Daylighting Tibbetts Brook: Walking along the proposed route

On November 19th, 2017, Eric Sanderson, Ecologist and Director of the Mannahatta Project lead a walk along the proposed route for daylighting Tibbetts Brook with CALL Co-Chair Charles McKinney and Amanda Schachter and Alexander Levi of SLO Architecture.

Eric Sanderson shares what happened:

My colleagues and I have been studying Tibbetts Brook as part of our investigations into the historical ecology of New York City, which started out with the Mannahatta Project, about Manhattan, and have now expanded to cover all five boroughs of New York city.  Historical ecology is important for urban sustainability because it places our current perspective on the city into a natural history context; it tells us how nature makes places; it helps expand our imagination; and finally, it helps us set metrics for sustainability success.  The historical landscape ‘before the city” was sustained by nature in such way that supported species (including people) and ecosystem functions for thousands of years.  We have no better role model for sustainability than nature.

Tibbetts Brook was once a free-flowing stream, that trained south to Spuyten Duyvil Creek from headwaters north of the city line.  The brook was freshwater it its upper parts, and tidal in its lower half, approximately from the southern edge of Van Cortlandt Park south to the Spuyten Duyvil Creek.  The valley of Tibbetts Brook is formed out of Inwood Marble, with Fordham gneiss on either side, rock formations that are 500 – 1,000 million years old.  The marble is softer than the gneiss, and so erosive process have created the valley.  When Europeans arrived some 400 years ago, they found a broad, meandering tidal channel, working along the western edge of the valley, and fed by the upper water portion of the stream.  The freshwater portion was dammed in the 17th century to power a grist mill, forming van Cortlandt Lake.  Historically the landscape of salt marshes and riparian forests would have been tremendously abundant for people and wildlife.  Cook, in his 1913 history of the Bronx, wrote:  “Besides the deer, the wild turkey existed in great numbers on the verge of the forest. It is said that flocks of them used to fly from the ridge west of Van Cortlandt Park across Tippet's Brook to a hill east of this little stream. The flight was always begun by a large black cock, and was made at sunset. The leader gave the note and the flock were at once on the wing.”  The Tibbetts Brook area was very important to Native Americans as well.  A small island near where Tibbetts Brook and Spuyten Duyvil Creek met was called “Paparinaman”, now lost under the pavement of the Kingsbridge section of the Bronx.  It’s notable that historically Spuyten Duyvil Creek wrapped north around Marble Hill, making Tibbetts Brook shorter than It would need to be today.

Restoring Tibbetts Brook would return some of the prior ecosystem functions to this part of the Bronx.  Streams can can help with flood control and as a conduit for stormwater; vegetation growing along the edges of the stream can slow the flow down.  Daylighting the stream, even if in a different location, can also help reconnect the anandromous fish communities, which almost assuredly, once used the brook.  A daylit stream can provide recreational amenities for local residents.  There is really nothing more lovely than resting by a sparking stream on a summer day.  Finally it’s the right thing to do.  It’s wrong to bury streams under concrete and asphalt.