State of the environment monitoring: river water quality annual report 2016

Author:
Kristi Holland, Anna Kleinmans, Ebrahim Hussain
Source:
Auckland Council Research and Evaluation Unit, RIMU
Publication date:
2018
Topics:
Freshwater

The Auckland Council operates a long-term state of the environment river water quality monitoring programme throughout the region. This report provides a summary of the data collected during 2016. This data can be used as evidence to inform policy, management strategies, monitoring objectives and trend analysis. These include the Auckland Plan, council Long-term Plans and the National Policy Statement for Freshwater Management. Data from the state of the environment monitoring sites noted in this report also helps with assessing the efficacy of council initiated environmental restoration projects. For example, stream daylighting projects.

Water quality is assessed monthly at 36 sites around the region using a combination of field based and laboratory tested parameters. The results are presented as box plots, which display the variation in the measured parameters at each site, and in tables, which provide a statistical summary of each parameter at each site.

The data was used to produce water quality indices, which allowed sites to be ranked and assigned a water quality class. This analysis allows the complex water quality data to be presented in a simple form. In 2016 the river with the highest ranked water quality class was West Hoe Stream, a native forest site, which was the only site classed as having ‘excellent’ water quality for 2016. Poor water quality was observed in streams with a mix of urban and rural land use, as well as at one site (Riverhead Stream) which is classed as having an exotic forest (pine plantation) catchment. Otara Creek (East Tamaki), an urban site, was found to have the lowest ranked water quality in 2016.

Auckland Council technical report TR2018/003

 

Last updated: 2018-06-28