Locals call it the “bathtub ring”.
The American West is drying up | The Economist
If the develop world cannot plan and manage their resources effectively, what of developing nations. Millions of village and local boreholes sunk without proper evaluation of the groundwater resource. Without proper hydrological assessments the availability of the resource and its quality cannot be determined. We have taken potable, fresh water for granted and assumed its infinite availability. Clearly that isn't the case. If you cannot and or don't wish to measure it, you can never manage it.