips along waterways where possible. Riparian strips help stabilise the banks of waterways, discouraging erosion and the leaching of sediment into the water.
• Report to the Council any pollution or activity which you think may pollute our waterways.