Technical Reports

Biomanipulation

• Review for the potential for biomanipulation of phytoplankton abundance by freshwater mussels in the Rotorua lakes NIWA (288KB, pdf)
• Using plants (algae) to strip nutrients from streams and lakes. - Warwick Silvester, Dept of Biological Sciences, University of Waikato, Hamilton.  24 October 2006 (54KB, doc)

Economics

• An economic evaluation of land use change options - Nimmo-Bell (347KB, pdf)
• Economic Evaluation of Water Quality Induced Changes in Rotorua and Rotoiti Catchments Nimmo-Bell (1.6MB, pdf)
• Rotorua Lakes: Evaluation of Less Tangible Values Nimmo-Bell (1.4MB, pdf)

Engineering Options

• Denitrification in a Rotoehu Stream, 2nd installation - Graeme Anderson, Landcare Research NZ Ltd & Matthem Taylor, Environment Waikato (2MB, pdf)
• Summary Report on Possible Dredging of Lakes in the Rotorua District - Analytical & Environmental Consultants, February 2007 (650KB, pdf)
• Impact of the Ohau Channel Diversion on Okere Arm, Kaituna River and Maketu Estuary - John McIntosh, Environment Bay of Plenty (1.1MB, pdf)
• Hypolimnetic Discharge Environment Bay of Plenty (318KB, pdf) 
• Lake Rotoiti Fieldwork and Modelling to support considerations of Ohau Channel Diversion from Lake Rotoiti - David Hamilton, Chris McBride & Toradji Uraoka - Centre for Biodiversity and Ecology Research, University of Waikato (2.8MB, pdf)
• Lake Rotoiti - Ohau Channel Diversion Feasibility Study Tonkin & Taylor (93KB, doc)
   - Diversion Option 1 (1.5MB, pdf)
   - Diversion Option 2 (1.5MB, pdf)
   - Diversion Option 3 (1.5MB, pdf)
• Lake Rotoiti - Ohau Channel: assessment of effects of engineering options on water quality M. Gibbs, I. Hawes, S. Stephens (1.5MB, pdf)
• Modelling diversion walls for diverting the Ohau Channel inflow from Lake Rotoiti Scott Stephens, NIWA (4.7MB, pdf) LARGE FILE
• Ohau Channel Groynes (36KB, doc)
• Rejuvenating Lake Rotoiti BOC Ltd (1.7MB, pdf)
• Supplement to Lake Rotoiti diversion wall modelling - refined wall designs and response to peer review Scott Stephens. (2MB, pdf)
• Tikitere Flow Diversion Report Rotorua District Council (2.8MB, pdf)

Fisheries

• Boat electrofishing survey of common smelt and common bully in the Ohau Channel (616KB, pdf)
• Lake Okareka and Tikitapu Fish Health Monitoring 2007 - Michael Landman, Jeroen Brijs, Chris Glover and Nicholas Ling, 30 October 2007 (386KB, pdf) 
• Implications of introducing Grass Carp into the  Rotorua Lakes - Matt Bloxham, Environment Bay of Plenty (302KB, pdf)
• Baseline study of the potential impact of increased trout numbers in the Kaituna River on whitebait (migrant galixiids) - NIWA, November 2005 (192KB, pdf)
• Potential effects on smelt of diverting Ohau Channel water out of Lake Rotoiti - NIWA, November 2006
• The Hamurana Stream in Lake Rotorua: some potential effects of its diversion on the trout fishery and on summer nutrient dynamics - NIWA, June 2005 (2.1MB, pdf)
• Effects of the cold, spring-fed, inlet streams on Rainbow Trout distribution in Lake Rotorua - NIWA, September 2006 (1.2MB, pdf)
• Kaituna River Fish Inventory NIWA
• Lake Okareka and Tikitapu fish health monitoring 2006: Trout baseline study, April Michael Landman, Nicholas Ling and Trevor Stuthridge (149KB, pdf)
• Lake Okareka Fish Health Monitoring 2005 Michael Landman, Mike van den Heuvel and Trevor Stuthridge (1.7MB, pdf)
• Lake Okareka and Tikitapu Fish Health Monitoring 2006 Michael Landman and Nicholas Ling (1.6MB, pdf)
• Smelt monitoring in the Ohau Channel and Lake Rotoiti: 2008-2009 (471KB, pdf)
• Ohau Channel Diversion Wall: an assessment of the koura and kakahi populations in the Okere Arm and Lake Rotoiti (912KB, pdf) Ian Kusabs
• Ohau Channel Diversion Wall: Monitoring of koura and kakahi populations in the Okere Arm and Lake Rotoiti (336KB, pdf) Ian Kusabs, Willie Emery and Joe Butterworth
• Utuhina Stream Monitoring 2009: Fish and Aquatic Invertebrates - CBER, University of Waikato (424KB, pdf)

