Where the Old Croton Aqueduct enters the City of New York, there is little to mark it as an engineering wonder. In fact, there is little to mark the boundary of the city itself. The linear state park in Yonkers that covers the Aqueduct-- which is essentially a dirt path in a tree-lined alley that delves between backyards-- blends easily with the land that belonged to the Van Cortlandt family a century and a half ago when the Aqueduct was built. Within the northern section of Van Cortlandt Park, a dirt and gravel path, at times nearly invisible between the trees, provides hikers and bicyclists with one of the most scenic nature-trails in the city. The path is officially named as the "Aqueduct Trail" on maps of the park.

This area of the park slopes slightly downward towards the west, and occasionally large retaining walls can be seen on the lower west side of the path, which allowed the ground to be built up so as to provide a solid foundation for the aqueduct. The tunnel in this section was built as an open cut, covered with a double-layered brick arch eight inches thick, and then covered with earth. Both the shape and materials in this part of the aqueduct are representative of tunnel along most of its 41 miles; as F. B. Tower explained, in his hagiographic 1845 book Illustrations of the Croton Aqueduct,

This three or four feet of cover makes most of the actual structure of the aqueduct nearly invisible. However, various components of the superstructure make their presence known with all the dignity of their simplified Egyptian Revival style, which was chosen by Chief Engineer John Jervis so that these structures would stand as proudly as the pyramids, "as if commissioned by Ramses or Cheops."

Coming upon the Waste Weir in Van Cortlandt Park less than a mile south of Yonkers, one can easily see both the magnificent solidity of this style, as well as its other virtue: it is absolutely simple. One of the books that Jervis used as a reference while building the aqueduct has its own description of Egyptian Architecture:

Except for the lack of cement, this is an adequate description of the architecture of most of the visible superstructure elements that remain extant from the original building of the Croton Aqueduct, except for the bridges and culverts, many of which rely on Roman arches. In fact, even inside the waste weir itself, high-strength arches play a prominent role, forming the aqueduct itself; the brick vaulting of an access chamber; and the roof of the actual run-off culvert. In light of this, it is perhaps surprising that such a high degree of simplicity was chosen in the visible exterior. Essentially, it appears as a square box, made of cut granite blocks, with projecting piers at the corners, a projecting cornice, and a horizontal course projecting near the ground.

It should be noted that most of the Croton aqueduct structures that remain within New York City itself are not original to the old aqueduct, and are built in a slightly different style that utilizes, for example, semi-circular arches over windows instead of flat lintels. This can be seen in the gatehouses on Manhattan, for example, which were built during the 1870s and later. However, the style was still very similar in terms of simplistic massing, heavy granite construction expressing permanence and solidity, and an absolute lack of articulation of interior function. Thus little distinction should be made between these two styles; and in fact many of the structures built in later years, such as the gatehouses built in the 1890s, could have been taken Jervis's original plans.

A significant factor in this choice of simplicity was the cost. The water commissioners had made it clear, when they fired the previous Chief Engineer and hired Jervis in 1836, that frugality was as important as functionality. The basic exterior design also had to be applicable to many different sites. Originally, there were six waste weirs along the entire length of the aqueduct, in addition to twenty-two stone ventilators built as 14-foot stone cylinders, and eleven larger ventilators that gave access to the aqueduct. In addition there were the numerous retaining walls, culverts, bridges, and embankments.

Jervis desired that all of these structures be as inexpensive as possible while still presenting a unified vision of strength and permanence to the viewer. The efficacy of his design can be seen in the fact that several of these structures are still standing, essentially undamaged, still expressing solidity over a century and a half later. And, in fact, most of these structures were nothing more than sheds, and so simplicity in design was very appropriate. However, it must be recognized as well that there was a high degree of functionality, oftentimes below ground level, that was not expressed.

For example, the Waste Weir tender, who lived in a wooden house near the Weir (the house in Cortlandt park is long since disappeared, although one still exists in Dobbs Ferry), was responsible for setting the maximum height of the water as it flowed by at about 1.5 miles per hour; within the Weir, he stopped the flow of water completely when engineers needed to gain access to the section of the tunnel to the south; and he drained that section of the aqueduct, with another set of iron gates, when engineers needed access to that section. The massive iron machinery involved in these processes, in all its rusting gothic beauty, remains inside the bland granite box as it slowly decays. Perhaps if more of this impressive machinery was visible, or expressed in the exterior structures, then strangers visiting the city really would visit "her noble Aqueduct" as F.B. Tower assumed they would. Currently, on a sunny day, it is unusual to see more than five people in an hour pass by this edifice as they enjoy the natural beauty of the path.

In the southern portion of Van Cortlandt Park, the aqueduct passes directly underneath the Moshulu Parkway, in the same area where the Major Degan Expressway passes over the Moshulu. Elsewhere, traffic priorities have necessitated destruction of the aqueduct conduit, in order to keep the roads at the proper grade, in a clear example of the city eating its historical infrastructure under the logic of growth. However, when the Moshulu Parkway was planned in 1888, the Old Aqueduct was still of vital importance in supplying the city with water, and was also sufficiently below ground level, that the roadway could be built over it without disturbing the masonry conduit. There is no external signifier of the Aqueduct in this region.

