Shannon water for Dublin

It won't help to alleviate flooding.

The project has never been promoted as an answer to flooding.

The original project was planning to abstract at the Inner Lakes on Lough Ree just North of Athlone.

Following strong local objection this plan was abandoned.

Irish Water to resubmit Lough Ree water extraction plan https://share.google/oghJksR6OgE0uLUaK

Rivers get bigger as they flow downhill toward the sea.

The water demand is an absolute number of litres - it’s not related to the size of the river.

At Birdhill, this demand happens to be about 2% of the volume of the river. If you move upstream, where the river volume is smaller, then that absolute volume is a higher percentage of the total.

Maths and geography aren’t political.

Most human consumption is put back in again further downstream (hopefully after being cleaned). The tiny amount of extraction that leaves and never comes back is far outweighed by the amount gained by inflows from tributary rivers and general runoff from the surrounding land.

Even the most ardent supporters of the proposal have never claimed that it will help to alleviate flooding.

I'm not from anywhere close to the Shannon, nor do I live in the Dublin region so I don't really have a vested interest in this but to characterise the opposition as "no more than just prevent Dublin getting it" doesn't add a whole pile to the discussion and comes across as fairly patronising.

I suspect at least some of the opposition to the project is in the reality that the flowrates being discussed currently are almost guaranteed to increase in the future and when the hot summer's day/week comes that there's a choice to be made between sending water to the reservoir for drinking purposes and maintaining a miniumumly sustainable river level downstream, there's only ever going to be one winner

I haven't read into the details but I presume that 2% figure is referring to the average daily draw as a % of the average daily flow? If you're to look at the worst case scenario though, it's the maximum daily draw at the minimum daily flow to that needs to be considered to get an idea of the possible effects on the river.

On top of that, you'd need to build in expected increases in that required maximum draw (due to increasing population in the Dublin region) along with any expected reductions (perhaps longer periods without rain due to climate change?) in the minimum daily flow. As I said, if at some point, there's a conflict in terms of where the water is needed, you can be sure that it won't be staying in the river.