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.
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.
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. . .
He mostly travelled along the River Nile by boat.
it started in Egypt because the Pharaoh's Pharaoh's dug ditches to make water flow so the Nile did not overflow