BO LING POT, (19 miles below Chattanooga.) The obstruction at this place is a high-water one altogether, and is caused by two points of land jutting into the river opposite each other, contracting the width of the river to 200 feet. Just below these points the width of the river increases suddenly, and at a distance of 300 feet from them it is 500 feet wide. This sudden increase in width causes very dangerous eddies to form immediately below the point of land, making it extremely difficult for ascending boats to get through the narrowest portion of the channel, without being swept on to the point on the left bank, they having to cross from the right bank and through the swiftest part of the current for the purpose of getting a line on the left bank to assist them in warping to a point above, from which they can ascend the river with the aid of steam alone. The current at high water through the narrowest portion of the Boiling Pot has a velocity of 15 miles an hour, and at low water 3 miles an hour. The improvement demanded at this place is the excavation of the point of land on the right bank, the material excavated to be thrown into the eddy immediately below it; this will increase the water-way enough to stop the formation of this eddy and decrease the velocity of the current so that ascending boats can get through without warping. The estimate is as follows: 5,000 cubic yards hard sandstone excavation, at $1...... THE SKILLET, (20 miles from Chattanooga.) $5,000 00 At this place there is a large sand bar on the right side of the channel, causing the current to become very rapid, at least 13 miles per hour for about two hundred feet. Half a mile below this rapid portion of the current the river becomes very wide and shallow, the water only being about eighteen inches deep on top of the rocks. These rocks are detached from any reef or ledge, and are scattered irregularly about, averaging about one cubic yard each. The rocks removed would give a depth of thirty inches of water; to increase this a wing dam will be required. The following is the estimate for proposed improvements: Removing 25 isolated boulders, averaging 1 cubic yard each 25 cubic yards, at $2 50...... Riprap wing wall 500 feet long, 6 feet wide, on top slopes 1 to 1; 746 cubic yards, at $1 50.... One capstan and fixtures to enable ascending boats to warp through the swift portion of the current near the head of the sand bar.... Total $62 50 1, 119 00 200 00 1,381 50 KELLY'S SHOALS, (28 miles from Chattanooga.) The obstruction at this place is a shoal place of about 1,000 feet in length, bottom gravel on the line of the channel, and to left of it, with a very slow current for a place so shallow. The proposed improvement is a wing dam on the right side extending from near the foot of the shoal up the river and towards the right bank, the length of which will be 1,500 feet. Estimate. Riprap, 1,500 feet; wing dam 6 feet wide on top, 4 feet deep, with slopes of 1 to 1; 2,666 cubic yards, at $1 50.. $3,999 00 LONG ISLAND, (63 miles from Chattanoogo.) This island is six miles long and about half a mile wide at its widest part. The Nashville and Chattanooga railroad crosses the river about the centre of the island. The steamboat channel is on the left side of the island, and in the channel are three reefs of flint rock, two above the railroad bridge and one below it, on which at low stage of the river there are but 18 inches of water. About two-thirds of the entire water of the river passes down on the right side of the island, but the chute is so wide that the water is very shallow, and this channel is only available for purposes of navigation at high water. If one-half of the water was taken from the right chute and thrown into the left it is thought there will always be three feet of water on the reefs. To do this a wing dam will be required at the head of the island six hundred feet in length, with a retaining wall at the point where the wing dam joins the island. It is also suggested that one foot in depth for a width of 100 feet be excavated from the three reefs in the left channel. The estimate for the proposed improvement is as follows: Riprap in wing dam, 700 cubic yards, at $1 50 ... Flint rock excavation at the three reefs, 450 cubic yards, at $2 50. Total.... WIDOW'S BAR, (74 miles below Chattanooga.) $1,050 00 333 00 1, 125 00 2, 508 00 The length of this bar is about 4,000 feet. The depth of water at the lowest stage of the river varies from 14 to 24 inches. Velocity of current 2 miles per hour. The most