Located just south of Van Cortlandt Park, the Jerome Park reservoir is a large concrete lake with a capacity of 773,000,000 gallons. It was completed in 1905 as part of the New Croton aqueduct, which comes very near to the Old Croton in the Bronx before diverging somewhat to the west. (It is also built at a much lower level than the old aqueduct, and so it is generally less visible and effects the surface of the ground less. A significant reason that so much of the right-of-way of the Old Croton Aqueduct remains undeveloped is that heavy construction or traffic might damage the masonry conduit. The depth of the New Croton protects it from this danger.)

The eastern border of the Jerome Park reservoir is formed by Goulden Avenue, and the line of the old aqueduct runs along this road. The reservoir was originally planned to expand to the east, on the site of an old racetrack, and the land was condemned by the city; but this project was abandoned in 1912 when need for water was alleviated by the Catskill system. This acquired land to the east now provides the spaces for the Kingsbridge Armory, three highschools, and Lehman College.

The Jerome Park reservoir and associated infrastructure still serves the New Croton aqueduct, and as such its contemporary functions have taken precedent over any retention of its historical structure. The area around the reservoir itself became a park in 1940.

This entire area of the Bronx shows, in the urban fabric, a powerful history of water supply structures. The Williamsbridge reservoir, for example, existed just south of Gun Hill road, to the east and south of Van Cortlandt Park. Originally used to help harness water from the Bronx river from 1888 to 1923, it was eventually discarded and the reservoir was filled, but development had already occurred around it and so the oval shape remained imprinted on the street pattern. It was converted into playground under Moses in the 30s, and the old reservoir is remembered in the embankment walls which surround the playground and in the old reservoir keepers house. There is a small road named "Reservoir Oval" around the space; another road named "Reservoir Place;" and yet another, this one associated with the Jerome Park reservoir, named "Reservoir Road."

The Old Aqueduct itself is remembered, even though there are no visible superstructure elements in this section, in the name of "Aqueduct Avenue." This is a very small road that begins where Goulden Avenue ends, south of the Jerome Park reservoir at Kingsbridge Road, and it runs directly next to the weed-filled alley that covers the old aqueduct right-of-way.

Despite the expression of urban memory inherent in these names, however, and despite the shaping power of the water-supply structures, which is obvious in a birds-eye view of the area, it is questionable as to how much real cultural memory these names signify. From the road level, it is difficult to comprehend the shape of the urban fabric. Even the water of the Jerome Park reservoir is mostly invisible behind fences and embankments, and the road names, like Wall Street or Canal Street elsewhere in New York, seem to have become simple names void of any historical signifying power. To people who already know the history, these names are clear signifiers of what was once there; but to all the rest, they are simply roads. This is of course natural in urbanity. Nonetheless, this lack of historicism is disturbing in the context of the continuing nature of the water-supply problems in New York City.

However, south of Kingsbridge Road, the memory has been preserved and celebrated, to some extant, in the linear park called "Aqueduct Lands." There are occasional small superstructural elements along this route. More importantly, the ground was very nearly at the grade of the Old Aqueduct in this area, and so the path of the Aqueduct Lands is built on the slightly raised ground that now covers the aqueduct. This helps make it obvious that the park is, in fact, built over the Old Aqueduct. A note in the parks file from 1935 describes the land:

This park is, essentially, the right-of-way of the Old Croton Aqueduct along Aqueduct Avenue West and University Avenue, divided up into ten separate sections by cross-roads. In 1930, the surface rights to the majority of this land were accepted from the Department of Water Supply, Gas, and Electricity, and turned over to the Parks Department on Feb 19th, 1930 by the Commissioner of the Sinking Fund, with restrictions. The restrictions were intended to protect the masonry conduit itself, and to allow the Department of Water access to the conduit and associated infrastructure when and if needed, and were very specific about the use of the land as parks:

The majority of the park has been developed as a paved trail with benches, known as Aqueduct Walk, and is a very attractive space that proclaims the historical existence and significance of the aqueduct. In the southern portion of the Park, the level of the aqueduct is significantly above the grade of the roads, and thus a supporting embankment arises like a long, low hill between University Avenue and Harrison Avenue. Unfortunately, as the aqueduct is above grade, it was destroyed at West Burnside Avenue to allow this road to pass at ground level. This results in a massive cut that not only creates a gap in the masonry conduit itself, but also interrupts the Aqueduct Walk. To follow the Aqueduct Walk to the other side of Burnside Avenue, a pedestrian must either jump a fence and make her way down a 45-degree slope, or walk a quarter-mile around. In at least one similar location in upstate New York, a light metal pedestrian bridge has been installed, but despite several efforts of preservationists, this has not happened in the Bronx.

In fact, correspondence between the Mayors office and the Parks Department of 1967 declares that a pedestrian bridge at Burnside had already been proposed for the 1967-1968 budget. However, this proposal was not approved.

More recently, Amy Barnett of the Columbia University Graduate School of Architecture, Planning and Preservation made the recommendation in her 1988 thesis that this site be utilized as the centerpiece of a wider effort of museumification of the artifacts of the Old Croton Aqueduct. She chose this site specifically because of the ways it intrudes into the above-ground urban fabric, and because the cut for the road had already necessitated a breach in the conduit itself. She proposed an intervention that would expose the cross-section and allow pedestrian to walk some distance into the tunnel itself, thus gaining an appreciation for the full scope of the engineering feat signified by the small part visible above ground. As she put it, "the remaining physical fabric of the of the aqueduct is not destroyed, but is adapted and reused, restored or revealed. Unique urban conditions created by the presence of the aqueduct system are used to advantage, and accentuated rather than obliterated, in order to preserve a sense of the layers of history which make up the urban fabric."

