The World's Greatest Aqueduct

Water From The Catskill Mountains To The City
Of New York
By Alfred Douglas Flinn, Engineer, Headquarters
Department of the Board Of Water Supply of the City of New York
from Century Magazine, 1909
The Catskill Mountain water system being constructed for New York City is one of the most notable engineering enterprises ever undertaken. Ranking with the interoceanic canals at Suez and Panama, the Assuan irrigation works in Egypt, and the projects which are converting Western America's arid wastes into fruitful fields, the Catskill aqueduct, with its tributary reservoirs, probably surpasses any one of them in the variety of problems to be solved. Although undertaken by a municipality, these works in magnitude and cost compare with national enterprises.
Imperial Rome's longest aqueduct was fifty-seven miles in length; the Catskill aqueduct will be ninety-two miles long. Rome, with hordes of laborers from conquered domains, carried its aqueducts at the hydraulic gradient across valleys on imposing masonry arches. Modern explosives and rock-drills enable New York to tunnel in solid rock beneath valleys and rivers, avoiding masonry, which is now expensive, and which is likely to suffer in New York's severer climate.


CATSKILL MOUNTAIN water, gathered from brooks that have been fed by melting snows and copious rains, and have tumbled over rocky slopes into the streams of the mountain valleys, will in a few years be served to the inhabitants of New York City. The project ranks as the greatest municipal water-supply enterprise ever undertaken, and as an engineering work is probably second only to the Panama Canal. The need of the water is much greater than is realized by a majority of the citizens or by the guardians of their interests.

Nothing can so quickly and completely disorganize the complex activities of a modern community as a shortage of suitable water; no single agency can so rapidly spread disease and death as a polluted water-supply. For several years New York has been using more water than its sources of supply can safely be depended upon to furnish in a series of dry years, such as have occurred within the memory of men who have scarcely reached middle age. Continuing years of abundant rainfall have masked the danger to which engineers have repeatedly called attention.

In 1905, as the result of a movement promoted by civic bodies in the days of Mayor Van Wyck and Mayor Low, a bill was introduced into the legislature, on the initiative of Mayor McClellan, which, becoming a law, enabled the city to start new systems of water-supply that, with the already existing permanent works, should ultimately give New-York the best and largest water-supply ever known.

As thousands of water-wise Americans know, New York City ("old New York") has used Croton River water for more than two generations. Similarly from the Ridgewood system of wells, streams, and reservoirs, Brooklyn has drawn its supply, often scanty. Approximately five hundred million gallons of water are consumed by the metropolis every day, a stream which would flow hip-deep between the buildings in Fifth Avenue's fashionable shopping district at a comfortable walking pace. For every man, woman, and child this allows a daily average of 125 gallons. Or, to put it still another way, for all domestic, manufacturing, and public purposes New York uses every day water which weighs about eight times as much as its population.

Compared with the 130, 140, 200, 220, and 320 gallons used every day for every person in several large American cities, New York's allowance is moderate, especially when one recalls the character of business and the methods of living which prevail in the metropolis. Liberal, even lavish, domestic use of water is not waste. The very necessities of life demand that there should be a maximum supply, in order to provide for the average-demand for the individual. The word "waste" should be properly interpreted. Its use in writing about water-supply has been unfortunate, for it has been employed both technically and popularly to characterize quite different conditions in the economy of water. To let a dozen glassfuls flow from a faucet in order to get one cool draft is not waste so long as this is the least expensive way to get cool water. In a broad sense, to permit water to flow from the faucets through cold winter nights is not waste so long as this is the least expensive way to protect one's plumbing fixtures. To allow even large volumes of water to spill over the lowest dam of a watershed is in no sense waste when the city has already taken from the stream all that it can use, or when the saving of occasional discharges of this sort would cost more than to get the same quantity of water, of equal or better quality, from another stream. Doubtless some water is carelessly or wantonly wasted in New York City, but not nearly so much as some persons assume. Waste should be discouraged and curtailed, but waste of water can no more be wholly prevented than the waste of energy and time. But if all the waste which it would be reasonably practicable to stop ceased, New York would still require more water-works to provide beyond peradventure for present needs and future growth.

