Is the construction of water fountains in a public school or mosques affiliated with the Ministry of Awqaf considered Sadaqah Jariyah (ongoing charity), or does their affiliation with governmental bodies prevent that? And what is the best Sadaqah Jariyah that can be performed if this option is not suitable?

The money mentioned, if it is due to the deceased, is part of the inheritance and should be divided among the heirs. It should not be spent on perpetual charity (sadaqah jariyah) except with their permission. All that the questioner mentioned, such as copies of the Qur'an or necessities for schools and mosques, falls under perpetual charity. The fact that these institutions are affiliated with government bodies does not invalidate the charity. It is preferable for perpetual charity to be given to needy relatives of the deceased, combining charity with maintaining kinship ties, as the Prophet, peace and blessings be upon him, said: "Charity given to a poor person is one charity, but charity given to a relative is two: charity and maintaining kinship ties."