Problem
The land which is best for agriculture happens to be best for buildings too. But it is limited—and once destroyed, it cannot be regained for centuries.
Solution
Preserve all agricultural valleys as farmland and protect this land from any development which would destroy or lock up the unique fertility of the soil. Even when valleys are not cultivated now, protect them: keep them for farms and parks and wilds.
Related Patterns
… this pattern helps maintain the Independent Regions (1) by making regions more self-sufficient agriculturally; and it will create City Country Fingers (3) almost automatically by preserving agricultural land in urban areas. But just exactly which land ought to be preserved, and which land will be built upon?
Keep town and city development along the hilltops and hillsides — City Country Fingers (3). And in the valleys, treat the ownership of the land as a form of stewardship, embracing basic ecological responsibilities — The Countryside (7) …
Alexander, Christopher. A Pattern Language: Towns, Buildings, Construction. Oxford University Press, 1977, p. 26.