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Source: https://erdc-library.erdc.dren.mil/jspui/ In connection with the MRC Potamology Program, movable-bed model studies were conducted of seven of the most complex and troublesome reaches of the Mississippi River to obtain some quick general indications of the effectiveness of plans proposed for the improvement and stabilization of those reaches. Because of the limited time available, the studies were conducted in an existing facility with little or no adjustment of the models and in some cases without a base test. Because of the limited size and shape of the facility, only a relatively short reach of the river including the problem could be reproduced in each model with little or no overbank areas. The horizontal scale varied with each reach depending on its size and shape and were much smaller with a higher distortion of the linear scales than was considered desirable for studies of this type. An analysis of the model results compared with developments in the river based on an evaluation of considerable prototype data indicated that the types of models used predicted, at least qualitatively, most of the principal trends that actually occurred in the river with the plans tested. The degree of accuracy of the models varied and depended to a considerable extent on the model adjustment, characteristics of the reach, flow conditions, and similarity between plan tested and actual construction. The analysis of model and prototype data permitted an evaluation of the performance of various types of dikes and dike systems and some of the principles involved in the developments within alluvial streams._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ Lake Dardanelle is a 51-mile-long reservoir formed by Dardanelle Lock and Dam which is located at mile 205.5 on the Arkansas River. The lake was designed to provide head for power, depth for navigation, and a trap for a considerable volume of sediment. The river was realigned and stabilized in the portion of the lake upstream of mile 238.4 with plans for progressive improvement of the reach downstream as deposition and channel development indicated the need for such improvements. Water was impounded in 1964; and by 1972, deposition had accumulated in the vicinity of Horse Head Creek such that it was beginning to hinder navigation. This study was conducted to determine the type and location of training and stabilization structures needed to develop a satisfactory navigation channel downstream of mile 238.4 and to provide a satisfactory channel approaching the navigation span of the proposed highway bridge at mile 234.9. A movable-bed model reproduced the reach of the Arkansas River and adjacent overbank area from mile 238.5 to 231.3 to scales of 1:120 horizontally and 1:80 vertically. Results of this investigation indicated that : a plan could be developed that would provide a satisfactory crossing toward the left bank and in the approaches to the proposed bridge. Navigation gaps could be used in the two closure dikes across the channel along the right bank during construction and development of the crossing. Some shoaling could be expected in the upstream approaches to the gaps and some scouring could be expected just downstream of the gaps. Development of a channel along the left bank upstream of the proposed bridge would reduce the tendency for erosion of the left bank in the upper portion of the bend downstream of the bridge. Permitting a portion of the left bank near the lower end of the bend below the bridge to erode would tend to improve the alignment of the channel over the crossing toward the right bank.

Source: https://erdc-library.erdc.dren.mil/jspui/ Aberdeen Lock and Dam will be the fourth structure proposed for the development of navigation on the Tennessee-Tombigbee Waterway. The lock and dam will be located in a bypass canal about 407.98 miles above the mouth of the Mobile River, or about 1 mile east of Aberdeen in Monroe County, Mississippi. The structures are designed to maintain a minimum upper pool during low flows extending 18 miles up the Tombigbee River and about 1.5 miles up Town Creek and into the Canal Section. The structures will include one lock with clear chamber dimensions of 110 by 600 ft and a dam with a 6-gated spillway section located in a bypass canal on the left overbank. A fixed-bed model reproduced about 1.0 mile of the Tombigbee River channel, the lock approach canal, and the adjacent overbank areas to an undistorted scale of 1:120. The model investigation was concerned with the development of satisfactory navigation conditions in the lock approaches, the distribution of flow through the gated spillways, and the effects on stages of the cofferdam, landfills, and relocation of the railroad. Results of the investigation revealed that satisfactory navigation conditions would require modi fication of the excavation in the upper approach to the lock and dam, a dike forming an extension of the upper guard wall, and a short wing dike near the downstream end of the riverward lock wall. Distribution of flow through the gated spillway, particularly in the two gate bays near the lock, would be adversely affected by the alignment of currents approaching the structure, but the drop in water-surface elevation through the spillway and along the lock and lock walls would not be excessive. Construction of the cofferdam for the lock and dam would have little effect on water-surface elevations and velocities in the area, but the cofferdam and landfills could cause an increase in stages of as much as 1.7 to 2 .0 ft with the higher flows. Relocation of the north-south section of the railroad would have little effect on water-surface elevations with adequate openings provided in the embankments.

