Tag Archives: ESB

The current at Killaloe

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

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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.

 

 

Ardnacrusha tours 2018

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

ESB archives

On Friday 13 October 2017 at 3.00pm, Deirdre McParland will speak at the Royal Irish Academy, Dawson Street, Dublin 2, about the ESB archives, whereof she is senior archivist. Admission is free but I am told that places should be booked here. I have not tested that link and I do not vouch for it.

I have, however, visited the ESB Archives site and suscribed to its RSS feed. They have one of those Titter things too: I gather it’s a communication method for the remedial classes, folk who can’t manage more than a paragraph of continuous prose.

 

 

 

Ardnacrusha tours

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.

Update July 2018: tours available again this year.

Building Ardnacrusha

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.

 

Trigonometry and obfuscation

Every so often Waterways Ireland (whom god bless and preserve) sends out a Marine Notice to warn people of sporting activities, so that they can avoid them, and of one or other of the hazards of the navigations. One such, No 68 of 2016, issued on 9 June 2016, says (inter alia):

The attention of all is drawn to the dangers associated with overhead power lines in particular sailing vessels, sailing dinghys and workboats with cranes or large airdrafts.

Vigilance is required especially in the vicinity of slipways and dinghy parks, while voyage planning is a necessity in order to identify the location of overhead lines crossing the navigations.

ESB Networks emergency number is (353)1850 372 999 and Northern Ireland Electricity Networks is (44) 0800 616 817.

Then on 21 July 2016 Waterways Ireland issued Notice No 89 of 2016, which was specific (as far as WI is concerned) to the Northern Ireland navigations. Extracts:

Many sailboats have masts of 9m (30ft) or more and, as most of these masts are made of aluminium, they are an excellent conductor of electricity. If an aluminium mast or rigging come into contact with or too close to power lines, it could result in a fatality.

NIE Networks advises all boat owners to take some simple precautions to stay safe.

  • Plan your route carefully when transporting your boat to or from where it is being launched, making sure you have adequate clearance under overhead power lines. When you are stepping the mast or erecting long aerials, be sure to do so in an area totally clear of overhead power lines.
  • Once out on the water, if you are sailing on inland waterways or near islands or headlands, you should still look for overhead lines as they do cross over waterways. You must ensure that your mast or aerial has proper clearance from any power lines.
  • Always check your charts when underway to ensure you are aware of the location of overhead power lines.

In order to avoid hitting an overhead power line with a mast, it would be useful to know how high off the water, perhaps at Ordinary Summer Level, the power line was. Then you could subtract from that the height of your mast, and some safety factor, and decide whether you could safely sail under the line.

If you don’t know how high the power line is, you have to resort to trigonometry. My recollection of these matters has perhaps faded a little, but as I recall you stand a small boy of known height on your cabin roof and, with your eye level with his feet, you measure (a) the horizontal distance from his feet to your eye and (b) the angle from the horizontal to a line from your eye that touches the top of the boy’s head and the bottom of the power line. Then the small boy falls off the roof, you have to tack, your pencil falls overboard and it all seems much more difficult than finding the height of a tree. And of course you can’t measure the distance to the power line without sailing up to it, which is what you’re trying to avoid until you can decide whether you can safely do so. [Note: this paragraph is not to be used for navigation.]

Life would, therefore, be much easier (and safer) if you knew the minimum clearance under the power lines. Happily, NIE Networks is happy to tell people what it is; I emailed and a speedy response including this:

The clearance on all NIE Networks overhead power lines which cross over navigable waters is 10.5m (lower bank to line or earth). All overhead power lines are marked on navigation charts for the Erne and Lower Bann waters.

However, it should be noted that this is the clearance for NIE Networks overhead power lines and applicable to Northern Ireland only. Clearances for overhead power lines in the Republic of Ireland may be different and would require confirmation from the Electricity Supply Board (ESB).

Big it up for NIE Networks, then. But over several years I tried unsuccessfully to get the ESB to give me the equivalent information for lines crossing navigable waterways in the republic; it would not do so. Without that information, boaters cannot “ensure that [their] mast or aerial has proper clearance from any power lines”, so ESB’s advice is useless blather.

It is some time since I last asked ESB for information, and perhaps it has since been made available, but I see no sign of it on the ESB website. I would be glad to hear from anyone who can supply reliable information.

Delegated authority in the ESB

Just over a year ago, in June 2015, I wrote — at some length — about the right to navigate the Shannon through Castleconnell, Co Limerick. A member of the staff of the ESB fisheries department told me

The legislation empowering ESB to regulate activity on the Shannon is contained in the Shannon Fisheries Act 1935 – Section 9.1 (D).

