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Report to the Minister for the Environment on Lake Rotoiti and other Rotorua lakes

5 September 2003

Summary

The water quality and oxygen levels in Lake Rotoiti are poor and some have concerns that the lake will collapse this summer. Environment Bay of Plenty and Rotorua District Council are working constructively together towards producing a plan to hold steady the nutrients that feed the algal bloom and investigating short-term action to deal with the symptoms of degraded water quality. Local community action groups are concerned that the councils are doing the right things but appear to have insufficient urgency. Farmers, including managers of Maori tribal lands, consider that proposed action to reduce nutrient inflows will restrict their ability to use and develop their land when farming run-off is not the only cause of the problem. There are no quick, cheap and easy solutions to the problems with the Rotorua lakes, but they are nationally important for tourism and recreation. We believe that the issue is important enough for central government to be informed and consider possible responses.

Action sought

We recommend that you:

  1. Agree to meet with representatives of Environment Bay of Plenty in Wellington soon to discuss the situation at Lake Rotoiti and other Rotorua lakes
  2. Note that the Ministry intends to ask the Working Group on the Water Programme of Action to include the Rotorua lakes among the issues they are working on
  3. Agree the Ministry contracting an expert in managing degraded lakes to advise and assist Environment Bay of Plenty in managing the short-term symptoms
  4. Note that the Ministry intends to discuss with Environment Bay of Plenty options for the Sustainable Management Fund to support a community programme of action
  5. Note that the Ministry will discuss with you further central government involvement once Environment Bay of Plenty has completed its investigations and has a proposed action plan for Lakes Rotorua-Rotoiti
  6. Agree to the release of this report to the key stakeholders.

Purpose

1. The Lakes Water Quality Society, Environment Bay of Plenty and others have written to you about the wide public concern caused by the algal bloom on Lake Rotoiti earlier this year. The Local Government and Environment Select Committee also raised concerns about the condition of the lake. This paper reports on a Ministry investigation during which we talked to key stakeholder groups and suggests options for Ministry involvement.

Background

2. There are eleven major lakes around Rotorua. Several of the lakes have suffered water quality problems for decades and the situation appears to be getting worse. The fundamental problem is excess nutrients (nitrogen and phosphorus) stimulating algal growth, cyanobacteria blooms and weed growth. Concerns grew when Lake Rotoiti, one of the major trout fishing and recreational lakes in the North Island, was entirely closed last summer for swimming. The severe cyanobacteria blooms on Lakes Rotoiti and Rotorua have received considerable media attention. There are concerns that Lake Rotoiti will become anoxic (lose its remaining oxygen) in the next year or two and that all life in the lake will die.

3. The regional and district councils have been criticised by community groups for lack of urgency in dealing with the problems and lack of cooperation. There have been calls from various parties for more substantial central government involvement. The Parliamentary Commissioner for the Environment has been following the issue and is committed to an investigation into ‘how can we actually move forward’.

4. Rotorua is the largest settlement on a lake in this country. For many years the sewage from Rotorua city was disposed of in Lake Rotorua, which is connected to Lake Rotoiti by the Ohau Channel. In the late 1980s central government provided $30 million to assist in diverting the sewage to land treatment. Since then the nutrients in Lake Rotorua water have reduced significantly, but the sediments in both lakes still contain high levels. The algal bloom in Lake Rotoiti is fed by nutrients from a range of sources, including the lake sediments, farm run-off, septic tanks (most of the settlements around the lakes are not yet connected to a sewerage system), and groundwater (which can take some decades to reach the lakes).

5. Environment Bay of Plenty says that the flow through the Ohau Channel from Lake Rotorua contributes more than 70 percent of the nutrients to Lake Rotoiti. For about half the year water from Lake Rotorua travels up to six kilometres up Lake Rotoiti, spreading nutrients up the lake. Over the last few years the depth down to which dissolved oxygen reaches in Lake Rotoiti has reduced year by year, so that the lake is close to losing the oxygen necessary to sustain fish and other life. The climate last summer had a strong influence on the algal bloom – similar warm weather this summer would increase the risk of the lake collapsing. The bloom generally starts about November.

Perspectives of key stakeholders

Local government

6. We spoke to political leaders and senior staff of:

  1. Environment Bay of Plenty
  2. Rotorua District Council

7. Environment Bay of Plenty is responsible for 11 lakes in the Rotorua area, of which five are below the target quality set in the proposed regional land and water plan. Some lakes have algal blooms every year. Action plans are being or will be developed for the five degraded lakes and working groups of key players are planned to help implement the action plans. Lake Okareka is a pilot for this work – Lakes Rotorua and Rotoiti are a much more complex problem with many questions still to be answered. The councils see the problem of restoring these lakes to a healthy state as pushing the boundaries of scientific knowledge.

8. The action plans to reduce nutrient flows into the lakes are likely to include a combination of retiring riparian land, changing land use, establishing wetlands and installing sewerage connections. To help reduce the nutrients going into the lakes, Environment Bay of Plenty has included “Rule 11” in its proposed regional land and water plan. This rule would limit any new development or farm intensification that might increase the nutrients flowing into the five lakes. (A decision on Rule 11 is expected by the end of the year.) These proposals are long-term solutions – they may help prevent the lakes getting worse but they will not improve the water quality for many decades.

