Find Brine in Southern Barrens.
If there is one lesson you must learn of water, it is this: water means rebirth.
Its power flows, erodes, and makes clean all manner of things. You will find its ability to heal and replenish incomparable, but only when it is pure.
When you understand that water, when polluted, can devastate all that it touches, you will appreciate how vital a resource it is.
If you wish the water sapta, find Brine deep in Southern Barrens. Her home is continually molested by the quilboar there.