Flocculants

• Phoslock Application - Lake Okareka Final Report Prepared by John McIntosh, Environment Bay of Plenty (149KB, pdf)
• Lake Okareka and Tikitapu Fish Health Monitoring 2007 - Michael Landman, Jeroen Brijs, Chris Glover and Nicholas Ling - Scion (386KB, pdf)
• P-inactivation efficacy of Z2G1 as a capping agent on Lake Okaro sediment - NIWA
• Melter slag sox at a Rerewhakaaitu stream (Report 1) R. W. McDowell and M. F. Hawke (300KB, pdf)
• Melter slag sox at a Rerewhakaaitu stream (Report 2) R. W. McDowell and M. F. Hawke (1.3MB, pdf)
• Assessment of the performance of nutrient reduction treatments for the Rotorua Lakes - Z Yang, M R van den Heuvel, T R Stuthridge (42KB, pdf)
• Environmental Impacts of Lake Okaro Mesocosm Trial Matthew Bloxham, Environment Bay of Plenty (4.5MB, pdf) LARGE FILE 
• Phoslock Application - Lake Okareka John McIntosh, Environment Bay of Plenty (408KB, pdf)
• Locally Available Absorbing Materials, Sediment Sealing and Flocculants for Chemical Remediation for Lake and Stream Water Analytical & Environmental Consultants (885KB, pdf)
• Sediment Capping Lake Rotorua (762KB, pdf)

Geology

• Lake Okaro: Explosions and Erosion Lyndon Hardy (1.9MB, pdf)

Geothermal

• Mixing of Tikitere geothermal discharges with sewage - GNS Science Consultancy Report, March 2006
• Water quality impacts of a point-source discharge of Tikitere geothermal water in Lake Rotoiti Rotorua District Council (1MB, pdf)

Groundwater

• Groundwater Age and Chemistry, and Future Nutrient Loads for Selected Rotorua Lakes Catchments By U Morgenstern and others. IGNS Science Report 2004/31 (4.4MB, pdf) LARGE FILE
• Groundwater age, time trends in water chemistry and future nutrient load in the Lakes Rotorua and Okareka areas Institute of Geological & Nuclear Science (6MB, pdf) LARGE FILE
• Prediction of Future Nitrogen Loading to Lake Rotorua  IGNS Science Report 2006/10 (500KB, pdf)
• Groundwater Catchment Boundaries of Lake Rotorua - GNS Science (5.7MB, pdf) LARGE FILE

Land use management and land use change

• Cost-effectiveness Analysis of Grazing Management Options for Rotorua Dairy Farms (890KB, pdf)
• Land Use Impacts on Nitrogen and Phosphorus Loss and Management Options for Intervention AgResearch (347KB, pdf)
• Nitrification and Urease Inhibitors D C Edmeades, agKnowledge Limited (301KB, pdf)
• Riparian Protection in the Rotorua Lakes Catchments Environment Bay of Plenty (1.2MB, pdf)
• Nitrogen exports from the Lake Rotorua Catchment - calibration of the ROTAN model - NIWA (1.8MB, pdf)

