We monitor water quality at 14 stream sites and eight lake/lagoon sites on the main Island.

Samples are collected on a quarterly basis and sent away for laboratory analysis. The data is collated and reported on every year, with more comprehensive analysis undertaken approximately every ten years to look at trends in the data.

Key findings from 2022

  • Flow regimes of the major river systems are now well understood and characterised for both low flow and flood conditions.
  • Poor and degrading water quality of waters across the island are likely caused primarily by climate patterns although changing farming emphasis to heavier livestock appear to strongly interact with climate. 
  • Reduction in state or degrading trends had reduced at some sites but were particularly notable at key sites.
  • The degrading water quality of Lake Rangitai is highly likely to be a result of its reducing area. Water is taken for stock water and domestic water use. With water resources largely used under sustained drought conditions, the lake becomes relatively small and shallow the water quality degrades.

Below are links to the reports published in the past 10 years:

Below is a list of the 22 sites we monitor and the site ID for each location. You can view the data for each site by searching the relevant site ID in Environment Canterbury’s Water quality data search(external link).

Site NameSite ID
Awamata Stream SQ34829
Awatotara Creek SQ34830
Te Awainanga River SQ34832
Washout Creek SQ34834
Whangamoe Inlet SQ34838
Nth Trib Rakautahi SQ34841
Blind Jims Creek SQ34844
Mangape Creek SQ34851
Mangahou Stream SQ34854
Te One Creek SQ34857
Waitamaki Creek SQ34860
Waimahana Creek SQ34863
Waitaha Creek SQ34849
Te Whanga Lagoon @ Airbase SQ34861
Te Whanga Lagoon @ Beach SQ34843
Te Whanga Lagoon @ Southern Basin SQ35082
Lake Huro SQ34859
Lake Marakapia SQ34893
Lake Rangitai SQ34846
Lake Te Wapu SQ34887
Tennants Lake SQ34842
Nairn River SQ35078