Sorry you didn't follow. I thought it was pretty clear but it was late, so maybe I worded it poorly.
The point is - if they dropped that little girl in a lake then chances are very, very good that she's gone and will never be found. If they were dumb enough to bury her within three mils of the house then the chances improve dramatically, but then again the EquuSearch search team suspended search operations due to flooding near the possible burial sites. The flooding could be the wildcard as well - if the child was buried in an area that was flooded, the waters could have unearthed the body or carried it somewhere they aren't looking.