Text included in the setting holotape guide.

1. Passive water resources generate settlement water points only if three conditions are met:
  1a. Settlement active water resources (pumps and purifiers) work properly.
  1b. The amount of water generated by active resources are equal or greater than population (water surplus).
  1c. The amount of surplus is equal or greater than the amount of water passive resources.
2. Every passive resource generates 1 water point per day, 2 points if water surplus is twice or greater than the amount of passive resources.
3. If positive water surplus goes to 0, passive resources begin to lose 1 water point a day. This feature is useful to avoid that a settlement instantaneously loses all water points after the destruction of active water resources (e.g. during an assault).

case #1 (ordinary)
active resources = 3 water pumps = 9 water points
passive resources = 2 water towers
population = 7 settlers
water surplus = water points - population + 1 = 9 - 7 + 1 = 3
water surplus (=3) >= passive resources (=2)? true -> each water tower generates 1 water point today.

case #2 (no surplus)
active resources = 1 water purifier = 10 water points
passive resources = 2 tanks
population = 12 settlers
water surplus = water points - population + 1 = 10 - 12 + 1 < 0
water surplus (-) >= passive resources (=2)? false -> no water points generated today.

case #3 (water points = population)
active resources = 1 water pumps = 3 water points
passive resources = 1 water cooler
population = 3 settlers
water surplus = water points - population + 1 = 3 - 3 + 1 = 1
water surplus (=1) >= passive resources (=1)? true -> water cooler generates 1 water point today.

case #4 (double surplus)
active resources = 2 water purifiers = 20 water points
passive resources = 5 tanks
population = 9 settlers
water surplus = water points - population + 1 = 20 - 9 + 1 = 12
water surplus (=12) >= passive resources (=5)? true -> every tank generates 2 water points today.