9. As short-term “first aid” for Lake Rotoiti, Environment Bay of Plenty is also investigating and costing engineering solutions such as diverting water from the Ohau Channel directly down the Kaituna River to reduce the flow of nutrients from Lake Rotorua into Lake Rotoiti, water treatment options such as aeration, and chemical solutions such as activated clay treatment to reduce release of nutrients from the sediment. These options are expensive and there is a risk that they may not work. Before they spend money, the councils want to be sure that they will improve the situation, not make it worse. Staff expect to put recommendations to their councils by the end of the year.

10. Both the political leaders and the senior staff of both councils told us that they are working well together. They have appointed a Senior Manager at Environment Bay of Plenty, Paul Dell, as their coordinator of action on the lakes. Research for the regional council is being carried out by council staff, NIWA and Waikato University.

11. Environment Bay of Plenty has endowed a Chair in Lakes Water Quality and Management at the University of Waikato, currently held by Professor David Hamilton. He and his students have been carrying out research on the Rotorua lakes. This research appears to have the strong support of both the regional and district councils and the community action groups. They are concerned that Professor Hamilton’s application to the Foundation for Research, Science and Technology for research funding was turned down, even though it would have direct application not only in Rotorua but also for other lakes facing similar problems. The Foundation has also cut funding for research by Geological and Nuclear Sciences into groundwater flow and age assessment, which would also have been useful. (However, other Crown research institutes have received new funding to address nutrient losses from land to water.)

12. The councils are very aware of central government involvement with action to improve water quality in Lake Taupo and hope for similar assistance with the Rotorua Lakes. They believe that the Rotorua lakes are also of national importance and that the problems with the lakes are greater than local government alone can deal with. They have been aiming to get all of their research and investigations completed before formally approaching central government for assistance, probably in March 2004, by when they expect to have a comprehensive plan.

Community groups

13. We spoke to representatives of:

  1. Lakes Water Quality Society
  2. West Rotoiti Action Group
  3. Lake Rotoiti Ratepayers and Residents Association
  4. Lake Okareka Residents Association
  5. Mourea Okawa Bay residents group

14. The members of the community groups are mainly residents in settlements around Lake Rotoiti and other degraded lakes. While Lake Rotoiti is their main concern at present, they see its problems as part of a general trend in the Rotorua lakes. They are distressed about last summer’s closure of an important recreational lake because of health risks and see a high risk of the lake collapsing next summer – when all fish and other life would die from lack of oxygen and the lake would become smelly and unpleasant to live near. They regard this situation as a national environmental emergency.

15. The community groups recognise that halting the degradation of the Rotorua lakes is a major challenge, let alone restoring them. They know that the possible solutions to the problems are difficult, both technically and politically – they affect people’s property rights and are likely to be expensive. However, the community groups claim that the response by the councils to the crisis in Lake Rotoiti has been ‘grossly inadequate’, lacks urgency, and has been marred by a history of tension between the regional and district council.

16. The community groups know that it will be March before the councils’ proposals for an action plan are ready for consultation, and even longer before action gets under way. The experience of those already involved in the Lake Okareka action plan does not give them confidence that they will see something happening soon to improve Lake Rotoiti.

17. The solutions proposed by the Lakes Water Quality Society are appointment of a co-ordinator to drive all lakes projects, the regional council to make an immediate start on the action plan for Lakes Rotorua and Rotoiti, the district council to reduce nutrient inflows from stormwater and sewerage, and urgent investigation of water treatment and engineering solutions. They also want central government involvement, both organisationally and financially, as with Lake Taupo.

Faming interests

18. We spoke to farming and landowning interests in the area, including people from:

  1. Federated Farmers
  2. Ngati Whakaue Tribal Lands
  3. Te Arawa Federation of Maori Authorities

19. There is a significant amount of agriculture in the catchments of Lakes Rotorua and Rotoiti. The farmers told us that agriculture and forestry represents 56 percent of the local GDP (compared with tourism at 14 percent). Much of the land in the catchment is Maori-owned, some of it well-developed farmland and some still in gorse and scrub but with development potential. The views of Maori farming interests are similar to those of other farmers.

20. The farmers told us that most of the waterways running into the lakes are already fenced off, farmers have carried out riparian planting and 75 percent have effluent systems that comply with the regional council’s requirements. (Much of the fencing was subsidised by central or local government.) The farmers are willing to work with Environment Bay of Plenty to develop nutrient budgets that will help farmers to manage their impacts on water quality.

21. The farmers are concerned that no-one has yet asked what standard of water quality is acceptable to people in the region and what level of impact on the local economy is acceptable to achieve a higher quality. They have reservations about the scientific modelling used to underpin proposals such as Rule 11 and want the science to be peer-reviewed. They are very concerned that the impact of septic tanks on nutrients in the lakes has not been recognised or dealt with (eg, at the last inspection five years ago, 71 of 108 septic tanks in Mourea/Okawa Bay failed. This area of the lake is among the worst in terms of water quality). The farmers support the macro-economic research that has recently been commissioned by the regional council. Farmers are also engaging consultants to assess the impact of Rule 11 on their future income. They, and the district council, see a risk of Rule 11 reducing district economic output.

