NYS SWPPP Question

[Apexpredetor]

I have been asked by a family member to help them with, what appears to be, a fairly simple SWPPP/SEQR permit.

He/She is expanding upon an existing Mobile Home Community. The expanded area is on slope, but will be terraced to properly build pads for the manufactured homes. there will only be about 30 pads over a 14 acre area. Gravel driveways, narrow roads, lots of green space left, with all trees left as best we can.

Here is my question:

Due to the terracing of the slope the post development runoff is less than that of the pre development. I am reading the NYS Stormwater Manual, but I can't figure out if I still need to account for the RRv, channel protection, or extreme flood conditions?

I actually signed up for a NYS Stormwater CEU class but it got cancelled.

Thanks all

 

[TerryScan]

You probably want to move this post to the Storm/Flood Engineering forum to get better responses.

 

[beej67]

I'm skeptical that you can make the claim of decreased runoff purely from 'terracing' while adding impervious coverage to the land, without some sort of study to back that up. That wouldn't fly down here, but I'm not familiar with New York engineering practices.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[rcspiel]

I am skeptical also about making a case about increase impervious area and decreased runoff. I'm not familiar with New York or the site, but the 100 year flood elevation needs to be taken into account with construction. How can BMP's be selected without taken into account all conditions?