BEFORE THE CANTERBURY REGIONAL COUNCIL IN THE MATTER of the Resource Management Act 1991 AND IN THE MATTER of Proposed Plan Change 5 to the Canterbury Land and Water Regional Plan _______________________________________________________________ STATEMENT OF EVIDENCE JEFFREY ALLEN PAGE ON BEHALF OF MERIDIAN ENERGY LIMITED 22 JULY 2016 _______________________________________________________________ ________________________________________________________________ ANDERSON LLOYD Level 10, Otago House LAWYERS Cnr Moray Place & Princes DUNEDIN Street, Private Bag 1959, Solicitor: S W Christensen DUNEDIN 9054 ([email protected]) DX YX 10107 Tel 03 477 3973 Fax 03 477 3184 INTRODUCTION Qualifications and Experience 2 My name is Jeffrey Allen Page. 3 I am employed by Meridian Energy Limited (“Meridian”) as its Environmental Strategy Manager. In this role I am responsible for managing a team focussed on obtaining, retaining and achieving compliance with the necessary statutory environmental authorisations for Meridian’s existing assets and new projects. As part of this role, I have a particular focus on the environmental management of the Waitaki Power Scheme. I have been employed by Meridian since October 2010. 4 I hold academic qualifications1, institute membership2 and experience3 as a professional resource management planner. I have provided expert evidence as part of many hearing processes, including before the Environment Court. I have also participated in a large number of resource management policy and plan development and implementation processes within Canterbury, including those relating to the Waitaki catchment. 5 I am not making this Statement as a planning expert. Rather, this statement is made as Meridian’s Environmental Strategy Manager. This means that this brief is a statement of fact as opposed to a statement of expert opinion. Scope of Evidence 6 In my statement I outline: (a) Meridian’s interest in water quality in the Waitaki Catchment; (b) The circumstances in which adaptive management or monitoring and response conditions are applied in Upper Waitaki consent processes; and (c) The water quality monitoring points Meridian seeks. 7 In this evidence, when I use the term: 1 BSurv (dist) and MRRP (dist), Otago University 2 MNZPI 3 I have worked as a professional planner in a number of local government and private practice roles since 1992. 1 (a) “Waitaki Power Scheme” I mean the lakes, canals and infrastructure of the entire Scheme, irrespective of whether it is managed by Genesis Power Limited (Genesis) or Meridian. Ownership of the Waitaki Power Scheme is as follows: (i) Genesis owns and operates the two Tekapo Power Stations, and associated canals, dams, lake control structures and other infrastructure, upstream of the tailrace of Tekapo B Power Station. These Power Stations are Tekapo A and Tekapo B. (ii) Meridian owns and operates six Waitaki Power Stations, and associated canals, dams, lake control structures and other infrastructure, from Lake Pukaki downstream to the Waitaki Dam. These Power Stations are: Ohau A, Ohau B, Ohau C, Benmore, Aviemore and Waitaki. Meridian’s interest in water quality 8 In this section of evidence I summarise Meridian’s interest in water quality within the Waitaki Catchment. This is to provide context for Meridian’s involvement in Plan Change 5. 9 The Waitaki Power Scheme has changed characteristics of water bodies in the Waitaki Catchment. In overview terms, as shown in Appendix 1: (a) Natural lakes are now managed as storage lakes – Lakes Tekapo (raised), Pukaki (raised) and Ohau (operated largely within its natural range); (b) Artificial lakes have been created by damming natural rivers – Lakes Ruataniwha (including the Wairepo Arm), Benmore, Aviemore and Waitaki; (c) Rivers have been modified: (i) By diverting the main4 source flows, except for spill flows – Tekapo, Pukaki and Lower Ohau rivers 4 Flows from Lake Tekapo, Pukaki and Ohau (via Ruataniwha). Below these lakes, there are a number of important tributary flows, such as the Forks Stream in relation to the Tekapo River. In addition, these rivers are used to manage ‘spill’ from the lakes, receive water when gates are tested and to provide periodic flows for the purposes of recreation (kayaking). 2 (ii) By mixing water higher in the catchment than would have occurred naturally – Lakes Tekapo and Pukaki water is generally mixed in Lake Pukaki (at the Tekapo B Power Station tailrace) instead of the confluence of the Tekapo and Pukaki rivers, and Lakes Pukaki and Ohau water is mixed at the confluence of Pukaki and Ohau canals and the confluence of Ohau A tailrace and Upper Ohau River instead of at the confluence of the Waitaki River (now dammed) and Ohau River. (iii) By changing flow characteristics – Upper Ohau River and Lower Waitaki River; (d) Smaller artificial water bodies have also been created – including Lake George Scott, Patterson Ponds, Lake Wardell, Lake Poaka, Lake Merino, Loch Cameron, Kellands Pond, Tomahawk Lagoon; and (e) The above, together with the Waitaki Power Scheme canal system, has undoubtedly modified the contribution of surface water to groundwater and groundwater flows. 