Source: https://erdc-library.erdc.dren.mil/jspui/ Aliceville Lock and Dam will be the second navigation structure proposed for the development of navigation on the Tennessee- Tombigbee Waterway. The lock will be along the left bank of the Tombigbee River about 333 miles above the mouth of the Mobile River, which is at the foot of Government Street in Mobile, Alabama, or approximately 67 miles above the proposed Gainesville Lock and Dam. The structures will include one lock with clear chamber dimensions of 110 by 600 ft and a dam consisting of a gated spillway and a fixed-crest overflow weir designed to maintain during low flows a minimum upper pool at el 136.0 extending upstream about 32 miles to the proposed Columbus Lock and Dam. A fixed-bed model reproducing about 2.8 miles of the Tombigbee River channel and adjacent overbank to an undistorted scale of 1:100 was used to determine navigation conditions with the proposed design and to develop such modification as might be required to eliminate conditions that would adversely affect navigation using the lock. The model was also used to determine conditions that might be expected during construction of the lock and darn with the proposed construction plan. Results of the investigation revealed the following: (A.) satisfactory navigation conditions in the upper lock approach could be developed with modification of the excavation along the left bank of the approach channel and excavation of the right bank in the bend near the upper end of the approach channel; (B.) navigation conditions in the lower lock approach could be improved considerably with a dike angled riverward along the right side of the approach channel; (C.) two-way traffic in the second bend upstream of the upper lock approach would be difficult and hazardous during the higher flows; (D.) recommended changes to the original plan would have little effect on water-surface elevations in the reach or on conditions that could be expected during construction of the lock and dam.

Source: https://erdc-library.erdc.dren.mil/jspui/ The Columbus Lock and Dam will be the third navigation structure proposed as part of the development of the Tennessee-Tombigbee Waterway for navigation. The structure will be located in a bypass canal about 370 miles above the mouth of the Mobile River at the foot of Government Street in Mobile, Alabama, or just downstream from the confluence of the Tombigbee and Tibbee Rivers and about 4 miles northwest of Columbus in Lowndes County, Mississippi. The structure is designed to maintain a minimum upper pool during low flows extending upstream to the proposed Aberdeen Lock and Dam at mile 408 and will include one lock with clear chamber dimensions of 110 by 600 ft, a five- gate spillway section of the dam located in the bypass canal on the left overbank, and a fixed overflow section along the left overbank to high ground. A fixed-bed model reproducing about 4.5 miles of the Tombigbee River channel, upper and lower lock approaches, the lock approach canal, and the adjacent overbank areas to an undistorted scale of 1:120 was used to determine the adequacy of the proposed plan and to develop modifications required to eliminate any adverse conditions indicated. The model investigation was concerned principally with navigation conditions into and within the lock approach canal and in the lock approaches and the distribution of flow through the gated section of the dam. Results of the investigation revealed that navigation conditions in the upper approach with the original plan would be difficult and hazardous during the higher flows but that satisfactory conditions could be developed by modifications within the upper lock approach and the construction of properly designed dikes along the approach canal to eliminate or reduce crosscurrents. Even with the modifications developed, two-way navigation in the upper approach to the lock could be difficult and hazardous during high flows and with a flood on the Tibbee River and little or no flow in the Tombigbee River. No navigation difficulties were indicated in the lower lock approach with any of the plans tested. Distribution of flow through the gated spillway was affected by the offset between the lock and right abutment of the dam but could be improved by placing a fillet between the two structures. Satisfactory navigation conditions into and out of the lower reach of the Tibbee River could be developed for limited size tows but conditions would tend to be difficult and hazardous during the higher flows.

