have had an interest in Old Croton Aqueduct (commonly called the "OCA") for over 45 years. When I was a graduate student at Columbia, I worked at a lab in Irvington NY and "the aqueduct", as we called it, went right through the property. We would walk to lunch on it and some times we would do a run along it in one direction or the other. So I organized a few co-workers from the lab and in 1970 we walked first from the lab to Manhattan (about half way), and then on another day from Croton back to the lab. One problem on our southern trek was the aqueduct bridge over the Harlem River was closed to pedestrians — and it stayed closed for some 45 years till this year.

Since those early treks I have run and walked many miles on the OCA, particularly in Highbridge Park and in various parts of the Bronx, Yonkers, Hastings-on-Hudson, Dobbs Ferry, Irvington and Tarrytown.

Finally, with the long awaited reopening of the High Bridge just this April (2015) I decided to put together one large post on the OCA in general plus this report on a trek over the Manhattan miles. Think of this as the completion of that 1970 trek that was stopped at the bridge.

But before you start your Manhattan trek, and perhaps now before reading this post, I highly recommend you read the general OCA post which will give lots of background for this post including a description of all the remaining features and remnants of the aqueduct. Here's the Link .

As always,
Papa Bear


A Running (or Walking) Route through Manhattan

his route starts at the NY Public Library and goes all the way to the High Bridge. And if you want to cross over the High Bridge and head up through the Bronx and beyond, more power to you. I've divided the route into two approximately equal sections for those who prefer smaller pieces to chew on.

You should also remember that following the route of the OCA involves choices of where to go where the original route was changed and in one case, where it went through the city mid-block and is impossible to follow since there is no longer a path along the route to walk on. So I've laid out a route that I would take.

The last thing to make note of is that the maps I put in below have little red circles at certain points where you can see features or remnants (or footprints) of the OCA.

Part 1: Fifth Avenue and Central Park — 4 - 6 miles

Fifth Avenue


The original OCA in 1842 consisted of the Distributing Reservoir (aka the Murray Hill Reservoir) between 40th and 42nd Street, west of Fifth Avenue — it was demolished in 1898-1901 to make way for the NY Public Library — and a set of iron pipes under Fifth Avenue up to 80th Street which carried the water from the Receiving Reservoir which was in the future Central Park.

e certainly don't need a map for Fifth Avenue, Just go up from the New York Public Library (for out-of-towners, that's on Fifth Avenue between 40th and 42nd Street) to Central Park and enter the park on the path just past the 79th Street Transverse, just before the Metropolitan Museum. Got it? Sound pretty boring, no? Well, let's check out some of the sites along the way, some well known, others not so much.

And if you've read somewhere that a remnant of the old Distributing Reservoir can be seen inside the library, read this for my take on that.

At first I wanted to highlight any buildings that either pre-dated or were built soon after the OCA was built. Well, there aren't any. Interestingly, the two oldest surviving buildings along Fifth Avenue are St. Patrick's Cathedral (cornerstone laid in 1858) and the Arsenal in Central Park (1847-51), plus, of course, Central Park itself. But the Arsenal is the oldest by far, predating St, Patrick's and Central Park by about a decade.

Central Park followed soon thereafter. Originally authorized in 1853, the plan of the park was approved after a design contest with the "Greensward Plan" by Olmsted and Vaux selected. It was constructed and opened to great fanfare in 1857. The old reservoir had been there for close to 20 years and the new one came along just as the park was being built and was included as an integral part of the plan. Then came the millionaires, and Fifth Avenue would never be the same.

There's some good pictures in the slideshow below showing of some of the notable structures along Fifth Avenue


Central Park


The original Receiving Reservoir (aka the Yorkville Reservoir) was built between 79th and 86th Streets from Sixth to Seventh Avenue in what was to become Central Park some 20 years later. It was decommissioned and filled in in the 1930s. The current Central Park Reservoir was completed in 1862.


ook at the map to the right — why did I choose that crazy path (the blue line)? Well, you'll see an outline of the old receiving reservoir in red and red circles to note where present day remnants can be found. The suggested route tries to hit them all.

It enters the park on the path between the 79th Street Transverse and the Met, goes through Greywacke Arch under the East Drive and circles around to the west side. When you come out from under the arch make a note of the long north-south berm (mound of earth) that marks the buried east wall of the old reservoir. When the route gets near the Delacorte Theater it heads up roughly along the old mostly buried west wall and touches the NW corner. Then it heads back east along the mostly visible north wall to the NE corner. Then it goes up for a stint on the "New Reservoir" (aka the Central Park Reservoir) and goes west along that great lake and finally exits the park at 85th Street. Incidentally, the entry and exit points (80th & Fifth and 85th & Eighth) are both where the original aqueduct passed through the park. And in 1842, the old reservoir was the only above ground feature visible in the park. All the conduits and pipes passing through, were below ground.

