In Jainism, upvas (fasting) is an important spiritual practice. The strictness of upvas can vary based on individual capacity, tradition, and sect (Shwetambar or Digambar).

• Shwetambar tradition: Generally, during upvas, no food or water is consumed from sunrise to the next sunrise (about 36 hours). Strict upvas means complete abstinence from both food and water.

• Digambar tradition: In the Digambar tradition, upvas also typically means abstaining from both food and water for the duration of the fast (sunrise to sunrise).

Exceptions: Some less strict forms of fasting, such as Ekasana (one meal a day) or Biyasana (two meals a day), may allow water, but traditional upvas does not permit it.

Summary: No, water is not allowed during traditional upvas in Jainism. The fast is observed without food or water from sunrise to sunrise. However, there may be variations based on individual health, age, or specific guidance from a Jain monk or nun.