What is the ruling on performing wudu with rainwater that has been sitting in a pond for more than a year?

Question:
In rural villages, we do not have bathrooms for wudu; rather, the water is in ponds or what we call “al-Hijrah.” This water comes from rain and remains for a long period, which may exceed a year or even more, until another rain falls on top of the first, and so on. The situation continues like this, and we perform wudu with it until a green layer forms on its surface. What is the ruling on wudu given the situation we have described? May Allah reward you with good and do you well. In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, Lord of the worlds. May Allah send prayers and blessings upon our Prophet Muhammad, and upon his family and all his Companions.

Answer:
There is no harm in purifying oneself with water, even if it has become stagnant due to its prolonged stay or long duration in its place, for this does not cause harm and does not deprive the water of its purifying quality. This is based on the saying of the Prophet (peace and blessings be upon him): The scholars have agreed that water remains in a state of purity as long as one of its characteristics is not changed by impurity. If its change, as you mentioned, is due to its prolonged stay, then this does not harm it. Performing wudu with it and purifying oneself with it, all of that is valid and there is no issue with it, and praise be to Allah.