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Roughly 78% of Environment Waikato monitoring sites fail to meet guidelines for satisfactory water quality. E-coli bacteria (from animal and human faeces) and arsenic are at such levels that it is not safe to swim or drink directly from the river. Water quality declines from its “excellent” source at Lake Taupo to the coast at Port Waikato. The health of the river reduces steadily as sources of pollution and nitrogen are added to the flow of water through the intensively farmed lower catchment area.
Source: Environment Waikato Website[accessed 10 October 2011
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The hydro dams along the upper River mean that the River flow is five times slowerEnvironment Waikato Website[accessed 10 October 2011
than what would occur naturally. The flow modification affects the quality of the water because a slower flow and warmer water in the summer months causes extensive eutrophication: the growth of free-floating algal cells (called phytoplankton). The photographs illustrate the colouration changes due to eutrophication from the clearer waters at Huka Falls to the River where it passes through Hamilton City.
The Huka Falls, just north of Lake Taupo, the Source of the Waikato River
Waikato River at the Malcolm Street Beach, Hamilton City.
For more information on the health of the Waikato River visit http://www.waikatoregion.govt.nz/
or read this report: gecreport