Recreational water quality monitoring underway

Waikato Regional Council’s weekly monitoring of popular rivers, lakes and coastal sites is now underway to check they are safe for swimming and other recreational activities.

The annual programme involves mostly weekly collecting and testing of freshwater samples for levels of E. coli and cyanobacteria (blue-green algae) at 32 sites, and seawater samples for E. coli and enterococci at 13 sites.

The water quality at over 80 other river locations is also estimated based on monitoring data.

E. coli and enterococci are indicators of faecal contamination, while cyanobacteria can produce toxins harmful to people and animals.

The monitoring results are shared with Land Air Water Aotearoa (LAWA), territorial authorities, iwi, community groups and public health officials in our region.

Results that may have public health implications will be communicated, with signs put in place. 

The public can find out the water quality at the last time of sampling on LAWA's Can I Swim Here? page. 

Waikato Regional Council Water Scientist, Dr Mafalda Baptista, says many of our freshwater sites are graded poorly for E. coli. 

“As a rule of thumb, you should avoid swimming near potential sources of contamination such as flocks of birds, stormwater or wastewater outlets. Avoid swimming for at least two to three days after heavy or prolonged rain, even for sites that have good water quality,” says Dr Baptista.

Algae occur naturally in our rivers, lakes and streams, and flourish during hot and fine conditions. However, algae can rapidly bloom to harmful levels. Play it safe – if you see water discolouration avoid contact or choose another site to swim. Find out more at waikatoregion.govt.nz/algal-blooms.

Most of Waikato’s beaches maintain excellent long-term grades, although the estuarine swimming spots see more fluctuations during rain periods due to flushing from the catchments increasing the freshwater influence. 

Waikato Regional Council Coastal and Marine Science Team Leader Dr Michael Townsend says Earth Sciences New Zealand (ESNZ) has predicted a warm and wet summer this year.

“With the expected conditions, we’ll be keeping a close eye on our estuarine sites. We always recommend checking LAWA, especially if it’s been raining in the week prior.. As always, if it doesn't look right, stay out!” 

Freshwater sites monitored weekly until the end of February:

• Lake Taupō 
• Lake Puketirini
• Lake Kainui
• Lake Rotokauri
• Lake Ngāroto
• Waikato River from Hamilton up to Tuakau
• Kauaeranga River
• Hikutaia River
• Ohinemuri River
• Waihou River 
• Waipā River
• Waitakaruru River. 

Lakes in the Waikato River monitored monthly for cyanobacteria until the end of April (and for E. coli until the end of February):

• Lake Karāpiro – Horahora Domain
• Lake Arapuni – Jones landing
• Lake Maraetai – Mangakino boat ramp
• Lake Ōhākurī.  
   

Coastal sites monitored until the end of March:

• Buffalo Beach (Whitianga)
• Hot Water Beach
• Tairua Beach
• Pepe Inlet at Tairua
• Pauanui Beach
• Whangamatā Beach
• Whangamatā Harbour entrance
• Onemana Beach
• Whiritoa Beach
• Ngarunui Beach (Raglan)
• Raglan Harbour (near the motor camp)
• Maraetai Bay (Port Waikato)
• Sunset Beach (Port Waikato).