The old structure was grandfathered into restrictive waterfront setback regulations. Because of current setback regs, if the building was going to be that close to the water, it had to have the same footprint where it was closer than current regulations allow.
Odd coincidence that you post this Jack, but our town tore down the library today, no more than 30' from my house (we're nighbors).
We're on a small stream, often bone dry in mid summer, but it puts us in Maine Shoreland Zoning so the same restriction (no expansion beyond footprint) applies to any of us within 75' of the stream.
There was nearly 10 years of local controversy (politics), petitions, votes, more votes, town meetings, broken friendships,....small town enthusiasm.
I've torn down more than my share of buildings so we knew what to expect. Buildings go up slowly but with one man in a good sized excavator, with a thumb on the bucket, they go down in a few hours.
Our library, as a building, had little historic value so I'm good with it (some were not). The new one will start going up a few months.
Life goes on. Your clubs new building looks like a terrific plan.