Croton River drains into New York's reservoirs the water of 360 square miles of forest and farm, and can safely furnish about 336,000,000 gallons daily. Two aqueducts, one thirty-four miles long, built in 1842, and having a daily capacity of 80,000,000 gallons, and the other thirty-two miles long, built in 1891, and having a capacity Of 300,000,000 gallons, bring this water to the city. To procure 500,000,000 gallons of Catskill Mountain water daily, over 600 square miles of mountain and meadow will be brought under tribute, several large reservoirs created, and an aqueduct ninety-two miles long built, with many miles of conduits within the city limits.

View looking north from West Point

View looking North from West Point Water Battery of the Hudson between Storm King and Breakneck

The extent of these existing and proposed works is not readily to be comprehended even when reduced to the common money measure. For the portion of the Catskill works needed to bring into the city every day unfailingly 500 million gallons an expenditure of $162,000,000 is estimated. But these disbursements will be spread over many years, and the burden will not fall heavily, except for possible temporary difficulties in raising ready money for construction payments. Indeed, the cost of water for every person will be on the average less than one cent per day. Furthermore, these water-works, well managed, will not only pay interest on the investment and cost of operation, but in a relatively few years will pay the capital cost. It is reasonable to believe that the works will be as permanent as those of Rome.


Because of its antiquity and impressive ruins, the water-supply of ancient Rome is doubtless the most famous in the world. In 97 A.D. the imperial city had no fewer than nine aqueducts, with an aggregate length of 263 miles; but if the water that all those aqueducts could carry (estimated at 84,000,000 gallons per day) were put into New York's Catskill aqueduct, it would rise only to the height of about three feet and three inches.

In the angle of the State west of the Hudson and south of the Mohawk are hundreds of square miles of territory partly forested, but in the main little cultivated and sparsely populated. From time to time the large timber has been cut; the farms have depreciated. From the hills tens of thousands of square feet of bluestone have been quarried for sidewalks,but within twenty years even this industry has been almost supplanted by the use of Portland cement concrete. There remain the bracing air, the attractive scenery, and the abundant rainfall; and thousands of holiday-seekers flock thither. Their entertainment now constitutes the most profitable business of the region, and will not be interfered with by the project. The city, therefore, is not destroying large commercial or agricultural industries, but is simply making the highest use of one of the principal resources of the region, its water.

After repeated investigations, the most thorough of which were those of the Burr-Hering-Freeman commission, eminent engineers appointed by Mayor Low in 1902, several large streams in the Catskills were selected for successive development as needed. Esopus Creek, above the best dam site, has a drainage area of 257 square miles; Rondout Creek has a useful watershed of 131 square miles; above the selected point of diversion, Schoharie Creek drains 228 square miles; and 142 square miles of the basin of Catskill Creek can be utilized. Thus, with the addition of several minor streams, a total water-gathering area of 885 square miles has been found, which, it is conservatively estimated, will yield even in a series of dry years about 770 million gallons daily. These waters are all of exceptionally high quality, and, barring Catskill Creek, are remarkably soft. In this respect even the latter suffers only by comparison with the unusual softness of the others.

Although turbulent torrents of great volume rush through the gorges of these mountain creeks in flood-time, in late summer the streams could all be run through four-foot pipe, one of the street mains of large city. But a great community does not use water in any such irregular fashion, and nature must be regulated to meet the necessities of man. The flow must be controlled, so that flood excesses may supplement drought deficiencies. Great impounding, or gathering, reservoirs are the means which engineers employ to this end. In the Catskill scheme eight large impounding reservoirs are contemplated, of which the first, to be constructed, and by far the greatest, is the Ashokan reservoir on the Esopus. In the southeastern corner of this mountain region geologic forces have provided a great basin in which can be stored not only the waters of the Esopus, but also part of the water of the other streams. Through one of the ridges a tunnel aqueduct ten miles long will bring in the Schoharie contribution, while the Catskill Creek water will flow through an arched masonry conduit, to be built mostly in trench along the eastern slopes of the mountains for thirty-two miles. From the Ashokan reservoir the main aqueduct, called the Catskill aqueduct, will convey the water to the northern boundary of New York City. Into this aqueduct, about six miles below its starting-point, a branch aqueduct will bring the water from Rondout Creek.


Map of the Catskill Aqueduct System

Map of the Catskill Aqueduct System


Section of "Cut-And-Cover" Aqueduct

 Section of "Cut-And-Cover" Aqueduct


rade Tunnel on Left, Pressure Tunnel on Right

Grade Tunnel on Left, Pressure Tunnel on Right

But what is an aqueduct? How large is this one? If the curious inquirer will visit Peekskill, New Paltz, or High Falls, where construction is in progress, he will come upon a great trench, in some places thirty feet wide at the bottom, with steam shovels, rock-crushers, concrete-mixers, and hundreds of men and horses at work.

