Maximizing Rain Collection
Rainwater collection is one of the most reliable water sources in wilderness environments. The key variables are collection area and efficiency. A single person-sized tarp (approximately 3-4m²) in moderate rainfall (10mm) can yield 24-32 liters of water — enough for several days.
Collection Efficiency Factors
A flat tarp with proper slope can achieve 80-90% collection efficiency. A poncho draped loosely might achieve 50-60%. Natural foliage is poor — leaves shed much of the water. In practice, a poncho collection system in decent rain (10mm) typically yields about 1-2 liters per hour for a single person.
💡 First FlushIn any environment with debris on your collection surface, discard the first 20% of rainfall to remove debris contamination. After that, water is relatively clean but should still be treated before drinking.