User blog comment:CNBA3/Fairy Tail Civil War!/@comment-27281341-20160406132206/@comment-27281341-20160411120821

Sadly, this feat of Gildarts was calculated as only Small City to City level of damage. And Natsu's feat is even more impressive, because in Natsu's case the lake evaporation was just a side effect of his attack, that wasn't even targeting the lake. Gildarts was targeting the ground and he was very angry when he attacked. So, all in all, as of now, Natsu by feats is above Gildarts by a decent margin.