a levee system.
Hasbeen,
We need a levy so we can do without dodgy levees. We have an insurmountable amount of rubbish so, why not mulch waste & mix with concrete sludge to make fill ?
You'd be surprised how much land could be built up in twelve months to provide solid foundations.

Hassy,

I put you in with the flat earth people, and those that believe the Moon is made of green cheese.

In the case of Brisbane, any flood mitigation project will involve incredible cost. Why should people who are smart enough not to buy properties in a flood zone be penalised though taxation to contribute to paying for it?

The best thing to do it just let the river be the river and realise that we have to adopt to it, not it to us. The best and most sensible course of action to take as a community is no action at all.

People who construct their houses/buildings on a known flood zone should be held responsible for their own actions and bear any loss themselves. We definitely should not offer any governmental financial assistance to people to rebuild if they are going to rebuild on the same plot (or rebuild at any other location that suffers form flood).

in above "adopt" should be "adapt"

In the case of Brisbane, any flood mitigation project will involve incredible cost.
thinkabit,
Only if Unions get involved & private consultants & Greenies & the EPA.

Rising sea temperatures means increased evaporation which in turn results in more rainfall - that's one obvious cause.

Flooding is exacerbated when populations build on known flood plains, which are increasing in size and building sea walls to stop coastal erosion is a temporary fix for the sake of preserving valuable real estate.

Lismore is known by locals as "the wok" for a reason and Sydney is much the same and simplistic options like raising a specific dam wall will not stop flooding when there are other rivers feeding into the same catchment area as happens on the Hawkesbury.

A solution would be to critically reassess where people are allowed to build and abandon various existing towns - neither of which are likely.

Meanwhile we just have to learn to live with the effects on allegedly non-existent climate change and have the same arguments all over again next time it happens.