[ noun ] the source of a river <noun.location> the headwaters of the Nile
Headwater \Head"wa`ter\ (-w[=a]`), n. The source and upper part of a stream; -- commonly used in the plural; as, the headwaters of the Missouri. [Webster 1913 Suppl.]
The sprinkling bans were imposed to reduce water drawn from the river and avert the need to tap six headwater reservoirs. Consumption in St. Paul and Minneapolis had dropped by nearly 30 million gallons daily in each city.