stormwater runoff

[eng2424]

For a site I'm designing, the stormwater runoff runs offsite into an existing creek. There is also an existing low spot where part of the site currently is graded to. How should I take this low spot into account for stormwater management? For my runoff calcs, should I just disregard the watershed area running to the low spot since it is not going offsite? The post-developement will not change this low spot or the watershed going to it, so another reason why to diregard it?
I may also need a detention pond on the site, this low spot would be a good place for it?

thanks in advance for any help

 

[sam74]

There is a Storm/Flood engineering forum. Anyway, it sounds like you have thought thru your situation pretty well.

 

[gbam]

Ok,
If you do not plan to change this sink then only mention that there is no change from pre to post developement. If you plan to use it as your deten pond then you will have to show that under existing conditions all flow to the sink will be contained or not. Then show that the proposed condition does not increase the flooding etc....

Goodluck & Have fun

 

[LHA]

...and make sure this local-low spot is not a sinkhole, or a depression, which is usually a sinkhole-in-formation. There is a geological reason why the earth formed this way.

Many Ordinances have restrictions against increasing flow toward a depression, so make sure you are allowed to detain here.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve