Dam the Liffey

Cost

Ecological damage

Salmon migration

all of those reasons are readily surmountable. The benefits greatly outweigh the cost and it could be a nice feature in itself. the only caveat is that in not be lower than Butt bridge otherwise it will further restrict the greatly reduced ability of boats etc to sail up the river.

Previous discussion on a weir on Archiseek
https://archiseek.com/content/showthread.php?t=331&goto=nextnewest

In the Construction of Dublin a proposal from 1997 by James Horan and Peter McGovern is mentioned. It included a salmon run and artifical island at City Quay with lock gates to allow movement of water traffic.

a weir at city quay would make a joke of the ability of the new Sean O’Casey bridge to open.

Well worth the investment IMO. The Lagan Weir demonstrates how effective such a scheme would be. Dublin would benefit even more than Belfast as the river runs rith through the city centre. See here also.

@Frank Taylor wrote:

solving the dirty walls and bad smells problem when the tide runs out and the shopping trolleys and traffic cones poke out from the slime?

It wouldn’t really solve it, it would only hide it. So various crap would still end up in there, and the extent would not be known. And the water traffic would suffer from it.

@Bren88 wrote:

It wouldn’t really solve it, it would only hide it. So various crap would still end up in there, and the extent would not be known. And the water traffic would suffer from it.

The worst problem is the awful stench from the decomposing mud in the summer. The weir would solve that. Your point makes little sense to me, it seems to claim that it’s good to know what sort of material has been dumped into the Liffey, even though no attempt is made to removed the stuff-lots of rivers aren’t tidal and are probably full of shopping trolleys and it doesn’t cause a major problem, though I’m not encouraging the disposal of anything into a waterway! The weir would kill the smell off and encourage more people to take in the river and let it return to prominance in our city, and that’s good enough reason to spend €30m in my book.

@murphaph wrote:

The worst problem is the awful stench from the decomposing mud in the summer. The weir would solve that. Your point makes little sense to me, it seems to claim that it’s good to know what sort of material has been dumped into the Liffey, even though no attempt is made to removed the stuff-

Did you honestly consider that I was claiming that it’s good to see what has been dumped into the river. My point was that raising the level like that would hide the current rubbish. And due to some of the lower bridges, the level could only be raise to a point. But all the crap would continue to build up.

The idea would help with the unsightly stains and mud. But all the dam would achieve would be a consent high tide liffey. And the current liffey is still very far from beautiful at high tide. The river is better at high tide, but I would find it hard to believe that the average high tide could “encourage people to take in the liffey”.

@Bren88 wrote:

Did you honestly consider that I was claiming that it’s good to see what has been dumped into the river. My point was that raising the level like that would hide the current rubbish. And due to some of the lower bridges, the level could only be raise to a point. But all the crap would continue to build up.

Fair enough, it wasn’t clear from your post is all. So the river needs more regular dredging, on that we’re agreed I presume.

@Bren88 wrote:

The idea would help with the unsightly stains and mud. But all the dam would achieve would be a consent high tide liffey. And the current liffey is still very far from beautiful at high tide. The river is better at high tide, but I would find it hard to believe that the average high tide could “encourage people to take in the liffey”.

Not in isolation, but coupled with the boardwalks and good weather, then yes, as the primary factor in people balking at the river is the stench in summer during low tides. Eliminate the push factor before creating pull factors that can’t do anything about the smell at the precise time of year that you want to maximise the river’s potential-peak tourist season.