Corner of garden in standing water after heavy rain last night

jamesharcourt

A corner of my garden is in standing water after heavy rain last night ... see below.  What can I do, I have two trees planted raised up to avoid this but I fear the drainage can’t keep up with the rainfall on nights like last night (Sussex UK).

jamesharcourt

I was wondering if the sloped shed roof might be exacerbating the problem and running some guttering along the front and sending the water away to the lowest point behind the shed might alleviate things?

Dovefromabove

That’s my initial thought ... guttering and a waterbutt would be my first move ... perhaps with an overflow to a bog garden. 🐸 There are some fantastic plants that would be happy in a bog garden.

treehugger80

you could always dig a sump ( a big hole filled with rubble and gravel and topped with soil and in most cases turf) that would at least keep some of the water off the ground surface

steephill

You need to think about where the water comes from and where it will go. If the lowest point is behind the shed then that is where you need some sort of drain. The water will be draining down to that point from the rest of the garden so the relative contribution from the shed roof will be small.

Collecting rainwater is always a good idea though so guttering and a water butt is worth doing but it will have limited impact on your winter water problem.

jamesharcourt

steephill said:

You need to think about where the water comes from and where it will go. If the lowest point is behind the shed then that is where you need some sort of drain. The water will be draining down to that point from the rest of the garden so the relative contribution from the shed roof will be small.

Collecting rainwater is always a good idea though so guttering and a water butt is worth doing but it will have limited impact on your winter water problem.

The shed has an apex roof sloping down to the front door, so the water is coming from the shed roof directly on to the area in front of it.  So a gutter in front of that seems to be an obvious choice, directing the water to the area between the RHs of the shed and the fencing there where it can flow down the general hill of the land (we're on a slope as you can tell - and the shed is at the lowest point of that slope - behind, rear, of shed is a fence and the road / pavement which is on a downhill slope).

steephill

If your shed wasn't there you would still have to deal with the same volume of water, no more and no less. All your shed roof does is delay the arrival of rainwater to the ground by a few seconds at most.

The problem is that however the water gets to that corner of the garden it isn't draining away fast enough to prevent surface flooding. Are your neighbour's gardens also flooded? Do their gardens drain into your's? Although you are on a slope you might still have a dip in levels which allows water to accumulate.

BobTheGardener

While I agree with the above, if the problem cannot be managed by better drainage in that area due to a local dip in the ground then I would try guttering and a large water butt.  As Dove said, you could then fit a drainage pipe/hose to the butt and the extra 'head' height this gives may allow the pipe/hose to be routed to whichever system your house roof drains to.  If you do this, make sure you fit a debris filter on the top of the downpipe to the butt to keep leaves etc. from getting in and later blocking the drainage pipe/hose outlet.  It will still likely overflow in very heavy persistent rain but keeping the butt half empty should help.

jamesharcourt

steephill said:

If your shed wasn't there you would still have to deal with the same volume of water, no more and no less. All your shed roof does is delay the arrival of rainwater to the ground by a few seconds at most.

The problem is that however the water gets to that corner of the garden it isn't draining away fast enough to prevent surface flooding. Are your neighbour's gardens also flooded? Do their gardens drain into your's? Although you are on a slope you might still have a dip in levels which allows water to accumulate.

I thikn the shed is directing the water to one localised area ... worth me mentioning that the shed wasn't there until 2 years ago (put in Jan-Feb 2018) and we didn't have this degree of waterlogging before in my memory.  It's not just standing water - the very bottom section (where the Astillbe is, next to the Fatsia Japonica) is actually underwater.

Dovefromabove

Yes, although it’s the same amount of water, now it’s all focussed into one spot and  the fact that the shed is there impedes evaporation and any run off onto the lower land behind the shed, which is probably used to be the way that area drained. 

raisingirl

In the short term, the trees will be OK. Most trees will put up with a bit of standing water in winter. 
Be careful where you site the water butt, or rather the overflow from it. 

On the upside, it's just a corner of your garden. The water table in my whole garden is about 2 inches above the surface at the moment - water is just running out of the hill. And it's still raining.