How Wetlands are Selected for Environmental Watering
Annual Watering Plans are developed to outline priorities for that water year based on likely available environmental water and environmental needs on a catchment-wide basis. This process also identifies suitable wetlands that may be appropriate targets to receive water during the water year. The criteria for selecting which wetlands may be a suitable targets include the volumes of water available, how efficiently water may be delivered, the time since last watering and the ecological needs associated with the wetland. To accommodate changes in available water that may occur during the year, a number of scenarios are developed. These include different water regimes which may occur under extreme drought, drought, average or wet conditions. The Annual Watering Plans and the results from using environmental water each year can be found in Lachlan Annual Watering Plans and outcomes.
Each scenario evaluates how the nationally, regionally significant wetlands and other important wetland habitats may be included in the annual watering plan under these various climatic conditions. As mentioned above, decisions on which wetlands might receive licensed environmental water, and when they may receive it, is based on:
- time since last watering;
- environmental assets supported by the wetland and their watering requirements;
- volumes available for watering, i.e. is there sufficient water available to achieve the environmental objectives;
- efficiency of delivery, i.e. whether the water can reach the target and/or whether other operational flows are also being delivered to the same target;
- degree of environmental need, i.e. bird breeding completion or averting fish kills may take precedence over other environmental needs; and
- land management practices undertaken within the wetland area.
An assessment considering all of these criteria is not only undertaken as part of the Annual Watering Plan but also as part of the longer term catchment strategy for investment in better environmental outcomes.
Decision-making Framework for the Annual Delivery of Licensed Environmental Water under Different Climatic Conditions
The decision-making process which prioritises wetlands by assessing how the delivery of licensed environmental water may meet objectives under different climatic conditions is illustrated in the climate scenario flow chart below.