Spence's Bend Environmental Water Management Plan
Total Page:16
File Type:pdf, Size:1020Kb
Spence’s Bend Environmental Water Management Plan DOCUMENT CONTROL Version Description Issued to Issue date number 1 Draft Report Mark Stacey 2010 2 Draft submitted to scientific panel for review Jane Roberts 2/6/2014 Simone Wilkie (Riverness 3 Incorporate Comments 14/11/2014 Pty Ltd) 4 Internal Review Mallee CMA L. Murphy & L. Chapman 18/02/2015 Simone Wilkie (Riverness 5 Incorporate Comments 4/03/2015 Pty Ltd) 6 Submission to DELWP Citation Please cite this document as: Mallee CMA (2015) Spence’s Bend Environmental Water Management Plan, Mallee CMA, Mildura Victoria Contact For queries regarding this document, please contact : Louise Chapman [email protected] Coordinator Waterways Mallee Catchment Management Authority This publication may be of assistance to you but the Mallee Catchment Management Authority and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purpose and therefore disclaims all liability for any error, loss or other consequence that may arise from you relying on any information in this publication. EXECUTIVE SUMMARY ...................................................................................................................................... I ACKNOWLEDGEMENTS ............................................................................................................................ 1 INTRODUCTION ............................................................................................................................................... 2 SITE OVERVIEW ................................................................................................................................................ 2 SITE LOCATION ....................................................................................................................................................... 2 CATCHMENT SETTING .............................................................................................................................................. 2 SPENCE’S BEND ...................................................................................................................................................... 3 CONCEPTUALISATION OF THE SITE .............................................................................................................................. 5 LAND STATUS AND MANAGEMENT ............................................................................................................................. 7 WETLAND CHARACTERISTICS ..................................................................................................................................... 9 MANAGEMENT SCALE ............................................................................................................................................ 10 SPECIFIC ASSESSMENT OF SALINITY RISK .................................................................................................................... 13 ENVIRONMENTAL WATER SOURCES .......................................................................................................................... 14 RELATED AGREEMENTS, POLICY, PLANS AND ACTIVITIES ............................................................................................... 14 HYDROLOGY AND SYSTEM OPERATIONS ....................................................................................................... 16 WETLAND HYDROLOGY, WATER MANAGEMENT AND DELIVERY ..................................................................................... 16 PREVIOUS ENVIRONMENTAL WATERING .................................................................................................................... 21 WATER DEPENDENT VALUES.......................................................................................................................... 23 ENVIRONMENTAL VALUES....................................................................................................................................... 23 SIGNIFICANCE ....................................................................................................................................................... 30 WETLAND DEPLETION AND RARITY ........................................................................................................................... 32 ECOSYSTEM FUNCTIONS ......................................................................................................................................... 34 SOCIAL VALUES .................................................................................................................................................... 35 ECONOMIC VALUES ............................................................................................................................................... 36 SIGNIFICANCE ....................................................................................................................................................... 37 ECOLOGICAL CONDITION AND THREATS ........................................................................................................ 37 CURRENT CONDITION ............................................................................................................................................ 37 CONDITION TRAJECTORY ........................................................................................................................................ 39 WATER RELATED THREATS ...................................................................................................................................... 40 MANAGEMENT OBJECTIVES ........................................................................................................................... 42 MANAGEMENT GOAL ............................................................................................................................................ 42 ECOLOGICAL OBJECTIVES ........................................................................................................................................ 42 HYDROLOGICAL OBJECTIVES .................................................................................................................................... 43 STAGED IMPLEMENTATION OF THE WATERING REGIME AT SPENCE’S BEND TARGET AREA ..................................................... 46 MANAGING RISKS TO ACHIEVING OBJECTIVES ............................................................................................... 51 ENVIRONMENTAL WATER DELIVERY INFRASTRUCTURE ................................................................................. 53 CONSTRAINTS....................................................................................................................................................... 53 INFRASTRUCTURE OR COMPLEMENTARY WORKS RECOMMENDATIONS.............................................................................. 54 DEMONSTRATING OUTCOMES ...................................................................................................................... 56 MONITORING PRIORITIES AT THE SITE ....................................................................................................................... 56 CONSULTATION ............................................................................................................................................. 56 KNOWLEDGE GAPS AND RECOMMENDATIONS ............................................................................................. 57 REFERENCES ................................................................................................................................................... 59 ABBREVIATIONS AND ACRONYMS ................................................................................................................. 62 APPENDIX 1 – FLORA AND FAUNA SPECIES LIST ............................................................................................. 63 APPENDIX 2 - ECOLOGICAL VEGETATION CLASSES (EVCS) .............................................................................. 85 APPENDIX 3 – CULTURAL HERITAGE CONTINGENCY PLAN ............................................................................. 88 Executive summary Environmental Water Management Plans (EWMPs) have been developed for key sites in the Mallee region. The Mallee Waterway Strategy 2014-22 (Mallee CMA, 2014) identified 23 Waterway Management Units (WMU). The hydrological interconnectedness and commonality of threats impacting on the waterways values were used to group them into planning units. This EWMP has been developed for the Spence’s Bend WMU Sub-Unit. Hereafter referred to as Spence’s Bend in this document. The EWMP will help to guide future environmental watering activities for this area. Spence’s Bend is located in the Robinvale Plains bioregion within the Mallee Catchment Management Authority (Mallee CMA) region 40 km south-east of Mildura and covers 1,210 ha. A regional context document provides further information on the region and has been created to compliment the Mallee CMAs EWMPs and should be read in conjunction with this document (North, 2014). The main features of Spence’s Bend are Bullock Swamp, Lake Iraak, Carwarp Creek and a series of smaller wetlands including Spence’s Bend Billabong and Callander’s Swamp. This plan focuses on a target area within Spence’s Bend, covering 341 ha, able to be inundated through environmental watering. Spence’s Bend consists of a forested floodplain area with several