Bourbon - Water
Fresh spring water.is needed for so the in the grain can be cooked and the developing extracted. were therefore built near springs that yielded enough
Kentucky and Tennessee are located on a large limestone layer that filters the water very well. In valleys where the limestone layer is broken, you can find springs that carry superbly clear water ideal for production.
Some of today's distilleries are located in industrial areas (e.g. Buffalo Trace). They don't use spring water but local supply , which is demineralised or deionised.