The trench keeps filling with warm water

I'm standing at the edge of a trench that was never meant to be this deep. The water keeps rising but it's warm, almost body temperature, and every time I reach in my hand comes up with a coin that's still hot from someone else's pocket. I know I should backfill it and walk away, but the strata beneath are still speaking and I can't make myself cover them. The light shifts and I realize I've been standing there for years.