Which of the following is NOT a source of water for firefighting?

The correct answer is that depleted reservoirs are not a source of water for firefighting. In the context of firefighting, effective water supply is crucial for extinguishing fires, and all sources must be readily available and usable. Internal tanks, pressurized sources, and static sources all represent viable options for supplying water.

Internal tanks refer to water storage containers within fire apparatus or municipal systems that can be readily deployed. Pressurized sources, such as hydrants or piping systems with active water flow, provide easily accessible and high-pressure water for firefighting efforts. Static sources, like ponds or swimming pools, can be tapped into as well, although they may require additional equipment for drawing water.

Depleted reservoirs indicate a lack of available water, meaning they cannot be utilized for firefighting operations. If reservoirs are empty or have insufficient water levels, they fail to serve the critical function needed during emergencies where immediate access to water is essential. Thus, the distinction of depleted reservoirs being incapable of providing the necessary water for firefighting makes it the correct answer to the question.