The Rainwater Harvester is a building which collects Water from rainfall events, stores up to 40 units internally, and provides it via a Pipe connection. It is the only source of Water available to supplement Farms until the Groundwater Pump is researched, though it still retains usefulness as a backup or alternate solution to Water collection as it requires no Electricity, Workers, or Maintenance.
During rainfall events, it can both simultaneously collection Water and provide it to the Pipe output.
On average, the Rainwater Harvester can collect 35-40 units of water per year. During rain it generates 0.5 units of Water, and 1 unit during heavy rain.