Dams and elections go together like strawberries and cream or tomato and basil. We’ve already had territory staked out for a big fight over a big dam in Far North Queensland.

Now the election is on and we can look at a key battleground state as the campaign’s dam wall.

Queensland filled up with Coalition wins in 2019 – finishing with a lopsided 23 out of the 30 seats – and the LNP knows if that electoral dam wall breaks the flood could reach Canberra.

Even a big spill over the wall might threaten the mortality of Scott Morrison’s government.

This is why the Liberals Nationals Coalition is playing an almost exclusively defensive political game in Queensland. They don’t want to lose any of those 23 seats. They will hunt and fight until the last dog dies – a fitting adoption of a Deep South saying for Australia’s Deep North.

Sure, the LNP will make forays into Labor territory. They’ll likely visit Lilley in Brisbane’s northern suburbs which is the most marginal electorate in the state.

They might pop into one or two other Labor seats – maybe Blair further to the north or Griffith across the Brisbane River to the south east of the CBD and if the polls turn remarkably, a visit to Moreton next door might emerge late.

A little remarked but worth remembering fact is that these four Labor seats are on margins (from 0.6 per cent in Lilley to 2.9 per cent in Griffith) sitting below the most marginal on the Coalition side of the pendulum, Longman (3.3 per cent).

This reflects the damage done to Labor by the LNP in 2019 – they swept through Queensland electorates without fear or favour. Such savage insurgent power is seldom repeated at a subsequent election (the 1977 Coalition landslide following the 1975 rout of Labor is the most glaring anomaly) so we should expect these seats to hold.

Also, the four seats have that other bit of not so secret sauce – popular local members who have dug in.

This personal following factor will also figure prominently in the LNP’s defensive strategy. Seats like Dickson, Petrie, Bonner, Forde and Leichhardt have shown advantage from settled incumbency.

Elsewhere, there are open contests where LNP members are retiring – Bowman on Brisbane’s bayside, Flynn around and inland from Gladstone and Dawson with a similar profile around Mackay.

Open contests often lead to opportunity for oppositions but this time maybe not.

Gladstone was very high on Labor’s target list but confidence of picking up the seat is waning.

Dawson is regarded by all as a bridge too far (it’s buffered with a 14.6 per cent margin) and if at any time it looks like Bowman (a 10.2 per cent seat) is in trouble for the LNP the bookies can start paying out.

The LNP’s real defensive game is going to be in the metropolitan seats of Brisbane (4.9 per cent) and Ryan (6 per cent). The seat of Longman could be hard to defend but has one wild card internal – a “none of the above” vote that’s run close to 30 percent for 25 years – that might tip it one way or the other.

Also, from that short first line list of seats with popular MPs, Leichhardt might fall despite Warren Entsch’s previous loyal following

If the Queensland LNP dam wall holds, Morrison’s path to stay in power is still tricky but not impossible. If the electoral water breaks through, it’s almost certainly the end.