Infographic Style Diagram

Clean infographic style illustration of [how rainwater is collected and filtered], drawn as a simple left to right flow of [four] stages joined by arrows. Flat vector icons with a thin consistent line weight, generous white space, subtle drop shadows. Palette of [navy], [sky blue] and [light grey], with [orange] used only on the arrows. Icons simple enough to read at small size, evenly spaced along one baseline. Leave an empty rounded box under each stage where a label will be typed later. Aspect ratio 16:9. No text, no numbers, no logos, no watermark.