Hi all,

As a civil/stormwater engineer I am accustomed to designing treatment practices to our state manual, but our manual (Vermont) is primarily geared toward sizing for treatment volumes, not conveyance and collection and the associated risk of flood damage to surrounding infrastructure. Is there any national building code that establishes proper sizing for certain collection components (e.g. pipe sizing, roof drain sizing, trench drains, etc..) Obviously we design to at least the size of our largest required treatment event, but I was just curious if there was a code out there that we were not aware of. I've seen a 25 year event as a standard, but sometimes this is too big or too small of an event for the application.

Thanks in advance.

check your drainage and floodplain ordinance for your jurisdiction. check with the city, county or state road department. check with the local building department. depending on the type of work you are doing, they will all have requirements and may all be different.

cvg is correct.
However, in some unincorporated counties and out of the way places, the regs are a little iffy.
In these cases, I default to the UFC (Unified Facilities Criteria, formerly Army Technical Manuals) concerning drainage issues. The UFCs are free at their website if you Google it. As cvg points out, you still have to meet all local codes.

For sources of nationally accepted standards, check Army Corps HEC publications, FHWA, and FEMA. But in terms of hydrology and hydraulics, just about everything is state or local dependent in my experience. Start by talking to your reviewer and local engineers to see what everyone else does there, since that's been working for them. It's a vast country, and every state is unique and different.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

Thank you all for the responses. I will take a look at some of the publications that were recommended.