It sets pulses racing among the business and engineering communities as just the sort of nationally significant infrastructure a bold government would encourage if it were serious about meeting the twin goals of green growth and a low-carbon economy.
But environmentalists have serious problems with barrages, despising the increased flood risk and threat to wildlife and livelihoods.
Given the cover offered by the comprehensive spending review, energy and climate change secretary Chris Huhne had the relatively easy task of kicking this one into the long grass.
This is, after all, the anti-nuclear politician in opposition now overseeing the next generation of nuclear power plants. Huhne may have offered a mealy-mouthed explanation that he has nothing against nuclear per se, merely the huge state subsidies it draws, but that's not really how anyone else remembers it.
There are only so many thrashings a coalition minister can take in one go. Even the partisan elements within the Conservative press were branding him "Huhne the hypocrite". But if business secretary Vince Cable can make an extraordinary U-turn on tuition fees, then Huhne can do his bit by taking one for the team.
But the barrage, like expansion at Heathrow Airport, is also one of those projects that have the resilience of Count Dracula. In ruling out public funding at this stage, Huhne has recognised that factors determining a barrage's feasibility will change over time.
The government may not intend to review tidal power from the Severn before 2015, but that's not as far away as it seems.
Within minutes of his announcement, engineers were keen to reiterate their support for the barrage and one of its key backers reasserted their determination to press ahead.
A barrage was first proposed for the estuary back in 1849. Since then numerous committees, commissions, teams of experts and consultants have had their twopennyworth. It is only a matter of time before this one is resurrected again.