Tributary Foreshore Assessment Report: Helena River (Mandoon) Version: 1.2 Approved by: Debbie Besch Last Updated: 31 January 2018 Custodian: Rivers and Estuaries Division Review date: Version Date approved Approved by Brief Description number DD/MM/YYYY 1.1 19/10/2017 Debbie Draft version for circulation Besch 1.2 31/1/2018 Debbie Final version for circulation Besch Tributary Foreshore Assessment: Helena River (Mandoon) Rivers and Estuaries Division January 2018 Department of Biodiversity, Conservation and Attractions Locked Bag 104 Bentley Delivery Centre WA 6983 Phone: (08) 9219 9000 Fax: (08) 9334 0498 www.dbca.wa.gov.au © Department of Biodiversity, Conservation and Attractions on behalf of the State of Western Australia January 2018 This work is copyright. You may download, display, print and reproduce this material in unaltered form (retaining this notice) for your personal, non-commercial use or use within your organisation. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and enquiries concerning reproduction and rights should be addressed to the Department of Biodiversity, Conservation and Attractions. This report was prepared by Alison McGilvray and Kim Sylva, Rivers and Estuaries Division, DBCA. Questions regarding the use of this material should be directed to: Alison McGilvray Rivers and Estuaries Division Department of Biodiversity, Conservation and Attractions Locked Bag 104 Bentley Delivery Centre WA 6983 Phone: 08 9278 0906 Email: [email protected] The recommended reference for this publication is: Department of Biodiversity, Conservation and Attractions, 2018, Tributary Foreshore Assessment Report – Helena River (Mandoon), Department of Biodiversity, Conservation and Attractions, Perth. Disclaimer: The Department of Biodiversity, Conservation and Attractions does not guarantee that this document is without flaw of any kind and disclaims all liability for any errors, loss or other consequence which may arise from relying on any information depicted. This document is available in alternative formats on request. Front cover: Helena River pool, Beelu National Park. Photo – Alison McGilvray/DBCA Tributary Foreshore Assessment: Helena River (Mandoon) Contents Acknowledgments ........................................................................................................... x Summary ......................................................................................................................... xi 1 Introduction ................................................................................................................. 1 1.1 Area description ................................................................................................. 1 1.2 Historical context ................................................................................................ 3 1.3 Cultural values ................................................................................................... 3 1.4 Natural values .................................................................................................... 4 1.5 Major threats .................................................................................................... 11 1.6 Management structure ..................................................................................... 11 1.7 Previous assessments ..................................................................................... 16 1.8 Major land use changes since 2006 and major proposals ............................... 16 1.9 Objectives ........................................................................................................ 17 2 Method ...................................................................................................................... 18 2.1 Previous assessments ..................................................................................... 18 2.1.1 Water and Rivers Commission ............................................................. 18 2.1.2 Department of Water and Environmental Regulation (DWER) 2006 .... 18 2.1.3 Swan River Trust 2004 - 2007 .............................................................. 19 2.2 Current assessment ......................................................................................... 19 2.2.1 Desktop assessment ............................................................................ 19 2.2.2 Data collection ...................................................................................... 20 2.2.3 Field surveys ........................................................................................ 20 2.2.4 Categorisation of segments .................................................................. 21 3 Assessment results ................................................................................................... 24 3.1 Land use .......................................................................................................... 25 3.2 Bank height, slope and stability ........................................................................ 26 3.3 Vegetation type and condition .......................................................................... 38 3.4 Weed cover and species .................................................................................. 46 3.5 Level of pressure .............................................................................................. 53 3.6 Pen and Scott grade ........................................................................................ 58 3.7 Other management issues ............................................................................... 63 3.7.1 Uncontrolled access to the riverbank .................................................... 63 3.7.2 Current management concerns ............................................................ 64 3.7.3 Other issues ......................................................................................... 64 Department of Biodiversity, Conservation and Attractions ` v Tributary Foreshore Assessment: Helena River (Mandoon) 3.8 Current management responses ...................................................................... 65 3.8.1 Restoration works ................................................................................. 65 3.8.2 Fencing/stock/human exclusion from watercourse ............................... 72 4 Strategy and recommendations ................................................................................ 73 4.1 General recommendations ............................................................................... 73 4.2 Categorisation .................................................................................................. 75 4.3 Site recommendations ..................................................................................... 80 5 Assumptions and limitations of the method ............................................................... 88 Appendices ................................................................................................................... 90 References .................................................................................................................. 139 Appendices Appendix 1 Vegetation complexes within a 500m buffer of the Helena River, from Heddle et al. (1980)................................................................................................... 90 Appendix 2 - Recognised natural values adjacent to the Helena River ......................... 93 Appendix 3 - Dominant native species .......................................................................... 96 Appendix 4 - Weed species sighted .............................................................................. 98 Appendix 5 - Suggested revegetation species ............................................................ 101 Appendix 6 – Pen and Scott foreshore condition grading............................................ 119 Appendix 7 - Data dictionary for field attributes in shapefile Helena_Segments ......... 121 Appendix 8 - Parameters used for the categorisation of river segments ..................... 129 Appendix 9 - Matrix for the categorisation of river segments ....................................... 132 Appendix 10 - Ratings for individual parameters of foreshore condition used by Siemon (2001) ........................................................................................................ 133 Appendix 11 - Known project sites along the Helena River ......................................... 136 Figures Figure 1: Extent of the Helena River assessment, Interim Biogeographic Regionalisation for Australia (IBRA), Perth NRM subregions, and Swan River Trust Development Control Area (DCA). ..................................................................... 2 Figure 2: Registered Aboriginal sites within a 500m buffer of the Helena River. ............. 6 Figure 3: Vegetation complexes and IBRA regions within a 500m buffer of the Helena River. .............................................................................................................. 7 Figure 4: Recorded natural values within a 500m buffer of the Helena River, Mundaring Weir to Pumpback Dam. ........................................................................... 8 Figure 5: Recorded natural values within a 500m buffer of the Helena River, Pumpback Dam to Scott Street. .................................................................................. 9 vi Department of Biodiversity,