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, 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 — and it stayed closed for some 45 years till this year. Later on, just Joe (one of the trekkers) and I met early one morning at the New York Public Library and walked the missing miles in Manhattan

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 collect all the information I've come across, together with links to my most recent OCA Running blogs. This effort resulted in one large post on the OCA in general — this web page — plus a web page on a proposed route over the Manhattan miles.

I will divide my future efforts into two types: 1) posts on general OCA features, history, remnants, etc. will be added to this web page, like a blog, and 2) posts of runs along specific parts of the OCA will be added to my running blog. Check the links in the last section for those.

As always, comments, questions or requests to join my mailing list are more than welcome. Use the link at the bottom of this web page to send a note, or just click .

As always,
Papa Bear

On this Page —

The Old Croton Aqueduct in Manhattan: Mostly Gone and but Not Forgotten

hen the Croton Aqueduct was built for New York City in the 1830s, Manhattan was New York City. Getting the aqueduct into Manhattan from the mainland (i.e. the Bronx) was a huge problem which was solved by The High Bridge across the Harlem River which will get special treatment below.

Lots of folks think they know more-or-less where the aqueduct went in Manhattan: 1) up Fifth Avenue, 2) through Central Park and 3) up Amsterdam Avenue to the High Bridge. But to determine exactly where the Croton Aqueduct went, a contemporary map is needed. In 1865 one Egbert Viele, a prominent engineer, published a map of Manhattan showing all the streams and ponds and other hydrological features of the island. The map was so detailed and accurate that to this day it is consulted by architects and building engineers to find what river or stream was flowing where they might want to put up a new structure.

The Viele map showed all the streets laid out by John Randel from 1811 to 1820 and lucky for us, it shows the precise route of the aqueduct. Here's a copy of the Viele Map I found on the net: . The date, 1865, is serendipitously perfect. The Croton Aqueduct and the two Manhattan reservoirs were all in place. Central Park with its "New Reservoir" had just been completed (but probably because its design kept changing, the new reservoir only made it onto Viele's map as a dotted line).

I also got a great deal of information from the Bromley Atlases and Land Maps which you can track down from a number of sources on the internet. I was lucky to find an 1891 Bromley Atlas shows every building lot on every block, which is a fortuitous date since all the major changes and upgrades to the aqueduct had taken place by that point in time.

Here are the Viele Map (about 9 MB) and the Bromley Atlas. If you click on the Bromley Atlas you will get to a page with the option to either read the atlas online or view the PDF file (which you can download). The PDF file has better resolution and you can zoom in or out, but it's humongously large (over 100 MB).

The best resource I have found detailing the building of the aqueduct and later changes throughout the 19th century is (on Google Books). Wegmann was an engineer for the New Croton Aqueduct, and the volume has everything you always wanted to know on the subject.

The Croton Aqueduct in 1842

he Croton Aqueduct in Manhattan as originally built consisted of five distinct sections. Here are the sections with annotated portions of the Viele Map to clarify the descriptions:

  1. The Distributing Reservoir and the Fifth Avenue Syphon:
    The distributing reservoir (aka the "Murray Hill Reservoir") occupied the eastern half of the two block rectangle between 40th and 42nd Streets west of Fifth Avenue. Water was taken from this reservoir via water mains to serve the lower Manhattan area.

    It was a massive structure in a faux Egyptian style, designed by none other than James Renwick. The top of the walls with views of both the North (Hudson) River and the East River were open to the public

    It had a limited lifetime, being demolished by the age of 60 in 1902. For a charming tribute to this structure, here is a NY Times article published Feb. 27, 1898: . It's a bit hard to read and the columns jump around a bit, but it's worth a little of your time. When it was written the reservoir was slated for demolition to make way for the New York Public Library. The author, one Amos K. Fiske, writes " ... The reservoir has been taken into the bosom of the city and cherished with vines and enlivened with a park on one side, only to be cast aside now that the limitless thirst of the population takes in the whole Croton Valley water supply and draws it through bigger pipes from larger sources. It gives way to a reservoir of literature and learning to slake an equally limitless mental thirst."

    The Fifth Avenue Syphon:
    This consisted of Two 36" pipes laid beneath Fifth Avenue from the distributing reservoir at 42nd & Fifth to the receiving reservoir at 80th & Sixth.

  2. Central Park: the Receiving Reservoir:
    The receiving reservoir was a rectangular structure with two sections occupying the land between Sixth and Seventh Avenues from 79th to 86th Street in what is now Central Park. The input was at 85th & Seventh and the output was at 80th and Sixth.

