What is the ruling on using public water for personal purposes, such as washing a car or filling a container for private use?

This matter is subject to the permission of the rights holder or common practice, whether it is a public entity or an individual. Whatever is absolutely permitted for use is permissible, and whatever is restricted, its restriction must be adhered to, either by an explicit text from its owner or by common practice. It is not permissible to transfer water designated for drinking (sabil) from its location unless the donor's permission is known or there is an indication thereof. If there is doubt, common practice and circumstantial evidence should be considered. The prevalent understanding today is that washing cars and similar activities are not permitted by the entities dedicating water for public use.