22. Overall, the farmers feel that all parties need to recognise their contribution to the problems in the lakes, rather than expecting farming families and Maori landowners to carry an unfair share of the burden. Equity is a key issue for them. If Rule 11 is modified, as requested by the district council, to exclude septic tanks and residential areas, it would become an agricultural rule. It would then constrain further development, such as switching to dairying and limit economic use of the undeveloped Maori land, but not limit subdivisional development. The farmers would appeal against the rule, and would ask for compensation for the loss of potential future earnings. (Legal analysis undertaken for our Lake Taupo work shows that compensation is not payable under the Resource Management Act for this type of land use restriction. Such rules, however, face compliance challenges.)

Te Arawa Maori Trust Board

23. The Crown is currently involved in Treaty of Waitangi Settlement negotiations with Te Arawa for claims to the lakes. The Trust Board is part of a joint Rotorua Lakes Management Strategy with Environment Bay of Plenty and Rotorua District Council, but has not really participated because of the Rotorua lakes Treaty claim. However, the Trust Board is committed to the relationship with local government and wants to be part of an ongoing partnership. They are concerned about the quality of the Rotorua lakes and suggested that the issues be managed locally as much as possible.

24. In addition to the stakeholder groups above, we also spoke to Steve Chadwick, MP for Rotorua, three senior scientists from NIWA who have expertise in lakes, and local journalists.

Our observations

25. There is a good chance that Lake Rotoiti will lose much of its remaining oxygen this summer. If this happens, the fish and all life in the lake will die and it will become an unpleasant and smelly place. However, there is no simple, quick or cheap solution to the problems with Lake Rotoiti and other stressed lakes in the Rotorua area.

26. The issue of Lake Rotoiti is one for the regional and local people to manage – but the lakes are nationally important for tourism and recreation. The problem of land use impacts on lakes water quality is nation-wide. The local people have legitimate concerns that the problems are so pressing that the councils cannot wait for a normal Resource Management Act timeframe to deal with the causes of the problems.

27. We consider that the political leaders and senior staff of Environment Bay of Plenty and Rotorua District Council are working constructively together to address the problems with the lakes. They intend to have a proposed ‘response plan’ for Lakes Rotorua and Rotoiti ready by March 2004.

28. The councils need to manage both reducing nutrients in the lakes in the long term and the short-term symptoms such as loss of oxygen. It is likely that the proposed response plan will preserve the status quo but not cure the problems. While the plan will be based on the best available science, science will not be able to give a firm recipe for a cure. Effective action to solve the lake problems will require a major effort. All sources of nutrients, particularly intensive sources, will need to be managed. Local government needs to move as quickly as possible to install a sewerage system that will control the problem of septic tanks near Lake Rotoiti. We have already expressed our general support for Rule 11 through a statutory submission.

Options for central government involvement

29. Environment Bay of Plenty is keen to brief you about the issues with the Rotorua Lakes and the work that they and Rotorua District Council are undertaking to address the problems. They have offered to come to Wellington to meet with you. We understand that you have agreed to this meeting.

30. Options for the Ministry to become involved in the process include:

  1. Meeting regularly with Environment Bay of Plenty and the Rotorua District Council to monitor progress with their investigations and discuss further central government involvement
  2. Asking the Working Group on the Water Programme of Action to include the Rotorua lakes among the issues they are working on
  3. Engaging an expert in managing degraded lakes to advise Environment Bay of Plenty on managing the short-term symptoms in the lakes. We know experts who have managed similar situations in Australian lakes.
  4. Commissioning work on identification of alternative low nutrient/high return land uses and sharing similar work undertaken at Lake Taupo
  5. Providing support through the Sustainable Management Fund for a community liaison and action programme similar to the landcare-type activity undertaken by the Taieri Trust in Otago.

A number of these options will require significant resources.

Recommendation

I recommend that you:

  1. Note the views of the stakeholder groups as outlined above and the Ministry’s observations on our discussions with them
  2. Agree to meet with representatives of Environment Bay of Plenty in Wellington as soon as possible for a briefing on the situation at Lake Rotoiti and to discuss central government involvement
  3. Note that the Ministry intends to ask the Working Group on the Water Programme of Action to include the Rotorua lakes among the issues they are working on
  4. Agree to the Ministry contracting an expert in managing degraded lakes to advise and assist Environment Bay of Plenty in managing the short-term symptoms
  5. Note that the Ministry intends to discuss with Environment Bay of Plenty options for the Sustainable Management Fund to support a community programme of action
  6. Note that the Ministry will discuss with you further central government involvement in this issue once Environment Bay of Plenty has completed its investigations and has a proposed action plan for Lakes Rotorua-Rotoiti
  7. Agree to the release of this report to the key stakeholders.

 

Barry Carbon
Chief Executive

Last updated: 6 January 2009