Here is the ESB’s Notifications page, with info on the rate of discharge from its hydroelectric dams and weirs. Today (14 December 2015) Parteen Villa Weir is discharging 440 cumecs (cubic metres per second or, roughly, ton[ne]s per second down the original course of the Shannon. That’s 44 times the 10 cumec usually discharged and more than replaces the 400 cumec diverted through the headrace to the Ardnacrusha power station. The Shannon is therefore running at its pre-Ardnacrusha levels and the Falls of Doonass have regained their power.

Of course if Ardnacrusha didn’t exist, its 400 cumec would be coming down the original course of the Shannon on top of the 440 cumec already there, which would make for interesting levels of flooding.

That ESB page has a link to this infographic, which shows the sort of information I was trying to get across here. I usually start from Leitrim [village]; the ESB starts slightly further upstream at Lough Allen. Note that the Shannon’s few locks are concentrated upstream of Lough Ree: between them and Killaloe are only two locks, at Athlone and Meelick, so the river’s fall is very slight.

Boogie on over to the splendid David Rumsey Historical Map Collection and put

ireland shannon

in the search box. All going well, you’ll get a set of 14 pages published by Generalstab des Heeres (the German Military High Command) in 1940, with drawings, maps, photos and a page of text about the Shannon. The set includes Clonmacnoise (no doubt because the Wehrmacht intended to go there on pilgrimage), Foynes and, in particular, Ardnacrusha, O’Briensbridge, Parteen Villa and Killaloe.

Industrial railway enthusiasts may also be interested.

And the collection includes many photos of British ports and other installations.

There is a television series called Building Ireland, about “Ireland’s building and engineering heritage”. A series of six programmes will begin on Friday 30 September 2016 at 8.30pm on RTÉ One, which is a television station.

The third programme, on 14 October, covers Ardnacrusha and the sixth, on 4 November, is entitled “Galway’s Corrib Canal” and covers canals in Galway and, I believe, may have some material about the Cong Canal.

Here is a PDF describing the series.

building-ireland-series-info-and-billings

I had a page with photos of the construction of Ardnacrusha in 1930; I have expanded that page to include

• photos taken in the 1920s by Eyre Chatterton and kindly supplied by Tony and Blair Chatterton
• links to the ESB Archive’s reports made by Siemens during construction; h/t Carthach O’Maonaigh for drawing them to my attention.

From 26 June through 1 September 2017, ESB will be providing guided tours of Ardnacrusha hydroelectric power station. It’s not usually open to the public and, if you haven’t seen it, it’s well worth a visit. Go here to book.

I have some information about the site here, here and here, but you should try to see it for yourself.

Here’s an event.

I think that Heuston Station means Kingsbridge.

Tours of the Ardnacrusha power station are available again this year; info here.

I have been known to complain about the absence [on the interweb] of information about the state of the Shannon downstream of Banagher and Meelick.

Waterways Ireland

On the Waterways Ireland website, on the “About Us” menu, there’s a “Water Levels” option which takes you to this OTT Hydromet page. Perhaps my security settings are too high (or too eccentric), but at the top of the page all I see is

Alternate HTML content should be placed here. This content requires the Adobe Flash Player. Get Flash

At the bottom I read

Click here to obtain list of todays 9am Values. Please Note – Levels are recorded in meters to MSL Malin Head.

There is also a disclaimer.

The link goes to this page where the locations of various gauges are categorised by waterway. The furthest south [on the Shannon] I can find is …

Meelick Weir Gauge SS_MEELICK Water level 0001 32.62m 2018-07-07 07:30:00 5400

… from which I deduce that the water level at Meelick Weir is 32.62 metres above mean sea level at Malin Head. From that, of course, I can deduce the depth of the water at Meelick, or I could if I knew how far the bed of the river was above MSL Malin Head, and by charting the daily returns I could see whether the level was increasing or decreasing.

