Is the prayer of one who performed tayammum in the mosque valid because there was no water in the restrooms?

Question:
Honorable Shaykh, may Allah grant you success, this questioner says: I caught up with the 'Isha' prayer at a mosque and found that there was no water in the restrooms there, so I performed tayammum and prayed with that tayammum. Is my prayer valid?

Answer:
No, you are in a town and there is water in the town. If you do not have water nearby, there is no harm. But if you are in a town and the water is to your right and left and close to you, go and ask for water. They say it is obligatory to seek water within a short distance and with a sign.