The topography of the aqueduct in this area is extremely amenable to the proposed intervention. This junction with Burnside Avenue is one of the few areas in the Bronx or Manhattan where the Old Aqueduct rises above the level of the surrounding ground. The aqueduct disappears back into the higher ground approximately one quarter mile to the south and one half mile to the north.

The construction of the aqueduct in this area also makes the proposed intervention particularly feasible. The embankment is approximately twenty feet high, to support the aqueduct at the desired height and the proper slope of 9.5 inches per mile. This embankment was created of "stone laid dry, and formed by using large stones laid in positions to give proper bond," and the aqueduct itself was built on top of this stone course, with stone sidewalls, a double-layered brick roof, and especially strong hydraulic cement to help ameliorate the possible effects of settling. Dirt was then piled on both sides of the built-up aqueduct, until the top of the aqueduct was covered with several feet so as to insulate it from freezing. More dirt was added to the embankment so as to form a ridge with sides sloping down at approximately 45 degrees. In addition, "[a]nother precaution has been taken to render the work secure, by plastering the interior of the Aqueduct over these foundation walls." This plaster-treatment of the interior gives the hard-baked bricks a smooth gloss, as if the tunnel was polished.

Thus, an intervention which made a cross-section of the aqueduct visible and provided access to the conduit itself would be particularly spectacular in this area. The cross-section would show not only the engineering expertise of the standard brick-work, but also the construction of the supporting infrastructure. Most importantly, it would help signify the full extent of the underground artifact. Currently, the only way for the public to experience the nature of the aqueduct underground is to participate in a tour of a double-arch weir in Ossinning, under the auspices of the Ossining Recreation center.

However, there is no indication that Amy Barnett submitted her proposal for city consideration. Nor is it even clear which city agency should be addressed. As explained above, the Parks Department has surface rights to the property, but the actual Aqueduct is still under the control of the DEP.

The vast majority of the Aqueduct Lands is developed as has described above, with benches and a paved path and occasional light playground equipment. However, there are two small sections that are worth mentioning separately.

The first is Barnhill Triangle, which is located where Goulden Avenue joins Aqueduct Avenue, directly across from the Kingsbridge Armory. This is a very small space, of 4,882 square feet, in the middle of a fairly busy intersection. In the late 1990s, it was renovated under the Greenstreets program, and in 2000 an historical sign was place on the triangle. This sign marks the site as "Barnhill Triangle," and seems to be a very good start in reconstructing the historical meaning of the area, inasmuch as it references the aqueduct structure which passes underneath, and helps to inform the reader about the urban history that shaped the park itself and the surrounding environs.

However, just as the small sign illuminates the urban infrastructure that is hidden underground, it also illuminates the unseen process of urban redevelopment of anachronistic spaces. This space is, in fact, triangularly shaped; nonetheless, until 1991, it was known as "Barnhill Square" and in fact had a sign giving it this name. In 1991, a proposal was created for the placement of a bench and the "remapping" of this space, some of which had been subsumed into the roads that border it. In the process of remapping, it was discovered that it was triangular. In order to rename the space and install the bench, however, the Parks Department had to correspond with nine other agencies, including the Department of Transportation, Con Edison, and the DEP. Ultimately, this correspondence passed between ten different departments and companies, and sixteen offices; and it was not until 1998, seven years after the original proposal, that a new official Parks Department map was devised and the name became "Barnhill Triangle."

This process, in fact, is only an extreme example of the processes involved with the development of many areas that are now under the Parks Department. Even within the Aqueduct Lands park itself, which has been presented above as a simple and one-time transferal of surface rights from the Department of Water Supply, Gas, and Electricity to the Parks Department, that only represents approximately 90% of the total park area; the other 10% was accrued by the Parks Department between 1935 and 1970 through tax foreclosure and further dialogue between the Parks Department, the Department of Water Supply, Gas, and Electricity, the Board of Real estate, and the Board of Estimate. The instigation of such dialogue-- which normally rested on the idea that "only reasonable and logical" to "combine jurisdiction in one agency"-- also requires knowledge of the particular area and a concern for a cohesive presentation of the space. It is quite possible, in fact, that this Park and several others associated with the Old Aqueduct, such as Highbridge, have been relatively marginalized because of their location in the northern parts of the city, which generally receives a disproportionately small percentage of Parks Department monies and development.

The second noteworthy space in the Aqueduct Lands is Morton Playground, which does not share in any of the problems discussed above. It is located at the southern end of the linear park, along University Avenue north of West Trement. Of all the spaces within New York City built above the Old Croton Aqueduct, it is the best at both providing a currently useful space while contextualizing itself into the history of the Aqueduct and thus the city. This success can be attributed to the $650,000 reconstruction of the Park in 1998, funded through the efforts Council Member Adolfo Carrion Jr. to redevelop the area of the Bronx along West Tremont Avenue. Having managed a community board in the Bronx for five years, and having been educated as an urban planner, Carrion was perhaps uniquely suited to bring to the site the cohesive understanding, planning, and political force needed in such a case.

The playground is clearly part of the line of the Aqueduct Walk, and it adds a great deal to the walker's understanding of this park. An Historical Sign was added in 1999 as part of the Parks Department Historical Signs Program, but more importantly, the playground contains a concrete map of the route of the Old Aqueduct, which shows landmarks along the path.