Here and there stretches of concave concrete paving have been laid in the bottom of the trench. Elsewhere this paving is being covered by a large concrete arch, thus forming a great tube, or conduit, shaped something like a horseshoe, seventeen feet high and seventeen and a half feet wide inside.

Over this concrete conduit, wherever it is not wholly buried by the depth of the trench, an embankment of earth will be built, except where the trench is mostly through rock, where the bank will be made partly of the rock fragments. Through this aqueduct a railroad coach could easily pass, with a man sitting on top, and there would be room on each side for a man on horseback. In this aqueduct water will flow at the maximum speed of four feet per second, or two and three quarter miles an hour, a comfortable promenading pace, or at the average daily quantity rate of 500 million gallons. This quantity of water, flowing at the velocity mentioned, would make a stream about four feet deep in the ordinary cross-town street of the Borough of Manhattan.

This is the cut-and-cover, or open-cut, type of aqueduct, and is built along the hill slopes or across the flat lands wherever the topography permits a trench to be dug at the proper elevation. In this kind of aqueduct the water flows freely, as in a brook, and not under pressure, as in a pipe under the street. Of the cut-and-cover aqueduct there will be approximately fifty-four miles.

But the topography and geology of the Hudson valley do not permit the Catskill aqueduct to follow a smooth grade. To avoid long and expensive detours around hills, and to pass ranges of mountains and hills which it would be impracticable to go around, tunnels are being driven through them at the same elevations that the cut-and-cover aqueduct would occupy if the topography were more favorable. Since, however, tunneling is more costly than open-trench work, the size of the aqueduct in these tunnels is less, the dimensions inside being thirteen feet, four inches wide, and seventeen feet high. In order to get the same quantity of water through them, a more rapid flow is necessary and therefore the slope is a little steeper.

Of such tunnels, known as grade tunnels, there will be twenty-three in all, aggregating thirteen and a half miles in length, or approximately as long as Manhattan Island. Virtually the whole length will be in solid rock, and, whether in rock or earth, will be lined with concrete, so as to provide a smooth, clean surface for the water and to prevent the falling of rock or earth from the roof or sides.

In passing, it may be well to explain that the concrete which will enter largely into the construction of the aqueducts and is a mixture of Portland cement, crushed stone or gravel, and water, very thoroughly combined in special machines. When first made, such concrete is plastic or fluid, according to the proportion of water, and can be formed or cast into any desired shape; but in a few hours it sets, or hardens, and rapidly becomes like stone, continually to increase in strength for months, and more slowly for years. Portland cement, a heavy, gray powder, is manufactured in many parts of the country, but that used in the Catskill works will doubtless come mostly from the Lehigh Valley district of Pennsylvania and from the vicinity of Catskill village, New York. The suitability and availability of concrete greatly facilitate and cheapen the construction of dams and aqueducts, displacing more costly brick and stone masonry. Forms of construction which would be impracticable with the latter are entirely feasible with concrete. In building the aqueduct, the soft, fresh concrete is placed against steel plate forms, or molds, erected in the trench or tunnel, thus securing a smooth, clean surface for the water.

The pathway of the Catskill Mountain water from the great Ashokan reservoir to New York City will have many an up and down, and some of the "downs" will be deep. West of the Hudson, several tributaries with broad valleys trend generally northeasterly, so that the aqueduct has to cross these valleys. The great river itself has to be passed, and east of it lies the important valley of the Croton, and at the southerly end of the aqueduct for about two miles even the high land is so low and the real estate so expensive that a tunnel under light pressure is the most economical type of conduit.

These valleys are so far below the natural level at which the water will flow that it will have to be carried across them under great pressure; for the valleys are much too wide for the stone arch construction which the very mention of the Roman aqueducts at once suggests, or for any other kind of bridge of the great height necessary. The most permanent and economical form of construction, therefore, is a tunnel through the solid rock, passing not only beneath the visible streams, but also under the pre-glacial gorges, now filled with earth and hidden from view. It is of the utmost importance that these tunnels should be driven through strong, sound rock, so that there will be not only no leakage of water, but sufficient weight and strength to resist the pressure which the water will exert due to its distance below the hydraulic gradient, or natural flowing level, for cut-and-cover aqueduct.

