[First indorsement.]

OFFICE CHIEF OF ENGINEERS,

Respectfully submitted to the Secretary of War.

U. S. ARMY,

January 25, 1892.

The subject of the establishment of harbor lines in the harbor at Five-Mile River, Connecticut, having been brought to the attention of the Secretary of War, the matter was referred to Col. D. C. Houston, Corps of Engineers, the officer in charge of the district in which this locality is situated, for report.

Col. Houston submits report dated January 22, 1892, and recommends for the approval of the Secretary of War the harbor and dock lines mentioned in the within report and delineated upon the accompanying chart.

It is recommended that the lines selected be approved, and that the secretary place his approval both upon the report and the tracing submitted.

Approved.

THOS. LINCOLN CASEY, Brig. Gen., Chief of Engineers.

[Second indorsement.]

WAR DEPARTMENT, January 26, 1892.

L. A. GRANT, Acting Secretary of War.

APPENDIX E.

IMPROVEMENT OF HUDSON RIVER; OF HARBORS AT SAUGERTIES AND RONDOUT, AND WAPPINGER CREEK; OF NEW YORK HARBOR AND RIVERS AND HARBORS IN ITS VICINITY, NEW YORK; AND OF RARITAN BAY, NEW JERSEY.

REPORT OF LIEUTENANT-COLONEL G. L. GILLESPIE, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1892, WITH OTHER DOCUMENTS RELATING TO THE WORKS.

1. Hudson River, New York.

IMPROVEMENTS.

2. Harbor at Saugerties, New York.
3. Harbor at Rondout, New York.
4. Wappinger Creek, New York.
5. Harlem River, New York.

6. East River and Hell Gate, New York.
7. Newtown Creek, New York.

8. Buttermilk Channel, New York Harbor.

9. Gowanus Bay, New York.

10. New York Harbor, New York.
11. Raritan Bay, New Jersey.

12. Removing sunken vessels or craft ob-
structing or endangering navigation.

EXAMINATION AND SURVEY.

13. For canal from main channel from Jamaica Bay easterly to Long Beach Inlet, New York.

HARBOR LINES.

14. Establishment of harbor lines in New York Harbor and its adjacent waters.

ENGINEER OFFICE, U. S. ARMY,
New York, N. Y., July 9, 1892.

GENERAL: I have the honor to transmit herewith annual reports for the fiscal year ending June 30, 1892, upon the works of river and harbor improvement under my charge.

Very respectfully, your obedient servant,

Brig. Gen. THOMAS L. CASEY,

Chief of Engineers, U. §. A.

G. L. GILLESPIE, Lieut. Col. of Engineers.

E 1.

IMPROVEMENT OF HUDSON RIVER, NEW YORK.

The Annual Report of the Chief of Engineers for 1885, Part I, page 677, contains a history of this improvement accompanied by original reports and two sketches showing its condition at that time.

The only part of the Hudson River which has been improved by the General Government is a stretch, about 20 miles long, beginning at the head of navigation at Troy, N. Y., about 6 miles above Albany, and extending down the river to New Baltimore, about 14 miles below Albany.

While there has always been enough water below New Baltimore for navigation, this upper section of the river, so far as its history is known to us, has always been obstructed by bars and shoals, due to the existence of numerous islands and sloughs and the consequent diversion of the river's waters through too many channels.

Prior to 1831, when the jurisdiction of the Federal Government over these waters was confirmed by judicial decision, the State of New York had made efforts to improve the navigation of this part of the river.

Since 1831 the improvement of the Hudson River has been conducted both by the State of New York and by the General Government, both building and repairing dikes and doing such dredging as seemed necessary. In the last few years, however, the dike work has been left almost exclusively to the General Government, and the dredging to the State of New York.

The general system of improvement has been the same throughoutthe contraction of the channels by the construction of jetties and dikes intended to deepen them by means of the scour so produced, and also the lowering of the bed by dredging where such work was indispensable.

But up to 1831 the work, which had consisted almost entirely of the construction of spur dikes and dredging, had produced very little permanent improvement.

After 1831, however, the United States began the present general system of improvement, which consists of contracting the channel by means of longitudinal dikes intended to aid in scouring the bars and shoals, instead of which spur jetties had formerly been used.

Under this system the United States constructed two dikes in 1835, 1836, 1837, and 1838.

Then followed a long interval of time in which nothing was done by the United States except in 1852; but in 1863 the State of New York took up the improvement on the general plan adopted by the United States in 1831, viz, substituting a system of longitudinal dikes instead of the jetty system, and between 1863 and 1867 built six important longitudinal dikes of this kind. (Annual Report of 1885, page 678.)

The work was again taken up by the United States in 1864, when, out of the general sum appropriated for river and harbor improvements, $33,000 was allotted for the Hudson River improvement, and this was followed by the act of June 23, 1866, which appropriated $50,000 for the same work.

