The Commonwealth Environmental Water Office (CEWO) supports the Commonwealth Environmental Water Holder (CEWH) to plan, manage and monitor a portfolio of water for the benefit of the environment. The Commonwealth’s holdings must be managed for the purpose of protecting or restoring the environmental assets of the Murray-Darling Basin. The CEWH's decisions on water use, carryover and trade have been made in the context of, and consistent with, the Murray-Darling Basin Authority’s Basin-wide Environmental Watering Strategy 2014, and annual priorities.
Fish are responsive to environmental flows, and managing water specifically for ecological benefits is one element in restoring populations of native fish that have declined across the Basin. Commonwealth environmental watering actions focus on providing environmental flows aimed at improving water quality, supporting native fish habitat, and migration, spawning and recruitment opportunities for native fish within and across catchment boundaries. These actions support native fish through all stages of their lifecycle, as well as contributing to a healthy and resilient Basin environment.
Long-term Intervention Monitoring (LTIM) commenced in 2014 and will monitor and evaluate the contribution of Commonwealth environmental water in the Murray-Darling Basin to June 2019. An important component of each LTIM project was the establishment of effective partnerships in environmental water delivery, including with environmental water managers, land and catchment managers, local environmental water management groups, State agencies, academic institutions and community members. A comprehensive data set from monitoring and evaluation activities will emerge over the five year lifespan of the LTIM program, however monitoring undertaken to date supports the CEWO by evaluating adult and larval fish responses to environmental water delivery, along with other indicators of river and wetland health. Examples of environmental water delivery have been provided where methods have been refined and developed in line with adaptive management principles and developing knowledge.