Two Fat Ladies Sail Again

Two Fat Ladies Sail Again

Monday, 8 September 2008

Lagan Towpath Flooding

When we had that mad flooding a couple of weekends ago after a couple of months worth of rain fell over the weekend, I cycled to work as usual along the lagan towpath on the Monday and Tuesday mornings. I noticed that part of the lookout point at the Lisburn Civic Centre was underwater and the river was unusually high but I had seen that before and didnt think too much about it.

Problems started at the Coca-Cola bottling factory in Lambeg where there was a stretch of the path about a kilometre long which was hub deep and more. I had only seen this flooded once before in my life and on the previous occasion it was only a couple of inches deep. I should have turned back at this point but couldnt be bothered cycling back through the flooded section upstream so I pushed on.

All was well again until just under the foot bridge close to Ballyskeagh greyhound track. The field beside this was a lake but due to the water levels starting to reduce this was draining across the towpath creating quite a cross current for mtb tyres in water that was again hub deep and worse.


There was about 100M of respite before the motorway brigde which again I have never seen flooded. Under here was relatively still water but it was almost covering my tyres! I was determined not to have to turn back but I had nowhit the point I thought would be the worst part. About 200M after the motorway there is a sharp 160 degreeish bend which previous experience told me is the lowest part of the towpath relative to the river. I have seen this flooded a few times and it had been flooded recently but usually its a couple of inches deep and the worst I had seen it was about knee deep and only for about 100M. I was worried about it today but pushed on anyway which was a bit of mistake. I could see from the hedge along the path that the water had actually dropped about 4 inches from its highest point but even so when the water got to the point that it was deeper than my handlebars I got off and walked! Because of the shape of the path at this point the water from the main river was actually flowing towards me and eventually got chest deep so it took me about 10 minutes to walk the next 50M trying to keep my backpack out of the water and coping with a bike that was floating without me on it.


Once I got to the point where I was going with the flow of the river and it was down to the level where I could see my handlebars I got back on and began cycling towards Drumbeg. The water came down to about the same height as my wheels which was cyclable but very draining. There was also a couple of bits of cross current which is very hard to navigate through. Eventually I got to Drumbeg and went up onto the road as under the bridge is a point where the canal sometimes linke itself up again where it has been split by the path. This is usually passable on a bike but today the water was the height of the safety fencing and the current as a wide river tried to get through a much narrower tunnel was mad. A couple of bemused pedestrians took a photo of me in the wheel deep water but a quick look a tthe path on the other side made me decide to go along the Malone road at for a while.


On the far side of the bridge the path dips sharply a couple of feet after 50M and it was already under water before this so common sence prevailed for the first time this morning. I went as far a Mary Peters track on the road then down the back of the track back to the towpath. The section here recently resurfaced was under a couple of inches of water. This is a part of the path I never thought I would see flooded! It was roughly this deep most of the way to Shaws bridge and then after that there where a couple of short sections a few inches deep all the way to the main wier at Stranmillis.


By tuesday morning the water had dropped another foot or so so I cycled the entire towpath. The part that I had missed was still wheel deep for quite a bit of it and also had two fallen trees to navigate. At Edenderry there is a tight bend beside the golf course and this is another part that I know is a low point relative to the river. This was still handlebar deep and so I was glad I had skipped this part on the Monday. By Wednesday they had opened every wier on the river and the water had gone from as high as I had ever seen it to as low as I had ever seen it.


Both mornings took me 1.5 hours which is more than twice what I normally take. I was wrecked both mornings as once the water gets this deep it is like cycling up a very steep hill and is exhausting.


For anyone who regularly cycles the towpath and happens to see this, I have some advice if there has been any heavy recent rain. If the path is badly flooded dont cycle along it. I know this path blindfolded and so know how far to stay from the hedge to keep on the path. The water is very silty so once it is more than 2 or three inches deep you cant see the bottom and as the path is only a couple of feet wide combined with being very twisty in some places it would be very easy to end up in the river. I am a pretty strong cyclist and this was very tiring for me so be carefull you dont get into trouble due to tiredness when you get to a really deep part. This would be more true if cycling up-river (which I didnt on either day).


For people who join the path at different points, the following might help guage how bad certain sections might be (the following all assumes you are traveling down river).
  • If the river is obviously moving very fast with a narow channel at any point carrying the majority of the foam generated by the water crashing over the wiers.

  • Also look out for the water flowing over the wiers so fast it is not foaming - this means the flow is very high.

  • Any vegetation under water also means that the levels are higher than usual.

  • If all the adjustable wiers are fully open then this can mean they are trying to drain a lot of water very quickly.

  • Lagan Valley Island - if the lookout points low down towards the water at the down river end of the island are under water at the edge (they slope slightly towards the river) think twice about using the whole towpath as there are likely to be points about 2 feet deep. If these areas are completely submerged think three or four times!

  • Coca-Cola factory - if any of the path along side the factory is even slightly submerged or the water is almost coming up over it then about a mile down river from this is usually at least a couple of inches deep. If this is a foot deep then seriously consider going further.

  • Any of the path close to Ballyskeagh - if this floods then there is likely much worse to come within a couple of hundred metres.

  • Motorway bridge - If it is flooded under this then other parts are possibly very deep.

  • 100M past the motorway - beware if this is flooded it hides that there is a fair dip in the path at the sharp corner. This is also against the flow and it is harder to walk against this than it looks.

  • Under the road at Drumbeg - this is always fast flowing so if it is more than 8-10 inches deep it is carrying a fair force and you are going across the current so be carefull.

  • Just past the previous bridge - The path dips suddenly about 2 feet so if you cant see this dip due to water then dont go down the path.

  • Sharp turn between the river at Edenderry and Malone golf course. The path here is quite low relative to the river so this is one of the first points where it gets deep.

  • If you can see lots of water, particularly if it is flowing, in parts of the towpath that are usually clogged with vegetation this means the river is unusually high.

  • Anywhere else - if the path is flooded anywhere else then I would not use the towpath as that means it is approaching at least as deep as dscribed above.

It is also worth noting that when they open the Wiers along the river to try and drain it these have differing effects depending which ines they open. Opening one of them only seems to have an effect a supprisingly short distance upstream. There are also a couple of points (such as at the sharp turn at Edenderry where the path floods supprisingly earlier than othe rparts that seem usually closer to the water. I suspect this is due to the water "piling up" at sharp corners.

I started to write this post with an idea in mind but given how long I have droned on I will keep that to a separate post.

Mark