Excessive water drift in a cooling water tower may be caused by all factors EXCEPT:

In a cooling water tower, excessive water drift can occur as a result of several factors that disrupt the normal functioning of the tower’s components. Proper functioning of the top deck assemblies and wood fill splash bars plays a crucial role in managing water flow and preventing drift. When these components are intact and level, they help to evenly distribute water and minimize the amount of water that escapes into the atmosphere as drift.

If the top deck assemblies and splash bars are intact and functioning properly, they are doing their job to reduce water drift, making this factor unlikely to cause excessive drift. Conversely, the other options represent conditions that could lead to increased water drift. For example, if eliminator sections are out of place, they cannot effectively separate water droplets from the airflow, leading to increased water being carried away with the exhaust air. If metering orifices are clogged with debris, water flow can become erratic, potentially increasing the likelihood of drift. Lastly, sagging fill packs or those with gaps disrupt the uniform flow of water and can cause localized splashing, contributing to excessive drift.

Therefore, an intact and level top deck assembly is the factor that would not cause excessive water drift, confirming that this is the correct answer.