Kakanui River morphology and riparian management strategy Version 1.0 – October 2015 1 Overview The Kakanui River morphology and riparian management strategy has been prepared by Otago Regional Council (ORC), with input from the local community, to help protect the recreational, cultural and ecological values of the Kakanui and Kauru riverbeds, and to enable long-term, sustainable use of the land which borders the river. The strategy, as summarised in the two diagrams below, is intended to help achieve this by guiding work programs, decision-making and activities, for the community, stakeholders, and ORC. It is therefore recommended that people who live, work or play within the Kakanui catchment consider, and give effect to the principles, objectives, and actions listed in this strategy. The strategy is not a statutory document; rather it is intended to present the aspirations of the community and the various stakeholder agencies. However, the statutory processes which do influence river management activities1 are more likely to be used effectively and efficiently if there is a general consensus on what is valued about the river, and commonly understood objectives. The strategy is intended to be a living document, which will evolve in response to new information, changes in the environment, the needs of the community and the work of ORC and other stakeholders. The strategy will be reviewed regularly, and this process will involve landowners with property alongside the river, other stakeholders and ORC,2 and will help to set priorities and work programs for all of these groups. The strategy document will also record progress made towards achieving the stated objectives. It is intended that version 2 of the strategy will include further guidance and plans for undertaking planting on riparian margins, for river management purposes and for habitat enhancement. 1 Including the Local Government Act (in regards to funding considerations), and the Resource Management Act (in regards to managing environmental effects) 2 In particular, staff with responsibilities for rivers and waterway management and natural hazards 2 Kakanui River Morphology and Riparian Management Strategy - Overview Purpose To provide guidance to landowners, stakeholders, and the community for good decision-making and appropriate activities within the riverbed and riparian margins of the Kakanui and Kauru rivers. Vision The long-term sustainable use and enjoyment of the Kakanui and Kauru rivers and their riparian margins. Functions The wise use of resources to: manage the risk to property Appropriate guidance and and assets active engagement to empower enable sustainable gravel good decision-making and extraction to ensure that activities are Facilitation Investment protect and enhance undertaken in a sustainable community values and appropriate manner improve community resilience. Understand natural river A shared vision of the rivers processes and morphological information Certainty values and features to be characteristics, and the potential utilised, preserved and effects of those on the river and enhanced. its margins. 3 Objectives & associated actions (these are further refined in Section 7 - implementation) 1 2 3 4 Recognise and Equip the community to Enable sustainable Promote activities that characterise natural live with the effects of gravel extraction enhance the natural river processes changes in river character and morphology enjoyment of the river Collect information Promote land-use Identify areas where Provide maps showing about flood and practices and the gravel accumulation the location and erosion processes. placement of assets can naturally occur. characteristics of Report on changes which reduce the Identify areas where features which are in channel risk associated with permanent removal of high value to the morphology. changes in riverbed of gravel may have community. morphology Provide information a detrimental effect Encourage the to the community. Consider all available on assets, riverbed establishment of options to manage morphology or riparian plantings Identify the location theeffects of bank community values. that are practical and of river corridors, erosion, including appealing. within which the Identify minimum bed structural and non- river will naturally levels/profiles, below Provide access and structural options. meander. which extraction will habitat for fishing and Enable works not occur. whitebaiting activities. that will, where Support pest and necessary, improve weed control activities. the conveyance of Discourage dumping, floodwater and ‘train’ and arrange the the river within its regular collection of natural corridor, without rubbish. compromising the features which are of high value to the community. 4 5 Contents Overview ...................................................................................................................................................................................................................................................................1 1. Introduction ............................................................................................................................................................................................................................................6 1.1 Report outline ......................................................................................................................................................................................................................7 2. Scope ............................................................................................................................................................................................................................................................12 2.1 Geographical .................................................................................................................................................................................................................... 12 2.2 Risk................................................................................................................................................................................................................................................... 12 2.3 Strategy development ...................................................................................................................................................................................... 14 3. Environment setting ............................................................................................................................................................................................................ 14 3.1 Geological setting .................................................................................................................................................................................................... 14 3.2 Geographical setting ........................................................................................................................................................................................... 17 3.3 Meteorological setting ...................................................................................................................................................................................... 18 3.4 Hydrological setting .............................................................................................................................................................................................. 18 3.5 Riverbed morphology ........................................................................................................................................................................................ 21 3.5.1 Kakanui River ............................................................................................................................................................................................ 21 3.5.2 Kauru River ................................................................................................................................................................................................... 26 3.6 Riparian margins ........................................................................................................................................................................................................ 28 3.7 Community setting ................................................................................................................................................................................................. 29 3.7.1 Ecological values ................................................................................................................................................................................ 29 3.7.2 Community values and feedback ........................................................................................................................... 30 3.7.3 Maori cultural values ..................................................................................................................................................................... 31 3.7.4 Gravel extraction ................................................................................................................................................................................. 31 4. Legislative context................................................................................................................................................................................................................