Since the signing of the Accord in 2010, there has been a lot of work to improve water quality in the Manawatū Catchment as well as the wider Manawatū-Whanganui region. An independent report has shown that this work is starting to have an effect, with water quality for sediment and E. coli showing improvement over the past 7-10 years. The case study was conducted by Land Water People (LWP) and reviewed by the National Institute of Water and Atmospheric Research (NIWA) and StatsNZ. It was commissioned jointly by the Ministry for the Environment and Accord member Horizons Regional Council as a way to understand improving water quality trends in the Manawatū-Whanganui Region.
Ministry for the Environment Deputy Secretary – Water, Cheryl Barnes, says the study provides useful information for central and regional government. “It shows that considerable progress can be made in reasonably short timeframes. The key was taking a planned, whole of catchment approach and prioritising effort and investment where it would make the most difference,” says Ms Barnes.
Lead author of the report, Dr Ton Snelder, says the report has shown strong evidence for regional improvement in water quality over the past ten years for sediment (suspended sediment, water clarity, and turbidity), as well as E. coli. “The reduction in sediment and E. coli has improved water quality for swimming. Overall the modelling concluded there has been a 5 to 8 per cent improvement in ‘swimmability’ in the region in the decade ending in 2016,” says Dr Snelder.
The report demonstrated a connection between land management interventions and the magnitude of the water quality improvements, suggesting these interventions are having a positive effect on the surrounding areas. Horizons Regional Council natural resources and partnership group manager, Dr Jon Roygard, says “the case study demonstrates how regulatory and non-regulatory intervention, including the benefits of supporting farm plans, targeting action on highly erodible land, upgrading point source discharges and undertaking fencing and planting of stream margins, can effectively improve water quality.”
Long-term targeted interventions, such as voluntary farm plans to reduce hill country erosion are in place under Horizons’ Sustainable Land Use Initiative (SLUI). SLUI came into effect following a major storm event in 2004. The programme is funded by central government, ratepayers and landowners, with assistance from the Ministry of Primary Industries (MPI). In addition to reducing erosion, SLUI aims to improve water quality and increase the resilience of the regional economy. This initiative includes measures such as tree planting and ‘retiring’ erosion prone land by fencing it off and letting it revert to shrub or native forest.
At the release of this article, 683 Whole Farm Plans covering 500,000 hectares of the region have been developed through SLUI. These include advice on ‘best’ farm practice for landowners for sustainable land use, along with the planting of 14 million trees planted and over 570,000 metres of waterways being fenced. This work programme adds to the fencing and planting that has also been completed through Freshwater Grants and the Clean Up Fund project through the Manawatū River Leaders’ Forum.
The case study highlights strong statistical evidence of an association between water quality improvement and point source interventions, changes in point source discharge consents, and significant upgrades to wastewater treatment plants under the Clean-Up Fund. Wastewater treatment plants (WWTP’s) in Woodville, Dannevirke, Pahiatua, Kimbolton, Feilding and Shannon have all been upgraded through the Accord and the Clean Up Fund.
It’s a long journey to improve the state of the Manawatū River but the results of the study are encouraging. Through combined effort, local scale interventions, co-funding, and applied science we can make a difference.
Assessment of recent reductions in E. coli and sediment in rivers of the Manawatū -Whanganui Region
Including associations between water quality trends and management interventions, published in February 2018.
