Understanding flood risk 

Flooding is a type of natural hazard which has potential to cause significant damage to property, infrastructure, and pose a risk to humans and their welfare.  

Climate change will result in extreme weather events such as flooding occurring more often and with greater intensity.  

Most residents of the Brighton municipality would be familiar with our major waterways, such as the Derwent and Jordan rivers. These waterways have water flowing in them permanently and have high natural amenity. 

You may be unaware of local minor waterways or natural drainage lines. Many of these have been piped, and many are dry for some or all of the year. Some of the minor natural drainage lines may only have water flowing in them in extremely heavy rainfall events. 

Because these minor drainage lines are not obvious, you may not be aware that your property may be in a natural pathway for water.  

Your property may be at risk of flood damage if: 

• you are near a waterway, including ephemeral waterways that are usually dry, and waterways that are fully piped underground 
• your property is in a natural depression, including at a dip in the road 
• your property slopes up into natural bushland 
• your property is in a low-lying area near the Derwent River. 

Floods can occur at any time of the year regardless of the season: in the last few years our biggest events were in May and December. 

Flood maps 

Council have undertaken overland flow path flood mapping for key urban areas in the municipality based on the stormwater management plan which Council has a responsibility to prepare under the Urban Drainage Act 2013. A key component of this plan was to identify the extent and effects of urban flooding. 

View Flood maps for each location here:

• Brighton; 
• Bridgewater & Industrial Area;  
• Gagebrook & Herdsmans Cove 
• Old Beach
• Old Beach – Tivoli Green

Council’s methodology for mapping the overland flow flood hazard is consistent with other Councils that have done this work across the state.  

The modelling has been done at a catchment wide level and provides an indication of potential hazards but may not be accurate at a property level. If a specific site needs high accuracy stormwater modelling, an independent opinion should be obtained from a person with suitable qualifications. 

The modelling identifies major flow paths during extreme events. It does not pick up localised nuisance flooding associated with undersized pits or pipes or localised road camber. It also does not pick up un-concentrated sheet flow, such as what occurs at the bush-urban interface. Just because your property is not within the mapped hazard extent does not mean you won’t be affected in a flood. 

The mapping will not only inform community about the overland flow impact on their land, but also help Council to make land use planning decisions about development applications and future rezoning’s to reduce the risk of flooding. 

If you have any queries or require further information, please contact Council’s Asset Services Department by telephone on 6268 7000 or via email to asset.services@brighton.tas.gov.au