The Back Bay Fens and the Muddy River presented Olmsted with the most difficult challenges he faced in designing the Emerald Necklace. The city was essentially facing an ecological disaster the likes of which we today would associate with troubled third world countries.
What led to the complete collapse of the once pristine Back Bay ecosystem where the Indians fished with their weirs and the Puritans hunted geese and dug clams? It's partly a tale of bedrock American capitalism run amuck (so to speak).
Throughout the colonial period Boston's population was never much more than 15,000 and in fact declined in the years leading up to the Revolution. In the fifty years following the war, however, the population exploded fourfold and just kept climbing with successive waves of European immigrants. This in a town that was only slightly larger than when it was founded 200 years earlier,
The town's infrastructure remained essentially the same as well as its size throughout the Federal period. The sewers of the Shawmut Peninsula, such as they were, drained directly into the Back Bay and the town dump was located where the Public Garden now sits. Stony Brook and the Muddy River also both dumped raw sewage and industrial pollutants into Back Bay from the many surrounding upland towns. The sea, the source of Boston's expanding wealth, was also counted upon to carry away the city's growing waste stream.
Boston has an average tidal range - the difference between the high and low tide water levels - of about ten feet. Twice a day, strong tidal currents swept up the Charles River estuary to inundate the salt marshes and mud flats of Back Bay, then the tide would turn flushing away much of the city's sewage and trash out into the harbor.
At this time the Industrial Revolution, emanating from England, was beginning to transform economies and societies. But two decades into the new century, Boston still hadn't developed any industrial base, it remained a maritime rather than a manufacturing power. It lacked two of the essentials for industrial development - the land for siting factories and mills and a steady supply of rapidly flowing water to turn the mill wheels.
Ten miles up the Charles, the town of Waltham offered both of these advantages. The river dropped ten feet in its race through the town and the water supply was reliable. This became the birthplace of the Industrial Revolution in the Americas, financed by a partnership of Boston investors known as The Boston Associates led by Francis Cabot Lowell, a wealthy Boston merchant.
