Along with municipal systems, which type of water system provides water under pressure through fire hydrants?

In the context of water systems that provide water under pressure specifically for firefighting purposes, a private water system is indeed a valid choice. These systems are typically owned and operated by an individual or an entity rather than a municipal authority. A private water system often includes water storage tanks and fire hydrants designed for fire protection, allowing a reliable source of water under pressure that can be utilized in case of a fire emergency.

Municipal systems are the more common sources for firefighters, but private systems play a critical role in areas lacking adequate municipal coverage. Larger private systems can be found in institutions, large housing complexes, or industrial parks, where the demand for firefighting water is recognized and addressed.

Other options like auxiliary, commercial, and industrial systems can have their own sources of water pressure, but they are primarily not focused solely on supplying water for fire protection at the level or with the infrastructure found in municipal or properly designed private systems.