Source: https://erdc-library.erdc.dren.mil/jspui/ The John H. Overton Lock and Dam will be the second navigation structure proposed for the development of navigation on the Red River waterways. The structure will be located in a cutoff channel in the left overbank about 74 realigned channel miles above the Mississippi River. The structure will include one lock located along the left bank with clear chamber dimensions of 84 by 785 ft and a dam consisting of a spillway with seven 50-ft-wide gates and a 330-ft-long fixed-crest overflow weir designed to maintain during low flows a minimum upper pool at el 58.0 extending upstream about 37.5 miles to the proposed Lock and Dam 3. A semifixed-bed model reproducing about 3.7 miles of the Red River channel and adjacent overbank areas to an undistorted scale of 1:100 was used to provide some general information on navigation conditions with the proposed design and to develop such modifications as might be required to eliminate conditions that would adversely affect navigation using the lock. Results of the investigation revealed the following : (A.) Satisfactory navigation conditions in the upper lock approach could be developed with modification of the excavation along the left bank of the approach channel and extending the length of the upper guard wall. (B.) The length of the overflow weir and excavation along the right bank of the cutoff channel could be reduced without affecting navigation conditions in the lock approaches or flow through the dam. (C.) Satisfactory navigation conditions could be developed in the lower lock approach with either a floating guide wall (land side) or a guard wall (river side). Conditions for two-way traffic would be better with the guide wall. (D.) The differences in the water-surface elevations across the dam with plans tested would tend to be small.

Source: https://erdc-library.erdc.dren.mil/jspui/ As part of the program for the development of navigation on the Tennessee-Tombigbee Waterway, the Gainesville Lock and Dam will be the first navigation structure proposed for the development of the waterway. The lock will be in a bypass canal about 266 miles above the mouth of the Mobile River, which is at the foot of Government Street in Mobile, Alabama, or approximately 49 miles above the confluence of the Tombigbee and Warrior Rivers and 53 miles above Demopolis Lock and Dam. The structure is designed to maintain during low flows a minimum upper pool extending upstream to the proposed Aliceville Lock and Dam at mile 332.6. The project will include one lock with clear chamber dimensions of 110 by 600 ft located in a bypass canal on the left overbank and a dam consisting of a gated spillway and fixed overflow section. A fixed-bed model reproduced about 2.6 miles of the Tombigbee River channel, about 3000 ft of the upstream end of the navigation canal, and the adjacent overbank areas to an undistorted scale of 1:100. The model investigation was concerned with the development of good navigation conditions at the entrance to the approach canal and in the two bends just upstream of the entrance to the canal, and in the distribution of flow through the gated spillway. Results of the investigation revealed the following : (a) Satisfactory navigation could be developed at the entrance to the lock approach canal by modification of the excavation along the left bank and in the bend adjacent to the canal. (b) Satisfactory navigation conditions for two-way traffic through the reach could be provided under most conditions by the excavation mentioned in (a) above, by increasing channel width, and by improving the curvature of the second bend upstream of the canal. (c) Improving the distribution of flow through the gated spillway with a training wall would have little effect on water-surface elevations upstream.

Source: https://erdc-library.erdc.dren.mil/jspui/ The Lock and Dam No. 3 navigation structure is located on the upper Mississippi River at about mile 797 above the mouth of the Ohio River and 44.2 miles above Lock and Dam No. 4. The structure is designed to maintain a minimum upper pool during low flows extending 18.3 miles upstream to Lock and Dam No. 2 on the Mississippi River and approximately 52 miles up the St. Croix River. The section of pool extending into the upper Mississippi River provides water access to Minneapolis and St. Paul, Minnesota. The four-gated spillway section is located in the main river channel, and the lock with clear chamber dimensions of 110 by 600 ft and the upper lock gates for a proposed second lock are located in a bypass canal on the right overbank. A fixed-bed model reproducing about 2 miles of the Mississippi River channel, upstream lock approach, a portion of Sturgeon Lake, and adjacent overbank areas to an undistorted scale of 1:120 was used to determine the adequacy of the proposed plan and to develop modifications required to eliminate any adverse conditions indicated. The model investigation was concerned principally with navigation conditions in the upstream approach to the lock, the development of modifications required to improve navigation conditions in the upper lock approach, and the effects of the modifications on the movement of ice and debris. Results of the investigation revealed that satisfactory navigation conditions in the upper lock approach could be developed by replacement of the guide wall with a guard wall with some excavation along the right bank or with a rock dike extending upstream from the right abutment wall of the dam. Ice gaps or openings would be required to reduce the accumulation of ice in the lock approach with either of the plans._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ This investigation is one phase of a general model study to determine the effectiveness of dike systems