Before these pressure tunnels could be designed, a great deal of information had to be obtained about the geology of the valleys. Hundreds of drill-holes, with individual depths often of several hundred feet, and aggregating many miles, had to be sunk through the earth into the rock in order to determine its character at different points, as well as its depth, so that the tunnels might be located safely, avoiding as far as practicable the rocks which were too weak or difficult for tunneling. Of course it has not been wholly feasible to avoid all these difficulties, but by going to great depths, satisfactory conditions have been found.

Two of the most important and beautiful valleys are those of the Rondout Creek and the Wallkill River. The Wallkill valley was found to be very simple geologically, Nature being satisfied with one kind of rock, through which tunneling will probably proceed with no more than the ordinary difficulties. Rondout valley, on the other hand, is somewhat of a geological museum, containing at least twelve different kinds of rock, varying from the hard quartzite conglomerate, locally known as Shawangunk grit, to soft, waterbearing, and treacherous sandstones and limestones. Sound, strong granite is found beneath the Hudson River and on both sides at the selected place for crossing between Storm King and Breakneck mountains, the picturesque northern gate of the Highlands of the Hudson, about four miles above West Point.

Several years of hard work will be required for driving and lining these tunnels. For the Rondout siphon,1 besides the shafts at each end, six intermediate shafts, making eight in all, have been provided to aid in construction, so that the digging of the tunnel may proceed at fourteen points. To aid in constructing the Wallkill tunnel, four intermediate shafts will be used. Each of these tunnels is about four and a half miles long. For the siphon beneath the valley of Moodna Creek, stretching south to the Hudson River, five miles long, there will be seven shafts. A shaft about 1200 feet deep is thought to be necessary on each bank of Hudson. To cross beneath the Croton reservoir, a tunnel with two shafts 510 and 560 feet deep will be required. These pressure tunnels, aggregating seven miles in length, will also be lined with the most substantial concrete masonry. Inside this lining, the waterway will be, circular, with diameters ranging from fourteen feet to sixteen and a half.

If to the new tower of the Metropolitan Life Insurance Company, at Madison Square, New York, there were added the height of a Fifth Avenue mansion, it would approximately equal the depth (708 feet) of the shaft at the southerly end of the Rondout siphon. Even in the shallower Wallkill siphon the cages carrying men and materials up and down from the tunnel level will travel a distance (in the deepest shaft, 480 feet, in the shallowest, 350 feet) greater than that from the sidewalk to the top of the towers of the Park Row Building, for a number of years New York's tallest building. From the bottom of each of the working shafts tunneling will be extended for an average distance of nearly half a mile before the headings from adjacent shafts will meet. When finished, each tunnel will be large enough for subway train to pass through. Pressure tunnels, being a more expensive type, have smaller waterways than the grade tunnels, and the water will flow through them at higher velocities.

Besides the great valleys to be crossed by pressure tunnels, there are many others too narrow or of too unfavorable geology to be crossed economically by tunnels. Steel pipes, incased in concrete and lined with cement mortar, will be used for passing these depressions. Three pipes will be laid across each valley, but only one will be laid at first, the others being deferred until the increase in the demand for water makes the expenditure necessary. In general the diameters of the pipes inside the lining will be approximately nine and a half feet north of Kensico reservoir, and eleven feet south of that reservoir. At each end of every siphon, and at every reservoir, there are to be buildings containing appliances for controlling the flow of the water, known as siphon-chambers and gate-houses. A total of seventy buildings for this and other purposes along the aqueduct will be required.


Map of the Ashokan Reservoir

Map of the Ashokan Reservoir


Typical Section Of Dike

Typical Section Of Dike


Maximum Masonry Section Of The Olive Bridge Dam

Maximum Masonry Section Of The Olive Bridge Dam


Elevation Of The Concrete Bridge Designed To Carry The State Road Across One Branch Of The Enlarged Kensico Reservoir

