tadcaster bridge collapsed

[agg221]

For me its because non of the basics are done anymore.

 

Council not clearing the gullies

 

Farmers not clearing the ditches and drains that run around their fields (for whatever reason)

 

Building on flood planes

 

None or little dredging on rivers

 

The removal of natural defences

 

Its ok to build big flood defences, but surely lets get back to basics first. Not having a go at anyone, just my thoughts.

 

The principle is correct, but there are two fundamentally different strategies you can adopt for water management.

 

1. A comprehensive drainage system, from the small ditches and culverts at the top end of a watercourse, right through to deep dredging and high banks on the lower watercourse. This is designed to move water as fast as possible from where it falls to where it exits (tidal waters) and prevent the level from rising.

 

2. A series of features designed to keep water where it falls and slow its progress as much as possible. This includes features such as bogs, ponds, pools/meres and natural floodplains.

 

You can combine elements of these but ONLY if you have 1. downstream of 2.

 

So for an example of 2. If a farmer raises the outflow level on a drainage ditch 500m long with a cross-section of 1m square (deliberately or just by letting it choke up) the ditch will hold back up to 500 cubic metres of water. If he does that on 10 ditches that's 5000 cubic metres of water.

 

Getting the approach wrong (1. upstream of 2.) if the ditches drain into a brook with a restricting bridge, which at times of high rainfall runs at full capacity under the arch then when the farmer digs those ditches to remove the obstruction, you now have an extra 5000 cubic metres to get through the bridge, which won't go. Assume normal slope away from the brook and you find that houses standing about 50m from the brook get flooded to around 1m depth.

 

The owners of the houses don't like this (obviously) so they campaign to get the flow under the bridge increased by widening it or deepening the channel. This just moves the water down to the next obstruction (2. is still upstream of 1.) so it does the same again, and so on all the way down to the sea, ie you eventually end up with 1. but with misery for everyone down the line in turn.

 

And this is exactly what happens when the plan for a watercourse is not joined up, people all do their own little bit as they please and other people who were previously at no risk of flooding suddenly find that they are, as a direct consequence of the actions of others upstream.

 

Which is exactly what is happening to us.

 

Alec

Edited December 30, 2015 by agg221

[mendiplogs]

The principle is correct, but there are two fundamentally different strategies you can adopt for water management.

 

1. A comprehensive drainage system, from the small ditches and culverts at the top end of a watercourse, right through to deep dredging and high banks on the lower watercourse. This is designed to move water as fast as possible from where it falls to where it exits (tidal waters) and prevent the level from rising.

 

2. A series of features designed to keep water where it falls and slow its progress as much as possible. This includes features such as bogs, ponds, pools/meres and natural floodplains.

 

You can combine elements of these but ONLY if you have 1. downstream of 2.

 

So for an example of 2. If a farmer raises the outflow level on a drainage ditch 500m long with a cross-section of 1m square (deliberately or just by letting it choke up) the ditch will hold back up to 500 cubic metres of water. If he does that on 10 ditches that's 5000 cubic metres of water.

 

Getting the approach wrong (1. upstream of 2.) if the ditches drain into a brook with a restricting bridge, which at times of high rainfall runs at full capacity under the arch then when the farmer digs those ditches to remove the obstruction, you now have an extra 5000 cubic metres to get through the bridge, which won't go. Assume normal slope away from the brook and you find that houses standing about 50m from the brook get flooded to around 1m depth.

 

The owners of the houses don't like this (obviously) so they campaign to get the flow under the bridge increased by widening it or deepening the channel. This just moves the water down to the next obstruction (2. is still upstream of 1.) so it does the same again, and so on all the way down to the sea, ie you eventually end up with 1. but with misery for everyone down the line in turn.

 

And this is exactly what happens when the plan for a watercourse is not joined up, people all do their own little bit as they please and other people who were previously at no risk of flooding suddenly find that they are, as a direct consequence of the actions of others upstream.

 

Which is exactly what is happening to us.

