Keswick flood defences and a centripetal force

I was interested that the flood defences were not an equal height all the way along. Surely the water will flow over the lowest bit... The answer is that the higher bit is on the bend. The water has inertia and would rather keep going in a straight line at constant speed. The bank has to push on the water to stop it going straight and push it round the bend. This force is a centripetal force. That's OK for the water that is actually touching the bank but water molecules aren't actually joined. Away from the edges there is little to stop the water layers sliding over each other and heading towards the edge. This means that at the bend the water level will be deeper on the outside than on the inside. Water is very hard to compress so there will be some form of rigidity lower down but the shear forces between layers to stop sliding will be weak.