    The picture shown is a view from the west with a small gatehouse on the front left where the aqueduct entered the reservoir and a rock outcrop inside the front right corner on top of which Belvidere Castle would later built when Central Park was established in the late 1850s. There appear to be people on the wall so presumably it was open to the public at least at this point in time.

  3. The Clendening Valley and the Conduit Beneath Tenth Avenue:
    A masonry conduit went all the way from the reservoir at 85th & Seventh to a gatehouse at 119th Street in the middle of Tenth Avenue. The section from about 93rd to 103rd Street was known as the Clendening Valley (Note: the spelling of "Clendening" varies on old maps), across which the aqueduct was on an elevated embankment. The conduit followed a path 100 feet west of Ninth Avenue in this section. For most of this section it blocked the cross streets and arches were built at 98th, 99th and 100th Streets to allow traffic to pass underneath. (Think Metro North tracks on Park Avenue north of 97th Street.)

    At the time, it was considered unlikely that streets in this area would be opened up for at least another century.

  4. The Manhattan Valley Syphon:
  5. Two 36" pipes were laid as an inverted syphon beneath Tenth Avenue across the Manhattan Valley from the 119th Street Gatehouse ending at another gate house on Tenth Avenue between 134th and 135th Street. At the low point at Manhattan Street (now 125th Street) the grade was over 100' below the hydraulic line of the aqueduct.

  6. The Conduit Beneath Tenth Avenue and up along the cliff side to the High Bridge:
    A masonry conduit ran from the 134th-135th Street Gatehouse to High Bridge beneath Tenth Avenue and turning down (between 151st and 153rd Streets) to the Kingsbridge Road (now St. Nicholas Avenue) and entering what is now Highbridge Park at 155th Street.

It's worth noting that south of 155th Street the entire aqueduct in Manhattan was underground except for its crossing of the Clendening Valley. If you walked (or more likely rode on horseback) along the the length of the aqueduct in the late 1840s you would see just 2 reservoirs, 2 gatehouses and about 11 blocks of the above ground section from 93rd to 103rd. Folks were known to have walked along the top of the distributing reservoir walls and probably at the receiving reservoir (in what would later become Central Park) as well. I would guess no one thought of doing an "aqueduct walk" (or even less so, an "aqueduct run") in that day and age.

And for those who like maps, here's the whole 1842 Croton Aqueduct in one big map (as Yoda would say "Big it is"), give the map a click and you'll see:

The aqueduct changed very little in the first 20 years. Most of the changes were out of sight, such as laying more pipes and water mains, and repairing leaking pipes under the streets. But the rapid rise of the city population and the inexorable northward march of development caused an ever increasing demand on the water supply. These trends were in part due to the fact that the city, at long last, had a plentiful and reliable supply of water. You might say the success of the Croton Aqueduct was leading to its undoing.

The Croton Aqueduct is upgraded and adapted due to increased demand, and the force of development

y 1860 it was clear changes to the aqueduct had to be made. These changes were of two types 1) to increase the supply of water by increasing the aqueduct's capacity, and 2) by moving the above ground parts of the aqueduct underground to make way for development. These changes were made incrementally in the 1860s, 70s and 80s until finally the powers-that-be agreed that a new aqueduct with much higher capacity was needed. And so it was that the "New Croton Aqueduct", with three times the capacity, was designed, built and finished in 1890. This also gave the original aqueduct its first name, and the the "Old Croton Aqueduct" became part of the city's lexicon.

The changes included a myriad of small upgrades. especially those involving increasing the number and size of pipes. But there were three very visible items: 1) The building of the "New Reservoir" (aka the Central Park Reservoir) in 1858-64 including 3 new gatehouses, 2) the building of the High Bridge Water Tower and reservoir in 1866-72 above the Manhattan end of the High Bridge and 3) replacing all the above-ground portions of the conduit below 155th Street with underground pipes (1865-75).

If you want all the details including maps, dates, size of pipes, &c. then Here are all the significant dates and the type of change made to the aqueduct:

Since it's hard to keep track of all those comings and goings of features, I've put the changes on the base map in the the slideshow below. I've started with the 1842 "As-built" version and annotated all the changes. Click each image to bring up the next one. And you almost certainly need to click on the "click here for larger image". To see the end point, study the last map, "The OCA as of 1894". I didn't think we needed maps showing the demolition of the 1842 distributing reservoir or the filling in of the 1842 receiving reservoir. You can figure that out yourself.

