Ormiston – Natural Hazards and Critical Infrastructure

Ormiston – Natural Hazards and Critical Infrastructure

Natural Hazards

Bushfire

Ormiston, similarly to Wellington Point has scattered areas of high to very high bushfire hazard. The largest of these areas is located along Hilliards Creek stretching from Hilliard Street south to the railway line. This section of high to very high bushfire hazard backs onto established residential areas and there are additional residential developments being planned in the vicinity.

Properties adjacent to bushland areas may be at risk of ember attack should there be a bushfire in the vicinity. During a wild fire, embers can travel up to 3 kilometres in front of a fire line which means residents need to be vigilant and be prepared. For more information about bushfire preparedness and what to do during a bushfire, visit the Queensland Rural Fire Service website at: www.ruralfire.qld.gov.au and download the Bushfire Survival Plan – PREPARE.ACT.SURVIVE.

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 Ormiston Bushfire Prone Map.

Flood Prone, Storm Tide

The most significant source of flooding in the Ormiston area is Hilliard’s Creek. Hilliard’s Creek is prone to both tidal inundation and flash flooding from heavy rainfall events. Unfortunately, the vast majority of land that is impacted by the potential flooding is the bushland corridor that surrounds the creek system itself where there is no residential development. There are however a couple of larger properties at the end of Beckwith Street that may be impacted by flooding that could be caused by either tidal inundation or flash flooding form heavy rainfall events. Flash flooding of Hilliard’s Creek has the potential to extend from the mouth of the creek in Ormiston, across the railway line at the end of Sturgeon Street, around Ormiston College and continue as far inland as Finucane Road, Cleveland.

Download the Ormiston Flood Prone, Storm Tide Overlay.

Landslide

Current mapping indicates that Ormiston has a limited landslide risk, being a low to medium landslide hazard generally along its eastern shoreline. Ormiston is a well populated area with residential development within the identified landslide hazard areas.

The Redland Planning Scheme, through the Landslide Hazard Overlay attempts to mitigate the 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 Ormiston 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

The vast majority of Ormiston is connected to the sewer network which links into the Alexandra Hills Sewerage Treatment Plant located to the east of Hanover Drive adjacent bushland identified as being a high to very high bushfire hazard.

The small number of acreage properties that are not connected to the sewer network 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

Ormiston receives its water supply from the Alexandra Hills Reservoir located at Hilltop Circuit, Alexandra Hills. The Alexandra Hills Reservoir services the Redland City’s northern suburbs via a pipeline network that is both gravity fed and pressurised. The reservoir holds a mix of water from the Leslie Harrison Dam and the Herring Lagoon bore field on North Stradbroke Island.

This is possible because the Alexandra Hills Reservoir connects to both the Leslie Harrison Dam and the Mt Cotton Reservoir at Tallow Wood Court, Mt Cotton. The Mt Cotton Reservoir is in turn connected to the Heinemann Road Reservoir, Mt Cotton which connects to both the South East Queensland Grid and North Stradbroke Island. 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 via the Heinemann Road Reservoir, Mt Cotton. This network of reservoirs, pump stations and pipelines ensures that water can be moved around the network and that multiple water supplies are available to residents living in all areas Redland City.

Electricity

Ormiston has even mix of both overhead and underground powerline networks servicing the suburb. This mix is due to the established acreage areas near the waterfront being more recently sub-divided for urban development. The overhead powerlines are more 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 Ormiston. There are however homes within the area that use gas bottles the 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

Ormiston is connected via landlines to the telecommunications and data networks. There is good mobile network coverage in Ormiston with limited to no 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.

Rail Network

The rail network enters Redland City via Thorneside, crossing the Tingalpa Creek to the north of the Thorneside sewerage treatment plant and continues on to the Thorneside Station. From Thorneside Station the rail network continues east to Birkdale Station and Wellington Point Station where the line turns south-east to Ormiston Station and Cleveland Station where it terminates.

Current Flood Prone, Storm Tide mapping indicates the possibility of the rail network being cut by flood water on the Redland City side of Tingalpa Creek, north of the Tingalpa Station. If this were to occur, rail transport in and out of Redland City would be cut along with rail access to Brisbane City. This would prevent any evacuations via rail to the RNA Showgrounds which is the primary evacuation centre for Brisbane and an alternate evacuation centre for Redland City residents should the city’s infrastructure be significantly compromised by a disaster event.