It isn't known which Pharaoh it was.
The babies would drown in the Nile and die.
The Pharaoh
He had been told in a dream that the a Jewish boy born during this period of time would destroy him. He wanted to wipe out any possibility of this happening. This is why Moses was put into a basket and floated on the Nile.
To keep him from death. the pharaoh though there were too many Hebrews and decided to kill the new born male babies.
There are no known hieroglyphics specifically depicting babies being thrown into the Nile. However, ancient Egyptian texts and art do reflect various aspects of life, death, and mythology, including depictions of gods, rituals, and funerary practices. The narrative of babies being cast into the Nile is more prominently associated with the biblical story of Moses, rather than Egyptian art itself. Overall, while ancient Egyptian imagery and writing convey numerous themes, this specific act is not represented in their hieroglyphics.
Only the pharaoh and nobles could afford to be made into mummies and have a proper burial, lower class were put in coffins and thrown into the desert. (The sand preserves the bodies naturally).
The Nile.
To control the population of the Israelites, Pharaoh implemented a decree that required the Hebrew midwives to kill all male infants at birth while allowing female infants to live. He feared that the growing number of Israelites posed a threat to his power and security. When the midwives defied his orders, Pharaoh escalated the situation by commanding that all male Hebrew babies be thrown into the Nile River. This brutal policy was aimed at suppressing the Israelite population and maintaining Egyptian dominance.
Cleopatra VII
the Pharaoh's daughter ( the pharaoh of Egypt) found baby Moses.
It was believed that the gods gave the pharaohs their powers to make the Nile flood for the farmers.
Pharaoh/Firoun died when he drowned in river Nile. . .