To view Natural Hazard mapping layers for bushfire, flood and storm tides, or landslides visit the Redlands Coast Disaster Dashboard.
Russell Island has the highest bushfire risk of the Southern Moreton Bay Islands, with the majority of the island being identified as having a high to very high bushfire risk. The properties at greatest risk are those located at the southern end of the island in the Sandy Beach and Rocky Point areas. There is a large area of inaccessible swamp south of Glendale Road which is boarded on the eastern side by the Sandy Beach community. If the prevailing winds during a bushfire event are from the south or west, they are likely to drive the fire towards the at risk properties. The main power line from the mainland supplying power to the Southern Moreton Bay Islands and North Stradbroke Island also runs across this area, putting the power supply to these islands at risk. Local residents have reported that approximately 30 years ago a significant fire occurred that burnt most of the bushland on the island. There has been no significant fire activity on the island since, resulting in considerable fuel loads in the swamp.
Flood Prone, Storm Tide
Flood prone, storm tide and drainage constrained land mapping has identified the potential for storm tide inundation to have significant inland penetration during a severe storm event which has the potential to isolate communities on Russell Island. Communities located at the southern end of Russell Island such as those at Sandy Beach and Rocky Point are particularly vulnerable. For the Sandy Beach area on the south eastern tip of Russell Island, indications are that the primary access road – Glendale Road, could experience flooding to the west of Jingella Avenue effectively isolating the entire area. For the Rocky Point area on the south western tip of Russell Island, access via Stradbroke Drive or Glendale Road could be affected. Stradbroke Drive could experience flooding to the west of South End Road, and Glendale Road could experience flooding to the west of Centre Road. Minjerriba Road also has potential for flooding near Maroondah Street which would effectively cut the primary land evacuation route from the southern end of the island to the barge and ferry service in the north of the island.
The majority of Russell Island has low to no risk of landslide. Areas of high to very high risk are limited mainly to the eastern coastline of the island; particular in the southern end from Seaward Drive south to The Boulevard at Sandy Beach. This area is dotted with residential development in the region of Wahine Drive, Naples Drive, Crescent Drive and The Boulevard.
Critical infrastructure on the islands at the time of a disaster event includes utilities such as power, water, sewerage and telecommunications, and water transportation including ferry and barge services. Impacts of a disaster on these services may have far-reaching long-term affects for island communities.
The sewer network operated by Redland City Council covers Coochiemudlo Island, parts of Dunwich, and Point Lookout on North Stradbroke Island. Those parts of Dunwich, Point Lookout and Amity Point not serviced by the sewer network utilise septic systems, as does all of the Southern Moreton Bay Islands (SMBI).
Many of the newer homes, businesses and the primary schools on Russell and Macleay Islands use modern sewerage treatment systems that require power to operate. Therefore during extended periods of power outage the toilets are unable to be utilised or risk failure if used. This limits the number of community buildings that can be used as evacuation centres during a disaster event.
The most serious affect of a failing sewerage system is the potential for highly infectious diseases to occur including dysentery and hepatitis. Mosquitoes and flies that spread a number of other illnesses can breed in areas where liquid waste reaches the surface. There are also risks to the natural environment including the health of waterways and Moreton Bay.
Water can be supplied to Russell Island via either North Stradbroke Island or the mainland. From Russell Island, the supply is then piped via Karragarra Island to Lamb Island and then onto Macleay Island. The water supply for Coochiemudlo Island is also piped directly from the mainland. The mainland water supply is connected to the SEQ water grid and therefore the risk of the water supply failing is extremely low. However the islands of Karragarra, Lamb, Macleay and Coochiemudlo only have one connecting pipeline. When one of these pipelines fails there will be a loss of supply and emergency supply measures will be put in place.
The North Stradbroke Island townships of Dunwich, Amity Point and Point Lookout source their water supplies directly from the bore fields located on North Stradbroke Island and again the risk of the water supply failing is extremely low.
The electricity supply provided by Energex to the SMBI and North Stradbroke Island comes via Russell Island. The supply originates on the mainland north of Cabbage Tree Point and crosses the Western Boating Channel, connecting to the southern end of Russell Island at Rocky Point, then continues north through the centre of Russell Island before branching off to service North Stradbroke Island and Karragarra Island. The electricity supply from Karragarra Island then connects to Macleay Island which in turn is connected to Lamb Island.
This sequence of connections highlights the importance of Russell Island to the electricity supply for SMBI and North Stradbroke Island. There is a substation on Russell Island to assist in ensuring the power supply to Russell Island is more robust and with less power fluctuations. There are a number of transformer connection points on Macleay Island which enables Energex to use generators to supply power to Macleay, Karragarra and Lamb Islands in the event of a major power failure; however this would be a reduced supply.
The main line that crosses to the southern end of Russell Island is strung on concrete poles high above the ground in a relatively inaccessible area of moderate to high bushfire risk. If the line was impacted by bushfire, Energex would restore the line as quickly as possible given the population on SMBI and North Stradbroke Island.
The electricity supply to Coochiemudlo Island comes via an underwater line from the Victoria Point reserve at the end of Colburn Street and connects to the western tip of the island near the golf club. The line runs underground until it meets the established road network and as such has limited impact from bushfire, tidal surge or flood hazards.
Landline access to North Stradbroke Island and SMBI is via a microwave link from the mainland to exchanges on the islands. The exchanges on North Stradbroke Island are located at each of the three townships of Dunwich, Amity Point and Point Lookout and for SMBI the exchanges are located on Russell and Macleay Islands. Coochiemudlo Island is connected via a submarine cable that runs from the Victoria Point exchange to the island.
The exchanges on North Stradbroke Island and SMBI require electricity to operate and all have battery back-up systems that operate for a limited period of time. During extended periods of power outage Telstra have generators that can be deployed from the mainland to provide additional capacity. Telstra also have other resources such as a mobile exchange, mobile satellite coverage and mobile base station that can be deployed if required.
There are no mobile phone towers located on SMBI or Coochiemudlo Island; coverage is from towers on the mainland and North Stradbroke Island. Mobile phone towers on North Stradbroke Island are located in each of the three townships which provide good coverage over these areas. The Amity Point tower also has a radio link to Karingal on the southern end of Moreton Island. There are mobile coverage black spots in the southern part of North Stradbroke Island and some parts of SMBI.
Other telecommunication issues that will impact the community during periods of power outage include cordless landline phones and access to the internet, both of which require power to operate. With more people using their mobile phones to access the Internet, more pressure is being placed on the capacity of the network.
North Stradbroke Island, Coochiemudlo Island and SMBI are all accessible via vehicle barge and passenger ferry, departing from Toondah Harbour, Victoria Point and Weinam Creek Marina respectively. Along with the barge and ferry service to SMBI, Bay Island Transit System (BITS) also operates the QAS boat Kitty Kat from Russell Island. The QAS boat is available 24/7 and an arrangement is already in place to transport Energex staff to SMBI in an emergency, if Kitty Kat is not required for patient transport.
The passenger ferries are designed to operate in rough seas and therefore the size of the waves in the bay or the strength of the wind is unlikely to stop the ferries from running – high winds are more of an issue for the vehicle barges. However, the safety of passengers as they board and depart from the passenger ferries and visibility during heavy fog or torrential rain does determine whether the passenger ferries will operate. The passenger ferries are able to land directly onto the island’s foreshores if the jetty or pontoons were damaged or destroyed. The main safety consideration in doing this is the loading and unloading of passengers.