Floodplain" is a short, spare poem about people living with a river that keeps threatening their home. The opening lines treat the river as an enemy, and the water has risen "to our hips," which makes the danger physical and close. The speaker says "our home" almost in the same breath, so the loss feels personal, not just a matter of property.
The second half shifts. The group imagines going somewhere "where it is thin as a drunk," a strange comparison that seems to describe the river at a narrower, weaker point, though the exact meaning is open. It suggests something unsteady, wandering, a little pitiful. There, the people would "all day make / only fire." Fire is the opposite of water, so the lines read as a small act of defiance or comfort.
The mood is wary and stripped down, with a quiet stubbornness underneath. The short lines leave a lot unsaid, which makes the fear feel restrained rather than loud.