Strategy and Policy Committee 12 March 2019
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Strategy and Policy Committee 12 March 2019 Report No. 19-29 Decision Required LAKES MANAGEMENT UPDATE 1. PURPOSE 1.1. This paper provides Council with an update on Horizons non-regulatory work programme around lakes including an overview of the lakes monitoring and research programme and lake restoration work. This report summarises information analysed in preparation for Horizons State of Environment report and also overviews recent reports completed in 2018 for Horizons to inform restoration planning for lakes in the Region. 2. EXECUTIVE SUMMARY 2.1. In 2018, the data from the regional lakes programme was analysed to inform the 2019 State of Environment (SOE) report. The regional lakes monitoring programme was introduced in 2014 expanding the monitoring programme from one lake (Horowhenua) to monitoring four lakes. In 2015 the programme was further expanded to monitor a total of 15 lakes (7%) of the 226 that are more than a hectare in size within the region. At the time this programme was introduced, Lake Horowhenua was already being regularly monitored, with a comprehensive monitoring programme to inform restoration as a part of the Lake Horowhenua Accord, however no other lakes were being monitored for Sate of Environment water quality reporting purposes. 2.2. The regional lake monitoring programme has provided a significant step forward to providing information on lakes in the region. This information was analysed and compared to water quality targets of the One Plan and new requirements of regional councils introduced via the National Policy Statement for Freshwater Management (NPS-FM) in 2011 and its amendments in 2014 and 2017. The results of this analysis are overviewed in this paper below and it is noted that the analysis is limited in terms of the representation of the state of lakes in the region due to the small number of lakes monitored and the low frequency of sampling events (quarterly sampling, rather than monthly). A review of the lakes monitoring programme is being scoped for the next financial year. 2.3. The monitoring results show that a number of the region’s lakes are in poor condition. A key finding of the analysis is that all lakes currently monitored for water quality in the Horizons Region fail to meet the national bottom line for at least one of the specified water quality attributes in the NPS-FM. Further detail is provided in the body of the report. 2.4. To date, Horizons has undertaken a range of regulatory and non-regulatory work around lakes. The regulatory programme has, through the One Plan, set water quality targets for lakes and identified some lake catchments as priority areas for nutrient management rules. Additionally, the One Plan has established non-regulatory methods for the protection and enhancement of Lake Horowhenua and other coastal lakes, as well as a method for lake quality research, monitoring and reporting. It is noted that the development of the One Plan, which was notified in 2007 predated the NPS-FM 2011 and its subsequent amendments (2014 and 2017) and that there are differences in the requirements of these policy documents. 2.5. Alongside the development and implementation of policy around lake management, there has been a range of consent and compliance work including consenting for restoration work at Lake Horowhenua and the ongoing consent process for the discharge of stormwater by Whanganui Prison to Lakes Pauri and Wiritoa. Trigger levels for Lakes Management Update Page 1 Strategy and Policy Committee 12 March 2019 groundwater abstraction in coastal sand country have also been introduced via consent processes where there is a risk of reduced flows to coastal dune lakes. 2.6. The non-regulatory programmes traditionally focussed on fencing and planting of lake margins and inflowing streams, as well as education around the potential for transfer of aquatic weeds through use of lakes for food gathering and recreation. Around 2010, the focus of these programmes shifted toward developing further understanding of lakes and how to restore them using a wider tool box for restoration options including both in-lake interventions and out of lake (catchment) interventions. Prioritisation of lakes for this science and restoration work has largely been based around the lakes that are used recreationally, the lakes that are in priority catchments for the nutrient management rules of the One Plan and more broadly, coastal dune lakes. Examples of this work are provided in the paper below including two lakes that have received significant regional investment by Council (Lake Horowhenua and Lake Waipu). In both cases Horizons, iwi/hapu, the respective local District Council’s (Horowhenua and Rangitīkei) and others, have invested as a part of a work programme receiving significant investment via Central Government. 