established low-water mark in the Cocheco River at Dover. The mean rise and fall of the tide is between 6.50 and 7 feet. A bench-mark was established at Roberts' brick-yard, being a nail driven into the root of a maple tree, the elevation of which is 26.47 feet above the assumed low-water plane. ADVISABILITY OF IMPROVEMENT. I was unable to ascertain any more reliable or definite statistics as to the present or prospective traffic of the stream than those given in your preliminary report, and my inquiries seemed to show that they were about correct. The principal benefit of the improvement would undoubtedly be the further development of the brick manufacturing industry, clay of the best quality for the purpose being found all the way along the stream. This clay is at present utilized as far up as boats of sufficient size to handle the bricks economically can go. It would therefore be reasonable to presume that any improvement which would give an increased depth of water on the upper part of the river would be followed by the utilization of the clay beds along that portion. The lessening of rates on coal, lumber, stone, and other bulky freight would be an item of considerable importance to this section. Very respectfully, your obedient servant, Maj. JARED A. SMITH, Corps of Engineers, U. S. À. F. S. BURROWES, APPENDIX B. IMPROVEMENT OF RIVERS AND HARBORS IN MASSACHUSETTS. REPORT OF LIEUTENANT-COLONEL GEORGE L. GILLESPIE, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1887, WITH OTHER DOCUMENTS RELATING TO THE WORKS IMPROVEMENTS. 1. Newburyport Harbor, Massachusetts. 4. Harbor of Refuge, Sandy Bay, Cape 5. Gloucester Harbor, Massachusetts. 6. Lynn Harbor, Massachusetts. 7. Boston Harbor, Massachusetts. 8. Malden River, Massachusetts. 9. Hingham Harbor, Massachusetts. 10. Scituate Harbor, Massachusetts. 11. Plymouth Harbor, Massachusetts. 12. Provincetown Harbor, Massachusetts. UNITED STATES ENGINEER OFFICE, Boston, Mass., August 3, 1887. GENERAL: I have the honor to transmit herewith my annual reports upon the works of river and harbor improvement in my charge for the fiscal year ending June 30, 1887. Very respectfully, your obedient servant, G. L. GILLESPIE, Lieut. Col. of Engineers. The CHIEF OF ENGINEERS, U. S. A. B 1. IMPROVEMENT OF HARBOR AT NEWBURYPORT, MASSACHUSETTS. The object of this improvement is to create at the outer bar a permanent channel 1,000 feet wide at its entrance, with a least depth of 17 feet at mean low water, or 24 feet at mean high water, so that vessels of as large draught as can reach Newburyport may enter the river. Previous to the commencement of the work there was on the bar a depth of about 7 feet at mean low water. The project is to build out from the shores north and south of the harbor outlet two converging rubble-stone jetties so located as to give proper direction to the channel, and by scour of the resulting currents to produce and maintain the desired results. The location of these jet ties is shown on the map in the Report of the Chief of Engineers for the year 1885. Their form and dimensions are shown on the map in the report for the year 1831. The channel at the eastern entrance will be 1,000 feet wide, and will be embraced by parallel sections of the two jetties, each 1,000 feet long. The project also contemplates the protec tion of the shores in the vicinity of the jetties, if necessary, and the construction of a dike across the basin of Plum Island to prevent the opening of a new channel should the outer beach be broken through. The location and details of construction of the dike are shown on the map in the Report of the Chief of Engineers for the year 1883. The estimated cost of the project was The amount expended to June 30, 1836, was $375,000,00 207,500.00 166, 757.54 No work was in progress at the close of the fiscal year ending June 30, 1886, and the condition of the works of improvement was as fol lows: 1. The north jetty was 2,675 feet long, of which 1,540 feet were fully completed, and the residue, 1,135 feet, were a core of stone built up to the plane of low water; both in good order. 2. The south jetty was 1,300 feet long, of which 1,077 feet were fully completed, and the residue, 223 feet, were a core of stone built up to the plane of low water; both in good order. 3. The Plum Island Dike was completed; it measured 817 feet long and 5 feet high above mean low water, except near the center, where a weir was left 150 feet long and 2 feet deep at mean low water. 4. Sand-catch in rear of south jetty was ruinous and needed repairs. The balance on hand for further improvements was $3,242.46. On July 15, 1886, sealed proposals for renewing the sand-catch were publicly opened according to law, and the contract was awarded to Thomas C. Rowe, the lowest bidder, for the construction of S60 feet of dike and spurs, at $2.67 per running foot. The work was begun early in August, and satisfactorily completed September 16, 1886, at a cost of $2,296.20. The dike consists of a double row of piles 5 feet high and 5 feet apart, securely united together, the piles in each row being spaced at 5-foot intervals, and the intervening space between rows is filled with brush weighted with stone in the proportion of 500 pounds of stone to the running foot of dike. The spurs have a like profile, and project 10 feet, and are spaced at 10-foot intervals on opposite sides of the dike. Since its completion the sand has piled well up against it, making it firm and solid, and adding throughout its entire length 5 feet to the height of the beach for some distance to the eastward and westward, thereby making the inner end of the jetty secure. The river and harbor act of August 5, 1886, appropriated $37,500 for continuing the improvement. It was decided to apply this sum towards the purchase of 18,000 tons of stone, to be used in extending the north jetty full section, at the entrance of the harbor, to a distance outward of 300 feet. Sealed proposals, after advertisement, were publicly opened, according to law October 12, 1886, and