1.1.1 Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan Document Control Version number Description Issued to Issue date First Draft of Wimmera Mallee Pipeline 1 Mallee CMA 08/09/2014 Wetlands EWMP Second Draft of Draft of Wimmera Mallee 2 Mallee CMA 24/12/2014 Pipeline Wetlands EWMP 3 External Review Riverness Pty. Ltd. 8/05/2015 4 Board Approval Mallee CMA 21/5/2015 5 Submission to DELWP DELWP 1/6/2015 6 Incorporation of DELWP review comments Mallee CMA 24/11/2016 7 Update shared benefits Mallee CMA 28/6/2017 Please cite this document as: Mallee CMA (2016) Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan. Mallee Catchment Management Authority, Mildura, Victoria. Contact For further information on any of the information contained within this document 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 Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan Contents CONTENTS ..................................................................................................................................................... II EXECUTIVE SUMMARY .................................................................................................................................... I ACKNOWLEDGEMENTS .................................................................................................................................. 1 1 INTRODUCTION ...................................................................................................................................... 2 2 SITE OVERVIEW ...................................................................................................................................... 4 2.1 SITE LOCATION ........................................................................................................................................... 4 2.2 CATCHMENT SETTING .................................................................................................................................. 5 2.3 WIMMERA MALLEE PIPELINE ........................................................................................................................ 8 2.4 SITE CONCEPTUALISATION .......................................................................................................................... 11 2.5 LAND STATUS AND MANAGEMENT ............................................................................................................... 13 2.6 WETLAND CHARACTERISTICS ....................................................................................................................... 14 2.7 MANAGEMENT SCALE ............................................................................................................................... 16 2.8 ENVIRONMENTAL WATER SOURCES ............................................................................................................. 16 2.9 RELATED AGREEMENTS, POLICY, PLANS AND ACTIVITIES ................................................................................... 16 3 HYDROLOGY AND SYSTEM OPERATIONS .............................................................................................. 18 3.1 WETLAND HYDROLOGY, WATER MANAGEMENT AND DELIVERY ........................................................................ 18 4 WATER DEPENDENT VALUES ................................................................................................................ 28 4.1 ENVIRONMENTAL VALUES .......................................................................................................................... 28 4.2 WETLAND DEPLETION AND RARITY .............................................................................................................. 38 4.3 SUMMARY OF SIGNIFICANT ENVIRONMENTAL VALUES AT EACH WMP SITE ........................................................... 39 4.4 ECOSYSTEM FUNCTIONS ............................................................................................................................. 41 4.5 SOCIAL ................................................................................................................................................... 42 4.6 ECONOMIC .............................................................................................................................................. 43 4.7 SIGNIFICANCE .......................................................................................................................................... 43 5 ECOLOGICAL CONDITION AND THREATS .............................................................................................. 45 5.1 CURRENT CONDITION ................................................................................................................................ 45 5.2 CONDITION TRAJECTORY ............................................................................................................................ 47 5.3 WATER RELATED THREATS .......................................................................................................................... 48 6 MANAGEMENT OBJECTIVE ................................................................................................................... 49 6.1 MANAGEMENT GOAL ................................................................................................................................ 49 6.2 ECOLOGICAL OBJECTIVES ............................................................................................................................ 49 6.3 HYDROLOGICAL OBJECTIVES........................................................................................................................ 51 6.4 SEASONALLY ADAPTIVE APPROACH .............................................................................................................. 54 7 MANAGING RISKS TO ACHIEVE OBJECTIVES ......................................................................................... 59 8 ENVIRONMENTAL WATER DELIVERY INFRASTRUCTURE ....................................................................... 64 8.1 CONSTRAINTS .......................................................................................................................................... 64 8.2 INFRASTRUCTURE RECOMMENDATIONS ......................................................................................................... 65 9 DEMONSTRATING OUTCOMES ............................................................................................................. 66 Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan 9.1 MONITORING PRIORITIES AT WMP SITES ..................................................................................................... 66 9.2 REPORTING ............................................................................................................................................. 66 10 CONSULTATION ................................................................................................................................ 67 11 KNOWLEDGE GAPS AND RECOMMENDATIONS ................................................................................ 69 REFERENCES ................................................................................................................................................. 71 ABBREVIATIONS AND ACRONYMS ............................................................................................................... 74 Wimmera Mallee Pipeline Wetlands Environmental Water Management Plan 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 2014a) covers 216 identified waterways which have been grouped into 23 planning units according to hydrological interconnectedness and commonality of threats impacting on the waterways values. This EWMP has been developed for one of these planning units, Dispersed Wetlands – Freshwater, which includes 31 sites which are spread over an area of 600,000 hectares. The WMP sites are located in the Wimmera-Mallee region, amid dryland cropping and grazing land. A former channel and dam system that provided stock and domestic water supply across this semi- arid landscape was removed and replaced with the Wimmera Mallee Pipeline (WMP) and tank and reticulation systems between 2006 and 2010. This significantly reduced the availability of open water across the landscape. To address the lack of open water, fifty-one sites consisting of either dams within terrestrial vegetation or wetlands with dams constructed within them, were connected to the pipeline to enable delivery of environmental water. The fifty-one sites are spread across three Catchment Management Authorities (CMAs): Wimmera, North Central and Mallee. The target area for this EWMP is the 31 WMP sites located within the Mallee CMA Region. Amongst these 31 sites, a number of Freshwater Meadows and Deep Open Freshwater wetlands exist,