The primary role of the space is as a playground, but even that function is construed in historically suitable ways: for example, sculpted beavers are built in as "spray showers," or fountains, for hot weather. This is particularly appropriate because some of the most public and reveled-in appurtenances of the Old Aqueduct when it was opened were the public fountains installed in the city, fountains that celebrated the water supply, proclaimed it visibly, and sometimes served the useful purpose as well of giving people easy access to the water. As F.B. Tower saw it, "[w]ith cleanly streets, and the public parts beautiful with the fountains which send forth cooling and refreshing vapours upon the air, the citizens will forget to leave the city..."

Between West 174th Street and West Trement, the Old Aqueduct passes underneath the center of University Avenue. This land was turned over to the Parks Department by the Department of Water Supply, Gas, and Electricity in 1936 with the same provisions as were implemented in the case of the Aqueduct Lands: only surface rights were vested, with a restriction on heavy building and tree planting, and the masonry conduit itself along with all associated water supply infrastructure was left under the jurisdiction of the D.W.S.G.&E. The official title of these four lengthy median plazas is "center plots;" they are interesting only for their complete lack of qualities. They are concrete with cursory and unmaintained detailing in inset brick; they do not go anywhere, nor do they draw anyone to come to them; there are not even benches. Bounded on both sides by the traffic of University Avenue, these insipid spaces are linear border vacuums without actually being on the border of anything. No greater contrast could be imagined to the ingenious conduit of perfectly engineered, double-layered and hand-laid brick that has rested undamaged for more than a century and a half only a few feet beneath them.

The progression of this paper has suggested a geographical continuity to the aqueduct relics, and this continuity is observable, for example, in the line of University Avenue itself, which follows the aqueduct as it curves west to cross the Harlem River at High Bridge. However, this continuity is not as obvious on the ground, and in fact it is difficult to realize, unless one already knows the line of the aqueduct, that these center plots are a continuation of the same history that formed the Aqueduct Lands Park. Thus, with no connection to anything that might give them meaning, they are completely de-historicized. At the same time, their relation to history, situated over the Old Aqueduct, means that they are restricted from being developed for any other use. An attempt to express the underground history and presence of the Aqueduct here-- for example, with the sort of large historical signs that have been appearing in various historic districts in NYC over the past years-- would therefore be both appropriate and extremely edifying, turning these non-programmatic spaces into important metynomic symbols of New York's water supply history.

The Old Croton Aqueduct's entrance into Manhattan, involving the High Bridge structure itself, other associated structures such as the High Bridge Tower, and the land now contained within Highbridge park, demonstrates a number of important elements in the original construction of the aqueduct as well as different approaches to the Old Aqueduct's integration into the contemporary urban fabric. The most important of these elements are the bridge itself, both as an engineered structure and as an indicator of New York's original conception of the Aqueduct project, and the High Bridge Tower, which has a very high visibility on the skyline compared to other extant elements of the Old Aqueduct system. Both these structures and the surrounding land, all of which is currently within the 120 acre environs of Highbridge Park, are important for the lessons they demonstrate in terms of the historical politics and processes that reformulate obsolete land uses into contemporary urban elements.

The bridge itself was a tremendous engineering marvel when it was completed in 1848. Its size alone was tremendous; in America there were few structures of any kind to match it, and in fact one of the reasons it took so long to build, in addition to planning and political delays, was the sheer length of time required to float the stone from numerous quarries down the Hudson, most of the stone coming upper New York, as well as Connecticut and even as far away as Maine.

Moreover, it represented a high degree of engineering accomplishment, making visible aboveground the same exactitude and creative planning that was necessary for the construction of all 41 miles of the mostly-hidden aqueduct. Jervis, the Chief Engineer whose work prior to the aqueduct had involved canals primarily, created a bridge that reflected not only expertise but innovation. Rather than creating a solid masonry structure, he made it as light and strong as possible by designing a system of interior walls and struts in the spaces between the arches of the bridge piers and the deck of the bridge, which carried the actual aqueduct. Although common today in concrete bridges, this system of "open and articulated structure...in which the main structural elements -- ribs, posts, deck -- stand clear and separate" was a somewhat revolutionary design at the time.

Just as the Brooklyn Bridge would loom over downtown Manhattan some 35 years later, so High Bridge loomed over the river and declared New York City's engineering prowess for all the world to see- or, at least, for New Yorkers to see. It became a favorite subject for sketching and prints, including some grandiose oil-on-canvas paintings in the style of Turner's dramatizations of sea battles. F.B. Tower, who spent the first fifty pages of his Illustrations of the Croton Aqueduct reveling in the measurements of the New York water system as favorably compared to aqueducts of other cities throughout history, tried to use the building of Highbridge to compare the Aqueduct to the Revolutionary War:

The importance of the bridge as a visible structure cannot be stressed enough inasmuch as it allowed New Yorkers to be aware of the water supply system which they began to take for granted so quickly after it was put into service. Most of the aqueduct, even where it was built aboveground with the same care and skill, was hidden due to a combination of the exigencies of physics and the demands of frugality; the embankments that raised the aqueduct above ground in Westchester and from 113th street to 92nd street in Manhattan, for example, were covered with mounded dirt until they looked like long earthen ridges, so as to keep the aqueduct below the frost line. But, as "Scribner's Monthly" pointed out in 1877:

The visual effect of the bridge, of course, was no accident, although it did represent a particular conjunction of circumstances. Jervis, impressed by the Water Commissioners with the need for economy in the Aqueduct, originally suggested a low bridge plan in 1837, with the largest arch 61 feet in height and spanning 120 feet. Work actually began on this bridge in 1838, despite some continued dissension about the plan. Some of the Water Commissioners advocated a high bridge structure, for the aesthetic value, despite the fact that it would be more expensive-- Jervis estimated that it would be more than $500,000 more expensive to build a high bridge, out of a total budget for the aqueduct of less than $10,000,000. Westchester citizens suggested that a low bridge would be a menace to navigation; other groups suggested that it would be more useful overall to have a high bridge which could serve as a highway bridge as well as carrying the aqueduct (because of the highly sloped terrain on both sides, a low bridge would not have been as useful for a road crossing). The "New York American" suggested that the advocates of the High Bridge plan were simply rich Westchester landowners who wished to increase the value of their properties with city-funded transit routes.

