Riparian: Relating to or situated on the banks of a river.
He enjoyed a riparian existence, sitting on the riverbank and casting out his line. This particular section was new to him and he was keen to see what he could catch.
The bank had looked pretty solid, but as he stepped closer to the water his boot sank into the soft soil. He managed to pull it out with a “glop” noise, but when he put his other foot forward it was pulled down and he couldn’t move at all.
“Help!” he shouted, but no one was around.
His heart went still as something gripped his ankle and tugged hard.