Natural hydrology - flow control.

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Pattree

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Jul 19, 2023
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I don’t want to take away from the floods thread. It’s good to know how members are getting on.
but

@Paul_B prompted me to think about natural ways of controlling water.
Today the water in the Seven started dropping. In a number of towns along the river they have introduced flood barriers. This is all very well but just shoots the water further down river faster. In the case of Ironbridge it floods the opposite bank and may be washing some of it away. Some folk who insisted that their local rivers be dredged have found that now water backs up-river much quicker than before.

Shropshire is reviewing its water control. The water meadows here do a great job of slow release but someone is doing joined up thinking: here
 
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Paul_B

Bushcrafter through and through
Jul 14, 2008
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It seems beavers were ahead of the game all along!

One thing we can all do is put drainage into your hard landscaping. Instead of impervious tarmac driveways why not use permeable surfaces instead on your driveway. Small things but the loss of free draining ground to hard landscaping is cumulative in housing estates.

I remember reading about an industrial estate that was built with hydrology designed in. Hard landscaping left rain through, there were areas given over to collect heavy rain and flood in a controlled way. Run off from roofs were dealt with naturally too through designed in water control. I think the aim was to slow the water to delay it getting into waterways and then on to high flood risk areas.

The tech to do this is out there. Flood barriers are always about protecting higher value land at the expense of lower value land. If we delay water into lower waterways perhaps we won't have to effectively say one person's property is worth less than the ones upstream.
 

Broch

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There was a good chat about Beaver Dam Analogues a while ago here:


We don't have to wait for the beavers to be accepted to start using the 'technology' that's for sure :)
 
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Toddy

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I think it's all very do-able for new builds, but it's going to take an enormous amount of money and effort to sort it out properly.

The riverside flood meadows were the most easily opened and used farmlands, so people settled there. Settlements become villages, towns and cities, and industrialisation crept in and overwhelmed.

Much of the very best farmland is now so built up that it's unreclaimable, but those buildings are considered so valuable that they will be afforded protection that doesn't really make sense in the wider scheme of things.....and that's the biggest hurdle.

Developers bought up farmland across the river from us and sought permission to build 600 new houses there. They keep coming back to the Council trying to gain this but the Council points out that that area is low lying and is actually a natural flood plain.
The other end of our village runs alongside the Clyde and the land there is known as Laighlands....low lying swampy ground.....but this village is now a commuter suburb and land is much sought after for building plots. The builders even suggested building up on piles ....but the land is a wildlife haven, even the peeweeps nest there.

These are just two instances among thousands up and down the country where there is a clash of land rights and uses and planning, etc.,

I keep wondering where all the money is coming from for all these houses that folks seem to want to build, because the news is full of folks with such difficulties finding affordable housing.
Profit can't be the driving force, not if there's a crying need for decent housing for everyone....but that's a political nightmare, isn't it ?

Channeling waters drained land and made it good farmland, or building or industrial land, but the reality is that the channels are too hard, water needs to seep, needs to be slowed and absorbed.

Could more not be done to help refill the aquifers too?
 

Pattree

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I have a tarmaced drive on a slope. We put in a trap drain that ran water out into the soil under a hedge. Our roof water drains into a soakaway and back into the ground. Not everyone can do it but it’s very simple for those who can -
and
You get a reduction in your water rates if roof and surface water doesn’t run into the road drains.

Edited to add:
I don’t know about all authorities but Severn Trent only require a cubic meter soakaway. From experience I recommend lining it with root resistant textile.
 
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Toddy

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They can, but many Councils do not allow them. They insist that all rones run into the sewer networks....ours does.
I'm pretty sure that's a suburbian thing though.
 

Kadushu

If Carlsberg made grumpy people...
Jul 29, 2014
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The temptation is to get rid of the water as fast as possible but that just exacerbates the problem downstream. Ideally the movement of water should be slowed which is what trees, soakaways and floodplains do.
 

TeeDee

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If one was using Willow as the green tech of choice to limit erosion along water , once the tree has safely established when would one prune it or otherwise limit its natural growth ?

How high 'up' can you take cuttings whilst leaving enough for new growth ? can one be quite aggressive?
 

Mesquite

It is what it is.
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If one was using Willow as the green tech of choice to limit erosion along water , once the tree has safely established when would one prune it or otherwise limit its natural growth ?

How high 'up' can you take cuttings whilst leaving enough for new growth ? can one be quite aggressive?
Usually pruning takes place over the winter months.

When you cut willow you can cut it right down to the ground and it'll come back no trouble. Most times it's trimmed pollard style about 5-6 ft off the ground. It's also a very easy tree to propagate from cuttings, I've seen it sprout from logs inserted into the ground upside down and it happily put shoots out. It'll even sprout from logs just laying on the ground.
 
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Broch

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Yep, once you've got it you can't get rid of it without pulling it up by the roots :)

I once took a willow stick from a river bank (discarded brash) and left it in the garage, the following spring it had shoots and leaves (it was a damp garage) - I stuck in the ground and we had a new willow tree :)

I've a goat willow that I have to cut every few years because it sits under some 415v power lines; I cut it to the ground each time.

If you've got the choice though, I'd mix in some Alder.
 
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Broch

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Only really to prevent a mono-culture of willow - mixtures look more natural and provide a wider range of food sources for invertebrates (such as Alder moth). Alder 'likes to have its feet wet' so is an ideal bankside tree and naturally occurs in carr condition with willow.
 
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TeeDee

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Only really to prevent a mono-culture of willow - mixtures look more natural and provide a wider range of food sources for invertebrates (such as Alder moth). Alder 'likes to have its feet wet' so is an ideal bankside tree and naturally occurs in carr condition with willow.

Good enough for me - I assume it can be coppiced in a ' chop-n-come-again' manner?

I shall source some.
 
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Pattree

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Just before you go planting willow, check where any field drains are running. Willow can block a four inch drain in three years.

Don’t plant willow near your house either especially if you’re built in clay. They will pump out water and make clay shrink.

On a river bank they are as easy as @Broch suggests. All along the Welsh “reens” You can see where four foot poles have been stuck in along the bank and left to grow. On a smaller scale just cut two or three foot stems and poke them in.
……. but then you have willow and there’s ain’t no cure!
 
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Laurentius

Bushcrafter (boy, I've got a lot to say!)
Aug 13, 2009
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Usually pruning takes place over the winter months.

When you cut willow you can cut it right down to the ground and it'll come back no trouble. Most times it's trimmed pollard style about 5-6 ft off the ground. It's also a very easy tree to propagate from cuttings, I've seen it sprout from logs inserted into the ground upside down and it happily put shoots out. It'll even sprout from logs just laying on the ground.
I pollarded a willow tree, left the felled trunk on the ground and the trunk turned into a hedge.
 
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Paul_B

Bushcrafter through and through
Jul 14, 2008
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There's a spot near derwentwater where there's a raised boardwalk above a boggy ground. To one side there's a steam with sloping gravel bank towards the boardwalk. They stuck a load of willow sticks in. We went there shortly after it being done. 2 years later they were proper trees 6ft high. I suspect it was to slow the stream down after heavy rain and keep the river bed more static in high levels.

When we first saw them my lad pulled one out. I told him to stick it back in the ground. He did somewhere different. 2 years later we could tell which one that was and it was also a successful tree. Surprisingly fast growing.
 

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