All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is established in Saheeh Muslim from Jaabir ibn ‘Abdillaah that he heard the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, saying: “Cover the vessel and bind the waterskin, for there is a night in the year when an epidemic spreads, not passing an uncovered vessel or an unbound waterskin except that some of that epidemic descends into it.”
According to most scholars, the command in this Hadeeth is not one implying obligation, but instead advice and preference. Imaam An-Nawawi reported it as preferable while titling his commentary on Saheeh Muslim.
Al-Haafith Ibn Hajar said in Fat-h Al-Baari: "Al-Qurtubi said: All the commands in this chapter are taken as advice for the common good, and are probably recommended, especially for the person who fulfills them with the intention of obeying a command."
We could not find any text or speech from the scholars that restrict making use of this water, so there is no harm in using it for cooking or ablution or otherwise. For more benefit, please refer to Fatwa 12116.
Allaah Knows best.