F 10. IMPROVEMENT OF BROADKILN RIVER, DELAWARE. In the last Annual Report a full exhibit was made of the condition and circumstances of the Broadkiln improvement, and recommendation was made that the application of the available balance of the appropriation be deferred until further action of Congress. Such action not having yet been taken, the matter remains as last reported, no reasons having presented themselves for altering the recommendations then submitted and approved. This work is in the collection district of Delaware, Wilmington being the nearest port of entry, the revenue collected there during the past fiscal year amounting to $50,530. The nearest fort and light-house are, respectively, Fort Delaware and Delaware Breakwater light. Total amount appropriated to June 30, 1882. $20,000 00 11,022 42 Money statement. July 1, 1881, amount available.. July 1, 1882, amount available.... Amount appropriated by act passed August 2, 1882.... Amount available for fiscal year ending June 30, 1883.. Amount (estimated) required for completion of existing project...... F II. IMPROVEMENT OF MISPILLION CREEK, DELAWARE. $8,977 58 8,977 58 5,000 60 13,977 58 36,500 00 16,000 00 The improvement of this stream was begun in 1879, with an appropriation of $3,000, and continued with the further appropriation of $4,000 in 1880. The general plan was to remove the shoals in succession downward from the head of navigation to a depth of 6 feet at lowwater, and a width of 40 to 50 feet. The details of operations are given in the Annual Reports of the Chief of Engineers for 1880 and 1881. During the past year, with the appropriation of $3,500 in the act of March 3, 1881, the work has been continued in accordance with the project. Contract was made and the work begun May 26, 1882, and continued until July 1, 1882. During this time a channel of the prescribed width and depth was made through the "Mushpot Shoal," a distance of 950 yards, requiring the removal of 5,550 cubic yards of mud which were deposited upon the bank. A similar channel was made through the "Fork Shoal," and an additional 793 yards removed, making a total of 6,343 cubic yards. In addition to appropriating for the improvement, the act of March 3, 1881, provided for a survey of the mouth of the stream, report of which has already been submitted, and will be found elsewhere, herewith. In the case of the Mispillion, as in that of most of the minor streams in Delaware tributary to the bay, the entrance is shallow, and its deepening both the most costly and important part of any valuable improve ment. The work already done in the stream itself has had, however, a cer tain beneficial effect in relieving the vessel-builders from the annoyance and expense of the delays heretofore encountered in getting their vessels down to the bay. These delays, in frequent cases, absorbed the profits of the builders, and seriously limited the dimensions of the vessels for which contracts could be made. Ship-building at Milford has during the last two years shown a considerable increase, and several vessels of from 400 to 1,000 tons were built during the last year. Three more are constructing, and several others are under contract. The business of the stream is reported to have increased about 25 per cent. For the completion of the present project of a 6-foot low-water navigation to the mouth, there will be required the sum of $6,500. It will always remain, however, to open the mouth of the stream to such extent, at least, as will admit of the entrance and exit of loaded vessels near the period of high-water. In this connection attention is invited to the accompanying report of the survey of February 20, 1882. To secure an available entrance depth of 4 feet at mean low-water would cost about $55,000, or for a 3-foot low water entrance, which with the rise of the tide would admit vessels drawing 7 feet, about $49,000. Mispillion Creek is in the collection district of Delaware, Wilmington being its nearest port of entry, the revenue collected there during the past fiscal year amounting to $50,530. Mispillion Creek light is the nearest light-house, and Fort Delaware the nearest fort. Total amount appropriated to June 30, 1882. $10,000 00 9,945 68 Money statement. July 1, 1881, amount available.. July 1, 1882, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1881.. July 1, 1882, outstanding liabilities.. July 1, 1882, amount available... Amonnt appropriated by act passed August 2, 1882. Amount available for fiscal year ending June 30, 1883 Amount (estimated) required for completion of existing project.. $3,451 72 $1,864 97 3,397 40 54 32 3,000 00 3,054 32 3,500 00 Amount that can be profitably expended in fiscal year ending June 30, 1884. 3,500 00 Abstract of contract entered into during fiscal year ending June 30, 1882, for improvement of Mispillion Creek, Delaware. EXAMINATION OF MOUTH OF MISPILLION CREEK, DELAWARE. UNITED STATES ENGINEER OFFICE, SIR: The following report on the examination of the mouth of Mispillion Creek, Delaware, is submitted, in compliance with the requirements of the river and harbor act of March 3, 1881. With a navigable length of about 18 miles, and discharging into the Delaware Bay about the same distance north-northwest from Cape Hen lopen, Mispillion is one of the more important of the Delaware streams, by reason of its considerable ship-building industries and the high repute of its native white-oak timber. The original examination of this stream was made in 1878, and the report printed in Annual Report Chief of Engineers, 1879, pp. 467–470. The improvement of the navigation, in progress since 1879, in accord ance with a project of that date, under small annual appropriations, aggregating $10,500, has been confined to the removal of shoals in the creek, beginning at Milford, the head of navigation and the site of numerous saw-mills and ship-yards, where vessels of over 1,000 tons are built. The details of operations are given in Annual Reports Chief of Engineers, for 1880, pp. 587-589, and for 1881, pp. 785 and 786. As is the case with nearly all the streams tributary to Delaware Bay, the most serious obstruction to navigation is found at the entrance, the chart of which, from a survey of last season, is forwarded herewith. It will be seen that the low-water contours of 2, 4, and 6 feet in the bay lie approximately parallel to the shore, at distances, respectively, of about 3,000, 4,000, and 5,000 feet, without any indication of a channel across the intervening shoals. The