 

Alec

 

HI ALEC no the army in they have kit to move sandbags pumps there doing a great job there thanks Jon

[aspenarb]

The bottom line here is Tadcaster is 45 feet above sea level so there is absolutely no excuse for it to flood other than lack of forward planning. That river could be widened,deepened and the bridges that are not fit for purpose replaced. This thread will probably pop up till hell freezes over before a proper solution is planned,funded and agreed, there will be millions wasted on EA consultations and mindless studies, whats needed is diggers , dredgers and bridge builders NOW

 

Bob

[easy-lift guy]

This flood was not only foretold ? it was publicly subsidised | George Monbiot | Opinion | The Guardian

 

Just read the article. The more things change the more they stay the same:thumbdown: And of course no criminal offenses were committed, yet the funding provided by the state continues to be available for those who are willing to play ball with the state while everyone else that pays taxes in your country and keeps being raked over the coals. Absolutely insane. Kevin can a suit like the one previously mentioned in the article now be reopened or be filed under a class action status like we have here in the USA. Not sure if it is possible, however may have more teeth than previous attempts.

easy-lift guy

[openspaceman]

The bottom line here is Tadcaster is 45 feet above sea level

 

And 28.6 miles of river to the tidal estuary, not a lot of fall to move water

[egnsean]

I'm no expert but it surely can't help that towns are almost entirely paved over? Front gardens are ripped up and replaced with block paving/tarmac, and rainwater isn't dealt with by the landowner, it's just all channelled into mains drains, never gets a chance to soak in to the ground.

 

these days you have to use permeable Block paving/Tarmac or create a soak-away in your garden, which works out sodding expensive the aggregate you have to lay the blocks on Laid to a depth of 200mm, 1 Bulk Bag covers 2.85m2

costing nearly £120 a bag

[easy-lift guy]

these days you have to use permeable Block paving/Tarmac or create a soak-away in your garden, which works out sodding expensive the aggregate you have to lay the blocks on Laid to a depth of 200mm, 1 Bulk Bag covers 2.85m2

costing nearly £120 a bag

 

Small price to pay compared to the alternative and the government refusing to protect the property both personnel and real that you pay taxes on every year for no return on investment.

easy-lift guy

[aspenarb]

And 28.6 miles of river to the tidal estuary, not a lot of fall to move water

 

Good enough for the river thats there now, why not just increase its capacity to cope or gouge out another one as a relief ? There is no future for the place until this is sorted properly so some big decisions need to be made. Same applies to the Somerset levels.

 

Bob

[egnsean]

Small price to pay compared to the alternative and the government refusing to protect the property both personnel and real that you pay taxes on every year for no return on investment.

easy-lift guy

 

True, another "big issue" (pun intended) is all the immigration = more and more houses needing to be built = more pressure on the infrastructure, drains ect, but will this be addressed? the day after Hell freezes over, this country is screwed!!

[openspaceman]

Good enough for the river thats there now, why not just increase its capacity to cope or gouge out another one as a relief ? There is no future for the place until this is sorted properly so some big decisions need to be made. Same applies to the Somerset levels.

 

Bob

 

I don't pretend to know any answers but how much rin has fallen upstream of tadcaster, what area has to drain down this bit of the foss?

 

The thing about balance ponds and big sponges is once they get full they don't hold any more back, so something designed to deal with everything but the 1 in 200 year flood isn't going to cope with the weather pattern shifting more rainfall into the winter months. Simple chaos theory says that as the energy in a system increases with increase temperature then the chaotic events are going to be more powerful, and it looks likely they will be more localised, Somerset last year, Cumbria, Lancs and Yorcs this.

 

Big sponges will be more important for maintaining river levels in the now drier summer months.

 

You and I are more fortunate at present, we only have to deal with 60cms of rain a year, Cumbria is over 200 isn't it and one month's worth fell in one day??

 

Even Ian in Cornwall gets 100Cms (I'm having a rethink about the retirement bungalow now).

 

We've been lulled into a false sense of security with a stable weather for 200years. Even active management like the Thames barrier has been deployed 16 times more than it was designed to.

 

Yes I think some active systems will be needed along with your dredging, like being able to evacuate water holding capacity quickly, unlike a sponge, to maximise the rivers' capacity between storms.

 

It's also an indication of the failure of commercially competitive insurance to spread the load by refusing to insure those that have been affected as they can now see their risk. Insurance works to the society's benefit when it is based on random statistics but not when they are allowed to decline specific risks.

 

We will soon see the same for health insurance when those predisposed to having expensive chronic illness will not be able to avail themselves of private health care.

 

It shouldn't concern me as I've already had a long healthy life and am unlikely to see the consequences but I do have offspring...

 

Although spending the Xmas break alone with 6 women is a bit much.