non-return-valve

Updated: August 17, 2026

This gate, cunningly arranged upon the non-return-valve principle, is normally kept open by the current from the Dal; but if the Jhelum, rising in flood, threatens to pour back into the lake and swamp the low ground and floating gardens, it closes automatically, and so remains sealed until the outward flow regains the mastery.

T. R. Swinburne - A Holiday in the Happy Valley with Pen and Pencil