Rainwater collection estimate
Estimate runoff collected from a roof or other collection surface.
How it is calculated
Potential liters = area in m² × rainfall in mm × efficiency. Retained = the smaller of potential and free capacity.
Assumptions & limits
Rain is assumed uniform. Losses include diversion, leaks and runoff. Collection does not make water potable. Defaults are illustrative planning inputs, not recommended minimums or a guarantee of safety.
Planning estimates only. Defaults are illustrative, not personalized recommendations. Do not use these calculations as medical, structural, electrical installation or other safety certification. For informational and educational purposes only. CivArk is not medical, legal, engineering or other professional advice. Verify information with qualified professionals and current local authorities. Estimates and preparedness plans cannot guarantee safety or survival.