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lows that Lower Louisiana has much to apprehend, in the course of time, from such unavoidable effect. Therefore, without entering into details too foreign to this report, it can be inferred from this short view that any improvement which could facilitate, in Lower Louisiana, the discharge of the Mississippi, would avert impending calamities, and confer benefits on the States bordering upon the Mississippi.
With a view to the same objects, the board have been directed to examine the Bayou Plaquemine. This bayou makes out of the Mississippi on the western side, and connects this river with Bayou Teche through the Atchafalaya. The Mississippi, at its junction with Bayou Plaquemine, nearly opposite to Bayou Manchac, rises about 28 feet in high freshets; the bottom of the Bayou is 224 feet below high water mark, and 5 feet above low stage in the river. The width is about 150 yards, but soon becomes, on an average, 60 yards, which width it retains down to its embranchment with Bayou Jacob.
Bayou Plaquemine is navigable when the Mississippi has attained its medium rise; and, at high water, the current becomes very rapid, owing to the short distance between the head and the foot of the fall. The entrance of this channel into the Mississippi, being at a re-entering bend of the river, is liable to be obstructed by drift wood from the Mississippi. Therefore, this channel of navigation and of discharge, is menaced of being shut up, to the great injury of Lower Louisiana. To guard against so serious an accident, as also to render commodious, through the outlet of Plaquemine, a water communication between the Mississippi and Bayou Teche, would require a steady observation of the facts connected with both objects-facts which would be obtained but by a long stay on the spot, and a close study of the river through its various stages.
With regard to La Fourche river, (about thirty-six miles lower down,) which might also be used as a channel of navigation and discharge, it would require much improvement to be fitted to that double purpose. The bottom of this river, at its junction with the Mississippi, is about on a level with the low medium stage in the latter; and, during the rise of the Mississippi, the river La Fourche affords a pretty convenient navigation to barges. However, at about the middle of its course, its bed is fast filling up on a distance of about sixteen miles, the width and depth have already diminished by about one-third of what they formerly were. This obstruction is extending gradually; and, being the result of a progressing growth of willows favoring the accumulation of fluviatic deposites, it cannot be removed but by digging the actual bed of the river, and extirpating the growth which menaces to stop the navigation.
By deepening, to a proper depth, the channel of La Fourche river, and raising along its margin the necessary dikes, this outlet would both assist the discharge of the Mississippi, and procure, at all times, a commodious communication to the Attakapas.
Such are the main outlets through which the surplus water of the Mississippi might disembogue laterally into the sea; and which could, besides, be used as navigable channels. These objects of internal improvement, being of a nature to be not only highly important to Lower Louisiana, but beneficial, also, to the States bordering upon the Mississippi, they might, at a future day, solicit the attention of the General Government. And it is under such impression, that the board have submitted, in the present report, these few considerations on the Delta of the Mississippi.
The coast on the Gulf of Mexico, between Tampa bay and Appalachi bay, cannot be approached by vessels drawing more than five feet in this latter bay, eight feet can be carried at high tide, to St. Mark. Besides, the ridge of the peninsula of Florida has a mean elevation of one hundred and fifty feet above the ocean, and its top does not offer, at any place, either natural reservoirs or heads of streams adequate to the supply of a canal having very large dimensions. Therefore, a ship channel destined to connect, through the peninsula, the Atlantic with the Gulf of Mexico, is not practicable.
The heads of Santa Fe river and of Black creek, present to a canal for boats, the best passage across the summit of the ridge. Natural reservoirs, in this vicinity, will supply the lockage at the dividing point, whilst it is anticipated that filtration from the ground will keep replenished the trunk of the summit level.
In this direction, a canal from the fork of Black creek to the mouth of the Santa Fe, would connect the St. John's with the Suwannee; therefore, the Alantic with the Gulf. Such a canal would be about seventy-eight miles in length, and the ascent and descent together, two hundred and fourteen feet.
But the Suwannee being much obstructed at its mouth, and having no harbor at its entrance into the Gulf, it will be expedient to continue the line of canal from the Santa Fe to the harbor of St. Mark. The whole route, from the fork of Black creek to St. Mark, or rather from tide water in Black creek, to tide water in St. Mark's river, will be one hundred and sixty-eight miles long, and the ascent and descent together, two hundred and twenty-four feet.
With a view to an uninterrupted inland navigation, parallel to the coast, from the Chesapeake to the head of St. John's river, it will be necessary to open a sloop canal from the harbor of St. Mary's to the St. John.
Respecting the coasting navigation from St. Mark to Lake Pontchartrain, it will be rendered secure, safe, and commodicus, by means of the following improvements: 1st. A canal along Crooked creek, from Ocklockony river to a convenient point in St. George's sound; through this sound and the canal, the Appalachicola will become connected with St. Mark. Secondly. The clearing and deepening of the Santa Rosa sound, at the meeting of tides. Thirdly. A canal from the bay of Pensacola to that of Mobile, through the Great Lagoon and the river Bon-Secour. Fourthly. The deepening of the Pass au Heron, between the eastern point of Dauphin island and the main..
Lake Pontchartrain can be connected with the Mississippi by a canal, which has been projected, at or near New Orleans, and by Bayou Manchac. This bayou, the rivers Plaquemine and La Fourche, can be rendered navigable at any stage in the Mississippi; and they deserve consideration, as offering the only outlets through which, in time of freshets, the Lower Mississippi might be relieved in the discharge of its waters. All which is very respectfully submitted.
BERNARD, Prigadier General, Member of the Board of Internal Improvement. WILLIAM TELL POUSSIN,
Captain Topographical Engineers, Assistant to the Board.
WASHINGTON CITY, February 19th, 1829.