Hoteo River Catchment: Environment and Socio-economic Review August 2014 Technical Report 2014/021 Auckland Council Technical Report 2014/021 ISSN 2230-4525 (Print) ISSN 2230-4533 (Online) ISBN 978-1-927302-31-6 (Print) ISBN 978-1-927302-32-3 (PDF) This report has been peer reviewed by the Peer Review Panel using the Panel’s terms of reference Submitted for review on 6 June 2014 Review completed on 8 August 2014 Reviewed by two reviewers Landcare Research review by Andrew Fenemor, Scientist and Programme Leader, Soils and Landscapes Team Approved for Auckland Council publication by: Regan Solomon Manager – Research Investigations and Monitoring Unit Date: 8 August 2014 Recommended citation: Hart, G and Scott, K (2014). Hoteo River catchment: environment and socio-economic review. Prepared for Auckland Council by Landcare. 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Hoteo River Catchment: Environment and Socio-economic Review Georgina Hart Kathryn Scott Landcare Research Landcare Research contract report LC1761 Executive summary Project and client The Hoteo catchment, one of the Auckland Council Sustainable Catchment Programme’s (SCP) rural catchments, has been prioritised for management with a focus on community initiatives to restore ecosystems in and around streams and rivers to limit erosion and sedimentation and to improve water quality. The Hoteo catchment has been selected as a priority catchment primarily because of the threat posed by river sedimentation to a key snapper breeding ground – sea grass beds situated in the Kaipara Harbour close to the mouth of the Hoteo River. This report has been prepared for Auckland Council as part of the SCP. The aim of this project was to review and collate available environmental and socio- economic information for the Hoteo catchment; assess current and potential future issues for the catchment; and consider key knowledge gaps and future needs for sustainable catchment management. This review is designed to inform 10-year rural plans and 1 to 3- year project plans being developed under the SCP. This report establishes the current biophysical, cultural, social, and demographic conditions in the catchment, and aims to identify current and future issues and key knowledge gaps in terms of biophysical and socio-economic information regarding the Hoteo catchment. Geographic Information System (GIS) mapping and combinatorial analysis have formed an important part of investigations underpinning this report. Background description: Hoteo catchment Set within the Auckland regional context, the Hoteo catchment is a 405km2, geographically diverse rural catchment predominantly in pastoral agriculture and exotic forestry that drains to the Kaipara Harbour. The original land cover of the catchment has been highly modified. Loss of indigenous biodiversity has occurred as forests have been cleared and wetlands drained. Remaining streams, rivers, wetlands and forest provide critical habitat for indigenous plants and animals, some of which are regionally or nationally threatened. Hoteo landscapes also provide for multiple recreational uses. The catchment has very low population density and a small resident population of around 2500. Most catchment residents are self-employed in the agricultural sector, with a smaller number working in a range of service sectors, mostly in Wellsford. Wellsford is the only town in the area, of which part falls within the Hoteo catchment. The land’s productive capacity underpins the local rural economy. Traditional pastoral agriculture in sheep, beef, and dairying dominates the landscape. More recently, there has been an increase in recreation and tourism sector activities in the catchment and rural subdivision for lifestyle blocks has increased population in the catchment away from Wellsford. __________________________________________________________________________________________ Hoteo River catchment: environment and socio-economic review i Key issues and knowledge gaps Degradation of water quality and soil quality, loss of biodiversity, flood risk, risks to cultural heritage, and a number of social and cultural issues have been identified for the Hoteo catchment. Knowledge gaps have been identified in the areas of water quality, indigenous biodiversity, cultural heritage, community knowledge and land use and management. Recommendations The following summary of recommendations has been developed in collaboration with SCP staff at Auckland Council, suggesting options for addressing identified issues and filling knowledge gaps. 1. Governance • Collaborate with relevant governance bodies of the Kaipara and Hoteo catchments • Acknowledge and ensure management is consistent with relevant Treaty settlement legislation • Identify and integrate with other work steams and projects in the Hoteo catchment • Include and respond to the relevant policies and strategies that relate to environment, land use biodiversity etc. 2. Erosion and sediment management • Develop more comprehensive estimates of sediment yields and sources • Target intervention for reducing sediment yield along the lower reaches of the Hoteo River and associated steep pasture land, and build on the work of Buikema (2012) to prioritise areas for riparian management • Investigate the risks of algal proliferation that could result from reducing sediment levels in the river 3. Indigenous biodiversity • Support and/or establish work to identify inanga spawning grounds and opportunities to protect and enhance them (working with the relevant biodiversity staff at Auckland Council) • Incorporate indigenous biodiversity management into sediment management programmes (e.g. riparian management could be designed to also enable protection of inanga spawning grounds; stabilisation plantings could include native species) 4. Cultural heritage and socio-economic • Establish a project that creates opportunities for mana whenua and residents to document and share their stories, and draw on this knowledge in catchment management and conservation efforts • Assist with the prioritisation and/or resourcing of an archaeological survey for cultural heritage sites in this area (working with the relevant cultural heritage team staff at Auckland Council) • Conduct or commission work to identify opportunities for diversified land use activities in the catchment, and investigate ways the SCP could support the catchment community to implement the more sustainable options __________________________________________________________________________________________ Hoteo River catchment: environment and socio-economic review ii Table of Contents Executive summary ................................................................................................................................... i 1.0 Introduction ................................................................................................................................... 1 1.1 Sustainable Catchments Programme for the Hoteo catchment .................................................. 1 1.2 Hoteo catchment ......................................................................................................................... 3 2.0 Methods ........................................................................................................................................ 4 2.1 Biophysical review ....................................................................................................................... 4 2.2 Socio-demographic, cultural and planning context reviews ........................................................ 5 3.0 Biophysical environment .............................................................................................................. 6 3.1 Geology and soils ........................................................................................................................ 6 3.2 Slope and elevation ..................................................................................................................... 9 3.3 Climate ...................................................................................................................................... 10 3.4 Erosion .....................................................................................................................................