Management

• A review of short term management options for Lakes Rotorua/Rotoiti (796KB, pdf)
• Lake Rerewhakaaitu Project Environment Bay of Plenty (2MB, pdf)
• Lakes Quality Risk Assessment and Action Plan Prioritisation Environment Bay of Plenty, Rotorua District Council, Te Arawa Maori Trust Board (343KB, pdf)
• Restoration of Eutrophic Lakes: a Global Perspective.  In:  Freshwater Management: Global Versus Local Perspectives.  M. Kumagai, W.F. Vincent (Eds) (1MB, pdf)

Rivers and streams

• An ecological overview of the Puarenga Stream with particular emphasis on cultural values (1.5MB, pdf) - Ian Kusabs and Associates Ltd
• Storm nutrient loads in Rotorua streams (2.1MB, pdf) - NIWA
• Nutrient load targets for Rotorua - a revisit - NIWA (127KB, pdf)
• Hamurana Stream water movement in Lake Rotorua - Max Gibbs, Eddie Bowman, John Nagels, NIWA (1MB, pdf)
• Natural Environment Regional Monitoring Network - Bay of Plenty Rivers' Water Quality 1989-2000 - J.R. Taylor and S.G. Park, Environment Bay of Plenty (2MB, pdf)
• River Invertebrate Monitoring 1991-2000 - T.K. Wilding, Environment Bay of Plenty (3MB, pdf)

Septic tanks

• On-site Wastewater Treatment System Environment Discharge Performance Appraisal For the Super Treat Aerated Wastewater Treatment System SB440 (N12) Environment Bay of Plenty (207KB, pdf)
• Setback distance between septic tanks and bathing shores of Lake Okareka Environmental Science and Research Ltd (771KB, pdf)
• Nitrogen reduction trials of advanced on-site effluent treatment systems Environment Bay of Plenty (100KB, pdf)

Stormwater

• Rotorua City: urban stormwater quality and prediction of environmental impacts: Extended summary (1.4MB, pdf)
• Rotorua City: urban stormwater quality and prediction of environmental impacts: Technical addendum (5MB, pdf)

Tourism

• Lake Water Quality Perceptions Survey 2005  - Destination Rotorua (62KB, pdf)

Water quality, monitoring and research

• Nutrient load targets for Lake Rotorua - a revisit - NIWA (127KB, pdf)
• Management of Phosphorus and Nitrogen Inputs to Lake Rotorua - J.C. Rutherford, R.D. Pridmore and E. White (1.4MB, pdf)
• An historical and contemporary review of water quality in the Rotorua Lakes - David Hamilton, University of Waikato. (336KB, pdf)
• A Statement of the Significance of Phosphorus and Nitrogen in the Management of Lakes Rotorua/Rotoiti - Jan 2004 - Technical Advisory Group (58KB, doc)
• Lake Rotorua Nutrient Load Targets (650KB, doc)
• Modelling deep chlorophyll maxima in oligotrophic lakes Lisa Chong (2.4MB, pdf)
• Okawa Bay Water Quality Study - Part One (1.3MB, pdf) / Part Two (1.2MB, pdf) D. Ray, M. Gibbs, et. al.
• Rotorua Lakes Algae Report T K Wilding, Environment Bay of Plenty (2.7MB, pdf)
• Rotorua Lakes Water Quality 2007 (2.1MB, pdf)
• The condition of twelve lakes in the Rotorua Lakes Region using LakeSPI  NIWA (550KB, pdf)
• Water level fluctuations in Lake Rotoiti and their ecological implications I. Hawe (227KB, pdf)
• Lake Tarawera Nutrient Budget (316KB, pdf)

Waterfowl

• First order estimation of the nutrient and bacterial input from aquatic birds to twelve Rotorua lakes Bioresearches (504KB, pdf)

Wetlands

• Constructed wetland treatment of streams flowing into Lakes Rotoehu and Okaro preliminary assessment C. C. Tanner (456KB, pdf)
• Lake Okareka: Ecological Functions of Marginal Vegetation and the Effect of Boat Lanes NIWA (835KB, pdf)

Other

• Lake Level and Volume Summary of the Rotorua Lakes Glenn Ellery, Environment Bay of Plenty (1.5MB, pdf)
• Rotorua Lakes Water Quality Research Bibliography Claire Millar et al. (148KB, doc)