Albert Park levee will be no worry to Southside houses
SOUTHSIDE residents are unlikely to notice any perceptible rise in flood waters if a levee is built at Albert Park, Aurecon engineers and the Gympie Regional Council have assured the community.
The impact of the height of the flood on the other side of the river would be "minimal" - most likely less than 10cm.
A range of levee sites to protect the CBD was considered in Aurecon's flood mitigation report - a levee within Nelson Reserve, raising the Bruce Hwy and a levee within the touch football fields next to Albert Park oval.
The Albert Park levee will be at least 50m wide at its base, 13m high at its highest point, and have an 80m spillway to allow controlled flooding of the area behind it.
This will clearly eclipse the lower touch football fields, which Gympie Regional Council plans to find a new home for.
Buying back flood-affected properties in the CBD would cost more than twice as much as the $22.7 million levee.
Removing the bottleneck at Fishermans Pocket to let the flood waters escape more quickly would cost hundreds of millions of dollars and possibly cause incalculably worse downstream flooding.
The most economically viable and achievable mitigation for the CBD is a levee.
But ensuring it is not a giant eyesore in the centre of the town will be a challenge for the engineers and designers who are expected to take another 6-12 months to fine-tune the plans and investigate more thoroughly, once funding is secured.
Indeed, Aurecon says there are several critical engineering design issues relating to the levee that will have to be fully analysed and resolved as part of its construction.
These include what to do if there is major rainfall within the Mary St catchment at the same time the Mary River is in flood, geotechnical issues due to the fact that Nelson Reserve, the Bruce Hwy and Albert Park were all built on landfill, flood infiltration through the mineshafts underground and residual flood risk should the Mary flood higher than 22m.
"The area was heavily mined during the gold rush period and the potential underground linkages to adjacent shafts are a significant risk," the report said.
The study considered flood issues across the region, and has completed assessments at the following locations.
The western district comprises flood-affected communities to the west of the Mary River such as Goomeri, Kilkivan, Widgee, Woolooga, Kandanga and Imbil.
The eastern district comprises flood affected communities on the Cooloola Coast: Cooloola Cove, Rainbow Beach and Tin Can Bay.
The Gympie district is flood affected suburbs within the city: Mary St, Commissioners Gully, Two Mile, Mt Pleasant, One Mile, Monkland/Glanmire, East Deep Creek and Southside.
The study's other key recommendations are:
- Goomeri: Assess the feasibility of a levee on the southern side of town to reduce the risk of flooding from Nangur Creek.
- Kandanga: Relocate the Kandanga Bowls Club which sits on the highly at-risk flood plain of Kandanga Creek.
- Coondoo Creek Bridge: Engage with Main Roads to raise the bridge on Tin Can Bay Rd so the 4000 properties on the Cooloola Coast are not so easily isolated in flood.
- River Rd at Centro Way: Engage with Main Roads to improve passage for commercial vehicles travelling south on the Bruce Hwy. These improvements, via River Rd and Pengellys Bridge would allow south-bound passage 6-10 hours earlier than via the (still flooded) Bruce Hwy Inglewood Bridge.
- Improved connectivity between Gympie and the Southside: Engage with Main Roads to ascertain where plans are at to build a flood-proof bridge across the Mary River.
- Voluntary buyback: Consider the voluntary buyback of residences and businesses exposed to frequent and significant above-floor flood inundation.