The Barwon River model and the tidal inflow locations are provided in Figure 6-8. The red, green and blue areas in indicate the different grid sizes which were used in the models, as listed in Table 5-2. The Barwon model was initially set as a 40 m grid (indicated in red) covering the wider Barwon Connewarre area. The large grid-cell resolution was required due to the size of the area as it must capture the storage characteristics of Lake Connewarre. Finer resolution is required to appropriately reproduce features in the township areas. As a result, three nested grids were incorporated to ensure greater detail at the relevant locations, such as the residential areas on the eastern and western banks of the river. One grid was a 20 m resolution (indicated in green) covering Barwon Heads, Ocean Grove and the Barwon River to appropriately assess the estuary entrance conditions to Lake Connewarre. Two 4 m resolution grids (indicated blue) covered Barwon Heads and Ocean Grove individually providing a model that is able to assess the expected impact of sea-level rise on individual properties in the townships. Key development features such as roads and shore protection structures were checked to ensure they were picked up as topographic features, and were refined where necessary. Culverts and pipes located along the main drainage path were incorporated into the model, as indicated by the pink dots in Figure 6-8.

As discussed in Section 4.3.3, the Barwon model was run with the 1% AEP storm-tide case in conjunction with a constant 99th percentile average daily flow (87 m ³/s) in the Barwon River. As with the Breamlea model the modelling was undertaken for a number of sea-level rise scenarios. Additional ‘high flow’ model runs were also undertaken for the 0.0 m, 0.8 m and 1.4 m SLR scenarios where the 10% AEP riverine flood event in the Barwon River was timed to coincide with the peak 1% AEP tide level in the Barwon Estuary.

Figure 6-8     Extent of Barwon River model, showing river and tidal inflows and culvert locations (pink circles)