Big turnout for lake science presentations
Tuesday, 2 July 2013 3:15 p.m.
More than 120 Rotorua residents turned up last week to hear about research being done into improving water quality in the Rotorua Lakes.
The evening, hosted by Bay of Plenty Regional Council and University of Waikato, presented research findings on nutrient reduction methods and provided an opportunity for questions from the audience.
Regional Council General Manager Natural Resource Operations Warwick Murray said the large turnout demonstrated how passionate the Rotorua community was about the Rotorua Lakes.
“Attendance at the event surpassed our expectations, and highlighted the community’s desire to know more about the lakes and what we are doing to protect and restore them,” he said.
"The Rotorua Te Arawa Lakes Programme is world renowned. Our achievements are only possible with robust science and innovative solutions. Our relationship with University of Waikato has been instrumental in providing this support to the lakes programme,” Mr Murray said.
The Regional Council has funded the University’s Chair in Lake Restoration, Professor David Hamilton, since 2002. His work on the Rotorua lakes aims to better understand how land use affects water quality and what might be done to preserve or restore water quality in the lakes. He also supervises undergraduate and postgraduate student research on lake issues.
Professor Hamilton said that presenting to the community on the research findings was important for his students.
“The students put so much work and effort into their research, and the results provide important information on interventions to improve water quality. Presenting the findings to the community is an important part of the research process. To have more than 120 people turn up and ask questions provides additional validation of the significance of the research they are doing,” Professor Hamilton said.
“The majority of the presentations were on research to reduce nutrients getting into the lake, and this is key to protecting and restoring Rotorua Te Arawa Lakes,” Professor Hamilton said.
Preventing phosphorus getting into the lake was the hot topic for the evening, with three presentations ranging from an analysis of phosphorus attached to sediment, transport of phosphorus during storm events and capturing phosphorus in detention bunds.
Copies of the power point presentations can be viewed on www.rotorualakes.co.nz
Caption: University researcher Rebecca Eivers tests water near a floating wetland
Research topics from the students’ presentations:
‘Variability in nutrient loading to Lake Rotorua from stormflows and associated impacts on water quality’ - Jonathan Abell told the audience that 50 percent of phosphorus in the Puarenga and Ngongotaha streams is delivered in storm flows that occur about 10 percent of the time. Land management is needed to prevent erosion to help stop phosphorus getting to the lakes in storm events.
‘The performance of detention bunds for sediment and phosphorus retention on farmland in sub-catchments of Lake Rotorua’ - Dylan Clarke gave an overview of his research into detention dams and their potential to capture phosphorus on farms in storm events.
‘Sedimentation basins and constructed wetlands for protection of lakes in agricultural catchments in the Waikato’ – Rebecca Eivers’ research investigated end-of-drain treatment systems such as silt-traps and constructed wetlands, and their effect on reducing sediment and nutrients to downstream waterways. Ms Eivers told the audience these could have an effect, but design needed to take into account soil types, catchment sizes and seasonality.
‘Analysis of Phosphorus forms in Waiteti Stream sediments’ - Jamie Peryer-Fursdon’s research was on sediment composition in streams and its potential effects on lake degradation. He told the audience that phosphorus attached sediment could add to the internal loading to the lake and confirmed the importance of detainment bunds to help capture phosphorus before it got to the lake.