Why the Charles doesn’t seem to flood as much as other rivers
Universal Hub has a great tidbit on why Boston, Cambridge, and other towns along the Charles aren’t as up-the-creek as some neighbors to the North:
…it might also have to do with a decision made by the Army Corps of Engineers in the 1970s. …The idea was that the various parcels of land would act as giant natural sponges during floods, absorbing vast amounts of water quickly, then releasing it slowly as the river receded. And it seems to work. During heavy rain (or the spring thaw), the Medfield/Millis border becomes a large lake - but since nobody lives on the Corps land, nobody has to be evacuated, either. You can see similar flood control in action from the top of Millennium Park in West Roxbury - or even across from the northbound side of Rte. 128 just past Great Plain Avenue.
Acquiring the land cost $10 million - or 10% of what the government had originally expected to spend on manmade structures.