shallow place is on a reef of rocks that extends across the river. Above the reef there is always plenty of water. On the reef at the lowest stage of the river there are only 14 inches of water. Just below it there are 20 inches, with a gravel bottom, which increases to 10 feet near the mouth of Widow's creek, 4,000 feet below the reef. Below the mouth of the creek there is always plenty of water. To the left of the point where the channel crosses the reef there is a large sand bar, over which the water always flows. The improvement suggested is by building a wing dam across the head of the bar S00 feet long and a wall 1,000 feet long, from the lower end of the wing dam parallel with the channel, thereby causing such an increase in the volume. of water and velocity of the current as will cut out the gravel below the reef to a sufficient depth for all seasons of the year. The reef at the head of the shoal will also have to be excavated a depth of 30 inches and a width of 100 feet, the estimate for which improvement is as follows: Estimate. Riprap in wing dam, 2,920 cubic yards, at $1 50 .... Solid rock excavation, 280 cubic yards, at $2 50. Total .... $4,380 00 168 00 700 00 5,248 00 LARKINS'S TOWHEAD, (112 miles below Chattanooga.) At this place there are two sand bars, one at the upper end of the towhead and one on the right bank opposite, the channel running between them, with two feet of water at the lowest stage of the river, and a current of two miles an hour. The length of the shoal water is 1,200 fect. Above and below this shoal there is sufficient depth of water at all seasons of the year. The improvement proposed at this place is by constructing a wing dam and parallel wall combined for a length of 1,200 feet, to be 6 feet wide on top, 4 feet deep, and the side slopes to be 1 to 1, the estimate for which is as follows: Riprap, 2,133 cubic yards, at $1 50 Estimate. MINK CREEK SHOALS, (117 miles below Chattanooga.) $3,199 50 The obstruction at this place resembles the obstruction at Widow's bar, with the exception of there being no reef at this place. The same plan and amount of wing dam is suggested as at Widow's bar, viz : Estimate. Riprap wing dam, 1,800 feet long, 6 feet wide on top, 4 feet deep, slopes 13 to 1; 3,200 cubic yards, at $1 50 BUCK ISLAND, (129 miles below Chattanooga.) $1,800 00 About a quarter of a mile above the head of the island the channel is very close to the left shore with a low water depth of 20 inches. From this point to a point one and a half miles below there are three shoal places in the river, caused by large masses of rocks scattered irregularly about in the channel. All these shoals have deep pools of water between them. The different shoals only average about 100 feet in length. The improvement suggested is by a wing dam at the upper shoal, and the removal of the rocks at the other three. The wing dam will be 500 feet long and half a cross section area of 50 feet. The estimate for the proposed improvement is as follows: Estimate. Riprap, 1,111 cubic yards, at $1 50.. Excavation of large masses of rock in island chute, 160 cubic yards, at $2 50. Total $1,666 50 400 00 2,066 50 TOWN ISLAND, (133 miles below Chattanooga.) At the head of this island there are a lot of boulders scattered about in the channel, which is close to the shore, with only 20 inches of water on them, at the lowest stage of the river. If the rocks are removed there will be three feet of water in the channel, at the lowest stage of the river, down to Gunter's bar. The estimate for removing the rock is as follows: Estimate. Boulders averaging 14 cubic yards each, 23 cubic yards at $2 50.......... $57 50 GUNTER'S BAR, (135 miles below Chattanooga,) is a rock reef, extending across the river near the lower end of Town island, on which, at the lowest stage of the river, there are but ten inches of water. To improve this place the reef will have to be excavated a depth of 33 inches, and 100 feet in width. The following is the estimate of the proposed improvement Estimate. Rock excavation, 470 cubic yards, at $2 50.... $1,017 50 GUNTER'S REEF, (138 miles below Chattanooga,) extends across the river, with 20 inches of water upon it, at the lowest stage of the river, and a current of about two miles an hour. This reef will have to be excavated for a depth of two feet, and 100 feet in width, to make the channel sufficiently large. Estimate as follows: Rock excavation, 300 cubic yards, at $2 50.... $750 00 FLINT RIVER TOWHEAD, (157 miles below Chattanooga.) Opposite this