Sylvester made up his mind and went on to make the two dams. He divided the men into two teams. One team was responsible for creating the dams, and the other was responsible for creating side passages for the river water to keep flowing and not flood the whole area instead.
So, they had to make two tunnels going from behind the first dam to the other side of the second one. This would require Earth magic, so he could only let the knights and other wizards work on creating the blockade on the river, away from the area of influence under the Bloodling.
The river was as deep as two metres and as wide as fifty metres. This was going to be an arduous task as the current of the water was also strong. Sylvester had to ensure that he did not change the intensity of the flow either, as that could adversely affect the parts downstream and flood various towns or villages.