The Water Commissioners decided, as they did in so many other sites along the aqueduct route, on the cheaper solution, and it was at that point in September of 1838 that the low bridge was commenced. However, responding apparently to Westchester citizens, the Assembly in Albany passed a bill in 1839 that demanded, for the purposes of navigation, either a tunnel or a bridge with arches at least 80 feet in span and 100 feet above the high water mark. Jervis was not particularly upset, writing to a friend that "I cannot say by any means that I regret this. As you know engineers are prone to gratify a taste for the execution of permanent works."

The tunnel would have been cheaper, but Jervis advocated the bridge; at that same time, Marc Brunel's tunnel underneath the Thames was under construction, and the problems encountered there suggested to Jervis that unforeseen difficulties were inevitable. He was probably correct; when the New Croton was tunneled underneath the river later in the century, the first attempt failed because of the unexpected fragmentation of the river bottom, and the tunnel had to be made much deeper. Thus the High Bridge was ultimately chosen, with a total cost of slightly less then $1,000,000, or nearly %10 of the Old Aqueduct's total cost. As soon as the cofferdams, or bases of the piers, were built, temporary pipes were laid across, and then the bridge was finished over the course of the next six years.

The shape and grandeur of the bridge, of course, was in every way intentional; Jervis himself desired a grand structure, but more significantly, the Water Commissioners demanded a visually impressive signifier of the Aqueduct. The Croton project was a vast expense for the city, and the Commissioners wanted to demonstrate that something magnificent was being produced. Due to both the nature of the structure and the importance of visual impact, a Roman rather than Egyptian model was used. In fact, it is not just based on a Roman model, but on the exterior it is a direct and faithful copy of the general pattern of Roman aqueducts, down to the articulation of the arches, the double horizontal courses at the top, and the oversized rectilinear capitols and pediments of the supporting piers.

The two 36" pipes that were laid across the bridge were, along with the pipes forming the "inverted siphon" in Manhattan Valley, the section of the Aqueduct with the lowest water-carrying capacity. In fact, the bridge itself acted as an inverted siphon as well; Jervis had chosen to build the Highbridge as low as the Assembly at Albany would allow, so as to keep the costs as low as possible. At the time, it was estimated that the maximum capacity of the Old Aqueduct would be 60,000,000 gallons daily, and this was considered to be more than enough; when it was brought online, only 30,000,000 gallons were supplied daily. Thus when Jervis built the bridge, he installed only the two 36" pipes, based on what he knew of the current water consumption needs. When the city's needs expanded, a new pipe was added at Highbridge just as new, larger pipes were added in Manhattan Valley. In order to accommodate the new pipe, the sides of the bridge deck were raised, and a new pedestrian walkway was built on top.

Because the water was flowing through the bridge under pressure, the new pipe had to be stronger than the masonry conduit along most of the aqueduct. This new pipe, installed in 1860, was a significant structural achievement in its own right; it was built of wrought-iron 0.5 inches inch thick, riveted together, with an interior diameter of 90.5 inches, and it had to take into account a significant expansion and contraction due to temperature variation.

The center span of Highbridge was replaced with a steel arch in 1923 by the Navy Engineers to facilitate river traffic, but except for that change the bridge itself remains much the same as it was in the 19th century. The huge iron pipe still sits inside the hollow deck of the bridge, rusted paper-thin in places.

The Highbridge Tower, just west of the end of the bridge, was completed in 1872 as a water tower with a 47,000-gallon tank to give water service to upper Manhattan. Because of altitude, much of upper Manhattan could not receive service directly from the Old Aqueduct. Along with the tower, the High Bridge reservoir was also built at the same time; this was released to the Parks Department in 1934 and turned into the pool that now exists.

The tower was designed by Jervis, and is composed of the same granite that Jervis had used thirty years before for other elements of the water supply superstructure. He chose to use load-bearing granite walls rather than iron framing technology of the time, and this means it is still as solid as the day it was built. It was intended to look like a medieval belltower, and it was both an impressive engineering accomplishment for its time and an asset to the beauty of the area.

There is no evidence that it was ever open to the public, but the beauty of the view from the windows over what was still a mostly non-urban river valley was stressed, as in this adulation from an 1877 magazine article:

This emphasis on the tower as an attraction adumbrates an attitude toward the waterworks in general that has been lost as the water-supply has gone deep underground in the 20th century: in the 19th century, these structures were places to visit because they were some of the highest, most imposing structures around. From its inception, for example, the distributing reservoir on Murray Hill at 42nd Street and 5th Avenue had been a place to visit and promenade along the walkway at the top of the walls; the height of the walls, combined with the hill that it rested on, gave one of the most commanding views of the city and lower Manhattan.

