Stony Brook (Charles River tributary, Boston)

Stony Brook
Stony Brook in Jamaica Plain in 1898
Location
City	Boston, Massachusetts, United States
Physical characteristics
Source	Turtle Pond, Stony Brook Reservation
• coordinates	42°15′56″N 71°08′30″W / 42.265499°N 71.1418°W / 42.265499; -71.1418
Mouth	Charles River Basin
• coordinates	42°21′07″N 71°05′32″W / 42.35187°N 71.092215°W / 42.35187; -71.092215
Length	8.5 miles (13.7 km)
Discharge
• average	10 cu ft/s (0.28 m3/s)
• maximum	>1,000 cu ft/s (28 m3/s)

Stony Brook is a 8.5-mile (13.7 km)-long subterranean river in Boston. The largest tributary stream of the lower Charles River, it runs mostly through conduits.^[1] Stony Brook originates at Turtle Pond in the Stony Brook Reservation and flows through Hyde Park, Roslindale, Jamaica Plain, and Roxbury. It empties into the Charles River Basin just upstream of the Harvard Bridge. Stony Brook is fed by four tributaries, all of which are partially or entirely in conduits as well.

Stony Brook originally meandered across a flat valley and fed into the Back Bay; as the Back Bay was filled, it was directed into the Muddy River in the Back Bay Fens. It powered industries and its clear waters attracted breweries, but the surrounding lands tended to flood during heavy rains and freshets. A section in Roxbury was placed in a conduit in 1851; by 1867, all of Stony Brook north of Roxbury Crossing was in conduits. Additional channelization took place in Jamaica Plain and Roslindale in the 1870s and 1880s, and a conduit built in 1881–82 allowed heavy flows to be directed directly to the Charles River. An 1886 flood demonstrated a need for greater capacity in the downstream conduits.

A new conduit was built from Roxbury Crossing to the Fens in 1887–89, for use with Frederick Law Olmsted's plan to use the Fens as a holding basin for Stony Brook overflows. Due to upstream sanitation issues, storm flow was directed along a new conduit to the Charles in 1905. Conduits were extended south from the 1890s to the 1950s, leaving only the first 1 mile (1.6 km) of Stony Brook above ground. Sewer improvements in the 21st century reduced sewage flow into the Stony Brook during storms, in turn improving water quality in the Charles.