Sheldon – Natural Hazards and Critical Infrastructure

Sheldon – Natural Hazards and Critical Infrastructure

Natural Hazards

Bushfire

Sheldon has a significant bushfire risk with the majority of the region being classified as having a high to very high bushfire hazard. Sheldon is a heavily treed bushland area being made up exclusively of large acreage properties where typically the home is set back deep into the property amongst the trees. These properties generally have a long single access driveway (some up to 1 kilometre long) which impacts the ability to evacuate those properties should a bushfire cut driveway access to the road.

These properties are also at risk of ember attack should there be a bushfire in the surrounding area. During a wild fire, embers can travel up to 3 kilometres in front of a fire line which means that all dwellings within the Sheldon area are at risk. Residents need to be vigilant and be prepared.

Along with threatening homes, a bushfire in Sheldon may also impact major power infrastructure which could have flow on affects for Redland City and possibly Brisbane City and Logan City as well. There is also a large quarrying operation in Sheldon that would be adversely impacted by bushfire.

Redland City Council employs a range of fire mitigation strategies to reduce the risk of bushfire in the area. These strategies include hazard reduction burning (back burns), fire breaks and weed management. Redland City Council is also investigating arrangements with Queensland Fire and Emergency Services to support fire mitigation activities around the city.

Download the Sheldon Bushfire Prone Map.

Flood Prone, Storm Tide

There are a number of creek systems in the Sheldon area, all of which feed into the upper reaches of the Tingalpa Creek which eventually runs into the Leslie Harrison Dam. These creeks do have the potential for flash flooding during heavy rain events as they have a history of cutting Avalon Road in a couple of locations. These locations on Avalon Road are well signed and include a depth indicator. Current flood mapping indicates that residential development in the Sheldon area would experience limited impacts from flash flooding.

Download the Sheldon Flood Prone, Storm Tide Overlay.

Landslide

Current Landslide Hazard mapping shows that Sheldon is considered to have a low landslide hazard with a few pockets of medium to high landslide hazard. Sheldon is typically a rural area with sparse residential development which limits the potential impacts of landslide. Furthermore, the Redland Planning Scheme, through the Landslide Hazard Overlay attempts to mitigate to impacts of the landslide hazard by requiring more robust engineering for developments built within the identified landslide hazard areas. It is important for engineers and geologists to evaluate slope stability and any landslide threat during development assessments so that effective and timely remedial measures can be implemented.

Download the Sheldon Planning Scheme, Landslide Hazard Overlay.

Critical Infrastructure

Critical infrastructure at the time of a disaster event includes utilities such as power, water, sewerage, telecommunications, gas and road and rail networks. Impacts of a disaster on these services may have far reaching long term affects for mainland communities.

Sewage

Sheldon is a rural suburb characterised by large acreage properties, consequently none of the properties in Sheldon are connected to the city’s sewer network and rely on a mix of gravity fed septic systems and on-site sewerage treatment plants located on the properties to manage the wastewater. The on-site sewerage treatment plants require electricity to function, therefore it is recommended that these systems have a back-up generator to cope with extended periods of power outages which can occur during severe weather events.

Water

Redland City is connected to the South East Queensland Water Grid via a pump station on Gramzow Road, Mt Cotton which allows water to be pumped to and from the city. This pump station connects to the Heinemann Road Reservoir, Mt Cotton which is also connected to Herring Lagoon on North Stradbroke Island ensuring two sources of water to the southern end of the city.

The Heinemann Road Reservoir services the Southern Moreton Bay Islands, Redland Bay, Victoria Point and Thornlands and is also connected to the Mt Cotton Reservoir at Tallow Wood Court, Mt Cotton which services Mt Cotton and Sheldon. The Mt Cotton Reservoir in turn is connected to the Alexandra Hills Reservoir located at Hilltop Circuit, Alexandra Hills making possible the supply of water to Redland City’s northern suburbs should there be issues with Leslie Harrison Dam which traditionally services the north of the city.

There are a number of rural properties in the Sheldon area with large dams that act as an independent water source for those residents. These dams may provide a potential source of water for aerial water bombing operations should they be required.

Electricity

Similarly to Mt Cotton, Sheldon has significant electrical infrastructure running through it. Power supply connection between Logan City and Brisbane City runs via a 110kV above ground powerline from the southern end of Sheldon behind the Karreman Quarries. The powerline travels north-west through Sheldon where it transverses heavily wooded terrain which is characterised as high to very high bushfire risk before crossing Tingalpa Creek into the Brisbane City area.

Sheldon is a long established rural area and as such the overhead powerline network that services the suburb is susceptible to damage during severe weather which can result in power outages and fallen powerlines. Fallen powerlines oppose significant dangers to the community, be aware that any object in contact with powerlines could be live. The area is more dangerous in wet conditions as water is an excellent conductor.

Remember:any metallic objects, including fences, will be electrified if they touch or are even close to a live fallen powerline. Even a tree branch can be a potential conductor of electricity if it is in contact with a live wire. Stay away from fallen powerlines and alert others of the danger – contact Energex on 13 19 62.

Gas

There is no domestic reticulated gas service within Redland City. Nor is there a gas main that runs through the suburb of Sheldon. There are however homes within the area that use gas bottles the service hot water systems and cooking appliances. Residents are reminded to diligent with the appropriate storage and maintenance of any gas bottles that they have located on their property.

Telecommunications

Sheldon is connected via landlines to the telecommunications and data networks. There is mobile network coverage at Sheldon however due to the terrain of the region, there are mobile reception black spots in the area. Telstra is the major supplier of telecommunications to the region; other suppliers include Optus and Vodafone.

Road Network

REMEMBER: If it’s flooded, forget it!

On 20 November 2012, Iain MacKenzie – Inspector General Emergency Management said “There is absolutely no excuse for motorists who deliberately drive or walk past a road closed sign and into floodwaters. Even if you are in familiar territory and believe local knowledge will get you through, think again. Floodwaters are treacherous and the dangers are hidden beneath the surface.”

Every year people are hurt, or die, trying to cross or play in flooded waterways. It can happen anywhere – roads, creeks, dams, parks or backyards. Residents should be aware of the dangers connected to floodwater or swift flowing water such as: slippery surfaces; uneven ground; strong currents; sharp objects; electrical current; fences; vehicles; rocks; long grass; tree branches; sewerage; and chemicals.

If you get trapped in floodwater, you not only put your life and the lives of the people with you at risk, but you also put the lives of the rescuers at risk too.

Localised flooding may temporarily restrict access and cut roads in some areas of Redland City. Please consider this when planning to drive during periods of heavy rain. A list of the areas impacted by localised flooding can be found here.

Rail Network

Currently there is no rail infrastructure in Sheldon and there are no plans to extend the rail network to Sheldon in the near future.