culvert size

I'm in the planning stages of putting in a road to a piece of property I bought. The road will be fairly flat , however, I will have to go over a seasonal drainage area of about 30 feet wide and 7 feet deep. Is there a formula about the size of culvert I should put in? Thank you.

 

[jugglerbri]

This is what professional engineers get paid to determine. It depends on the level of protection required (can flow overtop the road? If so how often?), the drainage area contributing to the culvert, the rainfall patterns of the area, the channel charecteristics of the downstream channel. After all this is determined, you can size the culvert and then, does it fit under the road? Will you have to raise the road to get the culvert under it? What kind of bedding is required? There really is no rule of thumb that I'm aware of for quick sizing the culvert. You can probably hire an engineer to design it for you (shouldn't cost too teribly much) and then you have the protection of his errors and omisions insurance in case something does go wrong.

Brian

 

[jheidt2543]

Another option is to contact your local county highway department. They control the right-of-ways along the county roads and most likely have requirements for access drives and culverts. They also would have the information on drainage ways in the area that could affect their roads.

It would be a good place to start.

 

[sta7240]

I agree with jugglerbri. In addition to what he says, you can also consider the regulatory process. You can't simply install a structure in a stream without a permit. Also, are you filling a wetland? How about sediment and erosion control? Normally, there is local, state and federal regulatory (COE) reviews requiring detailed information to gain approval for a project. Again, more reason to hire a professional engineer.