Monitoring has been running for several weeks, and has highlighted the sites that appear to be suitable for swimming and recreation most of the time - Waikawa Stream at North Manakau Road, the Ohau River at Gladstone Reserve and the Ohau River at Kimberley Reserve, although the latter two recently tested higher than acceptable for E.coli.
Other sites that registered levels of concern were both Waikawa and Hokio Beaches which have occasional elevations of bacteria that exceed Ministry of Health exceed Ministry of Health guideline values.
Recent tests also showed E. coli levels were too high for swimming at Kirkaldies and Gladstone Reserves and Tokomaru's Horseshoe Bend.
Ms Matthews said that water quality in Horowhenua is good until it travels down through urban and rural areas.
"Nutrients, bacteria and sediment can make their way into our waterways and affect their health," she said.
While a number of sites throughout our region do show signs of pressure, Horizons is also seeing encouraging signs of improvement.
"Scientists generally report two key measures for water quality: state and trend. State tells us about the current condition of a waterway, and trend tells us how things are changing over time. Recent analysis of 10 and 25-year trends highlights significant improvements in nitrogen, phosphorus and bacteria at a number of sites throughout the Manawatū-Whanganui Region," she said.
In the Horizons region, initiatives such as the Manawatū River Leaders' Accord drive change by ensuring urban wastewater treatment plants are performing as they should, and farmers are improving systems and practices to reduce the amount of sediment, nutrients and bacteria making their way into waterways.
"Reducing run-off through stock exclusion and riparian planting not only reduces in-stream nutrients and bacteria, it also provides much-needed habitat for fish and bugs," she said.
"As our knowledge of the complex relationships between soil, geology, water quality and ecosystems grows, so too does our understanding of the different levers we can pull to improve the health of our waterways." Horizons is running a Spruce Up Your Swim Spot competition. Ms Matthews said Gladstone and Kimberley were worthy competitors, but Horowhenua needs to "jump online and vote".
"We are asking the public to vote for their favourite spot, which could win a spruce up, such as weed management, sediment removal, improved access and signage in conjunction with the relevant city or district council," she said. "The two Horowhenua sites really need some votes!"
- Visit www.horizons.govt.nz to vote or find out more.