The Ashokan reservoir (Ashokan is an Indian name meaning "place of fish") will be situated about fourteen miles west of the Hudson at Kingston, eighty-six miles in air line from New York, and will center about the hamlet of Brown's Station on the Ulster & Delaware Railroad. It will be formed by a chain of masonry and earth dams having a combined length of over five miles. Another dam about half a mile long will divide the reservoir into two basins. It will be twelve and a half miles long, and the average width will be a mile. When the reservoir is full, its water surface will be 590 feet above tide; it will contain 128,000 million gallons, sufficient to cover Manhattan Island to an average depth of twenty-eight feet; 190 feet will be the maximum depth of water behind the dams, and fifty feet the average throughout the reservoir. With a shore-line of forty miles, it will have a water area of 12.8 square miles, and a nearly equal additional area of land has been taken to protect the margins. Approximately forty miles of new highway and thirteen miles of new railroad will have to be built. A concrete arch bridge at the dividing dam will afford connection between the northern and southern sides of the reservoir. Seven villages and many scattered dwellings and other buildings now dotting the valley will have to be razed. From forty small cemeteries all the bodies in 2500 graves must be removed. All trees and brush will be cut and taken away or burned. The landscape will be changed, but, guarded by the somber mountains, Ashokan Lake will add to the attractiveness of the scenery.

Olive Bridge dam is the greatest of the chain of dams. Nearly a mile long on top, it has a maximum height above its foundation of 240 feet.Its central portion is being built of solid masonry, with a top length of 1000 feet, minimum top width of twenty-three feet, and a maximum width at the bottom of 190 feet. This portion of the dam closes the main gorge of the Esopus. Concrete core walls are being built in the earth dams. These earth dams, or dikes, are thirty-four feet wide on top, and have flat slopes, so that their thickness at the bottom is great, reaching a maximum of 800 feet in the earth portion of Olive Bridge dam. If all the earth, rock, and masonry to be handled in constructing Ashokan reservoir were to be put in one heap, they would form a pyramid having a base a quarter mile square and of an equal altitude. The great pyramid of Cheops, in Egypt, was originally 756 feet square at its base and 481 feet high. Its volume, therefore, is only one eighth that of the material to be moved in building this one reservoir of the Catskill water-works.

Construction of the main dams of the Ashokan reservoir was begun in the fall of 1907, the contract, amounting to more than twelve and a half million dollars, having been awarded to MacArthur Bros. Company and Winston & Company. To provide for the thousands of laborers, many of whom have families, a great camp or temporary town has been built close to the scene of operations. This town has hundreds of houses, schools, a bank, a church, a hospital, a water-supply system, a sewerage system with a disposal plant, a great general store, a large bakery, a mess-hall, an office building, blacksmith and machine shops, streets, park, band-stand, bathhouses, ice-house, fire department, police, electric lights, and telephones. Great quarries and sand-pits are being developed to furnish materials for the dams, and ten miles of standard-gage railway, not to mention several miles of narrow-gage, have been laid, connecting with the Ulster & Delaware main line. For seven busy years Camp City will flourish, and then it will be obliterated as completely as possible. 

Near historic White Plains, thirty miles north of the New York City Hall, the valleys of the Bronx River and Rye ponds afford opportunity, by constructing one large dam, to form a reservoir of great capacity, approximately 40,000 million gallons, with its water surface 355 feet above tide. Its watershed is insignificant, but in it can be kept, relatively near the place of consumption, a water reserve sufficient to insure against the distressing results of accident to the aqueduct northward. Indeed, if necessary, that part of the aqueduct could be out of service for several weeks for inspection or repairs. Hence it also virtually safeguards the continuity of the flow from the Ashokan reservoir almost as well as if a duplicate aqueduct for these seventy miles bad been built at much greater expense. To be sure, a second aqueduct will be needed in the distant future, but the reservoir will continue to perform this function of insurance toward the two. From Kensico reservoir, also, in the future, additional aqueducts and pipes can be led in various directions, to distribute water to different parts arts of the vast district which, in all probability, will ultimately be dependent upon it.

Kensico dam will be of massive masonry, 1830 feet long, rising 150 feet above the ground and nearly 300 feet above its deepest foundation in the ledge rock underlying the valley. Conspicuously in view from the four-track suburban line of the Harlem Division of the New York Central Railroad, it will be the greatest monument to the city's enterprise of all the Catskill water-works structures. Ten years or more will be required for its building.


