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IMPROVEMENT OF ARANSAS PASS, TEXAS
Maj. GEORGE P. HOWELL
Corps of Engineers
The history of the improvement of Aransas Pass is typical of the vicissitudes encountered and the length of time taken in improving the harbors on the Texas coast. It is especially interesting, as the improvement has been undertaken in turn by private parties and by the general Government; and because it formed the battle ground for a contest between the Government engineers and the engineers for a private party endeavoring to improve the Pass. Although the first work of improvement was in 1868, at this date, 1911, the project is not yet completed and reports are still being submitted by boards of engineers.
Aransas Pass is one of the openings or inlets from the Gulf of Mexico through the chain of islands along the coast into the shallow waters behind them. It is 170 miles southwest of Galveston and 125 miles north of the mouth of the Rio Grande. Formerly, that is, in the seventies, almost all these passes or openings were being improved by the Engineer Department. Railroads in Texas were few and there were none paralleling the coast; consequently, transportation by water had to be used and advantage taken of every waterway, especially along the coast. At Aransas Pass there were regular schooner lines to New York and other eastern ports. Most of the commerce for northern Mexico came through this pass en route to Corpus Christi, whence it was taken overland. At that time there were no railroads west of San Antonio. In the past forty years great changes have taken place, owing to the spread of the railroad system and increased size and draft of vessels. It is necessary that conditions in those days should be understood, in order to arrive at a just appreciation of the engineering methods employed by these pioneers. Otherwise, we will be inclined to laugh at these attempts which seem so futile at this day. River and harbor work did not amount to much in those days. The great projects that have
opened the harbors of the country to the deep-draft vessels and have added to the fame of the Corps of Engineers had not been undertaken. The report of the Chief of Engineers for 1874 shows that 46 officers of the Corps of Engineers were engaged on river and harbor work, of whom only 15 were exclusively on this work. One officer, Capt. C. W. Howell, had charge of all the work on the coast west of and including the mouth of the Mississippi River. The River and Harbor Bill was small in amount, as the country was just recovering from the effects of a great war. No system of continuing contracts had been evolved. It was not known when a bill would be passed and the small driblets handed around would have shocked the executives and chairmen of river and harbor committees of these days. It seems to have been the general custom for the bill to fail and all work would consequently be suspended. The next appropriation for an improvement would be small, $25,000 or $50,000, which would get the plant in working order and very little more.
The aim was to open the passes so that boats of from 8 to 12 feet draft could use them. There were no railways, and so the material used in construction had to be of local origin. Also, when the project was formed and the estimated cost was found to be as much as $700,000 or thereabouts, the officer would know that it would be foolish to send in such a report, and that even if it were adopted the money would not be forthcoming. For instance, in 1874 an estimate was submitted for the Galveston jetties of $1,250,000. Appropriations were made as follows: 1875, $150,000; 1876, $112,000; 1878, $125,000; 1879, $100,000; and so on. The officer in charge of an improvement had therefore to cut his coat to fit the cloth and endeavor to work with material found in the vicinity, and with the knowledge that the work had to be done cheaply.
A brief glance at the projects of the Texas harbors will show how the attempt was made to solve the difficulties. It might as well be said that all of them failed. At Galveston parallel jetties were to be constructed by means of structures called gabions, 6 feet in diameter and 6 feet high, woven of brush, fitted with wooden covers as well as bottoms and plastered over with cement. They were to be placed in two rows to form the jetty and were to be filled with sand through a hole in the cover from a dredge alongside as they were placed in position. It was thought that the jetties would watch the drifting sand until they were covered, and that
afterward the sand would be carried over them rather than around their ends. They would be submerged jetties, since, ordinarily, the tops of the gabions would be 5 or 6 feet below mean low tide.
