H 21. [Printed in House Ex. Doc. No. 57, Fifty-second Congress, first session.] PRELIMINARY EXAMINATION OF MISPILLION RIVER, DELAWARE, WITH A VIEW OF CUTTING A CANAL SO AS TO SHORTEN THE DISTANCE TO THE BAY, AND MAKING AN OUTLET IN THE BAY WHICH WOULD FURNISH DEEPER WATER. UNITED STATES ENGINEER OFFICE, Wilmington, Del., November 3, 1890. GENERAL: In accordance with the instructions contained in Department letter of September 20, 1890, and the requirements of the river and harbor act of September 19, 1890, I have the honor to submit the following report upon the preliminary examination of Mispillion River, Delaware, with a view of cutting a canal so as to shorten the distance to the bay, and making an outlet in the bay which would furnish deeper water. The tonnage on the river and the shipbuilding interests would seem to require protection; and for the reasons and facts given in the report of the assistant engineer, a copy of which is herewith inclosed, the entrance to Mispillion River, to provide for a navigable channel across the bar which can be used at all stages of the tide is, in my opinion, worthy. of improvement, and a survey is recommended." The least amount required to make the survey and report, with project and estimate of cost of improvement, is $600. Very respectfully, your obedient servant, Brig. Gen. THOMAS L. CASEY, Chief of Engineers, U. S. A. WM. F. SMITH, (Through Col. William P. Craighill, Corps of Engineers, Division Engineer, Southeast Division.) [First indorsement.] U. S. ENGINEER OFFICE, Baltimore, Md., November 20, 1890. Respectfully submitted to the Chief of Engineers. In view of the facts and reasons stated by the local engineer, I agree with him that this river is worthy of improvement by the United States. WM. P. CRAIGHILL, Colonel, Corps of Engineers. REPORT OF MR. A. STIERLE, ASSISTANT ENGINEER. UNITED STATES ENGINEER Office, Wilmington, Del., November 3, 1890. SIR: In accordance with your instructions I have the honor to submit the following report upon the preliminary examination of Mispillion River, Delaware, with a view of cutting a canal so as to shorten the distance to the bay, and making an outlet in the bay which would furnish deeper water: Mispillion River forms part of the boundary between Kent and Sussex counties, Delaware. It is a narrow and rather tortuous stream, about 18 miles long, and flows into the Delaware Bay about 17 miles north of Cape Henlopen. The river (as Mispillion Creek) has been under improvement by the General Government since 1879, the project being for a channel 6 feet deep at low water and 40 feet wide from the town of Milford, the head of navigation, to the mouth. With the exception of a small shoal near the mouth, which requires removal to the projected depth, the project has been completed. The amount expended to date is $17,000. The improvement within the river has been of great benefit to navigation, as all vessels are now enabled to sail without a delay from one end to the other. Nine shoals formerly existed at various points, which during low tides often caused serious and expensive detentions. The remaining serious obstruction to an open and free navigation in Mispillion River at all stages of the tide is the shallow bar at the mouth. This bar is a physical feature common to all the tributaries of the Delaware Bay, and its existence is due more to the presence of a flat and extensive foreshore projecting far out into the bay, upon which the currents of these streams can make no impression, and to the shifting littoral drift of material carried along the shore during storms than to the deposits of material brought down the rivers. The main channel of the bay is in many cases several miles distant from the shore. The currents along the shore, and especially in the deeper and concave portions, are weak and variable, without a decided set in any one direction; the power of the currents of the tributaries in meeting this neutral region is, therefore, spent and lost, the outlet of these streams assuming a southerly or a northerly direction, depending entirely upon local causes or the prevailing winds and seas. The difficulty and great expense involved in making a practicable outlet for any of these rivers in Delaware has long been recognized by the Engineer Department. In all cases projects for the improvement of the channel within the streams were made first and the improvement of the mouths was left to a future urgency, though in some cases suggestions were made for a betterment of the present natural conditions. Nearly all the rivers in Delaware of any available size have been under improvement by the General Government during the last fifteen years. The channels therein have now arrived at such a state of completion that the demand for an improved entrance to all of them has become very urgent. It is claimed that an unimproved mouth prevents, in a large measure, the acquisition of a full benefit derived from an improved channel