Diverting rainwater into pond

[Nightjar]

A row of bricks each side and a paving slab across the top of them and you have a raised path across the lawn :-)

[Tim Lamb]

I think a riparian landowner is permitted to abstract up to 20 cu.m/day without a licence.

[Huge]

*grin*

And two more freaking edges to trim.

[Dave Liquorice]

You'll need a big or lots of water butts to act as a sensible buffer.

20 x 15 m roof 300 m^2 rain rate just 3 mm/hour will produce 900 litres (nearly a cubic meter). 3mm/hour is gentle steady rain, heavy rain will be more like 25 mm/hour, torrential 150 mm/hour. OK it doesn't often rain at 150 mm/hour for long but 6 minutes is 4,500 l...

I think you'd be better off with something around standard down pipe size fed from some form of hopper so if it blocks or can't handle a peak flow the excess goes some where harmless (existing drain to ditch?)

See what the price of 5 x 3 m lengths of down pipe are against other reinforced hoses. or land drain pipe. Is the pond lined? Would water getting into the ground end up in the pond?

All this assumes the pond is lower than the house and gravity will do the work. If it is down hill all the way and the pond not lined at apush you could just divert the downpipes way from the drians and let the water find it's own way to the pond. Or build an ornamental stream bed or put a linear drain across the lawn.

Also think about how the water enters the pond it might be going quite fast and be a fair bit of it. Errosion, stiring up of the pond bottom.

[PeterC]

If asked - it's a soakaway.

[Huge]

Thinking about using the workshop roof rather than the house and putting an IBC behind the workshop where it can't be seen. Makes the overflow arrangements easy, too, since that's where the ditch is.

Hmmm. Thanks for that - I should have "done the math"!!

Yep, I was going to arrange for any overflow to go back down the original route.

No. I expect that's one of the reasons it dries up. That and the willow growing in it. :o)

Not sure.

Now, *there's* an idea! Lots of work and expense (have you seen the price of cobbles?!?!?) but I've always wanted one of those "washes", "rills" or whatever they're called.

Ick. No.

Another good point.

Thanks muchly!

[news]

Yes I considered that, do we know the roof area of Huge Towers?

I was working on worst case of an inch of rain in an hour, so about 8 tonnes of water which would be 2.5 litres/sec so the pipe out would need to move it at 2metre/sec, what's the length to the pond, there are tables that give head verses flow rate for pipes.

Not really, just that the feed end of the pipe needs to be sufficiently above the pond and have a suitable head to drive the water down the pipe.

As you say the buffer only has to deal that rainfall the pipe feeding the pond cannot handle any more than that is just lost to the current ditch.

[Huge]

It's a bungalow (sorry, "single storey dwelling" - my wife hates the word "bungalow"), so "Towers" isn't really appropriate! :o)

And even I don't know what the roof area involved is. It's a conversion of an assortment of farm buildings, not rectangular in plan and the downpipe I'm thinking of using doesn't drain it all. I'd probably have to get up there to have a look, and I don't go above gutter level any more, not even on bungalows. :o)

Blimey. This turned out complicated. I was just going to bodge up some pipery so as not to "waste" the rain water!

[Chris J Dixon]

If I had much more space, a series of water features incorporating a rill would be part of my plan.

Avoiding buying lottery tickets saves me having to do any further planning. ;-)

Chris

[Andy Burns]

And a Ha-Ha too?

[Huge]

*grin* I know what you mean.

I found a tour of gardens in North Norfolk a couple of weeks ago slightly depressing.

[Chris J Dixon]

I wouldn't put it like that. I like to consider what my fantasy property would incorporate - the list keeps growing.

My partner's chief desire is a library, complete with one of those ladders that slides along a rail.

Chris

[Huge]

They were lovely, but made me think "I wish I'd started 20 years ago". A bit silly given that we moved 17 months ago.

Don't we all!?!?!?

Bedroom 3 is rather grandiously referred to as "the library" here, since it is entirely lined with bookcases (and has no bed). Most of it is my SF collection.

[Tim Lamb]

You just have to adopt a pioneering attitude:-)

Not a problem for roof water but our pond gets the run off from two largish yards. The water is thus high in nutrients which aid blanket weed growth in the pond.

Today I am taking my *up to 20 cu.m* from the R. Lea where the nutrient burden is whatever Thames Water have released from their upstream sewerage plants.

[S Viemeister]

I've wanted that since I was a child.

[F]

We have a rainwater diverter on a downpipe which fills two rainwater butts which are connected to each other with some 22mm overflow pipe. The second butt has 22mm overflow pipe running from the same level as the length joining the two butts down to ground level, under the paving to the edge of the pond where there's a short upstand, and then a short horizontal length to deliver the water into the pond.

When the pond fills, any overflow waters the plants in the border around it.

It's worked fine for several years now.

[Dave Liquorice]

My maths was assuming "domestic" 100 l water butt(s), I suspect a

1000 l IBC with a full bore down pipe outlet could well buffer all but the heaviest of rain.

Cobbles in 25 kg bags from garden/diy sheds are expensive. See what you can get in a dumpy bag from a builders merchant... Dig U shaped trench say 10" wide and 6" deep, line with suitable width DPC (to prevent errosion), row of cobbles down the middle, then ones interlocking along the sides. Have some smaller stuff (10 to 20 mm) to put in the gaps. It'll probably act more like a french drain than a visible babbling brook though.

[tabbypurr]

Pouring bitumen between the stones should keep the water on the surface. IIUC step level changes get you the babbling. Or cement Mr Speed in there.

NT

[harry]

Rainwater belongs to you until it crosses your boundary. Then it belongs to the local water company.