proposed for improvement of troublesome reaches on the Mississippi River. This report describes and gives results of tests concerned with the development of plans for the improvement of the New Madrid reach of the river, which is located about 890 river miles above Head of Passes. A movable-bed model reproducing approximately 11 miles of the Mississippi River to a horizontal scale of 1:480 and a vertical scale of 1:60 was used to develop plans that would improve and stabilize the navigation channel through the reach and eliminate or reduce the need for maintenance dredging. The channel in the vicinity of New Madrid, Missouri, has been especially troublesome because of the divided flow and poor channel alignment. Flow near New Madrid is divided by a large island and further divided by a large sandbar between the channel along the left side of the island and the channel along the left bank. The navigation channel at the time of initiation of this study was along the left side of the island and then turned sharply toward the left bank before crossing back toward the right bank downstream of the island. Maintenance of the channel along the right side of the island was required as an access to the port facilities at the city of New Madrid. The plans tested included the construction of four dikes along the left riverbank and the dredging of a pilot cut along the lower portion of New Madrid bar and modifications to the alignment or number of dikes. Results of this investigation indicated the following: (A.) Developments in the reach were affected to some extent by division of flow around New Madrid bar, flow across the bar during high stages, erosion-resistant material in the riverbed, and tendency for the channel to meander within its banks. (B.) Under most conditions, an adequate channel could be developed in the reach with the originally proposed plan. Some maintenance dredging might be required near the head of New Madrid bar, depending on the flow condition and movement of sand waves through the reach. (C.) Conditions near the head of New Madrid bar could be improved with a chevron-type dike at the head of the bar, but would require an additional spur dike along the left bank upstream of the four original plan dikes. (D.) None of the plans tested had any appreciable effect on conditions within the channel to the right of New Madrid bar. (E.) Stabilization of the left side of New Madrid bar would be required to maintain a satisfactory alignment of the navigation channel along that side of the bar.

Source: https://erdc-library.erdc.dren.mil/jspui/ This study is concerned with navigation conditions in the upper approach to a temporary 110- by 1200- ft lock under construction at the existing Lock and Dam 53 on the Ohio River. It became apparent during construction that the intensity of the crosscurrents in the approach to the existing lock would be increased with the temporary lock making navigation conditions extremely difficult and hazardous. The study was undertaken to determine the conditions that would develop with the structure as planned and to develop modifications required to provide satisfactory navigation. In order to provide results before construction was completed on the original plan, a semi-fixed-bed model utilizing existing facilities was used for the study. The model reproduced to an undistorted scale of 1:120 the dam, upper portions of the locks, and about 2 miles of the river upstream. Results of the investigation indicated the hazardous condition that could be expected with the structures as planned. Satisfactory navigation conditions could be developed with the temporary lock by extending the upper guard wall and providing sufficient ports in the wall to pass most of the flow intercepted by the wall.

Source: https://erdc-library.erdc.dren.mil/jspui/ Cannelton Locks and Dam, proposed for construction on the Ohio River, will replace existing Locks and Dams 43-45. The project comprises two locks with clear chamber dimensions of 110 by 600 ft and 110 by 1200 ft and a 1365-ft-long, gated, nonnavigable dam, with provisions for powerhouse facilities at the left end of the dam. An undistorted, 1:120- scale model reproducing 8 miles of the Ohio River, the locks and dam structures, the hydropower plant, and other structures that affect flow conditions was used for the investigation. The principal results of this investigation indicate the following : (A.) Velocities along the lock side of the channel will tend to be high. Ports will be required in the upper guard wall to eliminate or reduce the crosscurrents that develop near the end of the wall. Velocities in the lock approach can be reduced by placing submerged dikes along the right bank. (B.) Ice and debris will tend to move along the lock side of the river, with the concentration on that side increasing as the river discharge increases. With ports in the upper guard wall, most of the debris and ice moving along the right bank will tend to be trapped in the lock approach between the upper guard wall and right bank. (C.) Orientation of the powerhouse and tailrace can affect navigation conditions in the lower lock approach. Spoil placed on the overbank upstream of the powerhouse intake channel can affect flow through the dam gates adjacent to the powerhouse and increase river stages during high flows. (D.) Satisfactory navigation conditions can be developed over the overflow section between the spillway and powerhouse with some excavation along the left overbank upstream of the powerhouse intake channel. (E.) The head on the lower lock gate at the end of lock emptying can be as much as 0.6 ft, depending on velocities along the lock side of the channel. The head can be reduced to nearly zero by placing a vertical wall along the upstream side of the stilling basin.

