Short answer: under a strict Das Lakshan (Digambar) vrat, almond water would not be permissible.

Why:

• During Das Lakshan Jains practice heightened restraint and austerities. Commonly, days are kept with very plain food or even upavās (no food) and, in daylight, only boiled water is allowed. Almonds or any solid food would count as eating and thus would go against the usual upavās/easy-to-digest regime followed in this period. Different sanghs can have slight local variations, but the strict Digambar Das Lakshan practice emphasizes minimal, plain intake and often restricts even nuts. ( jainknowledge.com)

What you can generally expect:

• Daylight rules: many observe boiled water only during daylight hours.
• Solid foods (including nuts like almonds) are typically avoided or limited to very simple items, depending on the vow you have taken and guidance from your guru/sangh. ( jainknowledge.com)

If you’re unsure about your local practice, follow the guidance given by your acharya or the community you belong to, as customs can vary slightly.