Difference from sum of torque

[rc4]

I try to find the sum of torque for the object below:




The water must give the same torque than the solid, but I don't find 0:



For a radius of circle of 1 m, with a thickness of 1 m, water give a torque of 1666 Nm. But the solid give a torque higher. Where I'm wrong ?

I found the center of gravity of solid at 0.776632 m maybe this is wrong ? For me, it's 0.5 m from the square, added to the right at 4/3/pi from the part of disk with a weight of pi/4.