Praise be to Allah.
Imam Ahmad (6768) and Ibn Maajah (419) narrated from ‘Abdullah ibn ‘Amr ibn al-‘Aas (may Allah be pleased with him) that the Prophet (blessing and peace of Allah be upon him) passed by Sa‘d when he was doing wudoo’, and he said, “What is this extravagance, O Sa‘d?” He said: Can there be any extravagance in wudoo’? He said, “Yes, even if you are on the bank of a flowing river.”
Shaykh Ahmad Shaakir said: Its isnaad is saheeh. Shaykh al-Albaani (may Allah have mercy on him) classed it as da‘eef in Irwa’ al-Ghaleel, then he classed it as hasan in Silsilat al-Ahaadeeth as-Saheehah. The hadeeth was classed as da‘eef by a number of scholars because its isnaad includes Ibn Luhay‘ah, but al-Albaani (may Allah have mercy on him) stated that the hadeeth is also narrated by Qutaybah ibn Sa‘eed from him, and his reports from him are saheeh.
See: Silsilat al-Ahaadeeth as-Saheehah, 3292.
It says in al-Mawsoo‘ah al-Fiqhiyyah (4/180): They are unanimously agreed that extravagance in using water is makrooh. End quote.
Shaykh ‘Abd al-Muhsin al-‘Abbaad (may Allah have mercy on him) said: The scholars are unanimously agreed that extravagance in using water is forbidden, even on the sea shore, because of the report narrated by Ahmad and Ibn Maajah from ‘Abdullah ibn ‘Amr (may Allah be pleased with him), according to which the Prophet (blessings and peace of Allah be upon him) passed by Sa‘d… then he quoted the hadeeth mentioned above.
End quote from Sharh Sunan Abi Dawood.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: We should realize that using a lot of water for wudoo’ or ghusl is included in the words of Allah (interpretation of the meaning): “and waste not by extravagance. Verily, He likes not Al-Musrifoon (those who waste by extravagance)” [al-An ‘am 6:141]. Hence the fuqaha’ (may Allah have mercy on them) said: It is makrooh to waste by extravagance even if one is on the bank of a flowing river, so how about if water is drawn by mechanical means?
To sum up: wasting by extravagance when doing wudoo’ and otherwise is a blameworthy action.
End quote from Sharh Riyadh as-Saaliheen
And Allah knows best.