The flood came on fiercely and was hard to hold back.
Tips
usage
Common in 汹涌 ('surging, turbulent') and the doubled 气势汹汹 ('in a fierce, threatening manner'). The water sense extends to any overwhelming, menacing force.
The three-drop water radical on the left gives the meaning: the core image is water surging and rushing violently upward, which extends to any fierce, overwhelming force.
Supplies the sound on the right: 凶 xiōng gives the reading directly. Its sense of 'fierce, violent' also reinforces the menacing flavor of surging water.