towhead, which is one mile in length, there are always three and a half feet of water. At the lower end of the towhead there is a large sand bar, the lower point of which is about in the centre of the river. The channel crosses from near the right bank to near the left bank, passing close to the lower point of the bar, a short distance below which and in the centre of the river is another sand bar, that at lower water is dry. Between the two bars the water is only 25 inches deep at the lowest stage of the river. This depth continues for a very short distance, when the water again becomes deep enough at all stages of the river. On the right side of the lower sand bar there is a channel in which, at the lowest stage of the river, there are 20 inches of water. It is thought that if a wing dam is built connecting the two sand bars, thereby keeping all the water in the right-hand chamber, the increased volume of water and velocity of current would cut out the channel to a sufficient depth, the bottom being composed of sand and fine gravel. The length of wing dam to do this would be 300 feet, six feet wide on top, four feet deep, and have side slopes of one and a half to one. Estimate. Riprap in wing dam, 533 cubic yards, at $1 50.. $799 50 WHITESBURG SHOALS AND REEFS, (166 miles from Chattanooga.) The obstruction here commences at the head of Whitesburg island, that is three miles in length, and in this distance there are three places at which the water is only two feet deep at the lowest stage of the river. The bottom of the river at these places is composed of sand and fine gravel. Each of the shoals mentioned is 125 feet in length. Between them are natural pools, in which there are from six to seven feet of water, at the lowest stage of the river. Just below the foot of the island there is another shoal of the same character and dimensions as those already mentioned. These shoals are caused by the great width of river, it being 1,200 feet wide in the island chute. In a distance of two miles from the foot of the island downwards there are three other shoals, on which there are only two feet of water at the lowest stage of the river. The first of these is situated three-fourths of a mile below the island, the second one and a half miles below, and the third two miles. The first is about 300 feet in length, and the obstruction is caused by boulders scattered irregularly about in the channel. The second is about 60 feet in length, and consists of solid rock reef of flinty limestone, extending across the river. The third is about 30 feet in length, and is also a flinty limestone reef extending across the river. The improvement suggested at the three shoals in the island chute and the one just below the island is by a wing dam at each one of them to increase the depth of water and cut out the gravel bottom. This, it is thought, will give sufficient depth of water at all seasons of the year. The aggregate length of these dams will be 1,600 feet, and have an average area of cross section of 50 feet. The improvement at the shoal, three-fourths of a mile below the island, will be excavation of the limestone reef, 100 feet in width, at the shoal, two miles below the island; the improvement will also be excavation of the limestone reef, 100 feet in width. The estimate of the proposed improvement is as follows: Estimate. Riprap in wing dams, 2,963 cubic yards, at $1 50. $4,444 50 74 00 832 50 Solid limestone excavation at the shoal, one-half mile from island, 47 50 5,768 50 Total. LIMESTONE SHOALS, (186 miles from Chattanooga.) These shoals are about one mile in length, with an average velocity of current of two and a half miles an hour. About 600 feet of the upper end of the shoals has a bottom composed of sand and fine gravel, then follows 2,600 feet of a rough rock bottom, having from 20 to 25 inches of water in the points of the rocks, with deep pools between, at the lowest stage of the river. Below this 10cky bottom gravel and sand are again found for a length of about 2,000 feet, with a low-water depth of from 20 to 25 inches. The improvement suggested is the excavation of the rock bottom. The estimate is as follows: Limestone excavation, 3,000 cubic yards, at $2 50... $7,500 Estimated cost of removing obstructions from Chattanooga, Tennessee, to Deca tur, Alabama. Names of obstructions. Ross Towhead. 24 miles from Chattanooga. Larkin's Towhead, 112 miles from Chattanooga Cost. $3,004 00 697 50 2,020 00 1,036 50 8,047 50 5,000 00 1,381 50 3,999 00 2,508 00 5,248 00 3,199 50 4,800 00 2,066 50 |