Ōtūwharekai Ashburton Lakes

In addition to the long-term lake and stream monitoring, other science investigations have also been taking place since 2019. These include continuous in-lake monitoring stations to better understand lake dynamics, continuous nitrate monitoring in Gentleman Smith Stream, and a groundwater study using piezometers in the Lake Camp/Clearwater settlement area.

DOC commissioned NIWA to assess the state of kākahi (freshwater mussels) populations in eight of the Ōtuwharekai lakes in summer 2021 (you can read the full report). Kākahi were found in all eight lakes, with their populations remaining similar for most lakes compared with the last survey (in 2012). However, there was a concerning decrease in the number of kākahi found in Lake Emily and Māori Lake West. Also, the shells of kākahi from Te-Puna-a-Taka/Lake Clearwater were in poor condition. Like the 2012 survey, there was a concerning absence of smaller kākahi in the lakes, which likely indicates that recruitment has been impacted for many years.

DOC also commissioned NIWA to undertake stream health surveys (focused on aquatic invertebrate and habitat) on multiple streams throughout the basin this past summer.

The fieldwork is complete, and the data is currently being written up with DOC hoping the surveys will help determine the current state of stream health across the basin, and also see if any changes have occurred since the previous surveys from 2008 to 2012.

A mātauranga Māori cultural health assessment, led by rūnanga, was also carried out over late summer and the results are being reviewed. This mahi enables the gathering of information from iwi, including cultural heritage and mahinga kai resource gathering, to report on the health and mauri of the freshwater environment and identify areas of focus.

All the information collected will be used to increase knowledge and understanding of the lakes, streams and wider catchment, to better inform ongoing actions to reduce nutrients.

The Ōtūwharekai Working Group provided an update on work to the Ashburton Zone Committee in July and Environment Canterbury’s Council received this update on the collective actions and workstreams to improve outcomes for the lakes, including the voluntary nutrient reductions already made by landowners (see Update 1).

Members of the group are now working on the next steps needed to significantly reduce nutrient loads, including developing a lake-by-lake land use risk analysis, which will include the required nutrient reductions to improve lake water quality. The outcome will be an agreed set of mitigation actions for farms and lakes, which will build on voluntary actions taken to date to accelerate positive environmental change in this catchment. In addition, rūnanga partners are leading work to understand the changing environment through a mātauranga lens.

Lead: Environment Canterbury

This programme includes Environment Canterbury’s long-term monitoring programmes, as well as new site-specific monitoring.

• Detailed water quality information is being collated and analysed by the science team to give a better understanding of each lake’s unique ecology and how nutrients, algae, and oxygen are interacting with each other.
• Helicopter sampling to test water quality at the Ōtūwharekai Lakes occurs between December and April each year. Monitoring takes place monthly at Lake Heron / Ō tū Roto, Lake Denny, Lake Emily, Lake Emma / Kirihonuhonu, Lake Camp / Ōtautari, Lake Clearwater / Te Puna a Taka and the Māori lakes, for nitrogen, phosphorous, algal biomass and turbidity.
• We take monthly mid-lake water quality samples at Lake Heron / Ō tū Roto (since October 2020), Lake Emma / Kirihonuhonu (October 2020–September 2021) and Lake Clearwater / Te Puna a Taka (since September 2021).
• We test the main swimming sites at lakes Lake Camp / Ōtautari and Clearwater / Te Puna a Taka for bacterial contamination weekly over the summer months. This programme is now complete for this season and data is being analysed.
• Lake Heron / Ō tū Roto and Lake Clearwater / Te Puna a Taka have continuous monitoring equipment installed, which measures dissolved oxygen and temperature, plus turbidity, and chlorophyll a at Lake Clearwater / Te Puna a Taka.

Lead: Department of Conservation and Environment Canterbury

The Department of Conservation’s stream water quality monitoring sites are illustrated in Appendix 1 (PDF file, 1.81MB). The lake catchment boundaries are delineated in blue and are associated with Lake Heron, Māori Lakes, and Lake Clearwater. Sites shown as red points have been sampled since 2012, while sites in green have been sampled since December 2019. In addition,

• DOC has commissioned NIWA to undertake stream health sampling (aquatic invertebrates) of streams in Ōtūwharekai. This work is ongoing and is due for completion by the end of 2022.
• A report on Kākahi (freshwater mussel) populations is publicly available on the DOC website and it provides a commentary of the lake surveys that have been undertaken.

Environment Canterbury added a new continuous nitrate logger was installed at Gentleman Smith Stream in October 2021.