That accorded with my own untutored understanding: according to Section 9 (1) (d) the Board is empowered to

(d) terminate, restrict, or otherwise interfere with, either permanently or temporarily and either compulsorily or by agreement, any easement, way-leave, water-right, fishing right, or other right over or in respect of any land or water[.]

However, I responded to the ESB pointing out that the existence of a power does not prove that the power has been exercised, much less that it has been exercised validly. I asked for information on (inter alia)

 

[…] what strategic decisions the Board has made on this subject, or what decision-making powers it has conferred on its fisheries staff […]

whether the Board has actually decided to “terminate, restrict, or otherwise interfere with, either permanently or temporarily and either compulsorily or by agreement, any easement, way- leave, water-right, fishing right, or other right over or in respect of any land or water”

if it has so decided, what the details of the decision are: details both of its making and of its application [.]

 

The Act gave the ESB a power, but the power has to be exercised properly and there must be a record of the making of the decision. I have had no reply to my queries, and my working hypothesis is therefore that the ESB has not validly terminated, restricted or interfered with the right to navigate the Shannon at Castleconnell. If I receive evidence to the contrary, I will of course change my view.

One part of the problem is that the Act gives the power to the Board and, in my view, employees of the Board cannot of themselves decide to exercise that power unless the Board has validly delegated the power to them. The fisheries department cannot close the navigation unless the Board explicitly gave them the power to do so.

A case at the Court of Appeal, reported in the Irish Times today [11 July 2016: the article may disappear behind a paywall at some stage], seems to support that view [although I am not a lawyer: please consult your own legal advisers]. The relevant paragraph is

The board was entitled to delegate the power to issue wayleave notices to its chief executive but was not entitled to “sub-delegate” to the chief executive power to authorise such other persons as he deemed appropriate to issue wayleave notices, Mr Justice Brian Cregan held. Any such persons had to be directly authorised by the board.

I suggest that the same may apply to fisheries and navigation. If the navigation at Castleconnell was validly terminated, restricted or interfered with, either the Board took that decision itself or it explicitly delegated the power to do so to the fisheries department (or someone else). In either case, there should be a Board minute on the matter and it should be possible for the fisheries department to cite that minute.

 

Shannon lake levels

According to the Shannon Catchment-based Flood Risk Assessment and Management (CFRAM) Study Technical Assessment: River Shannon Level Operation Review [PDF: Office of Public Works v2_0 July 2012]

ESB collects and maintains records of rainfall, river and lake levels and flow data. Even though ESB has no responsibility to supply flood warnings under their regulations, it issues twice weekly lake level forecasts to all the relevant stakeholders since 2010.

Those stakeholders include Waterways Ireland.

As the levels of the lakes are of great interest to boat-owners and others, it would be really nice if either the ESB or Waterways Ireland were to publish those forecasts. WI wouldn’t need any elaborate new system: they could send them around as marine notices, and the cost would be minimal.

But perhaps the forecasts are already published somewhere? If, Gentle Reader, you know where they are, do please leave a Comment [preferably with a link] below.

ESB water discharge info

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.

Update 2018: the ESB has a new page with lots of interesting information here.

What’s a cumec, Daddy?

I don’t know, but here’s a picture of 415 of them flowing through Castleconnell. [Update 13 December: that may be only 405 cumec.]

Castleconnell 20151212 10_resize

415 cumecs on 12 December 2015

Actually, a cumec is one cubic metre of water per second, which is roughly one ton per second, which is a lot of water. And 415 cumec is the amount that, according to the blatts, the ESB is currently letting down the original course of the Shannon from Parteen Villa Weir; the minimum flow in that channel, as seen in summer, is 10 cumec.

Castleconnell 12 December 2015

Castleconnell 20151212 02_resize

Younger trees getting their feet wet

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Who’d have guessed?

Castleconnell 20151212 14_resize

Below the bridge

Castleconnell 20151212 21_resize

Above the bridge

Castleconnell 20151212 34_resize

Stormont

Castleconnell 20151212 37_resize

Pump

Castleconnell 20151212 40_resize

Sandbags

Castleconnell 20151212 42_resize

Sandbag Central

Castleconnell 20151212 43_resize

Sandbags filled here for distribution

Castleconnell 20151212 46_resize

Army engineers

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More equipment arriving

Clonlara 11 December 2015

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Ardnacrusha headrace, said to take 400 cumec

PEC Errina Bridge 20151211 04_resize

Errina bridge on the Plassey-Errina Canal

PEC Errina Bridge 20151211 01_resize

The stop planks seem to be quite effective …

PEC Clonlara upstream 20151211 01_resize

… as there is little water getting down the canal to Clonlara bridge

Park Canal 9 December 2015

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Depth gauge at Park Lock

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Lock chamber

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Full canal upstream