Flickr user paulbence

Folks on Buckfield Road in Sheldon got a scare after a ditch started smoking in the rain, and after water was pored on the solid smoking object it began to burn more.

I'll point you to WTOC 11's video report for more info; see it here.

Sounds like it could be some sort of alkali metal, like sodium, that "smokes" when combined with water. You can see that in the video below.