In 1924-1926 the City built a new reservoir and filtration plant. The reservoir was supposed to be covered like the Plant I FWR but the City said it would cost too much money, so they didn’t.
As can be seen in the top photo, flat supports were poured to hold the columns for the roof.
So the federal gov’t decides that all open reservoirs need to be covered. Instead of covering the existing FWR, they demolished it and built a new one. The old one was 20 million gallons. This one is about 32 million gallons. Speaking of millions – this new one cost millions and millions more than what it would have cost to cover it originally (couple hundred thousand)
So I ask, the old underground reservoir which has been there for 100 years or this new one – which do you think will last longer??