timely rain, life-giving rain
澍 centers on rain that arrives at the right moment to nourish life: a timely, life-giving rain that revives the land.
澍 combines 氵 (water) with 尌, which likely contributes the sound and may relate to standing or establishing, suggesting rain that establishes or sustains life.
Water 氵 beside 尌: imagine a standing figure (尌) receiving a shower of life-giving rain, the water pouring down just when it is needed most.
For シュ, picture a shoe left out in a timely rainstorm: the shoe fills with life-giving water, and shoe -> シュ.