How to deal with stormwater?

[bowmatty]

Hello guys,

I have one corner of my house that the stormwater runs to ground.

There is nowhere for the water to run off or collect to as it's in the back corner of the property. I have started digging and my initial plan is going to install 2x the following product in the pit, cover with geofabric and then backfill. Product states it can hold 252 litres of water. The only issue I have is the ground is clay.

Pit i have started to dig;

Also, I would like an overflow to point somewhere so it does not back up the downpipe and into the roof space.

Any suggestions would be great? 

[EricL]

Hello @bowmatty 

Thanks for sharing your question about your storm water overflow. Generally, this would have been an ideal solution to the overflow. However, due to the clay soil, I'm afraid the absorption rate will not be enough, and I suspect that the pit will overflow. 

I propose examining the issue further and perhaps using an Everhard Series 450 Stormwater Pit Case Only in combination with an Ozito 350W Dirty Water Submersible Water Pump. Since there is no storm water overflow in the area, the hose from the submersible pump can be directed to the overflow closest to it.

The other option is to dig a channel that will direct the overflow from the corner to your stormwater overflow at the front. Please note that both these procedures will involve plumbing, you'll therefore need to engage the services of a licensed plumber.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations. 

If you have any other questions we can help with, please let us know.

Eric

[Dave-1]

Afternoon @bowmatty 

I do like your thinking, and what I was going to suggest is very much like what @EricL has. 

With that stormwater pipe we can see how far away and height wise is the other stormwater that is plummed into the actuall stormwater?

The pit being in clay is just going to hold the water (unless you want a pond? and that could work with the submersible pump to keep the water level)

I have had to dig through a lot of clay for my stormwater pipes but consider it worth it and you certainly seem to like it enough to dig it out the way you have If you have a submerible pump you will have to factor in power for it or run it from a solar panel plus battery (always the issue if you have grey days and rain) If possible at all I would suggest to join up your stormwater piping as it will remove the pump from the equation. 

Note you will need to cover the pipe in gravel when you install it, up to level with the pipe. This will stop the compression of that clay from constricting the pipe in the years to come.

Stormwater rectification stage 1 

Stormwater rectification stage 2 

Are the stormwater project I did for my place. Lots of digging but it has worked nicely in the storms since Hopefully something in the projets will help you out.

btw I found using a crowbar to drive down the edge of the trench and lever it plus the square shovel you have worked best for me in working with clay.

Dave

[Nailbag]

Hi @bowmatty The first thing I thought of was to use a submersible pump which @EricL has already suggested. The outlet would then be connected to a pipe running back to your stormwater. This part has to be completed by a licensed plumber.

I have had to setup a similar system to prevent run-off water during storms entering a lower level living space. The only change I would make is the type of pump. Most submersibles have an external float, which don't activate until there is considerable water within the pit. You can get away with a much smaller pit if you use a model that has an internal float valve system like this one from K'Archer.  You will moist likely also need a sparky to provide an external GPO within the cable length of the pump.

The system will work a treat. As water fills within the pit, the pump will automatically kick in for a short period of time (almost silent underground) sending overflow water to your storm water.

Hope that Helps.

Nailbag