Strom Drainage Calculation 1

[atilashorse]

Hello!

Can somebody please indicate me the design approach and formulas to determine the legth adn diameter of Perforated Pipe in a rock bed (French Drain).
Additionally, what is the criteria to determine the amount and size of the catch basins connected to the drainage pipes?

This is a typical drainage system for a parking lot.

 

[LeoSC]

Since this is obviously an area of design for which you don't have the training and experience, I recommend that you retain a civil engineer with experience in storm water management, who can do the work quickly, properly, and economically. If you wish to do this yourself, the easiest way to make sure that you know what you're doing is to study; in that case, there are many good storm water management books, manuals, and guidelines that would be useful.

 

[bltseattle]

I agree with LeoSC in that whatever advice you get on this forum you need to check with the engineer of record in your office (the licensed civil for the project). That said, the FHWA manual HEC-22 is geared for urban drainage systems. Many local agencies have simpler criteria that are easier to apply than what is in the FHWA manual. This info is in the drainage manual/standards for the jurisdiction, or if they don't have one, for the state.

For many applications french drains are designed based on sizes and materials that have been demonstrated to work in the region, rather than theoretical calculations. Local drain pipe manufacturers/vendors can probably assist you as well.