Different ending with various steel pipes in movie The Two Towers

Gandalf the White in The Lord of the Rings: The Two Towers had defeated the bad people and there were water everywhere. I think there was another ending if there were various steel pipes at that time, no matter seamless steel pipe, ERW steel pipe or other steel pipes. This fragment in the movie showed us the improvement of the society. In the time of my parent’s childhood, there were wooden and plastic steel pipes for lots of engineering project. If they need to irrigate the farmland, they had to carry the heavy wooden pipes with lots of people. And now, we can make all of these mechanism as we can use cars to send these tools to farmland easily. Of course, the main advantage by using steel pipes are here: First, service life. We all know that steel pipes would have a long service life compared with wooden or plastic one. In addition, safety. As we know that the leakage problem would be serious if we use wooden or plastic pipes for transmit of oil or gas. Under this situation, steel pipes would be the better choice.