F 8.

MOUTH OF BLACK RIVER, NEW YORK.

An appropriation of $5,000 was made by the act of March 3, 1873, for removing the bar at the mouth of Black River, New York.

No survey having been made of this bar for more than thirty years, the first operation necessary was to learn its character and the causes of its formation. For this purpose, as soon as the spring freshets had subsided, Mr. Wm. P. Judson was ordered to make a survey of the mouth of the river and the bay in the immediate vicinity. The accompanying map, in connection with his report, fully shows the condition of affairs.

History of the work.

In 1836 Congress made an appropriation of $5,000 for the removal of this bar; and in October of that year a survey and examination was made, under the direction of the Chief of Topographical Engineers, by Mr. M. T. Stockton. A plan was submitted for the improvement of the harbor, which was to obtain a channel through the bar by artificially prolonging the banks of the river, by piers, to the deep water of the bay, and, by thus increasing the velocity, to carry off the sand and diluvial matter that formed the bar. The report is one of interest, and fully discusses the subject.

This plan was approved, and operations were carried on under it in 1837 and 1838, during which time 2,719 feet of the north pier and 2,408 feet of the south pier were constructed. In 1839 Lieut. J. E. Johnson, of the Corps of Topographical Engineers, assumed charge of the work, and at the end of that year the north pier had been extended 3,979 feet and the south 2,708 feet. No further appropriations were made until 1842, when Captain Canfield, of the Corps of Topographical Engineers, reported that the piers were useless, and would continue so until completed across the shoal; as far as carried the increase of velocity had been sufficient to scour out the channel, but the expansion at the ends caused the usual deposit.

No further action was taken until 1844, when $3,000 was allotted from the appropriation for harbors on the lakes generally, and 390 feet were added to the south pier.

Colonel Abert, in his annual report for 1844, said "that the work was commenced in the expectation that the current would scour a channel for itself, and that the piers had been extended upward of a mile into the bay, but without any decided good result."

The current, being obstructed by dams, &c., above the mouth of the river, was comparatively lost before reaching the end of the piers, the depth being but 4 feet for some distance beyond the pier-heads. The piers were also reported in bad condition, a large portion of them being under water. In 1845 Colonel Abert, in his annual report, said that the further prosecution of the work was not advisable unless a dredge could be obtained.

No further action has been taken until the present time.

An examination of the map transmitted will show that the Black River debouches into a wide bay before emptying into the deep waters of the lake. It is described in Mr. Stockton's report as follows:

Black River takes its rise in immense swamps in the midst of a country so sterile, that it will be ages before the ax of the settler will be used to expose its sources to

evaporation. For upwards of thirty miles of its course it presents as fine water-power as can be found in the world, with banks and bottom of solid limestone.

It is a succession of rapids, and numerous mills have been erected on its banks. The survey of the mouth of the river develops the fact that this very water-power has been used to the disadvantage of navigation; the bar at the mouth is found to consist in part of large quantities of sawdust and shavings. The mills on the bank for years have been throwing their refuse into the river; these materials being carried along by the current for miles, became thoroughly saturated, until, reaching the mouth of the river, they sank and formed the bar, the expansion of the water causing a corresponding decrease of velocity and the current being no longer able to carry them in suspension.

Careful inspection showed sawdust and shavings all along the bank, and until these deposits are stopped it will not be possible to maintain a channel through the bar without continuous dredging.

In order to maintain the desired depth across the bar, it is proposed to carry out the original plan with some modifications.

The south pier should be prolonged to the eastward 1,500 feet, in order that the body of water now seeking an exit through what is known as the natural or south channel, may be led into the new direction.

Both piers should be prolonged until they reach a depth of 12 feet; the dilapidated portions should be repaired, and a channel 200 feet wide dredged between them.

The lines of the piers as recommended are indicated on the chart, and converge so as to be 300 feet apart at the outer ends.

The action of the sea not being very great here, it is proposed to construct pile-dikes similar to those used on the Hudson River, building them to the height of ordinary high water, and placing crib pier-heads at the outer ends.

The following estimate for removing the bar and keeping the channel open is respectfully submitted:

Prolonging south pier eastward 1,500 feet, at $8.
Prolonging south pier westward 5,300 feet, at $8.

Prolonging north pier westward 4,200 feet, at $8.

Repairing 2,000 feet south pier, at $5.

Repairing 4,000 feet north pier, at $5

Removing 600-feet of north pier, at $5..

Dredging 350,000 cubic yards, at 20 cents.
Two pier-heads, at $1,500 each

Contingencies.

Total......

$12,000

42, 400

33, 600

10,000

20,000

3,000

70,000

3,000

This estimate is large, but the figures are based on the cost of work of a similar character, and it is presented under the supposition that it is desired to remove this bar and keep the channel open for vessels now navigating Lake Ontario.

In June, 1873, proposals were invited for dredging through the bar to afford temporary relief, the act of Congress making the appropriation having especially designated it for "the removal of the bar at the mouth of Black River, New York." At the opening of bids in July, the work was awarded to Mr. C. Daly, of Ogdensburgh, at 35 cents per cubic yard, measured in scows.

During the present season it is intended to remove by dredging 11,500 cubic yards of materials, and it is hoped to thus secure a channel 20 feet wide and 6 feet deep. at low water. This relief will, however, be only temporary, and it is anticipated that the freshet in the spring