The remnants of Hurricane Ida passed over Boston on September 2, 2021, dropping more than 4 inches of rain in neighborhoods adjacent to the Muddy River. The USGS gage at Netherlands Road recorded a maximum height of 15.23 ft, exceeding the USGS official threshold defining a “minor flood” event (15.00 ft). (Typically, during dry weather, the height of the river is approximately 8 ft at that location). During the storm, observers noted that the Riverway pedestrian path near the gage was under about 18 inches of water. After the storm, floodwaters receded quickly, and by the next day, the walkway was perfectly usable again.
Was this expected? Yes. Riverway Park was designed by Frederick Law Olmsted and constructed in the early 1890s. The design included everything from the riverbed at the lowest elevation in the park, the meandering course of the river, and the higher banks on either side of the river with footpaths and even a bridle path for public use. The design created a basin intended to manage stormwater flow, as needed, and prevent damage to adjacent properties and the Boston & Albany RR (now the MBTA Riverside line).
Decades of uncontrolled siltation have caused flooding to be increasingly severe—which is exactly the problem that the Muddy River Restoration Project is designed to address. Once all dredging is completed, the paths will still flood from time to time. But, river heights during storm events are expected to be significantly lower than what we observe now.
Flooded path in the Riverway the morning of September 2nd.
24 hours later, the path is dry.