Welcome back to Camera Obscura, Curbed's series of photo essays by Nathan Kensinger. This week, Kensinger examines the restoration of the Harlem River as part of a mini series exploring NYC's lesser-known bodies of water.

The Birdman of Inwood is on his knees, with a cockatoo on each shoulder. Using his bare hands, he is digging out a secret spring underneath a rock. The freshwater begins to flow, clear and cool, carving a path down to the edge of the Harlem River, and he leans back, savoring his work. "The first eight months was picking up the glass," says James Cataldi, aka the Birdman, who has been cleaning up this piece of New York City's waterfront for five years. "I personally have taken out 1,240 cubic yards of debris by hand."

For many decades, the Harlem River tidal strait between Manhattan and The Bronx was known as "New York's Forgotten Waterfront," its nine miles fragmented by a patchwork of industry, freight trains, chop shops, and communal dumps. In recent years, a loose coalition of concerned citizens and neighborhood groups has been working with the city to slowly reclaim the waterway, piece by piece, and today the Harlem River is showing renewed signs of life. Where abandoned boats and cars once littered the shoreline, a new system of parks, marshes, beaches and bike paths has opened, creating access for both humans and wildlife. This year, the latest additions to this network include Columbia University's Muscota Marsh, which opened in Inwood this January, and Bridge Park, a Bronx shorefront space so new it has yet to have an official opening ceremony.

Unfortunately, despite millions of dollars in city investment and years of hard labor, often by volunteers, some New Yorkers remain unaware of the Harlem River's recent successes. In an op-ed published this September by Crain's, one pundit called for the river to be filled in and used as a dump for construction debris, so that developers could build new towers above it, "a historic return to New York's golden age of monumental public works." When told about this proposal, the response from those who actually live and work on the riverincluding fishermen, boy scouts, artists, boaters and environmental remediatorswas unanimous: "ridiculous."

"New York is a water city," said photographer Duane Bailey-Castro, a Bronx native who has been exploring and documenting the Harlem River for seven years. "Access to the sea is what made New York. So it's odd that, despite that reality, we are still so disconnected from the water." With the much anticipated reopening of the High Bridge looming on the horizon, Duane believes this long-neglected waterway may finally gain the city's full attention. "I think it will be Uptown's High Line," says Duane, who is working on a book project that will detail the area's history. "It's not the Seine, it's not idyllic, it has its rough edges. Like New York, it's not always the most glamorous of places. But even despite that, there is a uniqueness to it, and if you look carefully enough you might be surprised by the beauty you find."

A walk along the shores of Harlem River today also reveals ample evidence of the return of nature. "There's a lot of life in there," says Freddy, who has been fishing the Bronx side of these waters with his son for the past year. "Porgie, eels, flounder, blues, catfish, toadfish, striped bass. There's some nice crabs. I wish I had a net. I jumped in the other day to get a crab and I was up to my waist." Last year, over 70 different species were catalogued at Inwood's North Cove by James Cataldi and his volunteers, including 45 types of birds that had stopped off at this remediated marsh, as well as mussels, clams, oysters, possums, raccoons, and muskrats. And even more species have visited Sherman Creek Park, where the New York Restoration Project is currently expanding Swindler Cove to reclaim the grounds of an abandoned boat club.

This past Saturday, Boy Scout Troop 729 from nearby Washington Heights was out in full force at Swindler Cove for the International Coastal Cleanup Day, picking up trash and removing invasive species like mugwort, ragweed and marigold. "To me, the Harlem River is precious," said Scoutmaster Antonio Camacho, but "as well maintained as this place is now, there is still an amazing amount of trash." Several community events have been planned in the near future to bring neighbors out to the waterfront, including a cleanup and music festival this Saturday at North Cove and the annual Harlem River Festival in October. However, much work remains before the entirety of this once forgotten stretch of shoreline is returned to the people and to nature.

On the Bronx side of the Harlem River, the newly opened Bridge Park gives the public access to one of the longest uninterrupted stretches of this waterfront.

This section of the shore is not cut off by trains or highways, a rarity along the strait, which is hemmed in by CSX freight tracks, Metro-North, the Harlem River Drive, and the Major Deegan Expressway.

The park includes a bike path, wide lawns, and seating areas, like this space under the Alexander Hamilton Bridge. This is the second major park to open recently on the Bronx side of the Harlem River, after Mill Pond Park, which opened in 2009.

The park provides a unique vista of several of the many bridges that cross the Harlem River, including pathways underneath the Washington Bridge.

Outside the south entrance of the park, workers used dumpsters to clean up rubble on what was once a dead end street. "I think they are going to clear it all out," said one worker. "Make it part of the park. Keep going all the way down."

At the nearby High Bridge, the city's oldest bridge, workers were still putting the final touches on the soon-to-be-opened public walkway, which will provide a pedestrian link between the Bronx and Manhattan over the Harlem River.

On the north end of the Harlem River, in Inwood, Columbia University and the Parks Department recently opened Muscota Marsh, a one-acre public park adjacent to the Columbia boat club.

The park includes a saltwater marsh and a new freshwater wetlands, meant to capture stormwater and lure in birds.

Columbia rowers ply the Harlem River, passing the Peter Jay Sharp Boathouse in Sherman Creek Park, a public park operated by the New York Restoration Project (NYRP).

Swindler Cove, which opened as part of Sherman Creek Park in 2003, was once a neighborhood dump and now offers one of the few public beaches in Manhattan.

Boy Scouts from Troop 729 were busy removing invasive species from the park. "I want my scouts to be stewards of the neighborhood," said Scoutmaster Camacho. "It's about maintenance, and claiming some type of ownership."

NYRP plans to build an education pavilion on this newly remediated peninsula, which was once home to the ruins of an abandoned boat club. It will be "a state-of-the-art, flood-resistant outdoor recreation and learning center."

At Inwood's North Cove, James "The Birdman" Cataldi is still working to clear out an area that was a communal dump for 35 years. "This is remarkably clean compared to what it was," said James.

A freshwater spring flows in to the Harlem River here. "I'm hoping this doesn't become a park, actually. I hope it stays a peoples place," said James. "We want as many people as possible to come down to what I call a jewel in the rough."

"In the winter, it's a wildlife sanctuary," said James. "At least 1,800 ducks and geese were here in the winter of 2013."

Across from the North Cove, a local Bronx dumping ground is still present, with abandoned trucks, sofas, and rugs at water's edge. Like the shoreline further south in the Bronx, this section of the Harlem River is largely industrial, with access cut off by train lines.

Large swaths of unused land are present on this side of the Harlem River. This empty lot is north of the University Heights Bridge, and part of a proposed Harlem River Brownfield Opportunity Area, which includes 162 acres of Bronx waterfront.

The property is currently accessible from the street and borders a concrete plant. It already resembles a park, with overgrown railroad tracks, dirt roads, open fields, and several stands of trees.

From atop a mountain of dirt in this open space, the Harlem River is plainly visible, as is the ongoing tension between industry, neglect, and public access along this waterway.

· Camera Obscura archives [Curbed]

· All Harlem River coverage [Curbed]