Sheldon – Natural Hazards and Critical Infrastructure

Sheldon – Natural Hazards and Critical Infrastructure

Natural Hazards

To view Natural Hazard mapping layers for bushfire, flood and storm tides, or landslides visit the Redlands Coast Disaster Dashboard.

Bushfire

Sheldon has a significant bushfire risk, with the majority of the region being classified as having a medium to high bushfire hazard. Sheldon is a heavily forested bushland area 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 1km 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 wildfire, embers can travel up to 3km 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. For more information about bushfire preparedness and what to do during a bushfire, visit the Queensland Fire and Emergency Services website to create your Bushfire Survival Plan.

Along with threatening homes, a bushfire in Sheldon may also impact major power infrastructure which could have flow-on effects 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 on Council owned land and impact to surrounding areas. These strategies include hazard reduction burning (back burns), fire breaks and weed management. Redland City Council works with its Local Disaster Management Group partners to undertake fire mitigation activities around the city.

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, with a history of cutting Avalon Road in a couple of locations. These locations on Avalon Road are well signed and include depth indicators. Current flood mapping indicates that residential development in the Sheldon area would experience limited impacts from flash flooding.

Hilliards Creek is also susceptible to flash flooding; the creek rises in the low hills of Sheldon and Thornlands either side of Taylor Road. Woodlands Drive forms part of the catchment boundary between Hilliards and Eprapah Creeks catchments. Hilliards Creek upper branches meet just north of Boundary Road and flows northward, through Alexandra Hills and Ormiston, draining into Central (Moreton) Bay. The upper Tingalpa Creek starts in the west Mount Cotton hills and the Venman Bushland National Park reserve land as many small meandering ephemeral streams, before flowing through Sheldon and towards Leslie Harrison Dam. Wallaby and Buhot Creeks are tributaries and there are many more unnamed tributaries of Tingalpa creek. The upper catchment waterways mostly flow through bushland.

Landslide

Current Landslide Hazard mapping shows that Sheldon is considered to have a predominantly 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. In addition to this, the Redland City Plan, 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.

Plants and tree roots help to prevent landslides occurring by absorbing water and holding the ground together. After bushfires, heavy rain combined with a loss of plants and roots can make the ground soft and heavy, leading to a greater chance of landslides. Landsides can carry debris such as rocks and trees downhill and cause serious damage to anything in their path. The risk of a landslide occurring in a burnt area depends on the volume of rainfall, how steep the land is, the amount of remaining vegetation to support the land, the soil composition and the structure of rocks below the surface. QFES assess landslide prone areas after a significant bushfire to determine if there is a landslide hazard risk.

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 effects 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 SEQ Water Grid via a pump station on Gramzow Road, Mount Cotton which allows water to be pumped to and from the city. This pump station connects to the Heinemann Road Reservoir in Mount 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 Mount Cotton Reservoir at Tallow Wood Court which services Mount Cotton and Sheldon. This reservoir in turn is connected to the Alexandra Hills Reservoir located at Alexandra Circuit, 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

Like Mount 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 can cause significant dangers to the community, so be aware that any object in contact with powerlines could be live. The area surrounding fallen powerlines is more dangerous in wet conditions as sea and tap water are an excellent conductor.

Energex offer a notification service for Emergency and Planned outages, and other alerts such as upcoming meter read if dogs are onsite or for certain customer service work requests. Click here to go to the Energex Notifications page to Register for this notification service.

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 000 or Energex 13 19 62.

Gas

There is no domestic reticulated gas service within Redland City and no gas main that runs through the suburb of Sheldon. There are however homes within the area that use gas bottles to service hot water systems and cooking appliances. Residents are reminded to be 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.

Connection to the National Broadband Network (NBN) is now available across the majority of Australia, with various connection types for both wired (copper, fibre optic, and hybrid fibre-coaxial) and radio (satellite and fixed wireless). It is important to know the type of connection you have; fibre to the building (FTTB), fibre to the curb (FTTC), fibre to the node (FTTN), fibre to the premises (FTTP), or hybrid fibre-coaxial (HFC), there is also satellite or fixed wireless. The majority of connections are FTTN and FTTP, closely followed by HFC.

It is important to note that any equipment connected via the NBN will not work during a power outage, including VOIP (Voice over Internet Protocol) phones. For more information about what happens in a power blackout for the type of connection at your residence, please go to https://www.nbnco.com.au/learn/what-happens-in-a-power-blackout. Certain connection types can request battery back-up solutions through their internet service provider; battery back-up is required for all Priority Assistance customers who suffer from a diagnosed life-threatening illness.

If you have a medical alarm, emergency call button, autodialler, security alarm, monitored fire alarm or lift emergency phones at your premises, please contact your equipment provider to confirm whether your equipment will work via the network in the event of a power outage. Further information is also available on the NBN website and how to register these devices; this assists the NBN in identifying premises where support maybe be required to minimise service outages https://www.nbnco.com.au/learn/device-compatibility.

Road Network

REMEMBER: If it’s flooded, forget it – BACK IT UP!

Summer months bring rain, cyclones and unstable weather conditions to Queensland. More than half of flood related deaths in Queensland are the result of people driving through floodwater. 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. See a list of the areas that may be impacted by localised flooding.

Don’t wait until it’s too late. Plan ahead and keep yourself, family and friends safe. Check out the Floodwater Safety information available here https://www.qfes.qld.gov.au/prepare/flooding

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.