And there's more in the park if you're up for it. You can run completely around the Reservoir and even go up to The Pool at 100th Street on the west side. I've read that this small pond was created, in part, from the overflow of the reservoir — see the item in the remnants section ().

So I've added a map (left) for those who want to earn "Extra Credit" in Central Park. Just go right when you get to the South Gatehouse after exploring the Great Lawn, and circle around the reservoir as shown on the map. Now you can say to your friends "You mean you went to see OCA remnants in Central Park and DIDN'T see The Pool Inlet? Dude, that is just soo lame!" Or whatever.

The slideshow includes the Fifth Avenue and Central Park portions of part 1 of the route. Click the cover picture to bring it up.

Part 2: The upper West Side and Highbridge Park to the High Bridge — just under 5 miles

Columbus (Ninth) Avenue


The OCA consisted of a brick conduit from Central Park all the way to 119th & Tenth (Amsterdam). From about 93rd to 103rd Streets it was above ground between Ninth and Tenth Avenue to cross the Clendening Valley. The conduit was replaced by under ground pipes in the 1870s. See the map below.


nce you set foot outside the park you need to think about alternate routes. Look at the map to the right. It's not so much a route map for your run/walk as it's a map of the various changes in the OCA over the 2nd half of the 19th Century.

The heavy red line is the route of the original 1842 conduit. In the map the purple lines show where the pipes were laid, first from 85th to 90th, and then from 93rd to 113th where the old conduit crossed the Clendening Valley and headed north up Amsterdam Avenue. And when I say replaced, I mean the old conduit was demolished and buildings were built on the former right-of-way. The only mid-block section to remain was from 90th to 93nd Street, and that too was built over after the OCA was deactivated in 1955. Once you reach 107th & Amsterdam it's all underground with no more choices to make.

So where should you run? My choice is the blue line. I picked my route mostly to go up on Columbus Avenue since that is closest to the original route, and I cross over to Amsterdam on 105th so you can see the only surviving lot-lines mid block (see Google Earth photo left). It's really cool to see a building suddenly go off an an angle in good old rectilinear New York City. So let's get moving.

Amsterdam (Tenth) Avenue
ow direct your attention to the next map on the left. It's really a map of features and remnants (and a few footprints). Starting with the 105th Street lot-lines it goes up to the 113th Street and 119th Street gatehouses with a few manhole covers thrown in between 111th and 112th. BTW: there's a great place for coffee and a sweets at 111th Street opposite the Cathedral. It's the Hungarian Pastry Shop and it's been an Upper West Side institution forever. After that snack break it's just 2 blocks further to the well preserved 113th Street Gatehouse. You'll step over two historic manhole covers in the sidewalk (look down) getting there.

But before we get to the next gatehouse 6 blocks further on, why not take a break and make a side trip to the Columbia University campus. I did that on a recent scouting trip for this article. Enter at 116th Street and take a glimpse of the main campus with Low Library (formerly a library, now an administration building) on the north end and the Butler Library (an actual library) on the south end as you walk along College Walk. It's a great tonic from the endless low rises, high-rises, churches large and small and endless bodegas and bars along the avenue. And if you have an extra moment, find your way up to the overpass up above Amsterdam Avenue between 117th and 118th Streets. Amsterdam Avenue from this vantage point is impressive all the way south to where it crosses the High Line and to the north you can really appreciate the Manhattan Valley and the vast impediment it was to the building of the aqueduct.

Now back on the avenue, go under that overpass and you'll get to the dilapidated 119th Street Gatehouse. Look at it and weep.

The OCA was a brick conduit (mostly replaced by pipes in the 1870s) from Central Park up to 119th Street and Amsterdam Avenue, but from there to 135th Street it consisted of underground pipes in what is known as an inverted syphon to cross the Manhattan Valley. From 135th Street it again consisted of a brick conduit all the way to The High Bridge.

Then when we're through with Columbia comes the Manhattan Valley. Like the Fifth Avenue section, this is a bit boring. It's just 16 blocks along Amsterdam (Tenth) Avenue that goes down and up again. And by no special intent, its goes from Columbia University to City College — although neither one was there when the OCA was originally built. Instead, where Columbia is there was an insane asylum and where City is there was an orphan asylum on one side and a convent on the other (hence "Convent Avenue"). It is a valley, and a fairly deep one (over 100 feet below the line of the aqueduct), and there was some thought of building a huge above-ground aqueduct across the valley, reminiscent of the ancient Roman aqueducts, but that was ruled out due to the expense. So an inverted syphon of pipes it was. Originally it was two 36" pipes, but later a 48" and a 60" pipe were added.

At the low point, where Tenth Avenue crossed Manhattan Street (now 125th Street) there was an underground vault (called a "blow-off" vault) where valves could allow the pipes to be drained for maintenance or cleaning. It may still be there under some manhole cover but good luck in finding that in that busy intersection which at the moment is a bit dug up. Maybe I'll go there some day when there's no traffic and sneak a peek down — wanna come? We may find alligators!