At the mouth of the Brazos River, the next opening below Galveston, two converging jetties of closely driven palmetto piles were to be used. At Pass Cavallo the project was first made for gabion structures, but when work began, in 1880, the jetties were built of brush mattresses and concrete blocks. At Aransas Pass, as will be shown later, brush mattresses and stone were used; and at Brazos Santiago, the last entrance, brush mattresses weighted down with bricks made in the vicinity of the Pass, weighing about 15 pounds each. It was probably just as well that Congress was not liberal with its money. Nevertheless, cor
Nevertheless, considerable money was spent and wasted. At Galveston, on the gabions $620,000 was spent; at Pass Cavallo, $290,000; at Aransas Pass, on the first mattress jetty and subsidiary works, $390,000; at Brazos Santiago, $257,000. No increase in depth was obtained.
The harbors on the Texas coast all have characteristic features in common. A sand cordon thrown up by the waves and littoral currents, at most points, extends along the whole shore, often forming a series of lagoons between itself and the mainland. The Texas rivers are small and, at times of low water, have too insufficient discharge to scour outlets into the Gulf. The lagoons, which are shallow and often inter-connected, cover extensive areas, but as the tidal oscillation which supplies the only constant power available for deepening the pass through the cordon, is only about 1 foot in height, the volume of tidal flow is, ordinarily, small, and the currents weak. When, however, long-continued southeasterly winds have raised the water level behind the cordon several feet, a sudden “norther” will force out an immense volume and in so short a time as to generate a current destructive to ordinary contraction works.
Aransas Pass is the outlet of Aransas Bay to the Gulf of Mexico. The area of the bay is about 80 square miles. It is connected to the southward with Corpus Christi Bay and to the northward with other shallow bays. The total area of these bays amounts to 350 square miles. The ordinary tidal range is about 1.1 feet, but at times of storms it is about five or six times as great. Aransas Pass lies between St. Joseph Island on the north and
Mustang Island on the south. Opposite the Pass lies Harbor Island, which is low and easily overflowed. It is formed chiefly of mud and is therefore more permanent than the sand islands. Between Harbor Island and St. Joseph Island is a deep channel which constitutes the harbor. Rockport, on Aransas Bay, lies about 12 miles to the northward, and at the head of Corpus Christi Bay is the city of Corpus Christi. A new town of Aransas Pass lies 7 miles from the pass across Harbor Island. These places are all on the San Antonio & Aransas Pass Railroad. Corpus Christi is also the terminus of the Mexican National Railway and the St. Louis, Brownsville & Mexico Railroad uses the latter's track to get into Corpus Christi.
The obstruction to navigation is the sand bar outside of the gorge, over which, between 1851 and 1890, the coast survey charts show a depth of 9 feet. Capt. George B. McClellan, Corps of Engineers, U. S. A., examining the locality in 1853, reported that the bar was composed of loose shifting sand exposed to change of position after heavy storms, causing a swash channel near St. Joseph Island and a deeper channel nearer Mustang Island, to which position the channel constantly tended to shift. He stated that if the improvement of the Pass by jetties was attempted, the effect would be to prolong the walls of the outlet to the present position of the bar and a new bar would form on the outside. The new outlet would be liable to be closed by storms, like the inlets on the Florida coast. In 1869, the first work of improvement was undertaken and it was done by private parties, $10,000 having been subscribed by citizens of Rockport. A jetty 600 feet long was constructed from St. Joseph Island, 1/2 mile from the channel, to cut off a secondary channel. (Fig. 1.) It was built of parallel rows of triangular cribs filled with brush and stone and it was expected to catch sand and throw the water into the main channel. Shortly after the jetty was constructed, this secondary channel shoaled about 2 feet and the main channel increased in depth by 2 feet, but pilots said it was due to storms. In 1871 there was no trace of the jetty.
The first plan of improvement of the Pass was made in 1879 by Captain Howell, the district officer. Ile recommended building a single jetty from St. Joseph Island, revetting the head of Mustang Island, and planting with trees the lower end of St. Joseph Island to prevent that island from losing sand by wind drifts. The cost was estimated at $140,000. He also recommended the closing of Corpus Christi Pass, the outlet to the Gulf at the lower end of