背せが立たつ

expression, godan verb (-tsu)

to be able to stand in water; to have one's feet reach the bottom

Used when a person's height is sufficient to stand on the bottom of a body of water, such as a pool, river, or sea. Often used in the negative form 背が立たない to indicate the water is too deep.

• この川かわは深ふかくて背せが立たたない。

  This river is too deep to stand in.

• 子こ供どもでも背せが立たつ浅あさいプールだ。

  It's a shallow pool where even children can stand.