Note: all of these maps are rather big (from 4+ to 6+ Mbytes) so it will take a moment to load each one as you click though the sequence.

If not Read on ...

Intact Features and Remnants or Footprints of Features of the Old Croton Aqueduct

he long and the short of it is that no intact features of the original 1842 Croton Aqueduct remain in Manhattan below 155st Street. The two 1842 gatehouses and the above-ground Clendening Valley aqueduct were gone by 1894. The original 42nd Street distributing reservoirs was gone by 1902 and the original receiving reservoir in what became Central Park was filled in in the 1930s. However we can nevertheless find remnants or footprints of some of the original features.

The only intact features to be found today below 155th Street are not original but were the result of changes and upgrades to the aqueduct, namely the Central Park Reservoir and its gatehouses (1858-64) and the three Upper West Side gatehouses (1875, 1890 and 1894).

First a word on my nomenclature:

So here's an accounting of what you can find:
  1. Intact original aqueduct features:

  2. Intact features of the changed or upgraded aqueduct (i.e. non-original):
  3. Remnants or footprints of original aqueduct features:
  4. Remnants or footprints of the changed or upgraded aqueduct features:

The Distributing Reservoir (1842) at 40th-42nd Street & Fifth Avenue —
   A Remnant in the New York Public Library? A Questionable Claim.

he 1842 Distributing Reservoir was a square structure (about 450' x 450') which rose almost 50 feet from the street level and supplied water to most of the downtown area. It was supplied via iron pipes buried under Fifth Avenue from the much larger Central Park Reservoir. Walking around the walls was a great tourist attraction. It was demolished in 1896-1902 to make way for the New York Public Library.

Here is the description of the reservoir from Wegmann pp. 58-60: and here is the plan from the same volume: (note: south is up on the diagram) both of which describe the complicated structure, the walls of which were actually hollow.

Several websites claim that part of the reservoir's foundation can be seen from the South Court of the Library which is open to the public — this area was recently renovated and is now a very attractive multi-media space. I have never seen a source of this claim and I believe it is mistaken. What you see is simply a section of the Library's foundation and not the reservoir's. It is possible that some of the stones from the reservoir were reused in the library's foundation but my intuition is that engineers would prefer cleanly cut stones rather that those retrieved from a demolition.

On the left is a composite of the reservoir outline superimposed over a Google Earth view of the Library. The outline was constructed using dimensions given in the original OCA plan and from vintage photographs which show how the reservoir fit into the street grid. I suggest you click on it to see the full image. The entire library lies within the reservoir and none of the main walls (which were hollow with a passageway inside) are near the south court. The division wall separating the east from the west reservoir sections does cross the south court of the library but not near the NE corner which is where the foundation is exposed.

Further to the issue, These two diagrams from Wegmann: and Show that the shape of the walls were not vertical and are not compatible with what is on view in the South Court of the Library.

In addition I found a very good web page on the subject: written by Charlotte Fahn on the Friends of the Old Croton Aqueduct website with this quote:

... The exposed stone wall visible at the lowest level of the New York Public Library South Court—the auditorium level—is not a remnant of the reservoir as is sometimes thought, according to a 2003 conversation with Ernest Batchelor, an architect at Davis, Brody & Assocs., the firm that carried out the South Court project. ...

So as far as I'm concerned it's nada in the New York Public Library for the distributing reservoir.

June 9th: The Restoration and Reopening of The High Bridge

n Tuesday, June 9th, I left home about 7:45 to go up to Highbridge Park for the opening of the High Bridge. (A word on typography: the name of the park is "Highbridge Park"; the name of the bridge is "The High Bridge".) I was told there would be an opening ceremony at 9:00 and then we could cross the bridge for the first time in 45+ years. When I got there about 8:40, it was already open and there was no ceremony. Oh well, whatever. It was a cloudy, drizzly day which was unfortunate since I wanted to get some good pictures. Too bad, we do the best we can.

I decided to intersperse my photos in the slideshow with a number of historic pictures all the way back to 1843. The pictures tell the story. What more is there to say? I went there, walked across and back and took a bunch of pictures. But the story actually goes back some 165+ years and you can be sure I'll be running over it in less than a week.

There were just a few folks out on the bridge, maybe 20, and it was very casual. People took photos of others or themselves and we looked into every nook and cranny of the bridge. And the views — up and down the river the views were marvelous. I had seen the bridge many times over the years (back to 1970), but always with a big metal gate across the entrance — and for the last 2 or 3 years with a construction fence and the bridge itself with scaffolding and coverings. But Tuesday was the day.

