Rai Valley Water Quality
Monitoring and improving water quality in the Rai Valley catchment
A look at the water quality issues in the Rai Catchment in the top of the South Island and the efforts of the district council, Fonterra and the local catchment group to improve it.
Marlborough’s Rai Valley has long been a forestry and dairying community. In days gone by there was a dairy factory. The community still benefits from forestry and dairying but the raw logs and milk are no longer processed locally. These days the local area school, Outward Bound students and tourists and trout fishers who stop while travelling through, have become important contributors to the local economy.
The high rainfall within the Rai and Pelorus catchments is essential to the surrounding communities, providing irrigation and recreation.
The Rai River attracts guided fishing trips on the hunt for rainbow and brown trout, providing tourism and recreational opportunities for the small community. It is also popular with Outward Bound as an outdoor classroom, while others use it for kayaking.
In the past, the river has recorded effluent spikes that breached bathing standards and Rai Valley dairy farmers have been trying to reduce the impact from their industry for many years. A series of spikes in the early 2000’s prompted a meeting between NZ Landcare Trust and farmers that led to an application to the Sustainable Farming Fund to find solutions.
Peter Hamill is the senior environmental scientist with the Marlborough District Council. He says the council has been monitoring the Rai Catchment since the late 1990’s. Around 2000, Outward Bound students using the Rai River close to the Rai Falls noticed they were getting rashes after using the river and reported the problem to the council.
MDC ran a series of investigations throughout the catchment and pin pointed effluent getting into the river system as a result of farm practices, in particular cattle in river crossings. That led to further work with farmers to improve and build crossings to keep stock out of the water.
MDC runs regular monitoring in the catchment – more often during the summer – to keep an eye on a range of indicators of water health. They check for fish life and use an invertebrate survey to rate the water quality on a rising scale, depending on water insects they find there.
While recent water quality tests showed the river is in better shape than previously thought – better than many around the country – it also showed room for improvement. Problems tend to relate to Escherichia coli (E.coli) levels rather than nutrients from surrounding farmland.
Rai farmers contend with a high annual rainfall of about 2m that can saturate paddocks, with run-off ending up in the river. They have the added problem of substantial flooding along the valley floor, also affecting water quality.
Improvements such as culverts and bridges were made several years ago to meet Fonterra’s Clean Streams Accord (CSA). The Marlborough District Council helped the process with waivers of resource consents.
NZ Landcare Trust got involved at the time spikes in the E.coli levels led to health issues with recreational users of the river. Landcare had already had considerable experience with a similar project in the Aorere Catchment in Golden Bay.
In Golden Bay, the efforts of the group have had a hugely beneficial effect on the shellfish industry that relies on the water quality from the Aorere River flowing into the bay.
Barbara Stuart says The NZ Landcare Trust put together a proposal to get funding to form a community group and get farmers engaged in helping improve farm practice and water quality. The Ministry of Agriculture (MAF) Sustainable Farming Fund (SFF) provided further money to enable completion of individual farm plans and to use the knowledge to assist other groups. In the early days of the project they got Golden Bay farmers to come to the Rai to talk about what had been achieved there.
At the Morgan Foundation NZ River Awards held in November 2013 the Rai River was recognised as the most improved in Marlborough. Council staff credited the work of farmers, who adopted the council programme for bridging and culverting streams, for improved water quality trends and the uptake of better management of dairy shed effluent.
Barbara says many of the farmers have done the “hard yards” such as culverts and bridges. “Working alone on issues can seem overwhelming, but by working together for a collective outcome, communities can get outcomes and enjoy the process.”
Mirka Langford is the Fonterra Sustainable Dairying Advisor for the region. She started working with dairy farmers in the Rai Catchment project using the catchment as a pilot programme to start rolling out a range of measures designed to encourage farmers to take the necessary steps to improve water quality all around the country.
In 2013 the Sustainable Dairying Water Accord was rolled out as the first part of a wider dairy industry strategy.
Among the commitments in the accord are a number of requirements that will have an impact on water quality :
- 90% exclusion of stock from all waterways by May 2014
- 100% exclusion by May 2017
- 100% exclusion from significant wetlands by May 2014
- Stock crossings bridged or culverted by May 2018
- Riparian management plans for all farms by May 2020
Farms must supply their dairy company with information that will allow for the modelling of nitrogen loss and nitrogen conversion efficiency.
- Data collected and performance benchmarked for 100% of dairy farms by November 2015.
All dairy farm effluent systems must be capable of being compliant with the regional council rules 365 days per year.
- 100% of farms to be assessed by May 2014.
Mirka says her role is to make sure farmers meet at least minimum standards for waterway, effluent and nitrogen management set down in their supply agreements with the co-operative.
She says she urged farmers to adopt best practice rather than just meet minimum standards and regional council rules. She also visited farmers who wanted advice on for instance, installing a new storage pond or when a member of the public had voiced concern about the way a farm was being run.
A timeframe for work to be completed was agreed with the farmer which she made sure was done, she said.