I appreciate the feedback. Our FEMA Region X hydrologist did some searching and found some documentation regarding the 'shadow effect'. It's on it's way to me via snail mail, so once I receive it, I'll be sure to post my findings.
I thought I'd post the answer I found to my own question for any of you who may be interested...
I spoke with a hydrologist from FEMA Region X. If a structure is to be built within the "shadow" of an existing building, no study would be required because the shadow is considered...
Do you know of any special FEMA exclusions for building a structure (e.g. garage) in a flooday, if it is in the 'shadow' of an existing structure? I have heard that there may be such exclusions, which would allow me to perform a simple 'no-rise' study in lieu of a backwater analysis.
Thanks.
Kelsy