Hydroelectric Salmon Weir

Birroc

Why isn't the salmon weir generating hydroelectric power? I imagine it would be pretty cheap to set up and would be very productive.

ronnie3585

And it would destroy one of the best salmon rivers in Europe.

Iwannahurl

Funnily enough, I was just musing on this very point recently.

Question: there used to be mills on the river; why did they not destroy the salmon?

The river was teeming with salmon when I were a lad. I don't think it was electricity generation that reduced their numbers...

yer man!

Ah there's a whole pile of problems with it, ESB looked into using the waterways near nun's island to generate power but it would have caused levels in the canal and surrounding rivers to go haywire. They found that in theory they could have supplied a lot if not all of the inner city's power, but water levels would go crazy for surrounding rivers and canals. NUIG's old engineering building has turbines on nun's island and that powers that building, not sure if actually supplies the grid with any but i doubt it. If they were to put turbines anywhere near the salmon weir everyone would go crazy as it would really affect the water levels and you'd have a lot of very angry fishermen...... They're already going mad over the proposed bridge parallel to the salmon weir bridge, wouldn't wanna rock the boat anymore (had to say it)

Zzippy

Iwannahurl wrote: »

Funnily enough, I was just musing on this very point recently.

Question: there used to be mills on the river; why did they not destroy the salmon?

The river was teeming with salmon when I were a lad. I don't think it was electricity generation that reduced their numbers...

There were mills on the canals, not the main river. Hydro turbines would not be feasible on the weir as they would interfere with salmon (and other species) migration.
Hydro power is not the environmentally-friendly alternative some people think, it has destroyed salmon runs on the Shannon, Erne, Lee and Liffey, 4 of Ireland's largest rivers and formerly prolific salmon fisheries. Small scale hydro also has serious impacts on fish passage at weirs. I've seen the damage turbine blades can do to fish and it's not pretty...

beeintheknow

but sure what do fish matter if I can get cheaper electricity?

kayos

Iwannahurl wrote: »

Question: there used to be mills on the river; why did they not destroy the salmon?

Mills using water wheels for power, those wheels just have loads of big buckets with blunt edges and rotate at slow speed.

Turbine? Think about it high speed blades that would cut a fish up into sushi quicker than any chef out there.

JohnCleary

Cause of da fishies!

Who would I sleep with then?!

JohnCleary

Zzippy wrote: »

I've seen the damage turbine blades can do to fish and it's not pretty...

Who's up for some mince salmon?

Salmon lasagne?

Chili-Con-Salmon?

Salmonballs?

Iwannahurl

Zzippy wrote: »

There were mills on the canals, not the main river. Hydro turbines would not be feasible on the weir as they would interfere with salmon (and other species) migration.
Hydro power is not the environmentally-friendly alternative some people think, it has destroyed salmon runs on the Shannon, Erne, Lee and Liffey, 4 of Ireland's largest rivers and formerly prolific salmon fisheries. Small scale hydro also has serious impacts on fish passage at weirs. I've seen the damage turbine blades can do to fish and it's not pretty...

I seem to recall that there was some infrastructural work done on a weir or something a few years ago which had to be redesigned when it was discovered that the salmon were not able to get past it. Ring any bells?

Robbo

Iwannahurl wrote: »

I seem to recall that there was some infrastructural work done on a weir or something a few years ago which had to be redesigned when it was discovered that the salmon were not able to get past it. Ring any bells?

There was a weir in Kilkenny which was causing a major problem a couple of years ago, are you thinking of that one?

extraice

There was 17 hydroStation in Galway back in the 50s
3 on the east side of the river , and rest on the west side off the city via the canals , Only one left you can see the wheel is in the Birdge Mill downstairs

there is plans to bring back hydroStation to pwoer some of the city, Plannig take 3 years from build to powering up

Sniipe

I'm all for saving the fish - but could they not have a filtering system before the hydro turbines? Water goes through but fish don't. Perhaps its a silly question...?

Zzippy

Iwannahurl wrote: »

I seem to recall that there was some infrastructural work done on a weir or something a few years ago which had to be redesigned when it was discovered that the salmon were not able to get past it. Ring any bells?

Robbo wrote: »

There was a weir in Kilkenny which was causing a major problem a couple of years ago, are you thinking of that one?

That's the one. They installed a fish pass but it provided inadequate attraction flow for fish to find it. It was redesigned to incorporate a "rock ramp" fish pass, which provides a more natural flow and is easier for fish to find.

The weir in Galway has a Denil fish pass in the centre, which a large proportion of fish travel up, but a lot of fish also swim up the face of the weir too. Downstream passage of migrating salmon smolts would be the main problem, as they are swept downstream by the current and can't avoid turbines.

Sniipe wrote: »

I'm all for saving the fish - but could they not have a filtering system before the hydro turbines? Water goes through but fish don't. Perhaps its a silly question...?

Turbine screens are only effective at low water velocities. At higher speeds, fish are swept onto the screens and basically get crushed against the screens, the smaller fish in particular (such as salmon smolts) cannot swim fast enough to escape. So they might be protected from turbine blades but the end result is the same...

dilallio

Zzippy wrote: »

... So they might be protected from turbine blades but the end result is the same...

Fish Squish