Water

Water is a core liquid resource used across industry and agriculture, and its availability is tightly linked to weather and groundwater management. In many starts, the early supply comes from groundwater reserves, which are finite but slowly regenerate when rain falls. This makes water one of the first resources players need to plan around, especially in dry climates or on maps with irregular rainfall.

Groundwater replenishment depends on both reservoir size and rain intensity. The regeneration formula is:

Daily Regeneration = (Reservoir Capacity × 0.00185) × Rain Intensity

Normal rain uses a rain intensity of 0.5, while heavy rain uses 1.0. As a result, larger reservoirs recover more each day, but only if rain continues to arrive. For example, a 15,000-unit reservoir regenerates 14 units per day during normal rain and 28 units per day during heavy rain. A 12,000-unit reservoir regenerates 11 units per day in normal rain and 22 units per day in heavy rain. Over a year with 40 rainy days, that same 15,000-unit reservoir would recover 560 units in normal rain or 1,120 units in heavy rain.

Water can also be gathered directly from rainfall. A Rainwater Harvester produces 0.5 units per day during normal rain and 1.0 unit per day during heavy rain. Farms also collect rainwater into their soil buffer, generating 3.0 units per day during normal rain and 6.0 units per day during heavy rain. These values assume a 100% global rain yield multiplier, so research or other modifiers can change the final output.

• Groundwater is reliable early on, but it is not infinite.
• Rainfall-based collection works best in wet regions and during favorable weather.
• Rainwater Harvester output is modest and is best treated as supplemental supply.
• Farms collect more water than a harvester, but their water output is still limited for large industrial demand.
• In dry climates, Thermal Desalinators are the practical way to stabilize supply when rainfall is insufficient.

Because groundwater depletion is a real risk, water planning is essential. Players need to watch reserves carefully and match their extraction and collection methods to the local climate. Rain-fed systems can support small or moderate demand, but they do not replace high-capacity sources once the colony’s water use expands into the mid and late game.