How flooding occurs on the Central Coast

To understand the potential impacts of flooding on your property, use our online flood risk tools.

Flooding comes in different types, sizes and durations:

1) Catchment flooding

Catchment flooding occurs from prolonged or intense rainfall (e.g. severe storms and East Coast Lows) that can lead to:

• Breaking the banks of creeks and rivers - Hawkesbury River, Erina Creek, Narara Creek, Ourimbah Creek, Wyong River, and many others.
• Filling coastal lakes and lagoons - Tuggerah Lakes, Wamberal lagoon, Terrigal Lagoon, Avoca Lake, Cockrone Lagoon, Pearl Beach Lagoon.
• Water flowing across normally dry land in both urban and rural areas on its way to waterways, due to the inability for the ground to absorb additional water.

2) Coastal flooding

Coastal flooding normally occurs when dry and low-lying land is submerged by seawater, often caused by tidal or storm-driven coastal events, including storm surge and wind-induced waves in coastal waterways.

Areas on the Central Coast that can be impacted by coastal flooding include:

• Brisbane Water and the lower reaches of Narara Creek and Erina Creek
• Coastline foreshores areas

3) Combination flooding

Catchment and coastal flooding can occur simultaneously. The impacts will vary depending on factors such as catchment characteristics and the specifics of the weather event.

4) Flash Flooding

Flash flooding is caused by sudden local or nearby heavy rainfall generally peaks within six hours of the onset of rain. 

Flood duration

Areas that are affected by coastal flooding, such as foreshore communities in Brisbane Water, may experience flooding which can typically last only 2 hours associated with a high tide.

Land adjacent to creeks and rivers can be flooded for a day or more; foreshore land around Tuggerah Lakes can be flooded for up to four days.