Subsoil drainage

[Bartz]

Actualy I have to work on a problem which contents subsoil drainage. I have to dewatering a area for rd. 200 farms, t.m. roughly 4,5 ha.
It would be very helpful, if anyone can give me some recommendations for codes and standarts (prefered BS or ASCE), weblinks and books for calculation a subsoil drainage network. I know, it is quite similar to a normal storm water network but as en example, how can I determine the distances between the preforated pipes?
Thank you for your help
Regards

 

[BigH]

Don't have anything right at hand - but why not check with US Agriculture Department? I've seen a book of Standards on Agriculture stuff and you'd be surprised at what they have.