inside the river, and that the utility of the latter is crippled or "bottled up," as it were, so long as these obstructions remain. At - two of the rivers coming under this class, at the Christiana and at the St. Jones, the entrance has been improved, and both are now accessible at all stages of the tide. In the case of the latter-named stream this improvement is especially noteworthy, since previously no channel existed at the mouth and vessels could enter and depart only at high water. The demand for an improved outlet for Mispillion River would seem to have special merits. Outside of the claims of extensive local shipping interests, which largely exceed those of any other river of the same size, there exists at Milford an industry in shipbuilding which deserves recognition. The shipyards at that place are the largest of any on the peninsula south of Wilmington. The vessels built here, all of wood, rate very high with the insurance companies on account of their superiority in material and workmanship. On an average about twelve vessels are built here every year. There were four on the stocks in process of building on the day of my visit-two barges of 350 tons each, one schooner of 400 tons, and one of 750 tons registered burden when finished. The hull of this last vessel is 153 feet long on the keel, 187 feet over all, and has 37 feet beam. Her draft of water will be 15 feet when loaded. It seems almost a matter of impossibility to float such a large hull down and out of a river which has an improved channel only 40 feet in width and many abrupt turns. The shipbuilders state that they have refused many offers to build still larger vessels on account of the difficulty of getting them out of the river and into the channel of Delaware Bay. The delay at the mouth, and expenses contingent thereto often cause a loss of the largest portion of the profits made in building. For similar reasons the shipyards at Milford are cut off from the business of repairing any of the numerous vessels trading up and down Delaware Bay and in 1 adjacent waters, as the risks at the mouth are too great, the branch of repairing and overhauling vessels, it is said, being the most profitable one of the business. There are seventeen sailing vessels owned by parties living on the Mispillion River, of a total of 1,600 tons burden; the smallest, of 40 tons, has a draft of water of 4 feet; the largest, a 200-ton schooner, draws 7 feet of water. Ten of these vessels trade regularly between points on the river and Philadelphia, and the remaining seven sail regularly to and from New York. Quite a number of transient vessels carry freight in and out of the river. The shipments and receipts by water, consisting princi pally of lumber, railroad ties, cord wood, grain, canned goods, lime, fertilizers, coal, iron, and general merchandise, amounted during the past year to 44,315 tons, valued at $916,250. All these vessels are subject to long delays at the mouth of the river, where the depth of water over the bar is only 14 feet at mean low tide. If the winds are unfavorable and the tides low, the depth at high water is often insufficient to float them across when fully loaded, and lighters have to be resorted to. The difficulties are more complicated when a vessel arrives at the bar and can not enter the river. She is often compelled to wait for days and weeks for a fair tide, and during that time is exposed to all gales from the north to south by east. A schooner drawing 5 feet 7 inches of water was once detained for twenty-two days at the bar by head winds and low tides. Vessel property is in consequence much depreciated and not as profitable an investment as it would be were the mouth of the river improved. A special survey of the mouth of Mispillion Creek was made during the summer of 1881, under the direction of Capt. W. Ludlow, Corps of Engineers, in compliance with the river and harbor act of March 3, 1881. A project was subsequently submitted for a 4-foot and for a 3-foot low-water channel across the bar, with a single jetty along the northern edge of the proposed channel, at an estimated cost of $55,000 and $49,000, respectively. Although this plan was greatly urged during the following years, it seems that no further action was taken. It has been recently suggested by persons interested in the navigation of Mispillion River to abandon the lower mile of the river, which has a due southerly course, and to make a new cut across the marsh in a southeasterly direction. Such a cut would shorten the distance several hundred feet and would enable vessels bound up Delaware Bay to depart freely if the wind should be from the south. There would appear to be some advantage in carrying out these suggested points, but it seems to me that the main obstacle to be dealt with is the flat and shoal bar, which for nearly a mile obstructs the entrance to the river. What improvements are proper and suitable to give Mispillion River a permanent