Completing The Arch Of A Section Of Cut-And-Cover Aqueduct

Completing The Arch Of A Section Of Cut-And-Cover Aqueduct


Section Of Cut-And-Cover Aqueduct Near Peekskill
Section Of Cut-And-Cover Aqueduct Near Peekskill


View Of The Spillway And Dam Of The Present Kensico Dam
View Of The Spillway And Dam Of The Present Kensico Dam

Just north of the city line, in Yonkers, on a large, flat-topped hill, will be built Hill View reservoir,2 an equalizing reservoir of approximately 900 million gallons capacity, to regulate automatically the differences between the steady flow in the aqueduct from Kensico reservoir and the fluctuating consumption in the city. This reservoir will be made by digging to an average depth of about twenty-five feet (maximum forty-four feet) over a large part of the hilltop, and using the earth thus obtained to build the sides of the reservoir higher. Its water surface will be 295 feet above tide, about 3000 feet long, and 1500 feet wide, and the water will be thirty-six and one half feet deep. A great concrete wall will divide the reservoir into two basins, and in this wall will be formed a by-pass aqueduct, so that water can flow to the city without entering the reservoir, whenever it may be necessary to clean or repair the reservoir. The reservoir will be lined with concrete and stone paving.

There will also be a by-pass around Kensico reservoir. From the paths on top of the embankment of Hill View reservoir magnificent views will be had of New York, the adjoining towns, the Hudson with its Palisades, and the blue waters of Long Island Sound.

From Hill View reservoir an extension of the Catskill aqueduct will deliver the water into the distribution pipe systems in the streets of the five boroughs of Greater New York. The busy, congested streets, already underlaid with subways, water and gas pipes, sewers, electric conduits, and other structures, and bordered by tall buildings having one or more stories underground, cannot well accommodate the great number of large pipes that would be necessary to bring Catskill Mountain water from Hill View to the consumers. Furthermore, the annoyances and dangers incident to digging so many big trenches and laying the pipes in the streets would be quite intolerable. If this pipelaying could be done quickly, the bother might be endured; but it would unavoidably spread over several years. Indeed, it might be said to be perennial, when repairs and replacements are taken into the reckononing, and a main distribution system of great pipes would be costly. Hence it is deemed wise to avoid as far as practicable the use of steel or iron pipes for the extension of the Catskill aqueduct for delivering water into the city.

Beneath the borough of the Bronx, Manhattan Island, and the edge of Long Island there is solid rock. Therefore a way of escape from many of the pipe troubles appears. Starting from Hill View reservoir, a great tunnel, like those under Rondout and Wallkill valleys, is to be driven deep into the rock, hundreds of feet below the street surface, and lined with concrete. Thus, disturbance of the streets will be avoided, and a permanent conduit will be secured. Shafts through which tunneling operations are to be conducted will be spaced from 3000 to 5000 feet apart at points where little inconvenience will be caused. After construction, these shafts will be the connections between the tunnel and the main pipes of the street distribution system. This tunnel will pass beneath the Harlem and East rivers, but the crossing of the Narrows to Staten Island will be made by heavy pipes, because the rock there is at too great a depth, and the quantity of water too small, to make a tunnel worth while. As a matter of precaution, two parallel pipes will be laid beneath the water some distance apart, and a reservoir to contain a reserve store of water will he built on high land on the island. 

The fountains of Versailles are famous, and thousands make pilgrimages to see them in their beautiful settings when the water is turned on. Two fountains of far greater volume -- scores of times as great -- will be incidental features of the Catskill water-works. At times water in reservoirs, as in natural ponds, becomes impregnated with unpleasant tastes and odors, due mostly to very small organisms which, in a favorable combination of conditions, develop in unusual numbers. Although. not deleterious, or not seriously so, the products of these organisms are disagreeable. Aeration has been proved by experience and experiment to be an efficacious and inexpensive means for removing these tastes and odors, and the most convenient form of aeration for the present purpose has been found to be nozles of a simple design arranged as fountain-jets. Of these great aeration fountains, one will be built where the water is drawn from Ashokan reservoir and the other at Kensico reservoir. In each fountain there will be upward Of 2000 jets in symmetrical groups within a basin 500 feet long by 250 feet wide. By using different combinations of these nozle groups, various quantities of water, up to the full capacity of the aqueduct, can be aerated. With appropriate landscape settings, these gigantic fountains will be also a lasting source of enjoyment.

In order further to safeguard and improve the quality of the water, filtration is to be provided, and northwest of White Plains a site has been selected for a great sand-filter plant which will be of about twice the capacity of the largest plant now in existence.

When all the works are completed, the Catskill water-supply will be one of the safest in the world. Its gathering-grounds are topographically and geologically of unusual excellence and are sparsely populated. Wide marginal strips of forest and meadow will protect each impounding reservoir. These great artificial lakes will afford long storage for the gathered waters, giving opportunity for the beneficial action of sun, wind, and sedimentation. By these various means pollution will largely be prevented, and objectionable bacteria, tastes, and odors will be almost wholly removed or destroyed.