The necessity for both the tower and the High Bridge reservoir decreased with the advent of the New Croton Aqueduct 1890, which was a pressurized tunnel that supplied the city with much higher-pressure water than the Old Croton Aqueduct had. In fact, both the Tower and the Highbridge crossing of the Aqueduct itself were becoming redundant enough that they were shut down during a sabotage scare in WWI, several years before the Catskill system came online.

Highbridge park had existed in some form since the 1949, as the area in which people picnicked as the visited the High Bridge itself. By 1954, most of todays' Highbridge park was already assembled under the Parks Department, but the bridge and the tower themselves were still under the control of the Department of Water Supply, Gas, and Electricity. Correspondence from Robert Moses to the Commissioner of the Department of Water Supply, dated August 13, 1954, suggests that there had already been some discussion of turning over the bridge to the Parks Department, and suggests that this proceed with al due haste:

When the transfer was actually made in 1960 it included both the Bridge and the Tower structures that had been retained by the D.S.W.G.&E. in the thirties. The D.S.W.G.&E. retained rights to the actual pipes within the bridge as well as the actual aqueduct tunnel, as well as retaining access rights, as explained above in the description of Aqueduct Lands park. The Board of Estimate gave the following rationale for the transfer: that the assignment would

At the time, this was perhaps a very reasonable idea; the Parks Department under Robert Moses, and particularly during the 1930s with the help of WPA programs, had constructed numerous facilities in the city such as the huge swimming pool in Highbridge Park on the site of the High Bridge reservoir. Not only had such facilities been built, but they were maintained and staffed. However, the history of the Parks Department since that time has, in many cases, been a history of facilities being closed or understaffed; bathrooms in parks being shut due to lack of personnel and maintenance funds; capitol improvements remaining uncompleted; and a progressive reliance in many cases on private organizations, such as the Central Park Conservancy, for the upkeep of parks. In many of these cases, the Department simply did not have enough money to maintain spaces or structures under their control.

This was recognized in the case of the High Bridge by 1969. An anonymous memo in the Parks Department Highbridge file from that year points out that the D.S.W.G.&E. still reserved jurisdiction over the actual pipes. "Find out if they still need any of these pipes," the memo demands, "we're trying to get rid of our jurisdiction of that bridge and if they still need the pipes, we get a good reason to give it back to them."

A similar sentiment is expressed in a memo from the office of the Parks commissioner dated November 10th, 1969, which says:

The memo goes on to point out that, at that time, the Department of Water Supply was requesting access to certain parkland sites for the construction of City Water Tunnel 3, and that, in exchange for this access, the Parks Department could force the department of water supply to reassume jurisdiction.

This did not happen. It is questionable what good a transferal of jurisdiction would have achieved; the expense of maintaining the bridge and its anachronistic waterworks would have been the same whatever municipal agency was responsible, and in New York City's general financial difficulties and policy of ignoring old waterfront infrastructure during this time period probably meant that High Bridge would not have received the attention it deserved no matter what city agency was in charge. The pedestrian walkway was kept open for some time, but the parkland on both the Manhattan and Bronx sides was allowed to deteriorate. The stairs leading down to the Bridge on the Manhattan side, for example, had completely disappeared by the 1980s. The bridge itself was closed due to vandalism and criminal activity, and exists now as a historical relic best viewed from far away. In 1999, in association with a Department of Transportation, improvements were made to illuminate the bridge with floodlights at the cost of approximately $500,000. The Bronx side of the bridge, in the area where a small closed gatehouse joins the masonry conduit to the bridge pipe, is under renovation to recreate the small "sitting park," with benches and paths and several chess-board picnic tables. This project was due to be completed in 2000 and is now (2001) almost complete. Despite the deterioration, though, the bridge still holds all of the majesty of the Roman aqueducts on which it was based.

The High Bridge Tower remained inaccessible and unimproved and mysterious, dominating the skyline but giving no indication of the purpose for which it was built. 1958, a carillon was donated by the Altman Foundation, in memory of Benjamin Altman of department store fame, and was installed in the tower where it "chimed daily over the local din." This was in line with the campanile style in which the tower was built, but surely must have added to the confusion about what, exactly, this architectural relic was. The tower was designated as a New York City landmark in 1967, which found that it "stands as a reminder of our City's remarkable water supply system." Both the carillon and the roof of the tower were destroyed by a fire (in which a homeless man died) in 1984. The Parks department replaced the roof of the tower in 1988 at a cost of $900,000, complete with copper minaret and weathervane; plans to open the top floors to the public were never consummated.

What is perhaps most striking in the tower's history since it was acquired by the Parks and designated as a landmark is how little has been done to articulate its history or meaning, despite the rather spectacular scenic value of the area, and the fact that the tower dominates the area both because of it particular location and its 195' height. In 1969, the American Water Works Association requested permission to install a plaque for the tower. The Parks Department denied the request, explaining that "...the plaque does not meet the design standards established by this agency for plaques to be installed on facilities over which we have jurisdiction," and expresses the hope that the Water Works Association would "reconsider the design of the plaque so that it would be more appropriate to today's design standards." Whatever reconsideration took place, there is no plaque or signifier on the tower today; its story, sweeping iron stairs, and beautiful views of the river are all locked tight behind its 130-year-old doors.