Source: https://erdc-library.erdc.dren.mil/jspui/ As part of the program for the modernization of navigation facilities on the Ohio River, Uniontown Locks and Dam will replace some of the existing lowlift locks and dams and provide a navigable pool about 69.7 miles long to the Newburgh Locks and Dam. The structures will include two parallel locks along the right bank and a dam consisting of a gated spillway and fixed overflow section. A fixed-bed model, reproducing about 8.6 miles of the Ohio River channel, Wabash Island with the back channel around the island, and about one mile of the lower reach of the Wabash River and the adjacent overbank areas, was constructed to an undistorted scale of 1:120. The model investigation was concerned with the study of the composition and configuration of the dam, arrangement of the locks and lock walls, and navigation conditions in the lock approaches. Results of the investigation revealed the following: (A.) Satisfactory navigation conditions could be developed with either the 10-gate or 12-gate spillway located in the main channel. With the gate sill of the 10-gate dam lowered 5 ft below that of the 12-gate dam, the water-surface elevation upstream showed little difference. (B.) Flow in the back channel, left of Wabash Islan, would tend to be considerably less than with existing conditions during flows that do not substantially overtop the fixed section across the channel when the gated spillway is entirely within the main channel. (C.) Flow through the back channel during low river discharge with the gated spillway in the main channel can be increased by excavation of the head of Wabash Island and the entrance to the back channel and with a training dike directing flow into the channel. (D.) Currents in the upper approach to the locks wou.ld be affected by the eddy forming in the scallop in the right bank. However, placing a fill along the bankline and extending across the scallop reduced the effect of the eddy on navigation. (E.) Ports would be required in the upper guard wall of the riverward lock to lessen the intensity of the crosscurrents near the end of the wall. (F.) Satisfactory navigation conditions could be provided with a third lock located either riverward or landward of the two adjacent locks. Replacing upper guide walls (land-side) with guard walls improved navigation conditions for downbound tows and reduced interference between tows using alternate locks. (G.) During construction of the spillway, navigation conditions could be difficult and possibly hazardous with the first-stage cofferdam under certain flow conditions._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ This investigation was concerned with the development of an adequate channel and access to the docking facilities along the right bank in Sawyer Bend and the reduction or eli mination of shoaling in the lower entrance to the Chain of Rocks Canal. The alignment of the channel upstream of Mosenthien Island and the movement of sediment from the Missouri River along the right bank caused an increase in flow through the chute channel to the left of Mosenthien Island and shoaling in the channel along the industrial docking facilities in Sawyer Bend. Shoaling in the lower entrance to the canal during low flows has created a serious problem because of the amount of dredging required and the lack of suitable disposal areas. The purpose of the model study was to develop plans that would provide a satisfactory channel in Sawyer Bend and reduce or eliminate the need for dredging in the lower entrance and approach to the Chain of Rocks Canal. A movable-bed model, constructed to scales of 1:250 horizontally and 1:100 vertically, reproduced the Mississippi River and adjacent overbank areas between miles 191.0 and 180.5. Results of the investigation indicated the following : (A.) Development of a satisfactory channel in Sawyer Bend can be accomplished by reducing the amount of flow through the chute channel to the left of Mosenthien Island and forcing the channel to cross toward the right bank farther upstream. This could be accomplished with the plan developed on the model and at the same time maintain some flow in the chute channel during all river stages. (B.) Shoaling in the lower entrance to the Chain of Rocks Canal during low flows is caused by the sudden expansion of the channel width at the lower end of the trail dike which results in the movement of sediment-laden bottom currents into the canal approach channel. (C.) A control gate at the upper end of the trail dike could be used to provide sufficient sediment-free flow into the entrance channel during low river stages which would tend to prevent the bottom currents and sediment from moving around the lower end of the trail dike and into the entrance channel. The effectiveness of the gate would depend on its size and type and method of operation. (D.) A low wing dike at the end of the trail dike could be used to reduce the amount of