APPENDIX B.

IMPROVEMENT OF RIVERS AND HARBORS IN EASTERN MASSACHUSETTS.

REPORT OF LIEUT. COL. S. M. MANSFIELD, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1893, WITH OTHER DOCUMENTS RELATING TO THE WORKS.

UNITED STATES ENGINEER OFFICE, Boston, Mass., July 6, 1893. GENERAL: I have the honor to transmit herewith annual reports for the works of river and harbor improvements in my charge for the fiscal year ending June 30, 1893.

Very respectfully, your obedient servant,

S. M. MANSFIELD, Lieut. Col. of Engineers.

BI,

IMPROVEMENT OF HARBOR AT NEWBURYPORT, MASS.

Newburyport is situated on the south bank, 24 miles, approximately, from the mouth of the Merrimac River. The river empties into the Atlantic Ocean midway between Cape Ann and Portsmouth, or about 30 miles a little east of north from Boston in a direct line.

The outlet of the river between Plum Island and Salisbury Point is 1,000 feet wide and 30 feet deep at mean low water. At a distance of nearly a mile outside lies a sandy bar, thrown up by wave action, through which, previous to the improvement, a channel, variable in position, direction, and depth, was maintained by the current of the river, increased by the tidal prism in a large interior basin, due to a range of tides equaling 73 feet.

For 1,000 feet outward from the gorge towards the crest of the bar the current was able to maintain a channel of navigable width and 18 feet deep at mean low water, and for a further distance of 1,500 feet a channel 12 feet deep. From the 18-foot contour line on the inside to the same on the outside the distance was 4,000 feet, and between the 12-foot contours the distance was 3,000 feet.

The depth on the crest of the bar was generally less than 7 feet at mean low water.

The object of the improvement is to create through the outer bar a channel 1,000 feet wide and at least 17 feet deep at mean low water, so that vessels may cross the bar and find a harbor at any stage of the tide with as great draft as can reach Newburyport by the river at high tide.

The project submitted September 16, 1880, proposed two converging rubblestone jetties, their outer ends parallel for 1,000 feet and about the same distance apart, and the protection of the beach in their vicinity. This was modified in 1882, so as to provide for the partial closing of Plum Island Basin, with a timber dike, about 800 feet long and 5 feet above mean low water.

The direction of the south jetty and the character of the shore protection was modified in 1883. The north jetty, from Salisbury Beach, is to be 4,000 feet long, approximately, and the south jetty, from Plum Island, is to be 2,400 feet, approximately.

Both are 15 feet wide on top, which is in a plane 12 feet above mean low water. The two jetties have slopes of 1 on 2 on the sea side and of 1 on 1 on the harbor side.

A map showing the location of the jetties is published in the Annual Report of the Chief of Engineers for 1885. Their form and dimensions are shown in the report for 1881. The location and details of construction of the dike are given in the report for 1883. The estimated cost of the improvement was $375,000.

The total appropriations to date are $277,500.

The amount expended to June 30, 1892, was $251,023.79.

On June 30, 1892, the condition of the improvement was as follows: The north jetty was completed for a length of 2,485 feet, and partly completed for 190 feet in addition; the south jetty was completed 1,077 feet, and partly completed for an additional length of 223 feet, and its shore end was strengthened by a sand catch; the dike had been completed so far as was prudent for its safety; it is 817 feet long, 5 feet high above mean low water, except that near its center a weir had been left, 150 feet long, its sill 2 feet above mean low water.

On July 18, 1892, it was proposed to expend the available funds in extending the full section of the north jetty. This recommendation was approved July 22, 1892.

On August 5, 1892, an advertisement was issued calling for proposals for the deposit of rubblestone in the north jetty. The bids received were opened September 9, 1892, and an abstract of them will be found in the annexed table.

On September 16, 1892, a contract was entered into with Mr. Geo.