On Fri, 3 Aug 2007 03:59:30 +0100, brian mitchell
wrote:

(WaltA) wrote:

On Fri, 3 Aug 2007 00:57:20 +0100, "Emrys Davies"
wrote:

"Kroma" wrote in message
.. .
Hello,

I have a very dry flower bed along the front of my house as it is
shielded
by part of my roof.
I'm planning to put a water butt at the corner of the house and run a
hose
from it as an overflow. I am hoping to 'drill' some holes along the
length
of the hose and lay this along the aforementioned dry flower bed.
Would
this then irrigate my flower bed as I hope (as long as the water butt
is
full).

Any tips or ideas gratefully received.

Thanks in advance,


Kroma

I do not think that it will work simply because the force of water will
not be sufficient for it to percolate effectively along the length of
hosepipe. Hopefully I am wrong.

Regards,
Emrys Davies.

You are right that the hydrostatic pressure will reduce along the pipe
the further from the butt, ( the loss will be determined by the size
of the holes I think, without going back to my books
however, there is a solution
( sorry for the pun!) :

The pipe from the butt should be taken to a 'Y' (to the bottom, tail,
of the Y junction)
The perforated irrigation pipe is then used as a loop between the two
other ends of the Y
( the top ends as she is written in english (!) )

That way equipotential is maintained along its length.

I see great Heath Robinson potential here.

The loop idea might ensure that the bed is equally irrigated but doesn't
deal with the bigger problem of the lack of pressure.

Not a problem I think,
There is a little pressure, a few (decreasing) feet of head, enough to
cause the water to leak out gradually. You dont want it all to be gone
in a day do you ?
If it were just a case of diverting ALL the roof runoff to the dry
bed, as it arrived, then an aqueduct of guttering and downpipes etc
would do.

Because the butt
is open and unpressurised, this would obtain even in the case of
torrential downpour, when the water that couldn't flow quickly enough
along the hose would just spill over the sides.

yes, that would happen if one's butt was not big enough

The system needs to be automatic and self-sufficient (no pumps), so I'm
seeing a header butt, mounted on the wall just beneath the eaves,

Mounted how ? Water is awful heavy !

Do I get the contract?

for deputy junior heath robinson, not sure yet. I'll put it to the
committee