the contract was awarded to Mr. Chas. H. Edwards, the lowest bidder, for 15,000 tons, at $2.23 per ton of 2,000 pounds, delivered in place. Work under this contract was begun November 10, 1886, and is still in progress. At the close of the fiscal year 7,937 tons had been delivered. It is expected that the contract will be completed in October, 1887. This office is indebted to Mr. Hiram F. Mills, hydraulic engineer of the Essex Company, at Lawrence, Mass., for the following data in re gard to the river freshets. The maximum discharge of the river at its mouth, which occurred on April 23, 1852, deduced from the observed discharge at Lawrence, was 105,477 cubic feet of water per second. During a "wet" year, such as 1870, the maximum discharge was, on April 21, 98,000 cubic feet per second. During a "dry" year, such as 1883, the maximum discharge was, on April 14, 36,500 cubic feet per second. The maximum discharge during the freshet of 1887 was, on April 13, 52,000 cubic feet per second; this freshet, though a large one, was ac companied and followed by almost continual easterly storms, and the consequent diminished effect upon the bar is observable on inspection of the thalwegs in general chart of the improvement. A comparative sketch accompanies this report, which shows the varying freshets at the mouth of the river for the years 1870, 1883, 1887. In order to determine the changes which had occurred during the year and the effect of the spring freshet in changing depths in the channel between the jetties and over the bar, a survey of the lower harbor from the gorge between Salisbury Point and Plum Island to the 24-foot curve of the ocean, was made in March, 1887, and another in June, after the abatement of the freshet. A comparison of the March survey with the previous one in 1886 indicates a continued improvement in the width and direction of the channel, although on the bar proper a decrease in depth was found. The frequent and long continued easterly storms during the winter had closed the 9-foot contours across the 12-foot channel of 1886. Four hundred feet outside of the line joining the present eastern ends of the jetties the 12-foot channel was 600 feet wide and the 9-foot channel 900 feet wide. The width of the bar between 12-foot contours was 700 feet, and between the 9-foot contours 200 feet, with a least depth of water of 8.3 feet at mean low stage. Outside of the north jetty the high-water line on the Salisbury beach had advanced seaward 125 feet, and on the outside of the south jetty the high-water line close to the jetty had advanced seaward 200 feet. The Plum Island basin had shoaled 250,000 cubic feet since the survey of 1885, and the beach at its head, separating it from the ocean, was 550 feet wide; an increase since 1885 of 150 feet. An inspection of the June survey shows a better condition of the channel generally than that of March, though the absolute increase of depth is slight, due, it is thought, to the opposing action of the easterly storms which prevailed during the period of the freshet and after its subsidence. The deep-water channel lies on the north side of the entrance, close to the north jetty. The bar has moved slightly seaward; the 12-foot channel, exterior to the jetties, has widened, and the 9-foot channel has deepened 1 foot and broken through the bar with two branches. The bar appears to be in an unstable condition, which encourages the prediction of an early eastward extension of the 12-foot channel across it. The "breakers" north and south of the entrance, which originally moved back and forth across the entrance under the action of prevailing storms, without any describable shape or direction, have, since the construction of the jetties, advanced bodily close up to the entrance and taken a direction parallel with the proposed direction of the parallel outer sections of the jetties, when completed. They have the shape of long and narrow sand-spits, and with their axes behind the jetties, and nearly at right angles with the shore, are visible above low water for a distance, outward from the shore, of 1,900 feet, approximately. The northern breaker is slightly the larger, and not so regular in shape. The bar lies nearly on the line joining their outer ends. The 12, 18, and 24 foot contours of the ocean in front of the bar have not apparently changed in position or direction, and the line of deepest navigable water across the bar still trends to the northeast. The improvement is in a very encouraging state and should be continued at once to completion. An appropriation of $167,500 is recommended for continuing the im provement, and, if made, will be applied towards the simultaneous extension of both jetties to the full projected length. The balance available July 1, 1887, will be expended in completing the existing contract. This work is located in the collection district of Newburyport, Mass., of which Newburyport is the port of entry. The nearest light-house is on Plum Island, at the entrance of the harbor. The accompanying commercial statistics for the fiscal year ending June 30, 1887, have been furnished by the collector of customs for Newburyport, Mass. July 1, 1886, amount available Money statement. Amount appropriated by act approved August 5, 1886.. July 1, 1887, amount expended during fiscal year, exclusive of liabilities outstanding July 1, 1886. July 1, 1887, outstanding liabilities July 1, 1887, amount available $3,242. 46 37,500.00 40,742. 46 $12, 445. 12 10, 673.54 23, 118.66 17, 623.80 167,500.00 (Amount (estimated) required for completion of existing project.... Amount that can be profitably expended in fiscal year ending June 30, 1889 167,500.00 Submitted in compliance with requirements of sections 2 of the river and harbor acts of 1866 and 1867. Abstract of proposals for repair of sand-catch, Plum Island, Newburyport Harbor, Massachusetts, opened July 15, 1886, by Major G. L. Gillespie, Corps of Engineers. Contract was awarded to Mr. Thomas A. Rowe, with the approval of the Chief of Engineers. |