Narrated Adi bin Hatim: The Prophet ﷺ as saying: When the animal at which you shot falls in water, is drowned, and dies, do not eat.
Related hadith on this topic
Explanation & Benefits
Hafiz Muhammad Ameen
English translation:
A hunted animal or bird does not become unlawful (haram) merely by falling into water while wounded; rather, it becomes unlawful only if its death occurs as a result of falling into the water. If it falls into the water in such a manner that it is found alive, then it is permissible to slaughter (dhabh) it and eat it. The meaning is that it should not have died by drowning in the water.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 4303