I promised that I would post a follow up to my question about using
sand to level depressions in my lawn caused bt the extreme drought in
my area, NE Alabama:

I used the sand to fill the depressions in my yard and it worked
really well on the smaller, shallower ones, but didn't do as well on
the larger ones. However, it worked better than I thought it would
and was definitely better than doing nothing. It worked great on the
St. Augustine in the more level front yard, and not as great on the
centipede on the slope in the back. That probably had more to do with
the slope of the back vs the level front than it did the type of
grass. The sand washed out more on the sloped back yard than it did on
the level front yard. All in all, it was enough of a success that I
feel it was worth the time and effort especially since the sand was
free.

Thanks,
Howard