Lead: Environment Canterbury with Ashburton District Council

In late February, a series of shallow monitoring bores were installed between Lake Camp/Ōtautari and Lake Clearwater/Te Puna-a-Taka to monitor ground water levels and determine rates of water movement between these water bodies. In addition, monthly water quality sampling is being undertaken of the groundwater.

This monitoring will inform understanding of the effects of the settlement on groundwater quality being received into Lake Clearwater / Te Puna a Taka and the effectiveness of ADC’s programme to decommission long drop toilets.

Lead: Environment Canterbury

Environment Canterbury and landholders are working together to identify high nutrient loss areas and the mitigation options to reduce nutrient loss.

All four farms are working together on a holistic approach for the whole catchment.

Lead: Aoraki Environmental Consultancy and mana whenua

Arowhenua rūnanga have been leading the work on the cultural health monitoring in the catchment.

Arowhenua have applied to Ministry for the Environment for funding to support ongoing Mātauranga Māori monitoring in the catchment.

Lead: Toitū te Whenua (LINZ)

The Crown Pastoral Land Reform Bill has now been passed and has received royal ascent. LINZ is currently working through the implementation of the Bill and what this will look like in terms of LINZ administration. Tenure review has formally ended for all those without a substantive proposal put to them.

• LINZ has begun consultation on proposed regulations and standards to support the implementation of the Crown Pastoral Land Reform (CPLR) Act which will come into effect on 17 November 2022
• LINZ has worked closely with our Treaty partners, High Country Accord, High Country Advisory Group, and the Department of Conservation to develop the proposed regulations and standards.
• LINZ is seeking feedback to ensure the regulations and standards are robust and workable while supporting the outcomes of the CPLR Act.
• Consultation on the proposed regulations and standards closes Friday 19 August 2022.

More information, including how to make a submission, is available on the LINZ website.

The proposed regulations include prescribing the information required for consent applications, matters the Commissioner of Crown Lands (Commissioner) must consider in deciding the level of adverse effects of a pastoral activity on inherent values, and infringements.

Two new standards have also been proposed:

• A standard set by the Commissioner for accessing applications for easements, transfers, and subleases of Crown land pastoral land.
• A LINZ Chief Executive Standard providing a framework for the Commissioner to follow when considering applications for discretionary pastoral activities, commercial recreation permits and stock exemptions.

LINZ is holding a series of sessions over the coming weeks for leaseholders and the public to attend to ask any questions they may have. This will be promoted shortly and details will be available on the LINZ website.

Lead: Ashburton District Council

This public consultation was undertaken earlier this year to inform the creation of a future strategy for the hut settlement and recreation around Lake Clearwater and Lake Camp. Feedback from more than 150 people who shared their views on the future of the area was received.

The draft plan was subsequently shared with the Ōtūwharekai Working Group agencies for feedback in June recognising that the discussion through Ōtūwharekai Working Group meetings also informed aspects of the plan content.

The plan will go to the Ashburton District Council meeting on 27 July 2022 and the working group members will be involved in implementation as appropriate going forward.

Lead: Central South Island Fish and Game

Central South Island (CSI) Fish & Game currently undertake an annual survey in late January/early February of paradise shelduck and black swan within the Ōtūwharekai area. 

More detail around this programme of work is provided in Appendix 2 (PDF file, 1.81MB).

Lead: Department of Conservation and Toitū te Whenua (LINZ)

Canada geese were monitored by CSI Fish & Game annually in June/July between 1986 and 2010. Counts were undertaken using the same method as for paradise shelduck and black swan.

In 2011 Canada geese were removed from the schedule 3 (game) and placed on schedule 5 (unprotected wildlife) and as a result annual surveys for the species ceased.

Earlier this year LINZ, DOC and landholders co-ordinated efforts on controlling geese populations in Ōtūwharekai

Lead: Multiple agencies

ADC, ECan and DOC are all agencies that all have some regulatory role on the impact and effects of the inappropriate use of Four-Wheel Drive vehicles (4WD), either in the environment or on their respective land.

Inappropriate 4WD use also impacts farmers in the area and it clashes with the values that other groups or individuals have in utilising this environment.

We recognise that this issue is not unique to Ōtūwharekai and that there are some very real challenges to implementing compliance actions. We will continue to work together and communicate non-acceptance of inappropriate use of these vehicles.

Lead: Department of Conservation

The Department of Conservations has an ongoing programme of work relating to the control and plant pest species on its land. This also includes the control of willow species.

Lead: Ashburton District Council

In 2021 ADC began a programme of work to decommission all long drops in the Clearwater settlement area. This has now been completed.

Lead: Multiple agencies

Communications staff from across the crown agencies and Ngāi Tahu meet online monthly. A key focus has been creating website information and updating each other on the progress of the work taking place to share with stakeholders.