outlet with a channel navigable at all stages of the tide can not be stated until a new survey has been made. This survey should include the hydrography from the 6-foot curve in the bay to the shore for 2 miles above and below the mouth of the river and that of the river for about 1 mile above the light-house. It is estimated that the survey and charts with estimates can be made for $600. Very respectfully, your obedient servant, Gen. W. F. SMITH, United States Agent. A. STIERLE, Assistant Engineer. SURVEY OF MISPILLION RIVER, DELAWARE, WITH A VIEW OF CUTTING A CANAL SO AS TO SHORTEN THE DISTANCE TO THE BAY, AND MAKING AN OUTLET IN THE BAY WHICH WOULD FURNISH DEEPER WATER. UNITED STATES ENGINEER OFFICE, Wilmington, Del., November 5, 1891. GENERAL: In compliance with instructions contained in Department letter dated November 22, 1890, I have the honor to submit the following report upon the survey of Mispillion River, Delaware, with a view of cutting a canal so as to shorten the distance to the bay, and making an outlet in the bay which would furnish deeper water, made under my direction in accordance with the requirements of the river and harbor act of September 19, 1890. A copy of the report of Mr. A. Stierle, assistant engineer, accompa nies this, and a tracing of the map of the survey is forwarded by mail to-day in a separate package. Not printed. The commerce of the river does not, in my opinion, justify the outlay of $65,000, the estimate for the third project of the assistant's report, in an improvement which would be constantly needing expenditures to keep it in condition. I would recommend the cut as laid down on the map, marked CC, because in that position the light-house would serve as a guide to the entrance both for night and day. With the character of the substratum on the shoal, a stiff blue clay, the dredging of a cut giving sufficient material to form a wall of the mud on the upper or northern side of the cut and above the highest tides will probably last for some years and at the end of that time require but a small amount of dredging to keep the necessary width and depth to the channel. For dredging such a cut the estimate would be 120,000 cubic yards of material at 20 cents per cubic yard, $24,000. Very respectfully, your obedient servant, Brig. Gen. THOMAS L. CASEY, Chief of Engineers, U. S. A. WM. F. SMITH, (Through Col. William P. Craighill, Corps of Engineers, Division Engineer, Southeast Division.) [First indorsement.] U. S. ENGINEER OFFICE, Baltimore, Md., November 6, 1891. Respectfully submitted to the Chief of Engineers. The project of the local engineer, as explained in his letter of November 5 and estimated to cost $24,000, is recommended. WM. P. CRAIGHILL, Colonel, Corps of Engineers. REPORT OF MR. A. STIERLE, ASSISTANT ENGINEER. UNITED STATES ENGINEER OFFICE, SIR: I have the honor to submit herewith a report upon the survey of the month of Mispillion River, Delaware, and projects "for cutting a canal so as to shorten the distance to the bay and making an outlet in the bay which would furnish deeper water." The survey was made during the latter part of August last and extended about one-half of a mile north and 1 mile south of the mouth of the river along the Delaware Bay shore, and for about 14 miles up the river. Soundings were taken within the river and for a distance of 14 miles from the shore. A tide gauze was set up at the light-house landing and referred to a permanent bench mark established at the light-house. Observations of the tide were made for a period of sixteen days. The average rise and fall for that time was found to be 4.02 feet and as the weather was generally fair there were no extraordinary high or low tides to be noted. According to the wording of the bill the order for the survey is explicit in stating that the object sought is to shorten the distance to the bay and to make an outlet in the bay giving deeper water. It is not quite clear to me where and how the distance to the hay could be shortened and why this should be done; the necessity for a better outlet in the bay, however, is perfe tly apparent. With regard to the first point it was ascertained that for many years two projects for a cut or a canal towards the bay shore have been discussed by the local savants which were to meet this requirement in a more or less degree. Some proposed a cut from Flat Reach, which is about 14 miles above the mouth of the river, across the marsh in an east-southeast direction with an outlet at a point in the bay shore called "Green Point." It is claimed that an outlet at that point would be less threatened with a closure from the drift sand moving along the shore, and that the shoals located immediately inside the present month of the river would be avoided. It is true that such a cut would shorten the distance to the bay about 3,000 feet, but the portion of the river to be sacrificed is in as fair a condition as any other parts of the river, and can be