The plans under which the present works of improvement of the river are conducted were adopted in 1866, and provide for securing a navigable channel 11 feet deep at mean low water from New Baltimore up to Albany, and 9 feet deep at mean low water from Albany up to Troy.

The range of tides, determined in 1876, is 2 feet at Troy, 2.32 feet at Albany, and 3.43 feet at New Baltimore.

The following is a description of the plan:

First. A system of longitudinal dikes to confine the current sufficiently to allow the ebb and flow of the tidal current to keep the channel clear. These dikes to be gradually brought nearer together from New Baltimore towards Troy, so as to assist the entrance of the flood current and increase its height, their height to be kept approximately at the level of the tidal high water, so as not to confine the freshets; the exact level, however, being left to be determined by experience as the work progresses.

Second. That the dredge be used so far as necessary to open the channels above described, which the current should not be allowed to do, except very gradually, lest accumulations dangerous to navigation be formed below.

Third. Keeping, as far as practicable, the side reservoirs open to the passage of tidal currents by gaps at their lower extremities, in order to increase the tidal flow.

Fourth. Dumping all dredged material in secure places, where it can not be moved back again into the channel by the current.

Fifth. Constructing the dikes of timber and stone, in a manner to secure their permanency, at a minimum cost, the details varying with the locality, to be left to the discretion of the local engineer, to be so designed as to admit of having an increased height given to the dikes if necessary.

Sixth. To protect, when necessary, the banks and islands against the abrading action of the currents by revetments.

Seventh. That limits, beyond which no encroachments upon the channel should be made, be prescribed, and that any such encroachments be reported to the engineer in charge.

The latest revised estimate of cost of this improvement is $1,424,435. From the nature of the materials which enter into the construction of the dikes and from the limited sums which are applied annually to renew the parts which become unserviceable, whether by natural decay or otherwise, it can be well understood that the estimates prepared from time to time for the completion of the project must be accepted as approximately accurate for only a short period of time. This statement is necessary for a correct understanding of the apparent discrepancy between the estimated cost of the project and the sums which have been appropriated for its execution.

The State of New York makes an appropriation at every session of its legislature for the improvement of the Hudson River, and prior to 1867 the money was applied to the construction of dikes on the left bank of the river from Houghtailing Island to Albany, to jetties, dams, and to temporary measures of relief, and also to dredging at the points where shoals were discovered after spring freshets. In the last few years, however, the dike work has been left almost exclusively to the General Government and the dredging to the State.

The growth of obstructive bars in the river was found to be so great after the spring freshets had subsided in 1891 as to require dredging to give immediate relief. During the spring and summer of that year, 55,148 cubic yards of material were removed in that way from different bars in the channel, extending from Mulls Cross-Over to the United States Arsenal at West Troy, and it is expected that a certain part of every future appropriation will be applied in like manner whenever the free navigation of the river becomes obstructed by like causes.

Sections 6 and 7 of the river and harbor act of September 19, 1890, make it unlawful to dump into the navigable waters of the United States any materials which shall tend to impede or obstruct navigation, or to excavate or fill or in any manner to alter or modify the course, location, condition, or capacity of the channel of said navigable waters, unless approved and authorized by the Secretary of War. These are wise provisions for the protection of the navigable waters of the United States, and it is hoped that a considerate enforcement of the law will serve hereafter to protect the channel of the river by maintaining its regimen, and at the same time to allow material to be taken freely from the river for private and public uses.

The average rainfall covering the past sixty-three years, from observations recorded in the report of the water commissioner of Troy, N. Y., for 1889, is 36.55 inches. The greatest rainfall in any year was recorded in 1878, when 49.23 inches fell; the least rainfall in any year occurred in 1839, when 18.32 inches fell. The greatest known rainfall in any one month occurred in October, 1869, when 13.8 inches fell; the least known rainfall in any one month was in May, 1840, when only 0.2 of an inch fell.

At times during the dry season of most every year, for a month at least, no water flows over the State Dam at Troy, and excepting what comes in through the lockage of the canals there is, during that period, little apparent fresh-water supply to the flow of the river. From this and the fact that the tide rises and falls at the State Dam, it is evident that the navigation of the Hudson River at the low stage is dependent in a large degree upon the tidal prism of the river. The mean rise and fall of tides

The mean duration of rise of tide at Albany is 5 hours 0 minutes, and the mean duration of fall, 7 hours 25 minutes.

The plane of mean low water at New York is below that—

The plane of mean high water at New York is below that

The heights of the greatest known freshets above the plane of mean low water at Albany are as follows:

That of February 9, 1857, due to an ice gorge at Van Wies Point, was 22.19 feet.

That of October, 1869, due to the great rainfall in that month, which reached 13.8 inches, was 19.04 feet.

That of February, 1886, due to an ice gorge, was 17.89 feet.

Generally speaking, the effects of rainstorms are shown by a rise in the river within twenty-four hours. The winds also materially affect