In Yasna 38, which is dedicated "to the earth and the sacred waters", apas/Apas is not only necessary for nourishment, but is considered the source of life ("you that bear forth", "mothers of our life").
In other Avesta texts, the waters are implicitly associated with [Spenta] Armaiti (middle Persian Spendarmad), the Amesha Spenta of the earth (this association is properly developed in Bundahishn 3.17).