improved with a small expenditure of money. This cut is generally called the "Green Point" project and is marked A A on the accommpanying map. It will be observed that in addition this project, to be of any use, requires a channel or outlet into the bay. The second plan of improvement discussed is a proposition to make a cut in a northeasterly direction, towards Clarks Point, from a turn in the river 3 miles above the mouth, called Sisters Reach, with an outlet in the beach 2 miles below that point. This cut would be about 3 miles long. Its principal advantage, according to its advocates, would be the location of the entrance in deeper water which here approaches the shore quite closely and is comparatively free from a shallow fore shore. The outlet, however, would nevertheless need protection by jetties. This cut is marked B B on the accompanying sketch of location and is known as the "Clarks Point project." As will be seen by the estimates given below, both of these projects are pretty costly and the expense of making either of them, to the full width and depth the capacity of the upper river requires, is not commensurate with the advantages gained. It is generally supposed that these cuts could be made of very limited width. This is a serious mistake; for the cross section of a tidal river near the mouth is a measure of its capacity above, and the more the currents are obstructed at the mouth during a tidal epoch the more rapid will be the deterioration of the upper river. The most economical and expeditions plan to accomplish the needed improvements referred to in the bill would be to utilize the present outlet of the river and to make a cut in a due southeasterly direction across the flats to the 6-foot depth beyond the bar. Six feet at mean low water is thought a sufficient depth for the present demands of navigation. The area of a normal cross section in the river not far above the month is at low water a thousand square feet. The cross-sectional area of any cut across the bar can not be less than that. With a depth of 6 feet throughout, the width required at the base of the cut is, therefore, 150 feet. The length of the proposed cut, which is marked CC on the map, is about 5,509 feet. The shoals within the mouth of the river are also to be dredged to the same depth, in comformity with the project of improvement already adopted for the river proper; they are not included in the estimate given below. It is necessary to protect the proposed cut on both sides, to concentrate the effluent currents and to prevent it being filled up again by drift sand. Especially is the protection needed on the north side, from which direction the movement of sand along the shore predominates, as shown by the long sandy point north of the mouth of the river, which is steadily growing southward, forcing the channel against and down the shore. The extent and the cost of such protective works will in any event be so great that it is imperative to construct them as simple as possible without at the same time endangering their permanency. The plan herewith submitted proposes, as jetties, two embankments, consisting internally of dredged material, forming the core, covered with brush fascines or mattresses 1 foot thick which are weighted down with large-size rubblestone. The top of the embankments is to reach to about high-water level. Borings made at various points across the bar indicate that the material to be excavated in making the proposed cut consists principally of stiff blue clay, a material which long resists the action of the waves. The jetty on the north side will be contiguous and parallel to the cut. Its construction should be carried on simultaneously with the excavations for the cut. As the shore end near the beach will be particularly exposed to the destructive action of the sea it will be necessary to make that portion quite secure by adding to the mattresses and stone a row of piles closely driven in the center of the embankment for greater stability. The piling should extend from high-water mark to a point 2,000 feet out, and, as shown on the map, the row of piles already driven there years ago is to form a section of it. The jetty south of the cut projects nearly at right angles from Green Point on the shore, about 2,000 feet below the mouth of the river, and after making a slight deflection southward, about one-half of a mile from the shore, gradually approaches the cut across the bar, and finally runs parallel with the latter for a distance of 800 feet as far as the outer end of the north jetty. As an experiment, it is proposed to build a greater portion of this jetty as a mud embankment only, with dredged material deposited upon the proposed line between the shore and the 2-foot contour. Beyond this depth the remainder is to be similar to the north jetty. The estimate has been made in accordance with this idea. It has been suggested that the north jetty alone might suffice to protect the cut |