Goethe once wrote, "Dem Menschen ist ein Mensch noch immer lieber als ein Engel."3 And so perchance the reader may be possessed of sufficient human interest to inquire by what marshaling of men's brains and brawn these great works are to be wrought. By appointment of Mayor George B. McClellan, under special legislation, John A. Bensel, a civil engineer, Charles N. Chadwick, a business man, and Charles A. Shaw, formerly president of the Hanover Fire Insurance Company, constitute the Board of Water Supply of the City of New York. They were chosen from lists of three names presented respectively by the Chamber of Commerce, the Manufacturers' Association of New York, and the Board of Fire Underwriters. Mr. Bensel is president of the board, and succeeded Mr. J. Edward Simmons, who resigned in January, 1908, and is now president of the Chamber of Commerce.

Two bureaus comprise the board's forces. In the Administration Bureau are the secretary, auditor, chief clerk, and purchasing agent, adjuster of claims, and chief of aqueduct patrolmen, each having a necessary corps of assistants, totaling for the bureau about 125 persons. Consulting Engineer John R. Freeman is the engineer adviser of the commissioners. At the head of the Engineering Bureau is Chief Engineer J. Waldo Smith. On his staff of consultants are Professor William H. Burr, Mr. Frederic P. Stearns, Allen Hazen, George W. Fuller, and a few other engineers and scientists of national and international reputation. Mr. Charles L. Harrison is Deputy Chief Engineer. Because of the geographical extent and the magnitude of the works, the Engineering Bureau has been organized in four departments: the Headquarters Department, with Alfred D. Flinn, Department Engineer, has charge of preparing designs and specifications for the dams, aqueducts, and other structures; executive and civil-service matters, inspection of manufactured materials for construction, and preparation of realestate maps and documents for all the departments, and in addition surveys and construction within the city limits. The Reservoir Department, with Carleton E. Davis at its head, is charged with all surveys and construction on the watersheds. Its chief work at present is the Ashokan reservoir, with its great dams and the headworks of the Catskill aqueduct. From the headworks to the divide of the Croton watershed sixty miles of Catskill aqueduct is under the care of the Northern Aqueduct Department, Robert Ridgway, Department Engineer, to whom falls the Hudson River crossing and the great siphons under the Rondout, Wallkill, and Moodna valleys. The remainder of Catskill aqueduct, with Kensico and Hill View reservoirs and the filters, falls to the Southern Aqueduct Department, with Merritt H. Smith as Department Engineer.

The departments are divided into three or more divisions, which in turn are subdivided into several sections. Including engineers, inspectors, stenographers, clerks, laborers, and other assistants, the Engineering Bureau contains nearly 1000 persons.

For purposes of construction, the work of building the reservoirs and aqueducts has been divided into many contracts, ranging in expenditure involved from a few tens of thousands of dollars to several millions. In the busiest summer, when the majority of these contracts will be simultaneously in progress, the contractors' employees will probably reach a total of 15,000 and the expenditure will approximate $2,000,000 per month. This autumn of 1909 will doubtless see 10,000 men at work, for by October the major contracts for the aqueduct will have been let, excepting part of the line between Kensico and Hill View reservoirs. Hill View reservoir will probably also he under contract; the main dams of the Ashokan reservoir are already in progress. A re-estimate of the cost of the Catskill project made since many of the large contracts were awarded shows that the original estimate of 1905 was sufficient, an unusual and gratifying fact in engineering projects of great magnitude.

Readers distant from New York may ask: "Why go so far for water? Why not take water from the Hudson, a relatively short distance above the city, just as many inland communities do from rivers on which they are situated?" Simply because the Hudson is a tidal estuary as far as Troy, and if sufficient water to supply even half the needs of New York were withdrawn in extremely dry seasons, the river water would be too brackish for domestic consumption as far north as ten or fifteen miles above Poughkeepsie, or eighty miles in air line from the City Hall, New York. It is only six miles farther to the head of the Catskill aqueduct. To be certain of maintaining an adequate fresh water flow, large compensating reservoirs would have to be built on the head,waters of the river in the Adirondack Mountains to store the surplus waters of wet seasons for discharge into the upper tributaries of the river at a suitable rate in dry seasons. Furthermore, much unpurified sewage enters the river above any point at which the city's works could be located. Since the water would be taken at tide-level, it would have to be raised several hundred feet by powerful pumps in order to deliver it in the city under suitable pressure. Hence, to obtain Hudson water, purify it, and convey it to the city, extensive and very costly works would be necessary; and when all was done, the supply would be inferior in quality. It has been said that the nineteenth century discovered dirt -- that is to say, the true nature of filth and its relation to human health. In the light of that discovery, communities are learning to prefer clean water, if such is available. Consequently the Board of Water Supply, with the concurrence of other city authorities and the approval of the State Water Supply Commission, very sensibly concluded that it was more economical and prudent to take some of the Hudson water from some of the lower tributaries in the Catskill Mountains before it became contaminated, and at an elevation from which it could flow by gravity to the city and be delivered at a level 165 feet above that at which the Croton water is delivered.

