North Central CMA Region Loddon River System Environmental Water Management Plan
Total Page:16
File Type:pdf, Size:1020Kb
North Central CMA Region Loddon River System Environmental Water Management Plan EWMP Area: Loddon River downstream of Cairn Curran Reservoir and including Tullaroop Creek downstream of Tullaroop Reservoir, Serpentine Creek, Twelve Mile Creek and Pyramid Creek Document History and Status Date Date Version Prepared By Reviewed By Issued Approved 1 (Ch 1-3) 27/2/15 Jon Leevers Louissa Rogers 15/3/15 1 (Ch 7-9) 12/3/15 Jon Leevers Louissa Rogers 17/3/15 1 (Whole) 13/4/15 Louissa Rogers Emer Campbell 17/4/15 DELWP (Melanie Tranter on behalf of Suzanne Witteveen, 2 17/4/15 Louissa Rogers 5/5/15 Susan Watson) Project Steering Committee (PSC), Community Advisory Group 3 21/5/15 Louissa Rogers 29/5/15 (CAG) 4 2/6/15 Louissa Rogers Emer Campbell 5/6/15 5 5/6/15 Louissa Rogers DELWP FINAL Distribution Version Date Quantity Issued To 1 (Ch 1-3) 27/2/15 1 Louissa Rogers 1 (Ch 7-9) 12/3/15 1 Louissa Rogers 1 (Whole) 13/4/15 1 (electronic) Emer Campbell 2 17/4/15 1 (electronic) DELWP (Suzanne Witteveen, Susan Watson) 3 21/5/15 ~35 PSC, CAG 4 2/6/15 1 (electronic) Emer Campbell 5 5/6/15 1 DEWLP (FINAL) Document Management Printed: 18/09/2018 2:42:00 PM Last saved: 20/04/2018 10:07:00 AM File name: Loddon River EWMP.docx Authors: Louissa Rogers and Jon Leevers Name of Organisation: North Central CMA Name of Document: North Central CMA Region Environmental Water Management Plan for the Loddon River System Document version: Version 5 SharePoint link: NCCMA-63-41009 For further information on any of the information contained within this document contact: North Central Catchment Management Authority PO Box 18 Huntly Vic 3551 T: 03 5448 7124 F: 03 5448 7148 E: [email protected] www.nccma.vic.gov.au © North Central Catchment Management Authority 2015 Front cover photo: Top Left: Loddon River Reach 1 near Rumbolds Road - Source; Jacobs 2015a; Middle Left: Loddon River Reach 3a at Newbridge - Source: Louissa Rogers (NCCMA); Top Right: Floodwaters receding from Canary Island (Reach 4b and 4c) showing Loddon Fan formation - Source: Phil Slessar (NCCMA), Middle Right: Loddon River Reach 4a -Source: Phil Slessar (NCCMA), Bottom: Loddon River Reach 5 near Benjeroop - Source: Louissa Rogers (NCCMA). North Central CMA Region Environmental Water Management Plan for the Loddon River System is a ten year plan for the Loddon River downstream of Cairn Curran Reservoir and including Tullaroop Creek downstream of Tullaroop Reservoir, Serpentine Creek, Twelve Mile Creek and Pyramid Creek. The EWMP is compiled from the best available information. This publication may be of assistance to you, but the North Central Catchment Management Authority and its employees do not guarantee that the publication is without flaw of any kind and, or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on information in this publication. Please cite this document as: North Central CMA (2015) Loddon River System Environmental Water Management Plan , North Central Catchment Management Authority, Huntly. Executive Summary The Loddon River System Environmental Water Management Plan (EWMP) sets out long-term management objectives for priority water dependent environmental values of the Loddon River System. The area that the Loddon River System EWMP covers includes the Loddon River downstream of Cairn Curran Reservoir to the Murray River, Tullaroop Creek downstream of Tullaroop Reservoir, Serpentine Creek, Twelve Mile Creek and Pyramid Creek. The EWMP is an important part of the Victorian Environmental Water Planning Framework. It provides the ten year management intentions (with potential for mid-term review), based on scientific information and stakeholder consultation, that can be used by the respective agencies; North Central Catchment Management Authority (CMA), Department of Environment, Land, Water and Planning (DELWP) and the Victorian Environmental Water Holder (VEWH); for both short and longer-term environmental water planning. This EWMP is not a holistic management plan for the river, but is focused on environmental water management so that the Loddon River System can continue to provide environmental, social, cultural and economic values for all users. The following components are the main sections featured in the Loddon River System EWMP. Hydrology and system operations Prior to regulation the Loddon River would have experienced high flows in winter and spring, with regular (multiple times a year in most years) occurrences of minor to moderate flooding of the floodplain. In summer and autumn, as inflows from the catchment reduce, the unregulated Loddon River System would experience lower flows with cease-to-flow events occurring in most years. Under