Namoi Water Resource Plan Surface water resource description Published by the Department of Primary Industries, a Division of NSW Department of Industry, Skills and Regional Development. DPI Water (2017) Namoi Water Resource Plan: Surface water resource description. First published April 2018 More information www.dpi.nsw.gov.au Cover images Namoi River at Gunnedah; river red gum leaves; eel-tailed catfish; Split Rock Dam spillway. Photos courtesy MDBA (main image) and Department of Primary Industries Acknowledgments This document was prepared by Dayle Green. It expands upon a previous description of the Namoi Valley published by the NSW Office of Water in 2011 (Green, Burrell, Petrovic and Moss 2011, Water resources and management overview – Namoi catchment ) The maps in this report were prepared by Bilal Hossain. They contain data sourced from: Murray-Darling Basin Authority © Commonwealth of Australia (Murray–Darling Basin Authority) 2012. (Licensed under the Creative Commons Attribution 4.0 International License) NSW DPI Water © Spatial Services - NSW Department of Finance, Services and Innovation [2016], Panorama Avenue, Bathurst 2795.http://spatialservices.finance.nsw.gov.au NSW Office of Environment and Heritage Atlas of NSW Wildlife data © State of New South Wales through Department of Environment and Heritage (2016) 59-61 Goulburn Street Sydney 2000 http://www.biotnet.nsw.gov.au NSW DPI Fisheries Fish Community Status and Threatened Species data © State of New South Wales through Department of Industry (2016) 161 Kite Street Orange 2800 http://www.dpi.nsw.gov.au/fishing/species-protection/threatened-species-distributions-in-nsw © State of New South Wales through the Department of Industry, Skills and Regional Development, 2018. You may copy, distribute and otherwise freely deal with this publication for any purpose, provided that you attribute the NSW Department of Primary Industries as the owner. Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (April 2018). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of the Department of Primary Industries or the user’s independent adviser. Namoi Water Resource Plan: Surface water resource description Contents 1. Introduction .......................................................................................................................... 1 1.1 Overview of the plan area ............................................................................................. 1 1.2 Water management units .............................................................................................. 3 1.3 History of water management in the Namoi WRPA ....................................................... 5 2 Regional setting ................................................................................................................... 8 2.1 Climate ......................................................................................................................... 8 2.2 Land use ..................................................................................................................... 10 2.3 Topographic description .............................................................................................. 12 2.4 Streamflow characteristics .......................................................................................... 16 3 Environmental assets ......................................................................................................... 21 3.1 Parks and reserves ..................................................................................................... 21 3.2 Wetlands ..................................................................................................................... 22 3.3 Hydrologic indicator sites ............................................................................................ 23 3.4 High ecological value aquatic ecosystems .................................................................. 23 4 Water quality ...................................................................................................................... 28 4.1 Background ................................................................................................................. 28 4.2 Upland region ............................................................................................................. 29 4.3 Midland region (Namoi and Peel) ................................................................................ 29 4.4 Lowland region ........................................................................................................... 29 5 Riparian condition .............................................................................................................. 30 6 River operations and management .................................................................................... 32 6.1 Storages and regulating structures.............................................................................. 32 6.2 Licensed water use ..................................................................................................... 34 6.3 Water trading .............................................................................................................. 41 6.4 Environmental water ................................................................................................... 43 Glossary .................................................................................................................................... 45 References ............................................................................................................................... 48 iii DPI Water, June 2017 Namoi Water Resource Plan: Surface water resource description Tables Table 1: Land use in the Namoi WRPA ..................................................................................... 10 Table 2: Lower Namoi Floodplain Management Plan ecological assets .................................... 23 Table 3:Assessment of the Namoi River against MDBA key environmental assets criteria .. 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Table 4: Regulated river share components for the Namoi WRPA 2016 ................................... 34 Table 5: Unregulated share components for the Namoi WRPA 2016 ........................................ 39 Table 6: Town water supply entitlements from unregulated water sources in the Namoi WRPA 39 Figures Figure 1: Namoi Water Resource Plan Area (SW14) ................................................................... 2 Figure 2: Regulated and unregulated water sources in the Namoi WRPA ................................... 4 Figure 3: Average annual rainfall in the Namoi WRPA ................................................................ 8 Figure 4: Average monthly rainfall for selected stations .............................................................. 8 Figure 5: Average annual evaporation across the Namoi WRPA ................................................. 9 Figure 6: Average monthly evaporation at Gunnedah ................................................................. 9 Figure 7: Land use of the Namoi WRPA .................................................................................... 11 Figure 8: Sub-regions of the Namoi WRPA ............................................................................... 12 Figure 9: Annual flow in the Namoi River at Gunnedah 1892–2016 .......................................... 16 Figure 10: Daily flow in the Namoi River at Gunnedah .............................................................. 17 Figure 11: High, median and low daily flows in the Namoi WRPA ............................................. 18 Figure 12: Annual flow in the Peel River 1930-2015 .................................................................. 19 Figure 13: Daily flow in the Peel River 1930-2016 ..................................................................... 19 Figure 14: High, median and daily flows in the Peel River at Taroona ....................................... 20 Figure 15: Instream values for the Namoi WRPA ...................................................................... 24 Figure 16: Distribution of threatened fish species within the Namoi WRPA ............................... 25 Figure 17: Endangered ecological communities in the Namoi WRPA ........................................ 26 Figure 18: Water quality condition of the Namoi WRPA ............................................................ 28 Figure 19: Native riparian vegetation cover in the Namoi WRPA ............................................... 31 Figure 20: Geomorphic recovery potential in streams in the Namoi WRPA ............................... 31 Figure 21: Keepit Dam storage levels 1975-2016 ...................................................................... 32 Figure 22: Split Rock Dam storage levels 1990-2016 ................................................................ 32 Figure 23: Location of weirs in the Namoi WRPA ...................................................................... 33 Figure 24: Distribution of regulated licences in the Namoi WRPA ............................................. 35 Figure 25: Long term simulated water availability for the Namoi River (excluding Peel) ............ 36 Figure 26: Water availability in the Upper