OPW

Alternatively, I could use the OPW’s gauge at Banagher, only a little way upstream, which shows me the depth, the change over 35 days and the level in relation to various percentiles of previous levels. That is a lot easier to read and a lot more useful: although a measure of flow would be more useful still, I can assume that a high level will be accompanied by a faster flow.

ESB

I have recently discovered that the ESB has a page with (admittedly for a small number of sites) information in a more user-friendly format than either WI or the OPW. To find it from the home page, select “Our Businesses”, then “Generation & Energy Trading”, then “Hydrometric Information”, then “River Shannon”, then “Beware of the leopard”. Alternatively, try www.esbhydro.ie/shannon for a list of PDFs.

Either way, the files available include

• a hydrometric forecast for the Shannon
• one-year charts showing levels at each of five locations: Bellantra sluices, Lough Ree; Thatch, Lough Ree; Athlone Weir downstream; Portumna Bridge; Pier Head, Killaloe
• even more useful for anyone going near Killaloe Bridge, the total flow [in cubic metres per second] at Parteen Villa Weir and at Ardnacrusha.

Here, in flagrant breach of the ESB’s copyright, is the chart for Parteen Villa Weir:

The flow at Parteen Villa Weir

The flow has been pretty well flat, at 0, for some time. The Parteen and Ardnacrusha charts have accompanying tables giving the figures for the last 30 days; here are those for Ardnacrusha:

The flow at Ardnacrusha

Each of Ardnacrusha’s four turbines uses about 100 cubic metres per second [cumec]. The flow through Parteen Villa Weir is divided between the old course of the Shannon [which must get 10 cumec] and the new channel through Ardnacrusha. The combined flow through Parteen has been 11 cumec for the past week, and Ardnacrusha has been getting nothing (except a tiny amount on 3 July). That explains why the level of water at Castleconnell, on the old course, is slightly higher than normal summer levels (11 rather than 10 cumec).

And with no water going through Ardnacrusha, the level of Lough Derg is normal (see the chart for Killaloe) and there is no strong current at Killaloe.

Note, by the way, that the levels shown by the ESB are referenced to the older Poolbeg ordnance datum, not the Malin Head used since 1970: “Poolbeg OD was about 2.7 metres lower than Malin OD.”

Other sites?

If, Gentle Reader, you know of any other accessible web pages with user-friendly information on flows or depths on the waterways, do please leave a Comment below.

The Western Mail & South Wales News of 19 April 1929 had an article by M Franklin Thomas about “Ireland’s Big Engineering Scheme”. The article was illustrated with a map and three photographs were reproduced on the newspaper’s “picture page”. It had a couple of interesting points about the headrace and tailrace considered as navigations; I can’t recall seeing these points made elsewhere.

Current

This [headrace] canal is level, but a flow of about 3½ miles per hour will be maintained owing to the water released through the turbines and navigation locks.

I don’t recall seeing a figure for the current. I presume that that is with three turbines running flat out.

There is an interesting account of the laying of the concrete apron that protects the banks against the “wave action set up by navigation, and the flow of the stream, wind, &c”. And the lock was to have an “ingenious arrangement by which the entering streams of water neutralise each other’s effect”.

Tailrace

Mr Thomas says

The tail race is one mile and a half long, cut from the solid blue limestone, and one of the most interesting points was the method adopted to permit barges to ascend the tail race against the enormous scour from the turbine discharges.

A special navigation channel is cut from the locks to a point some 200 yards below the outfall, and the bed of the tail race rises 20ft in the mile and a half, so that the depth of water will be 35ft at the outfall from the turbines and 15ft at the junction with the Shannon.

This will give a cushioning effect, and the rate of flow will be thus reduced to enable barges to navigate upstream. A bend is also provided where the special navigation channel joins the tail race and the rate of flow is estimated to be the same as that of the head race — 1.5 metres per second, or about 3½ miles per hour.

I would be glad to hear from anyone who can cast further light on this, and especially on whether the rising bed does have the intended effect.