Required drainage pipe size for catchment

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Joined:Sat Oct 01, 2011 6:24 am
Required drainage pipe size for catchment

Post by Duncan » Sat Oct 01, 2011 6:36 am

Hi All,

As part of installing a driveway I need to cross a gully. To do this I need to provide drainage under the crossing for the council approval. For a total catchment area of 39000m squared with an average grade of the catchment being 1:5 does anyone know what pipe diameter I would need to install.

I am able to get 2 lengths of 450mm diameter PVC pipe and to build a head wall around them at the start of the crossing so all of the water is directed through the pipes. If anyone is able to let me know engineering wise, if they are large enough, that would be tops.

Strangely enough, the council said the catchment was 39,000m squared but a surveyor told me is was 22500m squared. Is it possible to have an answer regarding pipe sizes for both estimated areas?



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