The available water is not enough for washing all the organs in Wudu'
Q: Is it
permissible to perform Tayammum (dry ablution with clean earth) when unable to find sufficient water in the desert to perform Wudu’ (ablution)?
All praise be to Allah Alone, and peace and blessings be upon His Messenger, and his family and Companions. (Part No. 5; Page No. 338)
The available water should be used as purification for the parts it can suffice to wash, and then make Tayammum for the remaining parts, for Allah (Exalted be He) says (what means):
So keep your duty to Allâh and fear Him as much as you can
The Prophet (peace be upon him) said:
“When I command you to do something, do as much of it as you can.”
(Agreed upon by Al-Bukhari and Muslim)
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.