A fabric is water repellent when it allows water slide over its surface without seeping in.As a result, the fabric does not soak up water & stays light, breathable & warm.The water repellent property is achieved by treating the fabric's exterior.This treatment must be renewed throughout the garment's lifetime (with every or 3 washes). How to restore the water-repellent properties:https://www.quechua.co.uk/advice/how-do-you-restore-water-repellent-properties-your-jacket