Holding water in the hills

[Devil's advocate]

Not a solution of course, dredging is the solution.

But maybe combined with dredging, holding back water is part of the solution.

I don't own the land but in the high pennines there are many steep gullies some artifically made by "gripping" steep peat covered moors. Would it be possible to dam these with either dams with a pipe out of the bottom or a leaky dam.

Owners should be well paid for this of course.

I'm doing some of this on my own land but the slopes will only hold a few thousand gallons. Unpaid but I think it will help with soil erosion, so I'm happy.

 

[farmerm]

Dredging won’t help on this end of the Severn, slowing water upstream is certainly the answer. Some of the reservoirs on the Severn are held too full through the winter so overspill in storms as they have little capacity to be able hold back high flows... this only happens because we have a serious shortage of reservoir capacity, water management priority is to ensure they do not run dry in the summer rather than managing flow rates to reduce downstream floods. More total reservoir capacity would allow them to be operated with larger deficits during winter and this have more scope for buffering flows.

I think gullies are the wrong place to dam water, to hold volume they require high dams and the pressure of deep water requires massive dams. I would think it may be more cost effective to hold back water over larger areas with relatively shallow dams and flood gates.

 

[Wilberforce]

As a wiser man than I pointed out if you hold back today's water what do you do with tomorrow's water?

 

[betweenthelines]

Have a look at Anton Coaker's comments.

As he points out, the "hills" haven't changed their water retention abilities in hundred of years.

However, an inch of rain on an acre of ground is about 100 tonnes of water, so with a housing density of about ten/acre, every house built since the war means another 10 tonnes of water with nowhere to go.

 

[ILovebaling]

How much rain have we had in 12 day? And how the hell are you going to hold it back 'in the hills'? And for those of you who live in the flat land I think you need to realise the hills are saturated and the usual thing that happens to water that falls on a hill is that it then runs down it. And the steeper the hill the faster it flows. So please, educate me, how do you hold it back. Without building a resivor, which you'd never get permission to do anyway.

 

[farmerm]

As a wiser man than I pointed out if you hold back today's water what do you do with tomorrow's water?

Hold that back too, it will be drier tomorrow, or the day after... it may be wet but we do not get a deluge every day for weeks on end, flood management is all about smoothing the peaks.

 

[Wilberforce]

Hold that back too, it will be drier tomorrow, or the day after... it may be wet but we do not get a deluge every day for weeks on end, flood management is all about smoothing the peaks.

Only so much you can hold it back. Can't stop it coming down but by dredging we can get rid of it quicker.

 

[Highland Mule]

Only so much you can hold it back. Can't stop it coming down but by dredging we can get rid of it quicker.

They manage to hold back water on the Conon Valley, and even generate a few megawatts of power when it’s finally released. Not rocket science to hold some back - worst case you run out of space and it’s as bad as it would have been without it, but not often that happens and even then the land below is much drier than it would be otherwise.

 

[farmerm]

How much rain have we had in 12 day? And how the hell are you going to hold it back 'in the hills'? And for those of you who live in the flat land I think you need to realise the hills are saturated and the usual thing that happens to water that falls on a hill is that it then runs down it. And the steeper the hill the faster it flows. So please, educate me, how do you hold it back. Without building a resivor, which you'd never get permission to do anyway.

Those permission challenges are the thing that has to change for solutions to work!

Trees on hills hold back massive amounts of water One idea I have is on flatter tributaries placing rows of large boulders at intervals across the river, each would significantly slow the speed of flow, each row acting like a leaky dam holding back a few feet of water. Very cheap with very little environmental impact and little impact on low flow

 

[glasshouse]

Those permission challenges are the thing that has to change for solutions to work!

Trees on hills hold back massive amounts of water One idea I have is on flatter tributaries placing rows of large boulders at intervals across the river, each would significantly slow the speed of flow, each row acting like a leaky dam holding back a few feet of water. Very cheap with very little environmental impact and little impact on low flow

Except it floods the farmers out

 

[ILovebaling]

We've got 6 resivors, decent sized ones not including other some ones on the hills around here, all have been full since end of September, we've got trees, lots of them, yet still the water flows. It rained so hard in July that it moved stone from the top of the hills onto farmers fields at the bottom of the valley, stone walls and even stacked bales of silage.

I'm really not sure where we could store more water in the hills around here, without building a big dam in the valley and flooding thousands of homes.

 

[ILovebaling]

Except it floods the farmers out

Yes but as long as its someone else then some people don't care. You can't hold the water on 'my' land so hold it further up the hill on 'his' land.

Can't make up some farmers thinking.

 

[glasshouse]

Yes but as long as its someone else then some people don't care. You can't hold the water on 'my' land so hold it further up the hill on 'his' land.

Can't make up some farmers thinking.

Holding it is bollox
Get it to feck down the river

 

[wanton dwarf]

Flooding kills every land living thing on it, destroys crops, destroys livestock and the resultant desolate land scape causes disease - been in the bible for at least 2,000 years and forgotten by the Environment Agency.

 

[Hilly]

We live on an island , you can’t be any further than 100 mile from the sea , sort the rivers and drainage out and get rid of the water quick

 

[Pennine Ploughing]

Holding it is bollox
Get it to feck down the river

That does not always work, Carlisle flooded in 2005, this was due to a high spring tide and strong winds fetching the tide in further, water had no where to go,
So dredging cannot really help on that one,
Dredging some parts and holding water up stream in low dams would help
When I say holding water up stream, it should be on the lines of a dam with a big pipe in the bottom, so water flows naturally 99% of the time, yet in heavy rain it fills the pipe to full bore, allowing a metered amount of water through, enough to fill rivers down stream , yet not to much to flood towns and villages

 

[glasshouse]

Towns like carlisle will always flood, they are on a flood plain.
Houses should be modified so damage is minimal

 

[SilliamWhale]

Have a look at Anton Coaker's comments.

As he points out, the "hills" haven't changed their water retention abilities in hundred of years.

However, an inch of rain on an acre of ground is about 100 tonnes of water, so with a housing density of about ten/acre, every house built since the war means another 10 tonnes of water with nowhere to go.

They may have changed their retention capacity but it may not be the main issue. But the bigger factor that is demonstrably true is that rainfall is more intense than it used to be.

When you see the flow through places like Ironbridge etc dredging would be of no impact. The channel isn't large enough to hold the flow - the same would be true of a lot of flooding through towns and villages esp when people expect the water to be speeded up

 

[renewablejohn]

Couple of years ago Lancashire flooded due to United Utilities keeping its reservoirs at full capacity. There was so much outrage about this I believe UU have changed there policy so that normal capacity is now 75% allowing 25% for storm surge, With so many reservoirs in Lancashire there is no excuse for Lancashire flooding no matter how much rain comes down.

That said it looks like they have gone back to there old ways and expect flooding shortly.

Reservoir levels | United Utilities

Details about the levels of water in our main reservoirs - updated weekly

www.unitedutilities.com

 

[wanton dwarf]

That does not always work, Carlisle flooded in 2005, this was due to a high spring tide and strong winds fetching the tide in further, water had no where to go,
So dredging cannot really help on that one,
Dredging some parts and holding water up stream in low dams would help
When I say holding water up stream, it should be on the lines of a dam with a big pipe in the bottom, so water flows naturally 99% of the time, yet in heavy rain it fills the pipe to full bore, allowing a metered amount of water through, enough to fill rivers down stream , yet not to much to flood towns and villages

Bridgwater has a sea gate.

I don't know if the lay of the land is similar but if a Sea Gate can be used .. could be combined with pumps to continue water moving out of the town even with a high tide.