Rainwater drainage!

[PeteB]

I would think I live in a pretty ordinary, early 80's, three bed detached house, thrown up with some haste and maybe some corners cut in the name of profit/haste...I've lived here about 12 years and had a constant battle with rainwater sitting on my driveway and on several occasions, flooding my drive, garage and garden with surface water and "brown" water. Over the years, myself and others have moaned bitterly about this to the various bodies involved and got fobbed off by their experts who claim it doesn't happen, is beyond physics, the once in 50 year event etc....

 

Basically, we are at the bottom of the hill so any rainwater that misses a drain heads my way. There was a blocked surface water drain into the brook behind which was  fixed but the puddles still kept getting into my brick blocks...sensors where fitted to the sewers to alert them when they were flooded and a NRV fitted in my system to prevent it coming back up my loo.

 

A short time ago, a well informed chap came from the council, took one look and said that there was a surface water issue and he would try to get it altered but not to anticipate anything too quick. He took me to one side and we had a deniable conversation. The estate was built with too much haste, the inspections at the time were wrong and incomplete, the drainage was inadequate and wrongly laid (it has to flow uphill at one point), the rainwater off the roofs should have gone into either proper soakaways or fed back in to the drains. Each side of my roof drains into a gravel filled hole, possibly a meter square, and added with the stuff that flows downhill, cause the flooded driveway. He suggested that I get a couple of water butts and regularly drain them. 

 

This was done. Last week, they were both at tap level as I let them drain slowly into the dried up lawn. This morning, they are full again! And, my drive isn't flooded! I never really considered how much rain falls and how crap these house were built!

[donnk]

Simple fix is to put the downpipes straight into the sewer. Not really allowed on new stuff anymore but plenty of older houses have it. Instant fix. 

 

If and when the council sorts the rest so you can have a proper soakaway and revert them.

 

What you are doing with those butts is a manual soakaway in effect.

Edited June 7, 2020 by donnk

[harvey b davison]

I had similar with mine. My rear guttering went into a soak away 3 ft from house and always blocked. I put in a drainage channel in from my downpipes and all the way across my drive and fed the pipe work directly into the manhole. Not had a problem since.

[openspaceman]

19 minutes ago, donnk said:

Simple fix is to put the downpipes straight into the sewer. Not really allowed on new stuff anymore but plenty of older houses have it. Instant fix. 

Naughty and deprecated

19 minutes ago, donnk said:

 

If and when the council sorts the rest so you can have a proper soakaway and revert them.

 

What you are doing with those butts is a manual soakaway in effect.

More of a manual balance pond, set the tap at the bottom to constantly drain at an acceptable rate in the winter, shut it and use the water in the summer.  A heavy rainstorm will be dumping 1.5m3 of water on a 50m2 roof with 1" downpour and my water butts only take 500 litres each.

 

Basically you have to prevent water coming in to the garden and buffer the amount that falls off the roof to empty between downpours.

 

Put something heavy on any sewer inspection covers in the garden and consider raising a mound around the garden.

[Sutton]

A mate's old house is on clay on a slight incline with no DPC nor double skinned. The bricks used to soak up rainwater making it damp indoors. He resolved it without plumbing into/overloading the sewerage system. Why? Because of the number of houses in the area and the distance to the green box pump stn

[PeteB]

The drive, garden and garage flooded again yesterday. The butts overflowed despite them connected to hoses that went to the bottom of the garden and on the other side of the house, the water from the down pipe wasn't getting into the hole quick enough and overflowing, with the surface stuff coming down the hill, it was couple of inches deep pdq!

 

I checked my bill and I pay a rainwater tariff so decided to route the one down pipe direct into waste water. The OfWat web page seems to say that this is okay. It rained again and the garden and garage etc flooded again! Water was boiling out of the 'soakaway' and this was causing the flooding. It appears that I don't have soakaways, but have drains. Somewhere between me and the brook, it is blocked! I got to find out who is responsible for it next.....

[Stubby]

5 minutes ago, PeteB said:

The drive, garden and garage flooded again yesterday. The butts overflowed despite them connected to hoses that went to the bottom of the garden and on the other side of the house, the water from the down pipe wasn't getting into the hole quick enough and overflowing, with the surface stuff coming down the hill, it was couple of inches deep pdq!

 

I checked my bill and I pay a rainwater tariff so decided to route the one down pipe direct into waste water. The OfWat web page seems to say that this is okay. It rained again and the garden and garage etc flooded again! Water was boiling out of the 'soakaway' and this was causing the flooding. It appears that I don't have soakaways, but have drains. Somewhere between me and the brook, it is blocked! I got to find out who is responsible for it next.....

Get Eggs on the job ! ?  @eggsarascal

Edited June 17, 2020 by Stubby

[dig-dug-dan]

20 minutes ago, PeteB said:

The drive, garden and garage flooded again yesterday. The butts overflowed despite them connected to hoses that went to the bottom of the garden and on the other side of the house, the water from the down pipe wasn't getting into the hole quick enough and overflowing, with the surface stuff coming down the hill, it was couple of inches deep pdq!

 

I checked my bill and I pay a rainwater tariff so decided to route the one down pipe direct into waste water. The OfWat web page seems to say that this is okay. It rained again and the garden and garage etc flooded again! Water was boiling out of the 'soakaway' and this was causing the flooding. It appears that I don't have soakaways, but have drains. Somewhere between me and the brook, it is blocked! I got to find out who is responsible for it next.....

What's the soil structure like there? If it were me, I would dig a soakaway and fill with attenuation cells, NOT rubble, ideally you will need to measure the roof area and drive area to calculate the exact size. I have done this so many times for customers, and not one has failed yet!!

[Stubby]

1 minute ago, dig-dug-dan said:

What's the soil structure like there? If it were me, I would dig a soakaway and fill with attenuation cells, NOT rubble, ideally you will need to measure the roof area and drive area to calculate the exact size. I have done this so many times for customers, and not one has failed yet!!

Dan . Is that those plastic cages wrapped in a semi permeable membrane ?  

[dig-dug-dan]

5 minutes ago, Stubby said:

Dan . Is that those plastic cages wrapped in a semi permeable membrane ?  

Yep. They look like milk crates, they hold 97% of their volume in water, a rubble filled soakaway holds 10, and slits up too quickly. Dig the hole, put the required number in, wrap them in terram, and backfill with 20mm shingle. Job done