The story of the Old Croton aqueduct in Manhattan is in some ways less visible and more complex than in the sections discussed above. Because of the intense urban development on Manhattan, history is paved over with astonishing rapidity. When the aqueduct was first built, the street grid was planned out, but there was little development other than farming in upper Manhattan. Central park did not exist. As Wegmann put it in his 1896 book The Water Supply Of The City Of New York , "At that time...no person anticipated the wonderful growth of the city." This wonderful growth, of course, first stressed the abilities of the old Aqueduct; then made it obsolete; and finally destroyed much of its southern portion.

Currently, the original masonry conduit exists southward to 135th street, except for some small sections where the original tunnel was rebuilt in concrete. This section includes several tunnels that were blasted through the hard gneiss of Manhattan's hills, no easy task. This was one of the few areas of the masonry conduit in which the rock was structurally sound and impermeable enough for it to be constructed without the arched brick roof; the raw stone itself forms the tops of these tunnels. In fact, the longest tunnel of the entire Aqueduct, at 1215 feet in length, was constructed in Manhattan, underneath Amsterdam Avenue. Another section of masonry conduit exists between 119th and 113th Streets, underneath Manhattan Avenue; however, much of this section was backfilled with rubble and concrete when the aqueduct was taken out of service.

Some portions of the conduit are still reflected in the shape of the city, however. Edgecombe Road in upper Manhattan, for example, is built over landscaping and retaining walls that were originally built for the Aqueduct. A small linear park at 155th street and St. Nicholas shows the line of the aqueduct; the surface rights, with restrictions on building, were turned over to the Parks Department to avoid any damage to the Old Aqueduct while it was still in use. A more notable example of its imprint on the urban fabric can be seen in the between 154th and 152nd streets, just west of St. Nicholas. Here the Aqueduct makes a turn to the west before following Amsterdam Avenue straight south. The cross-block diagonal from 405 W. 153rd to 475 W. 152, therefore, as well as a small triangle on the corner of 154th and St. Nicholas, could not be built upon, so as to avoid damaging the conduit with their foundations. The buildings along this diagonal are built with a highly angled footprint, leaving a wide alley. Both the triangle-shaped space and this alley, despite being city property, are used as gated yards by the residents of the neighboring buildings, and seem to be well enjoyed in an otherwise highly-built-up area. There is nothing mentioning the underground presence of the aqueduct in these areas, however.

Built into the original system was a small gatehouse at 142nd Street, a gatehouse at 135th Street, and another gatehouse at 119th street, all in the center of 10th Avenue (now Amsterdam Ave.) The 135th and 199th street gatehouses served the Manhattan Valley inverted siphon system, which took the water 104' below the grade of the aqueduct. An underground vault and sewer connection at the bottom of Manhattan valley at about 125th Street allowed for cleaning of the Manhattan valley pipes: underground iron gates would be opened, and the water from the pipes would rush out through these gates, washing out the silt, and carrying it through a half-mile sewer into the Hudson. Jervis had considered a high crossing here, but decided against it. As F.B. Tower explained it:

Instead, the crossing was effected with two 36-inch cast-iron mains buried underground, to which were added two 48-inch cast iron pipes in 1853 and 1861.

However, as the city expanded, Amsterdam Avenue became a more well-traveled road, and the gatehouses in the middle interfered with traffic. As well, the New Croton Aqueduct, which was begun in 1885, demanded new facilities to deal with a higher volume of water. The new 135th street gatehouse was built from 1884-1890, at 135th street and Convent Avenue, as the connector between the Old and New Aqueducts. For the Old Aqueduct, this gatehouse replaced both the 142nd and 135th street gatehouses, and these were both torn down to leave the center of Amsterdam Ave clear.

The 135th Street gatehouse is a magnificent if somewhat bizarre structure, perhaps best described in a New York Times article:

It was, in fact, just a shed; the building, including its glorious castle-like tower, was and is simply hollow space. However, it must be recognized that at the time, the passion for both glorious works of engineering and for a plentiful supply of water-- the Old Aqueduct had been running at capacity for some time, and so people were looking forward to the New Aqueduct-- was very high. The New Croton Aqueduct represented a massive effort and would ensure a plentiful supply of water; and yet it was for the most part hidden completely underground. As one of the few visible expressions of the New Aqueduct, it is understandable that the building was somewhat overbuilt, despite the fact that today, taking water for granted, the citizens of New York might be disinclined to build such an impressive container for their water.

The New Croton Aqueduct is still in use, with much improved machinery; all of this machinery is located in vaults deep beneath the area. None of the machinery, however, comes aboveground, and the 135th Street Gatehouse has stood derelict and closed since 1984. In 1981, the building was named a city Landmark. The DEP released the building to the Department of General Services in 1991. It is now scheduled to be rebuilt as a theater for the nearby Aaron Davis Hall, with funds from the Upper Manhattan Empowerment zone and philanthropic organizations; the renovation, under OhlHausen DuBois Architects, will try to retain all of the original structure and renovate the exterior to its original condition. As the Architects point out, this use as a performance space will, to some extent, be a public use of a building that was originally built for public uses, and thus it is true to the building's meaning. However, such a use will not reflect its role in the water supply, and it will take away from the city the opportunity to develop this unique, celebratory space as a relic or museum for the water supply.

After the construction of the 135th street gatehouse much of the city's water was shunted through a new set of pipes, but the line of the Old Croton was still in use. The old 119th street gatehouse in the middle of Amsterdam, however, was considered a traffic hazard, and was replaced from 1894-1895 with a new Gatehouse on the east side of the road-- the south-east corner of 119th and Amsterdam Ave. It was not officially taken out of use until 1990, although the aqueduct underneath had long since been unused. The floor and subsurface piping of the building has been backfilled with dirt and cement, and it was declared a New York Landmark in 1999. Currently, it sits as an empty granite box.

