I am not specially good with calcs, but I actually think que results must be higher than that. With the Volume of the Buda, a Cylinder seems to be more according to the characteristics that it's actually have, been more circular than rectangular in his base and structure, obviously including the head.
With that in mind, we can apply his Formula, using the Height and Width like the Base Radius. It gives us a Volume of 1157.3576065033 m^3. Using the density of ice, this would be 1064768.99798 Kg. The Specific Heat Capacity of Water actually is 4186 J/Kg in the Calculations Page. Making the maths, the results is 89142460511.1 Joules. Then using 2108 J/Kg according to the calcs, would be 11222665238.7 Joules. And with the Energy to Freezing Water of 334,000 J/Kg, the results are 355632845326 Joules. All of this would yield an energy of 455997971076 Joules or 108.98 Tons of TNT, that is Multi-city block+. Plus, I think is correctly if we use de Kinetic Energy for the Buda, too.
When Kanao and Inosuke came after Douma, inmediatly we can see the Buda standing in front of them, and both seems surprised, that can be a sign that both of them were incapable of at least notice when the Ice Sculpture was rising from the water to the top of the scenario. This can make applicable the perception of the brain of 13 milliseconds. The Height of 16.82 / 0.013 gives 1293.84615385 m/s. And with the previous Weight, it gives us a Energy Yield of 891232000000 Joules, equal to 213 Tons.
Final Tally: 108.98 Tons of Freezing. 213 Tons for KE. 321.98 Tons in total. Multi-city block+.