Upper Amsterdam Avenue
ongratulations, you've just climbed the only hill worth the name on the whole route and now you are in City College territory. But before checking that out turn right on 135th Street and you'll see the unmistakable gatehouse on the corner of 135th and Convent Avenue. If you think this looks rather different architecturally from any of the other gate houses, including the two you've just passed on Amsterdam and the gatehouses on the Central Park Reservoir, you're absolutely right. It was completed in 1890 for the New Croton Aqueduct and shows a difference of some 50 years in both technology and sensibilities.

The NCA, as it is called, differs from the OCA in several notable ways, 1) It's supplied by a much larger Croton Reservoir behind the New Croton Dam, 2) it was built entirely underground, and 3) it has a capacity of 3 times the OCA. This gatehouse at 135th Street was the end of the line for the NCA Conduit — about half the output went to the Central Park Reservoir and the rest went directly to the city water mains.

This gatehouse had a peculiar set of needs to fill. First off, the OCA gatehouse at the north end of the Manhattan Valley syphon was sitting a half a block away in the middle of Amsterdam Avenue where it had stood for some 50 years — and it was blocking traffic that would have been unimaginable when it was built. Secondly, the New Croton Aqueduct came down under Convent Avenue from Highbrige Park after passing under the Harlem River and was close to 100 feet underground here, and under pressure. And Third, the NCA would not have a Manhattan Reservoir to hold its entire flow, but rather split it's output between the Central Park Reservoir and the city water mains. And as for that Egyptian fortress (sic) down on 42nd Street, talk was already in the air of getting rid of it. The plan for its construction from Wegmann is on the left. Try to see the fine print and you'll get the idea.

And it did it's job so well that this year, 125 years after its construction, the valves under the gatehouse were used to switch the water from the reactivated NCA into the distribution system of the city.

Now back to Amsterdam and on with our trek. As you crest the hill you'll see Amsterdam Avenue stretched out before you for about another mile to 155th Street. The old conduit is under the road here but not far under. On your right you'll pass with a mixture of beautiful old buildings of dark granite with limestone trim and a nondescript assortment of ugly new buildings. Its worth a look when you pass the main gates at 138th Street and 139th Street.

Now keep moving and before you know it you're in the 150s. When you get to 152nd, take a right and on the left side you'll see that characteristic lot-line cut at an odd angle that just screams "AQUEDUCT". The buildings on both sides of this cut go off at about a 45° angle. The cut is now a community garden and it's gated at both ends but on the last two visits I made to this place, first one end, and the other end was open. So I would walk one way and had to turn around and the other time, ditto in the other direction. Maybe you'll be lucky and find both ends open. I call this the "last block of the aqueduct in Manhattan". Some day I'll get through it from end to end. When you go through it, or alas, around it, head up St. Nicholas to 155th (that's Macombs Dam Bridge down the hill — Note: all the old maps and documents spell it "McComb's Dam".) and cross the street; turn slightly to the left just east of the subway station and walk down along the little triangle of green and you'll be in Highbridge Park

Highbridge Park: at last the Real, Original and Genuine Old Croton Aqueduct!


The last section of the OCA we will cover is in Highbridge Park. It's the original aqueduct with rock retaining walls and deep rock cuts along the side of the steep cliffs in this park. The High Bridge took 6 more years to finish. The watercolor on the right dates from 1849, within a year of the bridge's completion.


he OCA crosses 155th Street diagonally and heads down along the west side of the triangle of green west of Edgecombe Ave. Cross over and you'll be on the sidewalk next to Highbridge Park. After crossing a playground and stairs down to the bottom, get on the OCA opposite 158th Street. It's about a mile to High Bridge and the first half is on dirt.

And when you see the rock cuts the aqueduct went through such as that in the picture on the left, remember the workers had only pick and shovel and dynamite to work with. Those cuts plus the steep cliffs both above and below the route can only make you marvel. And whether this is the first or last segment you've seen, there is NOTHING else this rugged in the entire 41 miles of the OCA.

After a little detour around a rocky knoll, you'll get on a paved portion which also serves as a bike path. You'll know it when you get to the bridge since there will be lots of folks looking around checking out the newly reopened bridge.

Even if you're not going on through the Bronx, go over the bridge and back anyway and enjoy the view. You've never seen the Harlem River from this vantage point. Take a look back at the High Bridge Water Tower which used to supply water to this portion of Manhattan.

I put together a post about the bridge, its restoration and reopening this June on the main OCA page and included a slideshow just about the bridge (here: ). It is especially informative on the bridge and its history.

If this is your end point, go up the stairs and find your way over to the A train at 168th Street and Broadway and if you're going on, good luck for a longer run or walk, Go dté tú slán!

Now here's the slideshow for this part of the route. Enjoy your virtual tour and then get out and do the real thing.


Links TO OCA related posts on Beyond Central Park

 Links to OCA related posts on Beyond Central Park 
 August 2015   
 June 13, 2015   
 June 20, 2015   
 June 24, 2015