Rainwater soakaway construction.

[Flying Torquewrench]

A couple of years ago we applied for planning permission to build a barn in our field. Planning permission was refused due to neighbours complaining about potential noise issues. We are planning to keep 50 chickens and 6 goats. Our property is in a rural location (Green belt) and our closest neighbours is 75 yards away, no chance in hell that they will have any noise or odour issues.

We appealed the decision and had noise and odour modelling done, subsequently planning permission was granted. Before we can use the building for its intended purpose we need to provide a rain water drainage plan to the council. This is were our problems start.

For a soakaway we need to dig trail pits and calculate the water infiltration rate. Our soil is heavy clay and has hardly any infiltration at all. Today I dug out an area to about 3 metres deep. With the JCB 8016, so that was a challenge!

Unfortunately a 3 metres I am still on clay soil and any water poured onto it just sits there. I am considering my options here. I can dig a ramp into the pit so that I can dig it down to about 5 metres, obviously making it large enough to avoid being killed by a cave in. Hire a larger excavator that digs down about 25 feet. Or hire a post hole auger for the JCB and make extension pieces to get 25 feet deep.

Every option has its own problem as we live on a very narrow road and a large excavator will have to be walked from the main road to the site, roughly 1/2 mile. Even a professional drill will have to be dropped off at the main road as anything over 7.5 tonne will not fit down our lane. Even if you wouldn’t mind the scratches then there is a 90 degree corner that you won’t get past. It will then be a case of reversing back up the lane.

As all of you are in the trade, I am sure that you have come across a soakaway on clay ground problem before. Any advice will be greatly appreciated.

 

[fred]

run it to a pond, from pond to nearest watercourse ?

 

[Monkeybusiness]

Green roof? ££££ though!

 

[Monkeybusiness]

Blue roof is actually what you need though.

 

[GazCro]

Up until recently building control were plenty laid back on this but couple of years ago with regs changes they now require it. Last couple of new build houses i have done there had been no chance of a soakaway. Most places where i am (lake district) they just do not work. Pond was used on one but the other option is a holding tank with a calibrated outlet size to restrict the flow into a watercourse.

 

[OBL]

How bigs the barn?
Assuming it’s clay all the way down...
Maybe a large water harvesting tank underground to reduce the flow to the soak away and free water for the animals, washing down etc.
Can pump it out slowly to disperse into a new ditch or pool with willows
May not satisfy the planners however unless you can model it well.

 

[JD450A]

Dig pond. Use water from pond for irrigation and livestock purposes. Calculate your daily usage to more than the shed could reasonably produce as run off

 

[hiluxman]

Can you not get a 3cx in for a day

 

[Flying Torquewrench]

Cheers. Closest watercourse is 200 yards away and runs on private property. in addition to all of the above we are on a sloping site.

Last resort will be a deep bore soakaway at a massive cost.

 

[Flying Torquewrench]

3CX will not be a problem but I have no idea how deep the layer of clay is. So ideally need something that digs deep.

 

[GazCro]

Cheers. Closest watercourse is 200 yards away and runs on private property. in addition to all of the above we are on a sloping site.

Last resort will be a deep bore soakaway at a massive cost.

But you've got to find a layer that drains underground. If you ask me having been down 3 meters without finding it its not there, or certainly not viable cost wise.

 

[fred]

if your on a sloping site, pond at the top. Let gravity takes its course.

 

[Flying Torquewrench]

Barn is 12 x 8 meters, producing roughly 75m3 of water a year.
The plan is to put a rainwater tank in. The animals will need about 30m3 a year which leaves 45m3 to get rid off. We will also use the water to water the field and our garden (1 acre in total).

 

[Jimoz]

I think what @JD450A was saying is what if you have exceptionally thirsty chickens and goats which need 75m3, do these pen pushers at the council actually crunch the numbers - I doubt it in the planning dept.

End of the day whatever water falls on the roof of that building used to fall on the land within the footprint. Providing the building is a small percentage of the size of the field I'm sure theres ways of making it stack up.

 

[GazCro]

It's all down to discharge rates. What used to fall on the ground now falls on a roof which concentrates it at a higher flow rate into a pipe. It's unfortunately something which if you want to build you have to adhere to end of. You can always fudge the percolation results to make it easier, there is a new housing estate near to me which did this and floods about half a dozen houses further down the road from it. Pond would be the cheapest solution but unless you have a discharge beyond it you may have issues with the council.

 

[Monkeybusiness]

Bauder Blue Roof Systems - Bauder

Bauder's blue roof system, BauderBLUE, is an innovative sustainable urban drainage solution (SuDS) which manages water attenuation. Learn more here.

www.bauder.co.uk

 

[Furniss]

Swale

 

[Flying Torquewrench]

I have the feeling that my options are quite limited. A pond would certainly be an option.

I can increase the amount the animals use each day a bit. Together with watering the field & garden and we need more water then falls on the roof! It seems that our area has a separate department that advices people on water management. Might have to give them a call on Tuesday. With a 20000 liter tank we can store 6 months of average yearly rainfall. that is just based on what the animals use, when taking into account the watering of field & garden and this should be more then enough. But I will give them a call to see what the requirements are.

 

[GazCro]

Is there any drainage on the land of any sort that you know of. Discharging into existing drainage be it land drains for example can simplify things.

 

[Flying Torquewrench]

No drainage at all! There used to be a building but that discharged straight onto the road which is no longer allowed.

We have no water run-off at all from the field during heavy rain so the top layer absorbs some water. Just not enough to build a soakaway.

I will see what the drainage department says on Tuesday otherwise I may have to get creative.