MWRPP Report 18.1: Cockatoo Swamp Inundation Modelling.

The Waterway Ecosystem Research Group and Melbourne Water are researching environmental watering requirements for swamp forests in the Cockatoo Swamp, Yellingbo Nature Conservation Reserve. A hydraulic model was developed using TUFLOW to estimate historical inundation patterns, incorporating new topographic and water level data.The model, consistent with a previous 2014 version, was calibrated using recent survey datasets, including LiDAR and feature surveys. Calibration was performed against two events: a short-term July 2014 event and a long-term February 2014 to December 2015 event.After iterative adjustments, the calibration achieved a good match with gauged water levels, particularly in dieback-affected areas. Modelled levels tended to be slightly lower than gauged data but slightly higher than surveyed point water levels. The model performed better for high flow events than for low inflows or drainage flows.The calibrated model was used to simulate historic flow series (1998-2018), producing daily water level grids. This data will support research on environmental watering requirements for the swamp forests, aiming to develop targeted watering regimes to foster forest regeneration and improve habitat quality for endangered Helmeted Honeyeater and lowland Leadbeater's Possum populations.