| 09 Dec 2022

Health Warning lifted for Algal Bloom in Saltwater Creek (Timaru) near the SH1 bridge (Ōtipua)

Te Mana Ora | Community and Public Health has lifted its algal bloom health warning issued for Otipua/Saltwater Creek near SH1 bridge on 09 December 2022.

Recent water testing at Otipua/Saltwater Creek near SH1 bridge has shown the concentrations of potentially toxic blue-green algae (planktonic cyanobacteria) in the river has reduced and concentrations are now below levels that are of concern to public health.

Dr Matthew Reid Medical Officer of Health for Te Mana Ora, National Public Health Service Te Whatu Ora, says Environment Canterbury’s sampling of Otipua/Saltwater Creek near SH1 bridge will continue on a weekly basis throughout the summer.

“The public will be informed if testing shows that concentrations have increased and there is a risk to public health again”, Dr Reid says.

Facts about cyanobacteria

  • Cyanobacteria occur naturally but can increase rapidly during warmer months.
  • Algal blooms are caused by a combination of nutrients in the water (such as nitrogen and phosphorus), and favourable weather conditions (e.g. increased temperature, calm days).
  • If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact.
  • Not all cyanobacterial blooms are visible to the naked eye and toxins can persist after the blooms disappear.
  • Cyanobacterial concentrations can change quickly with changing environmental conditions (e.g. wind). If a health warning is in place avoid contact with the water.
  • If a health warning is in place avoid contact with the water.
  • Although district or city councils may place warning signs, these may not be seen at the numerous river access points, hence the need for people/ dog-walkers to treat every low-flowing river cautiously.

For further details visit: https://www.lawa.org.nz/explore-data/canterbury-region/

Or contact Te Mana Ora on (03) 364 1777:


For more information about Mahinga Kai:



For further information, contact:

Karen Berry
Communications Manager
Te Whatu Ora South Canterbury  
021 139 7442