Is washing with river water sufficient for purification from janabah?

For ghusl (ritual bath) from major ritual impurity (janabah), there are two essential pillars without which it is not valid: intention and covering the entire body with water. Anything beyond that, such as performing wudu (ablution) before ghusl, and starting with the head and the right side, is considered a sunnah (prophetic tradition). So, if a Muslim immerses himself in water and intends to remove janabah, his purification is valid, even if he does not perform wudu; based on the Almighty's saying: "And if you are in a state of janabah, then purify yourselves." However, it is preferable to follow the prophetic method of ghusl.