Water
Parameters
Annual renewable yield per square meter
450
The map’s renewable groundwater budget: 450 L a year per square metre of land, which is 450 mm of water. A 10 m tile adds 45,000 L a year (about 123 L a day) to the city-wide cap. 450 sits in the 325–500 mm/year recharge class the USGS mapped for the glaciated northern US, while Microlandia’s region is Mediterranean and coastal, so the figure is an assumption about this region, not a local measurement. Recharge is not sustainable yield either: wells also draw down storage and take water that would have fed streams (USGS Circular 1186). The game folds all of that into one budget, set from the land area and the map’s groundwater multiplier when the city is founded and frozen after, so later balance changes do not rewrite an existing city’s limit.
Basis: scenario
Water use by building
These rates apply to staffed farms. The game spreads annual irrigation evenly across operating days.
Farmland
125 L per tile per day
At 10 m × 10 m per tile, that is about 456 mm of irrigation per year.
The 2023 US irrigation survey reports 81 million acre-feet applied across 53.1 million acres, about 465 mm/year. The game spreads that annual average across every staffed day.
Source: USDA NASS 2023 Irrigation and Water Management Survey
Vineyard
50 L per tile per day
At 10 m × 10 m per tile, that is about 183 mm of irrigation per year.
A University of California study found wine grapes generally received less than one acre-foot per acre in its study areas. The game uses about 0.6 acre-foot per acre and spreads that irrigation evenly across staffed days.
Source: University of California, Agricultural water use accounting (2020)