I want to know the answer to the following question:
To prevent high water pressures at lower elevations what were built on many of the city's buildings?
All the background I'm provided with is that "In the 1800s, the city required their installation on buildings higher than six stories to prevent the need for excessively high water pressures at lower elevations, which could break municipal water pipes.". Is that enough to answer the question?
Answer: no