current conditions flow in the Loddon River System is regulated by the operation of the Cairn Curran and Tullaroop reservoirs, as well as a series of weirs (Laanecoorie Reservoir, Bridgewater Weir, Serpentine Weir, Loddon Weir and Kerang Weir) that either re-regulate flow or pool water for diversion to the floodplain. The Loddon River System also receives inflows from other river systems, including the Goulburn River (via the Waranga Western Channel) and the Murray River (via the National Channel and Kow Swamp). Due to river regulation flows in the Loddon River System are characterised by reduced frequency of minor to moderate overbank flow, reduced high and bankfull flows in winter and spring and increased flow magnitude and duration over the irrigation season (usually late spring, summer and early autumn). Water dependent values The Loddon River System supports populations of threatened native fish, including the nationally vulnerable Murray Cod and critically endangered Silver Perch, the State threatened Murray-Darling Rainbowfish and the regionally significant River Blackfish. The river provides important in-stream habitat for other aquatic fauna such as the near threatened Platypus. It has a relatively intact River Red Gum canopy along the river banks of the upper and mid Loddon River System, and Black Box being the dominant canopy species in the lower Loddon. Many of the native vegetation communities located along and within the Loddon River System are endangered or vulnerable. Ecological condition and threats According to the Sustainable River Audit, Index of Stream Condition and the Victorian Environmental Flows Monitoring and Assessment Program (VEFMAP), the Loddon River System is currently in relatively poor condition. Its native fish populations, in particular its large bodied fish, are significantly degraded with monitoring catches consistently recording very low abundances, particularly when compared to historic records, over the last six years. The Platypus population was significantly impacted by the Millennium Drought, with the community noting a marked decrease in the frequency of sightings. The riparian zone primarily comprises a mixed aged canopy species, although recruitment levels of River Red Gum is low and understorey shrubs and groundcover is relatively degraded. These key components of the river ecology require targeted management of environmental water to facilitate natural recruitment. Loddon River System Environmental Water Management Plan 1 Management objectives A long-term management goal has been defined for the Loddon River System: Loddon River system long term management goal Promote a widespread and diverse aquatic fauna community particularly native fish and Platypus, by providing high quality breeding and feeding habitat and where possible facilitating movement throughout the Mid-Murray Floodplain System. Rehabilitate riparian River Red Gum vegetation communities along the river and where possible connect floodplain habitats through the provision of an appropriate flow regime. The ecological objectives and environmental flow recommendations that sit under the long-term management goal for the Loddon River System were first established for the Loddon River in 2002, and reviewed for the river downstream of the Loddon Weir in 2010. This assessment also included Twelve Mile Creek. Environmental flow assessments were undertaken in 2014 for Serpentine and Pyramid Creeks. The ecological objectives and flow recommendations for the Loddon River and including Tullaroop Creek and Twelve Mile Creek have been reviewed and refined during the development of this EWMP. Managing risks to achieving objectives The threats to achieving the ecological objectives that are external to environmental water are identified. Key threats include instream barriers to fish movement and grazing of riparian vegetation. Risks associated with the delivery of environmental water and management strategies have also been identified. Environmental water delivery infrastructure Constraints to the delivery of environmental flow recommendations (such as bankfull flows) have been identified. Infrastructure recommendations have been made and include investigating the feasibility of increasing the delivery capacity of Cairn Curran, Tullaroop and Laanecoorie reservoirs and the upgrade of in-stream structures to provide connectivity for aquatic fauna. Demonstrating outcomes Monitoring is required to allow the CMA to adaptively manage annual environmental watering (intervention monitoring). It is also required to enable the CMA and VEWH to demonstrate the long term outcomes of the implementation of the Loddon River System EWMP. As the State is currently reviewing the Victorian Environmental Flows Monitoring and Assessment