Levels of E. coli in the region’s freshwater indicate plenty of room for improvement, much like the rest of New Zealand, according to a recent report.
A just-released study by government-funded research body Our Land and Water highlights contaminant levels in New Zealand’s freshwater and indicates it will be “extremely challenging” to achieve national water quality goals.
The study suggests that three-quarters of all land in Aotearoa is contributing more E. coli to our water than is allowed.
Research lead Ton Snelder said reducing E. coli levels to the “minimum acceptable state” is possibly even more challenging than the research indicates.
“The maps produced by this study highlight the entire area of a catchment where contaminant reduction is needed, but this includes land largely untouched by humans, such as the DOC estate,” Snelder said.
“That means significant action needs to be taken to reduce E. coli entering water from the areas of land that are being managed, and in particular land being used to produce food.”
E. coli is a type of bacteria commonly found in the guts of people and animals.
When E. coli is detected in water, it’s a good indicator of faecal contamination and the presence of disease-causing organisms such as Campylobacter.
Greater Wellington Regional Council [GWRC] environment group manager Lian Butcher said the council is aware of E. coli issues in some catchments and is committed to taking a wider catchment-based approach to contaminant issues.
“How we improve water quality is not about pointing the finger at people but about understanding the catchment, the inherent risks, the various land uses, and how we can work together to make meaningful change that incorporates relevant issues and values.”
Data provided by GWRC shows that out of nine popular recreational sites that are monitored, five are ranked as having ‘poor’ water quality.
These sites are the Waipoua River at Colombo Rd, and the Ruamāhanga River at Te Ore Ore, Kokotau, Morrisons Bush and Waihenga Bridge.
The ‘national bottom line’, according to GWRC, means it is unacceptable for a site to be graded ‘poor’ and measures must be taken to improve the water quality at that site.
The majority of E. coli breaches are related to a period of heavy rainfall.
Butcher said monitoring shows that water quality in Wairarapa rivers and the coast is “generally quite good” except for when the region is experiencing a downpour.
“This is because rain will wash contaminants from the land and into the waterways. Sewer overflows can also occur in wet weather,” Butcher said.
“As an example, for the nine recreational sites we monitor, seven of these breached the “action level” just once each last summer, and all of those were rainfall-related.
“That is why we recommend that you avoid swimming for two days after rain as urban or agricultural run-off can affect bathing water quality, even at sites with generally good water quality.”
Over the next few years, Butcher said, GWRC will focus on helping Wairarapa landowners with Freshwater Farm Plans to define actions that will protect waterways, including reducing E.coli levels.
“These will be audited regularly for progress, and Greater Wellington will provide ongoing support to these landowners with action planning and delivery.”
National regulations recently brought in make Freshwater Farm Plans compulsory for farms that are larger than 20 hectares.
However, the GWRC Natural Resources Plan already requires farmers in priority catchments to have a Certified Farm Environment Plan that meets the requirements of regional rules.