Of the original masonry conduit from 113th Street to the Receiving Reservoir intake gatehouse at 85th Street and 7th Avenue, nothing remains. The receiving reservoir itself is disappeared, and not even its original rectangular shape is recalled in the oval of the Great Lawn in Central Park that took its place.

The section from 85th street to 92nd street, which was raised to cross Glendenning Valley, was torn down and replaced with 6-foot underground mains in 1865-1866 (although there was so much trouble with these huge pipes that they were replaced with smaller ones later on in the century.) This replacement also changed the line slightly, so as to avoid cutting diagonally through so many blocks-- the new pipes made a more abrupt right-angle turn to go straight east under 90th, and then headed straight down 8th Ave, and then east again at 85th street to go into the Receiving Reservoir.

The section of masonry conduit from 92nd street to 113th street, which had been slightly above ground on an embankment when the Aqueduct was originally built, was torn down and replaced with six parallel 48" cast-iron mains, running underneath the roadbed of Amsterdam Ave, between 1870 and 1875. In order to facilitate the change of pipes at 113th (and Amsterdam) and at 92nd (and 9th Ave), two gatehouses were built, completed in 1876. The gatehouse at 92nd was built at the northwest corner of 92nd street and 9th Avenue; however, this was torn down as the area became more developed.

The gatehouse on the northwest corner of Amsterdam Ave and 113th still stands, although in February of 1993 it was sold at auction by the city to the Amsterdam Nursing Home and Adult Daycare center. The auction was a formality, inasmuch as the city had already chosen its buyer; a condition of the sale, in fact, was that the future development of the property be limited to "'nursing home' use and uses ancillary thereto."

The building was not landmarked, nor was it under specific legal protection as to how it would be renovated. It is unclear if a retention of the building itself was a condition of sale. However, an impetus towards historical preservation came from the staff of nearby St. John's Cathedral, who threatened to bring suit if the historical value of the building was not respected in the renovation. As the lawyers for the Cathedral would work pro bono, this was an application of economic pressure on Amsterdam House, which would have had to pay its lawyers. Retaining this structure implied a severe loss for the Amsterdam Home, which would otherwise have utilized the site for a multi-story structure. As well, the Cathedral staff requested a retention of the original form of the gatehouse exterior; this meant, for example, no gutters, and resulted in costs associated with underground drainage. In this case, therefore, history was preserved through non-institutional means-- but the cost of this preservation was borne, unwillingly, by the Amsterdam Home.

The building was renovated by the Geddis Partnership Architects. Essentially all exterior superstructure was retained, and two of the four original riveted-iron door panels were saved (they are now on the 'inside' doorway, where the old gatehouse gives access to a hallway leading to the main building). However, the interior was plastered, and the substructure was removed in order to allow for an expanded basement section. The section of masonry conduit in the immediate environs of this gatehouse had already been backfilled when renovation took place, and thus there was no conflict between water-supply equipment and foundation or basement needs.

It is appropriate that we celebrate and preserve the remnants of the Old Croton Aqueduct that exist today. It was a tremendous work that New York should continue to be proud of; and moreover, it hints at the work that is involved in the water supply system today.

If and when the pollution in the watershed regions necessitates expensive filtration plants or climactic changes limit the amount of water available to the City, the issue of making New Yorker conscious of their water consumption will become tremendously important. The idea that New York could suffer a real water crisis, while somewhat far-fetched, is not inconceivable; real changes in precipitation patters are occurring due to human activity, and many cities throughout the country are being affected. Even in New York City's watershed areas, which in years past relied on consistent, cyclical precipitation, now must rely on storm events to fill up reservoirs.

In the case that patterns of conservation and water-consciousness become important to the city, no better forum for teaching could be found than the relics of this original system. As in other cases where presentations of urban history are presented in a relic of that which they present–like the Tenement Museum in an old tenement house, or the Transit Museum proposed for the old City Hall Subway station–such presentations take real power and meaning from the original uses of their locations. It is perhaps unfortunate, therefore, that various elements of the Old Croton Aqueduct superstructure are being redeveloped in ways so different from their original function, rather than being developed as a coherent set, scattered in the city but connected in meaning, just as the water system itself is scattered but functionally unified. The Department of Parks and Recreation, which could potentially have developed such a presentation, has failed to do so, although the Aqueduct Lands park and Morton Playgrounds shows how such a project could be approached.

However, the Aqueduct system is a unique structure inasmuch as so much of it is underground. This helps preserve it, as it is protected from the forces that normally devour urban history. At the same time, it is hidden from public view, and thus hidden from being appreciated for the magnificent relic that it is; unlike, for example, the Brooklyn Bridge, it has no role in the skyline and thus remains unseen by the fickle eye of popular urban memory.

Ultimately, to one who knows its history, it seems inevitable that this relic will be rediscovered and celebrated by the City, which loves best those elements of history that reflect well on it. Sadly, bulldozers and development plans are sometimes wielded by those who do not know history, and who have different ideas of inevitability. Sadly as well, the process of plowing over history is a constant one, whereas celebration and rediscovery will have to wait for either a crisis in the water supply, or an excess of municipal funds applied to the Parks Department. Neither one of these things occurs often in New York.

In the meantime, the Old Aqueduct will continue to rest quietly underground, occupied only by bats and a few feet of water.