2.7. A key part of the investment in lake restoration, including seeking external resourcing from central government, has been obtaining the monitoring and science information to develop restoration options. To assist with development of further restoration work for other lakes in the region, two Envirolink-funded reports were commissioned to review existing data for lakes and to identify knowledge gaps for restoration planning. The reports were split based on lake types using examples of a small number of deep lakes (including Lakes Pauri, Wiritoa and Dudding) and shallow lakes (including Lakes Waipu and William). It is noted that these reports do not provide detailed action plans for restoration of the lakes. Another level of planning and information is required for lake specific action plans to be developed. As such, these reports identify data and information necessary to undertake the further work of developing restoration options, and subsequent action plans. 2.8. The restoration planning reports and more recent information from the regional lakes monitoring programme shows that some of the lakes in the region are at risk of ‘flipping’. This is a process where the lake shifts from having aquatic plants to being in a state where the lake is dominated by algae, where cyanobacteria blooms can dominate. Monitoring data from both Lake Dudding and more recently Lake Wiritoa, have shown signs of the lakes progressing to flipping. This paper provides further detail and discussion around this issue for both lakes. Some further information is being gathered for these lakes prior to a meeting of lake experts to advise on the issue. An initial workshop with lake experts is to be held this financial year for Dudding Lake, with an aim to obtain recommendations around any further information that is needed, an assessment of potential intervention options, information on the degree of risk of flipping and level of urgency for action. This workshop is being developed in collaboration with Rangitīkei District Council. A similar workshop is intended for Lake Wiritoa following initial data collection. Workshop outcomes will be reported to Council. 2.9. The initial focus for the lakes programme has been around the characterisation of a small number of the region’s coastal lakes with a view to establishing their current state and initiating work around lake restoration for some lakes. The combination of the state of environment reporting and the recently completed restoration options reports has provided insights into the state of water quality in some of the regions lakes and the amount of information available to analyse this. With this information now available, the programme would benefit from a wider review to ensure that future work is aligned with both regional and national monitoring and reporting requirements, and that sufficient information is collected to inform interventions for restoration. A number of identified options for monitoring or further restoration work are identified in the reports however are outside the current capacity and resourcing of the existing programme. As a part of the work programme in the next financial year, a group of experts will be engaged to work with Horizons staff to review the lakes programme including establishing a range of options for upgrading the monitoring programme to improve overall reporting on lakes in relation to the Lakes Management Update Page 2 Strategy and Policy Committee 12 March 2019 national and regional policies and to inform potential restoration work. This will include an option to reconfigure the use of current budget and options for increased investment. The outcomes of this work will be reported to Council for consideration. 3. RECOMMENDATION That the Committee recommends that Council: a. receives the information contained in Report No. 19-29. b. endorses the proposed approach in the paper. 4. FINANCIAL IMPACT 4.1. There are no current financial impacts associated with this item. This report reflects previously endorsed budgets approved as part of Council’s annual planning and long term planning processes, and identified work programmes delivered as part of the Science and Freshwater Operational Plan’s, including use of resources from other partners such as central government. 5. COMMUNITY ENGAGEMENT 5.1. This item is a public item. Further presentation of information around lake ecological condition and water quality will be made to the public as part of Horizons State of Environment reporting during 2019. 6. SIGNIFICANT BUSINESS RISK IMPACT 6.1. No significant business risk has been identified. 7. BACKGROUND 7.1. In the Horizons region there are 226 lakes greater than one hectare in size. These range from coastal dune lakes such as Lake Wiritoa and Lake Horowhenua, through to dammed water courses found throughout the hill country to the north of the region, and volcanic lakes such as Crater Lake at Mt. Ruapehu. 7.2. Our region’s lakes, and their associated wetlands, provide for a range of community values. In addition to ecological, cultural and spiritual values, a number of lakes in the region are also popular areas for water sports, fishing and hunting and gathering of kai.