December in Concord? Pool was almost certainly empty. BTW, my morning commute is mostly through Concord, by back roads, but nowhere near this. Concord is swampy and much of it is subject to flooding in spring. The current version of the Old North Bridge is about the fourth or fifth, the others long since washed away.
Where I live is more rural, and we have no, zero, fire hydrants. Pumpers draw water from ponds, streams and swamps. There are even strainers near the roadside for them to draw from in places.
A few years ago I was talking with the chief of a very well equipped and trained VFD. He told me they had a mutual aid call 20 miles away in the more urban area. That’s when they realized none of their guys had ever connected to a hydrant.
Part of the reason many rural homes have ponds is for fire control. Built in water supply