What does a bad percolation test mean?

[broadex]

14 minutes ago, joe90 said:

However if you don’t use all the rainwater the excess has to go somewhere so a soakaway is still required.

 

Thanks guys. 

 

I'm not in the building industry but i just cant believe that my planning application seems stuck on this one issue - 'how to manage rainwater' yet at the moment the surface water drains well into the garden without any water poodles. 

 

With all the technology available,  i would have thought i any easy solution would be nearby:)

 

And the planning officer seems to take this more seriously than i intially envisaged. 

 

As my next suggestion i would have rainwater harvesting in addition to using soakway crates/and a pond for kids play area.

 

 

[saveasteading]

Flooding is very serious in some areas, and so is taken seriously. Rain falls much faster in recent years.

If there is no puddling in the garden then it is either running away, which could cause issues, or is soaking away. If it is soaking away easily then you will get a good percolation test, and can use a soakaway..

 

Soakaway crates also need a throttle for slow release. Either spend £1,000 or more or design a simple, but controlled, overflow.

[Phaedrus]

2 hours ago, broadex said:

Has anyone used rainwater harvesting as an alternative? The planning request for percolation tests were for surface water management and i just thought before i go back to planning, i can suggest using some sort of rainwater harvesting. 

Thanks for clarifying that it was soil infiltration tests you did for surface water soakaway assessment.  You stated that your results were bad.  How bad? - it would be helpful to confirm this and also what the surface water drainage arrangements are for the existing house.  It has been the wettest winter since 1910 in the east of England so if your garden has been dry throughout this period it suggests the ground water level is well below the surface and the conditions are reasonable.

 

My site is sandy/gravelly clay with infiltration rate measured at 2.2 x 10-6 m/s.  The proposed solution is to discharge rainwater from the roof into pervious paving which stores the water in the granular fill and eventually allows it to infiltrate into the ground over a large area.  I am required to have rainwater harvesting for water saving purposes but this doesn't really help with stormwater management as the volume of the tank is small and you cannot rely on it being empty when the storm arrives.

 

https://forum.buildhub.org.uk/profile/8466-saveasteading/ has already given you good advice regarding other options from the SUDS manual including attenuation tanks and swales.  If you are able to discharge to the ditch then you'll be expected to control the flow to the existing runoff rate.