Skip to main content

He whakapai ake i te kounga wai i ngā muriwai

Improving water quality in lagoons

​We are working with the community to improve the water quality at Karekare, Piha, North Piha, Te Henga, and Little Oneroa lagoons.

​Current state of the lagoons

These lagoons are currently not safe for swimming due to faecal contamination from humans, and from animals like cows, ducks and dogs. 

Human contamination is coming from untreated wastewater from households getting into waterways. This happens when septic tanks, long drops and hi-tech systems are not properly maintained. 

During summer, there is also an increase in visitor numbers in the area. As a result, there is also an increased load on septic tanks. 

How we are addressing the problem

  • Awareness programmes focusing on better management of septic systems within the catchments. 
  • Better follow-up of known septic system issues. 
  • Better management of council-owned wastewater systems in the area. 
  • Supporting landowners to fence their livestock from waterways. 
  • Discouraging bird feeding, and encouraging picking up after dogs. 
  • Our 'Retrofit your septic tank' initiative. 

Help us keep the lagoons clean

  • Maintain your septic tank system and get it checked by a professional.
  • Spread out shower and laundry use to avoid a water ‘rush hour’. 
  • Manage water use when you have lots of visitors. 
  • Use eco-friendly cleaning products. 
  • Watch out for signs of a septic system failure. 
  • See Managing wastewater on your property.

 Related topics



Install or alter an on-site wastewater treatment and disposal system or alter an on-site wastewater treatment and disposal systemCheck when you need a consent to install or alter an on-site wastewater system, what you need to know before you apply for a consent, and your responsibilities after you've installed the system.aspxBuilding and consents
Managing wastewater on your property wastewater on your propertyYour septic tank needs a regular pump-out service to remove scum and sludge buildup. Check for specific requirements if you live in Waitakere or Waiheke. aspxWater quality
Onsite wastewater system compliance wastewater system complianceA regional compliance system ensuring property owners with onsite wastewater units provide regular documentation that their systems have been inspected and are in good working condition.aspxEnvironment
Safe Networks NetworksSafe Networks conduct monitoring and investigations in our streams, watercourses and stormwater network to identify contaminants and track them to their source.aspxEnvironment
Help to improve the marine environment in your area to improve the marine environment in your areaThere are local groups actively contributing to the health of our marine environment and coastlines. Find out what these environmental organisations do. aspxWater quality
Stormwater and waterway projects and waterway projectsThrough improvement projects on our stormwater network and waterways, we try to minimise flood risks, manage stormwater and prevent water contamination. aspxStormwater