10 In the context of Plan Change 5, as outlined above Meridian influences water quality not by introducing contaminants into the environment, but by altering the path and timing of natural movement of water through the Waitaki Catchment. 11 In addition, other influences have emerged within the Catchment that relate to the achievement of water quality outcomes: (a) Agricultural land use has intensified, resulting in increased nutrients in the receiving environment; (b) Activities such as aquaculture have commenced and expanded, resulting in new and increased nutrients in the environment; and (c) Invasive aquatic plants have established in the Catchment5. 12 Meridian’s operation of the Waitaki Power Scheme is both directly and indirectly influenced by water quality within the Catchment. The direct operational consequences of the changes in water quality arise from 5 Elodea, Lagarosiphon which first appeared in February 2003, and didymo which appeared in approximately 2006. 3 increased aquatic plant growth. This increases the costs of the management of the Waitaki Power Scheme through increased aquatic weed management and civil engineering responses (such as the installation and operation of further screens on intakes). At present Meridian: (i) Manages and cleans intake screens in the Ohau B and C power stations. This activity has been undertaken since at least 2009. Currently, the top part of the screens are raked about 3 times per year by Meridian staff and the bottom part cleaned by contracted divers6 annually or less as need arises. It is estimated that approximately 5m3 of weed is removed from the Ohau B Station screens and 4m3 per year from the Ohau C screens. The annual cost of this activity is $30,000; (ii) Is planning to replace and upgrade the Ohau B and C power stations screens. Aquatic weed is currently causing the screens to bend by creating water resistance, hence hydraulic pressure. This both shortens the life of the existing screens and represents an unacceptable failure risk of the screen breaking and debris being transported through generators. The replacement will provide for more effective screen cleaning. The cost of this project is currently estimated at $1.3M to $1.5M; (iii) Undertakes removal of aquatic weed within its canals. Meridian is observing weed mats floating down its Ohau B and C canals, and increased weed presence in the Pukaki/Ohau Canals confluence area. Aquatic weed removal (generally by Diquat spraying, to date), began as a systematic programme in 2011, although more ad hoc activity occurred prior to this. Currently this has an annual cost of approximately $30,000 to $50,000; (iv) Partners with Land Information New Zealand (LINZ) on a yearly basis to control lagarosiphon in Lake Benmore in order to avoid, or at least, slow its spread in relation to 6 This requires flow in the canals to be considerably reduced to create safe diving conditions. 4 Benmore, Aviemore and Waitaki Power stations. This partnership began in the mid-2000s. Currently this has an annual cost to Meridian of between $175,000 and $200,000; and (v) In partnership with LINZ, Environment Canterbury and Genesis, is undertaking aquatic weed (including didymo) surveillance throughout the Upper Catchment. Currently this has an annual cost to Meridian of approximately $40,000. 13 Meridian is concerned that as water quality decreases, it may be required to change the way it manages7 river flows and lake levels in order to remedy or mitigate the consequences of degraded water quality, such as periphyton. It anticipates this may result in requirements for flushing flows and manipulation of water flows through lakes. Ultimately, this reduces generation potential and generation flexibility. 14 The indirect consequence is decreasing water quality may erode the community benefits of the Waitaki Power Scheme by decreasing the amenity, sports fishery habitat and recreation suitability of rivers and lakes. For Meridian, it is concerned that a diminishment of these local benefits may change the perception of what might be judged as a ‘fair’ outcome within the Catchment from the existence of the Waitaki Power Scheme. 15 In response to the above, and the allocation of water for increased agricultural intensification8, Meridian has worked to understand the potential for water quality change within the Upper Catchment. This