An abundance of clear, soft, pure, and wholesome water is the most fundamentally essential commodity for any great community. New York City has expended to date for the construction of existing water-works, exclusive of interest and maintenance, about $137,000,000, not taking into account the investments of private water companies, several of which still purvey to portions of some boroughs. Recent projects for additional supplies from the Catskill Mountains and Suffolk County will involve during the next half century the expenditure of about $225,000,000 and will increase the safely available daily supply to two and a half times that now available, and provide bountifully for the city's needs as far in the future as can be reasonably foreseen. And the Croton, Ridgewood, Catskill, and Suffolk County systems will be permanent, even if long continuance of the city's remarkable growth should in the distant future lead to a demand for water in excess of the combined capacities of these sources.

New York's present population is 4,500,000 and her daily consumption of water for all purposes from works owned by the city is, as I have said, 125 gallons per person. At this rate, a year's supply would be a lake twenty miles long, three miles wide, and having an average depth of twenty-five feet. The ordinary summer flow of the Niagara River over the American Falls is now about 8000 million gallons daily, which is only fifteen times the stream consumed in New York. It must be remembered that Yonkers, Mount Vernon, New Rochelle, and even more distant suburbs may be added to the metropolis, or at least to the metropolitan water district, in the not far distant future, making yet greater demands upon the water-works systems built by the city, and many local sources of supply will have to be abandoned because of insufficiency and pollution. With all these vast figures representing demand and expenditure, it is comforting to find by computation that the average cost of all water for domestic, public, and manufacturing uses each day to each person will be less than one cent, including maintenance, interest on capital investment, and sinking fund.

Of the great works for collecting and conveying the Catskill Mountain water, many of the most difficult and interesting parts will be totally hidden from view after completion. Indeed, of the Catskill aqueduct scarcely anything will be visible except the long, neatly graded embankments over the cut-and-cover portions and the occasional buildings housing the gates and other devices for controlling and measuring the water. Most conspicuous will be the great reservoirs, with their huge dams of masonry and earth. Many of these visible structures will be comparatively inaccessible. It is fitting that these conspicuous structures should be made esthetically pleasing, not by elaborate and expensive ornamentation, but by simple and dignified treatment. Here the dominant civil engineer will be aided and guided by the architect and the landscape engineer.

Subterranean river! The mere name has always held a mysterious and romantic fascination. A reversed subterranean river is what the Board of Water Supply is creating. Instead of beginning with tiny streams in dark fissures of the rock or some surface rivulets which sink out of sight, this river will start at its large end from the Ashokan reservoir, an extensive artificial lake, and flow for scores of miles without change of volume, coming to the light only in the beautiful Kensico Lake and Hill View reservoir's huge bowl, whence it will ramify through the hundreds of miles of tunnels and pipes beneath the city streets, issuing finally through faucets and hydrants in thousands of jets to serve those who have bidden it flow thus in constraint. Several years of very active work must, however, elapse before Esopus water will reach the city.




1) By way of explanation, aqueducts, or conduits, beneath valleys are frequently called inverted siphons, or simply siphons, because of their similarity to true siphons turned upside down. Of course there is no siphonic action. <BACK>

2) London dedicated in the spring of 1909 Honor Oak reservoir, a covered masonry reservoir 824 by 587 feet, occupying, with its embankments, fourteen and a quarter acres. Hill View reservoir will be 3000 feet long and 500 feet wide, and will occupy, with its embankments, 163 acres. Ultimately Hill View reservoir will have a concrete, groined-arch roof, supported by pillars of concrete.<BACK>

3) "To mankind men are always dearer than angels." <BACK>


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