Chowilla Anabranch System Surface Water Information Summary
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Chowilla Anabranch System Surface Water Information Summary Peter Stace and Ashley Greenwood Knowledge and Information Division Department of Water, Land and Biodiversity Conservation June 2004 Report DWLBC 2004/06 Knowledge and Information Division Department of Water, Land and Biodiversity Conservation Level 1, 25 Grenfell Street, Adelaide GPO Box 2834, Adelaide SA 5001 Telephone NationalU U (08)U 8463 6978 International +61 8 8463 6978 Fax NationalU U (08)U 8463 6999U International +61 8 8463 6999 Website www.dwlbc.sa.gov.au Disclaimer Department of Water, Land and Biodiversity Conservation and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein as regards to its correctness, accuracy, reliability, currency or otherwise. The Department of Water, Land and Biodiversity Conservation and its employees expressly disclaims all liability or responsibility to any person using the information or advice. © Department of Water, Land and Biodiversity Conservation 2004 This work is copyright. Apart from any use as permitted under the Copyright Act 1968 (Cwlth), no part may be reproduced by any process without prior written permission from the Department of Water, Land and Biodiversity Conservation. Requests and inquiries concerning reproduction and rights should be addressed to the Director, Knowledge and Information Division, Department of Water, Land and Biodiversity Conservation, GPO Box 2834, Adelaide SA 5001. ISBN 0-9757438-1-3 Stace, P M and Greenwood A J, 2004. Chowilla Anabranch System Surface Water Information Summary. South Australia. Department of Water, Land and Biodiversity Conservation. Report, DWLBC 2004/06 Cover Photographs H. J. Johnstone, Australia 1835-1907, Evening shadows, backwater of the Murray, South Australia, 1880, London or Paris, oil on canvas, 120.6 x 184.1 cm; Gift of Henry Yorke Sparkes. Art Gallery of South Australia, Adelaide (with permission June 2004). Ian Overton, A backwater on Monoman Island, Chowilla Floodplain, March 2003, (© CSIRO, with permission June 2004). FOREWORD South Australia’s water resources are fundamental to the economic and social wellbeing of the State. Water resources are an integral part of our natural resources. In pristine or undeveloped situations, the condition of water resources reflects the equilibrium between rainfall, vegetation and other physical parameters. Development of surface and groundwater resources changes the natural balance and causes degradation. If degradation is small, and the resource retains its utility, the community may assess these changes as being acceptable. However, significant stress will impact on the ability of a resource to continue to meet the needs of users and the environment. Degradation may also be very gradual and take some years to become apparent, imparting a false sense of security. Management of water resources requires a sound understanding of key factors such as physical extent (quantity), quality, availability and constraints to development. The role of the Knowledge and Information Division of the Department of Water, Land and Biodiversity Conservation is to maintain an effective knowledge base on the State’s water resources, including environmental and other factors likely to influence sustainable use and development, and to provide timely and relevant management advice. Bryan Harris Director, Knowledge and Information Division Department of Water, Land and Biodiversity Conservation Chowilla Anabranch System i Report DWLBC 2004 / 06 Surface Water Information Summary Contents CONTENTS FOREWORD ........................................................................................................................I CONTENTS.........................................................................................................................II SUMMARY OF RECOMMENDATIONS ..............................................................................1 Flow .................................................................................................................................1 RIVER MURRAY ....................................................................................................................... 1 CHOWILLA FLOW TO RIVER MURRAY.................................................................................. 1 ANABRANCH SUBSYSTEM FLOWS....................................................................................... 1 Salinity and salt loads ......................................................................................................1 RIVER MURRAY ....................................................................................................................... 1 LINDSAY RIVER ANABRANCH................................................................................................ 1 CHOWILLA ANABRANCH SUBSYSTEM................................................................................. 2 Elevations, water levels, bathymetry ...............................................................................2 1 INTRODUCTION .........................................................................................................3 2 AIM ..............................................................................................................................5 3 METHODOLOGY.........................................................................................................6 4 HISTORICAL DATA AND REPORTS..........................................................................7 4.1 Information summary report.................................................................................7 4.1.1 HYDSTUDY SPREADSHEET ...................................................................................... 7 4.2 Additional reports .................................................................................................7 4.3 Digital datasets ....................................................................................................8 4.3.1 HYDSTRA TIME SERIES............................................................................................. 8 4.3.2 RIVERLAND REGIONAL FILES .................................................................................. 8 5 TOTAL SALT LOAD TO RIVER MURRAY ..................................................................9 5.1 Calculation of total salt load using daily read EC data.........................................9 5.1.1 DATA USED — DAILY EC READINGS ..................................................................... 10 5.1.2 DATA USED — DAILY FLOW CALCULATION ......................................................... 10 5.1.3 SALT LOAD CALCULATION...................................................................................... 13 5.1.4 SALT LOAD RECESSION.......................................................................................... 16 5.2 Calculation of total salt load using continuous EC data .....................................18 5.2.1 CONTINUOUSLY RECORDED EC DATA................................................................. 18 5.2.2 CONTINUOUS RECORDED EC COMPARED TO DAILY READ EC ....................... 19 5.3 Preliminary uncertainty analysis in daily EC data ..............................................20 5.3.1 PROCEDURE............................................................................................................. 20 5.3.2 RESULTS AND DISCUSSION ................................................................................... 22 5.3.3 CONCLUSIONS AND RECOMMENDATIONS .......................................................... 27 6 CHOWILLA CREEK FLOW .......................................................................................28 6.1 Calculated flow...................................................................................................28 Chowilla Anabranch System ii Report DWLBC 2004 / 06 Surface Water Information Summary Contents 6.2 Measured flow....................................................................................................31 7 EVAPORATION LOSSES..........................................................................................33 7.1 Surface water area.............................................................................................33 7.1.1 CHOWILLA ANABRANCH ......................................................................................... 33 7.1.2 RIVER MURRAY — MAIN STREAM ......................................................................... 33 7.2 Calculation of evaporation loss ..........................................................................34 7.2.1 CHOWILLA ANABRANCH ......................................................................................... 34 7.2.2 RIVER MURRAY MAIN STREAM .............................................................................. 34 8 FLOW AND SALINITY STUDIES ..............................................................................35 8.1 Detailed dataset .................................................................................................35 8.1.1 DATA SOURCES ....................................................................................................... 35 8.2 Total Chowilla Anabranch salt load increase .....................................................36 8.3 Chowilla Anabranch components ......................................................................36 8.3.1 CHOWILLA ANABRANCH COMPONENT FLOWS................................................... 37 8.3.2