Darling Downs roadworks take unexpected turns
Roadworks to repair a key transport route on the Darling Downs took unexpected turns courtesy of two unlikely sources, unsuitable soil and an endangered lizard.
Toowoomba–Cecil Plains Road connects Toowoomba with the rural town of Cecil Plains about 80 kilometres west of the Garden City.
Located on the Condamine floodplain, the road is susceptible to damage from flooding.
Sections of the road were damaged by heavy rainfall in late 2021 with subsequent severe weather events in 2022 compounding damage to the road surface and drainage along the road.
Emergency works were undertaken to maintain access following each event.
Comprehensive reconstruction works to repair and reseal the road surface, repair culverts and clean drains commenced in March 2023 and were completed in November 2023.
However, work on some sections of the road was complicated by the presence of a black soil subgrade.
Although ideal for local crop growing, the soil’s tendency to expand and contract significantly depending on the weather makes it unsuitable for roads.
Not surprisingly, the soil failed a proof rolling test necessitating its removal and replacement.
Whilst that work was relatively straightforward, a very different challenge faced TMR when it came to repairing a priority culvert site known locally as the Evanslea Floodway.
The floodway was identified for resilience works as part of the 2021–22 Betterment Program.
Works included a full-scale pavement rehabilitation, and the installation of table drains to direct the water away from the road.
Under normal circumstances, this work would be considered routine.
However, the Evanslea Floodway forms part of the known habitat of the endangered Condamine earless dragon (Tympanocryptis condaminensis), a tiny lizard that lives in natural grasslands on the Condamine floodplain, including along road reserves.
The species was thought to be extinct until it was rediscovered in 2001.
With sightings of the lizard confirmed near the culvert site, in 2023 TMR obtained an approved Animal Breeding Places Assessment and Impact Management Plan from the Department of Environment, Science, and Innovation allowing it to complete the flood repair works while simultaneously protecting the vulnerable species.
With the plan in place, TMR commenced work in late May 2024 with practical completion in late August 2024. As often planned for these types of projects, TMR will come back later in the year to do the final seal and line-marking.
The recovery works are jointly funded by the Australian and Queensland governments through the Disaster Recovery Funding Arrangements (DRFA).
For up-to-date information about works on Queensland’s state-controlled network, including current restrictions and closures, call 13 19 40 or visit www.QLDTraffic.qld.gov.au.