You might ask since the bridge restoration was so beautifully done, what's with the "Grand Staircase" shown in my pictures. The Parks Department docents said that the stairs are on Department of Transportation land taken when the adjacent highways were built and they were hopeful that the stairs would be transferred to Parks which would fix them up. Hmm ...

When you run the slideshow I suggest you turn the rep rate up (or is it turn the rep rate down?) so you can take time to read the captions. The default is just 3 seconds. I find 5 or 6 seconds works for me.


The OCA and the Jerome Park Reservoir

hen I ran with Melissa in June along the OCA in the Bronx, we ran along Goulden Avenue when we got to the Jerome Park Reservoir. Then I ran with Ed a week later and we went along the other side of the reservoir. I really never thought about where the OCA went, other than more or less in the north end and out the south end of the reservoir and ultimately to Kingsbridge Road, across from the Kingsbridge Armory. But some of the parkland along Reservoir Avenue (last Saturday's route) looked a lot like the OCA sections further south between Kingsbridge Avenue and the Harlem River. So I did a little research and found out a number of interesting tidbits (see , starting at about page 15 and ) from the NYC Department of Environmental Protection, aka NYC DEP, website. It's a report published with the meeting minutes of a meeting where the DEP met with members of the local community to discuss various issues. Note that the historical narrative included in these posts were taken from the which was written by Robert Kornfeld, AIA. The designation was approved in 2000. For a general paper om the effort to presrve the Jerome Park Reservoir, see .

First off, earlier in the 19th century in the 1870s when this part of the Bronx became part of NY City, none other than Frederick Law Olmsted, one of the designers of Central Park, laid out a plan for the streets and parkland in this area. Much of that plan was accepted and the lovely streets and parks Ed and I discovered in our run west of the reservoir reflects Olmsted's design. See this map: , which shows this part of the Bronx in 1879 — after Olmsted had created the plan. His street plan, which extended west to Riverdale, is shown in very light lines, the existing streets are shown in normal print. Where the reservoir would eventually be built, there was a park, "Jerome Park", with a race track within it. Hence the name of the future reservoir. The map shows the aqueduct going right through the park, from Gun Hill Road at the north edge of the map, to Kingsbridge Road and on towards the south. Most of the parcels show no current streets, just the owner's names. This was farm land.

Then in the decades following, when the New Croton Aqueduct (aka the NCA) was being built and the reservoir was designed, it was intentionally fit into this plan.

And lastly, the original plan for the reservoir was to have a portion east of the present day Goulden Avenue as large as, or larger than the portion actually built. See the 1907 design plan to the left. Due to politics and budgets the "East Basin" was never built and the land already taken was eventually given over to other city departments. So all the schools from Dewitt Clinton High School, Bronx High school of Science and Lehman College are sitting in the old East Basin. The unbuilt part was originally designed to go all the way south to Kingsbrige Road to the site of the Armory (built in 1912 after the East Basin plan was scrapped). So what was once a wall dividing the West Basin (built as designed) and the unbuilt East Basin is now simply the east wall of the reservoir.

The OCA originally ran near where this wall was to be built, so they relocated the OCA slightly and put it inside the east basin wall, mostly to protect it. Look carefully at the 1907 plan above left and you can see the dotted line for the original OCA path and the East Basin wall built very close to it. Here's a Google Earth screenshot which I have annotated to show the relocated path of the OCA from the Gate House to Van Cortlandt Park: (the original path is shown in blue, the relocated path in red). After the NCA's completion, the OCA would continue to serve as one of the major sources of water for the city and a backup for the NCA for close to 60 more years. So neither aqueduct just flowed in one end and out the other end, as I naively thought. They both entered and exited the reservoir through a gate house designed for that purpose (the gate house is still there, see photo on the right).

And for obsessives like myself who want to "get it right" when doing an OCA run, just running along the Goulden Avenue sidewalk is fine. Don't attempt to run along the reservoir wall. It's between two fences and you might get arrested as a terrorist, or at least as a wacko! Besides, in places the Goulden Avenue sidewalk is closer to the original path of the OCA anyway!

Blog Links, Sources, Maps, and OCA Websites

Links to OCA Related Blog Posts from Beyond Central Park
   August 2015    
   June 13, 2015    
   June 20, 2015    
   June 24, 2015    
   June 2017    
   June 2017    
   June 2017    
Source Documents
   see sections 7 - 11.  
News Articles
OCA and Related Websites