storm water system with steep slopes

How are storm water systems designed when several 12% sloped streets 700
feet long meet with a perpendicular nearly flat grade street that drains to
a culvert. Are drop structures used along the long steep streets? What would
be a maximum for velocity and slope? Any insight would be appreciated.
Dave

 

Probably the wrong forum, but here goes anyway:

First place to look is the local regs, notably the highway or
engineering department and/or the planning regs. After that, 10 Feet per
second is about maximum. There is some flexibility there but I wouldn't
want to go 700 feet. Use drop structures and keep the pipe slopes down
to about 8 - 10 FPS. Manning will help. As far as the almost level
portion, min. slope depends on diameter. Better not to let the design
storm flow go below 2-3 FPS. Slopes in the neighborhood of .005 to .0005
are used. Don't forget to build in a drop across the structures. 3" from
inlet to outlet is frequently used.

rs

 

I know it's the wrong forum, but this was the most interesting post that I
have read all day. Thanks.

 

Really slow day, eh?

rs

 

DJK -

You need to post where the civil/land users post.

You may find more appropriate information and receive better
responses by posting future Land Desktop related questions in the
Land Desktop discussion group, available at:

Web browser: http://discussion.autodesk.com/forum.jspa?forumID=83
Newsreader: news://discussion.autodesk.com/autodesk.land-desktop

 

Yes I am sorry accidently on wrong group, will do.