trend of the shore line is about north by east. All winds from the northward and eastward, therefore, tend to supplement the action of the ebb-tide of the bay in the gradual transfer of sand and mud southward along the shore. Under these circumstances, the effluent current from the creek is deflected, and by the loss of power from constant choking is able to maintain an entrance depth of from 1 to 13 feet only at low water, by following the shore half a mile southward. The short line of pile dike, shown on the chart above the entrance, is the evidence of an ineffectual attempt by the local authorities, some twenty years ago, to guard against further encroachments due to the littoral movement of sand. The design was correct in theory, but the dike, both in development and construction, was manifestly inadequate to modify the action of the forces in operation. For the maintenance of a channel entrance of any desired depth, it is necessary not only to prevent the intrusion of sand at the mouth, but the transporting and distributing action of the waves and tidal currents of the bay as well. For these purposes, after determining the line, a jetty should be built. starting from the north side of the entrance, with a reliable shore connection, and extending out into the bay to at least the depth desired. Along this jetty the channel may be dredged to such depth and width as shall make it available for the vessels which are to use it. The low-water navigation in the Mispillion is about 6 feet, and under ordinary circumstances it would be desirable to continue this depth into the bay, but the rise of tide in the bay is about 4 feet, while at Milford the rise does not exceed 23 feet. The entrance depth, therefore, might be reduced to 4 feet at low-water without serious disadvantage and with a large saving in the cost of the necessary works. The distance from the shore to the 4-foot low-water contour in the bay is about 4,000 feet, and a jetty of this length will be required. Its posi tion and plan are shown on the tracing. The jetty should be built to about high-water, with its shore end suitably secured by riprap or loaded brush. The inner 2,500 feet of length may be straight, the outer 1,500 slightly curved southwardly. The jetty should terminate in a substantial cluster of piles, bound together, rising well out of the water, and supporting a rough structure of some description to mark the entrance. The construction of the channel should follow up that of the jetty, beginning inside the mouth of the creek. The material from the first cut of the dredge may be thrown over the jetty; that of the remaining cuts should be towed away to a suitable dumping-ground, light-draught scows being used. The amount of dredging necessary to make a channel 4 feet deep and 150 feet wide is about 80,000 cubic yards; but the current from the creek would aid the dredging operations so soon as the cuts had been made through the beach beyond low-water mark. Some temporary obstruction in the present creek bed, below the new channel, might be found desirable to direct the flow at the outset. The cost of the various works above mentioned would be about as follows: For a 3-foot channel the jetty would be shortened about 500 feet, with a considerable reduction also in the amount of dredging. The estimate is as follows: The work in either case could be advantageously completed in one season, with suitable time for preparation, but might be divided between two seasons without serious increase of expense. The commercial statistics given on the accompanying schedule are from the Annual Report Chief of Engineers, 1880, pp. 588 and 589. Respectfully submitted. The CHIEF OF ENGINEERS, U. S. A. WILLIAM LUDLOW, Captain of Engineers, COMMERCIAL STATISTICS OF MISPILLION CREEK, DELAWARE. Milford, about 18 miles by the windings of the creek from its mouth, has about 3,000 inhabitants, whose most important business interests are shipbuilding and the lumber trade. Vessels built there are of a superior stanchness. At present there are on the stocks, building, one vessel of 1,100 tons, one of 850 tons, and several of lesser tonnage. The shipping consists of five schooners of from 50 to 75 tons, running regularly between Milford and Philadelphia, and about an equal number of transient vessels, making each eight or ten trips a year. Milford is also the center of a large wheat and fruit growing district. The imports are about 1,000 tons fertilizer and 2,000 tons coal, with merchandise to the value of $100,000. Mispillion Creek is in the collection district of Delaware, Wilmington being the nearest port of entry. F 12. IMPROVEMENT OF DUCK CREEK, DELAWARE. The entrance to this stream has been under improvement for the last two years, with successive appropriations of $5,000 in 1880, and $3,000 of March 3, 1881. As stated in the last annual report, the work was put under contract in July, 1881, and completed early in August. The channel made had a length of about 600 yards, width of 75 feet, and a low-water depth of 8 feet. A further sum of $4,500 will be required to complete the construction of the channel to the full width of 100 feet, as originally projected. In the great number of cases, a channel through shoals obstructing the entrance to a stream will need for its maintenance the protection of a dike or jetty to concentrate and direct the currents and prevent a dredged channel from filling. The material composing the shoals at the mouth of Duck Creek is in part a stiff clay, capable of resisting the action of a moderate current. It seems advisable, therefore, before estimating for permanent constructions, to complete the excavation of the channel through the shoals, and observe the subsequent current and tidal action. For this purpose an appropriation of $4,500 will be needed. This creek is in the collection district of Delaware, Wilmington, being its nearest port of entry, the revenue collected there during the past fiscal year amounting to $50,530. There is a light-house at its entrance, the nearest fort being Fort Delaware. $8,000 8,000 Money statement. July 1, 1881, amount available Amount appropriated by act passed August 2, 1882. July 1, 1882, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1881 Amount (estimated) required for completion of existing project Amount that can be profitably expended in fiscal year ending June 30, 1884.. 14,000 00 14,000 00 Abstract of contract entered into during fiscal year ending June 30, 1882, for improvement of Duck Creek, Delaware. |