Right phonetic
㐬 — supplies the sound (liú, exact match). Pictographically depicts a baby being washed away in water, head-down with hair streaming, the very picture of 'drift, flow.' Adds a faint semantic flavour reinforcing the water radical: not just any water but moving, carrying, sweeping water. Same phonetic in
硫 (sulphur),
琉 (lapis lazuli),
梳 (comb).