shoaling in the lower entrance to the Chain of Rocks Canal. The effectiveness of such a structure would depend on flow conditions, elevation and length of the wing dike, and the amount of sediment moving along the river side of the trail dike. (E.) Reduction of flow through the chute channel to the left of Mosenthien Island would tend to decrease the amount of sediment moving along the trail dike and the amount of shoaling in the lower entrance to the Chain of Rocks Canal._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ The Suck Bend Reach of the Chattahoochee River is in the upper end of Columbia Lock and Dam Pool about 1.5 miles downstream of the Walter F. George Lock and Dam. Suck Bend is essentially two adjacent and alternate bends in the form of a relatively flat "S" curve. Shoaling that occurs in the bend during flood flows and at times during powerhouse operation has been a problem for navigation when there is little or no flow from upstream. A movable-bed model reproducing about 1.5 miles of the Chattahoochee River to an undistorted scale of 1:72, model-to-prototype, was used to develop plans that would eliminate or reduce shoaling sufficiently to permit uninterrupted navigation and to improve navigation conditions for larger tows through the bend and in the approach to the proposed State Highway 10 bridge. The results of this investigation indicated the following: (A.) Navigation conditions in Suck Bend are affected by shoaling of the channel in the bend, elevation of bedrock, and adverse currents. (B.) Shoaling in the bend can be eliminated with training structures but the structures would not provide satisfactory navigation conditions through the bend and in the approach to the proposed State Highway 10 bridge for the larger tows because of the limited channel width and adverse currents. (C.) Satisfactory navigation conditions could be provided with training structures and with excavation and filling along the right bank in the bend to eliminate the irregularities in the bank line and increase the radius of curvature of the channel in the lower bend. (D.) Downbound tows of the larger size (435 ft by 78 ft) would have to flank to become properly aligned for passage through the bridge span even with the realigned right bank because of the short approach to the bridge after making the turn in the lower bend. (E.) The alignment of the currents through the proposed bridge could be improved with vane dikes along the left side of the channel upstream of the bridge but the dikes would reduce the maneuver area available and could be a navigation hazard.

Source: https://erdc-library.erdc.dren.mil/jspui/ This report covers the results of a general investigation to determine and demonstrate some of the principles involved in shoaling in harbor entrances and some of the factors to be considered in the development of solutions to the problems. The model used was not a reproduction of a reach of any stream but was designed to fit in an existing facility and provide for two bends and a straight reach between the bends. The model was of the movable-bed type with scales established arbitrarily as 1:400 horizontally and 1:100 vertically. Tests were conducted with the harbor entrance located along the concave bank of the upper bend, in the straight reach, and along the convex bank of the lower bend simultaneously. Results of this investigation provided the following general indications: (A.) There is a natural tendency for shoaling in entrances to harbors involving openings in bank lines of alluvial streams because of the sudden expansion in channel width and the lowering of the water level causing sediment-laden bottom currents to move toward the opening. (B.) The tendency for shoaling in harbor entrances varies with the size of opening in the bank line, the location of the entrance with respect to the channel alignment, and flow conditions. (C.) Harbor entrances located along the concave bank of a bend would tend to have less shoaling problems than if located in a straight reach or along the convex side of a bend. Entrances located in straight reaches would tend to have less shoaling problems than those located on the convex side of a bend. (D.) Shoaling in harbor entrances depends on the principle of lateral differential in water level. An opening in the bank line required for a harbor entrance tends to cause a lowering of the water level at the entrance. When there is a lowering of the water level on one side of the channel, there is a greater tendency for the slower moving bottom currents with sediment to move toward the lower elevation. Therefore, plans for the elimination or reduction of shoaling in entrances should be designed to reduce the amount of lowering of the water level near the entrance or to prevent the movement of bottom currents toward the lower elevation. (E.) Shoaling in harbor entrances located on the concave or convex side of a bend will depend to a considerable extent on the superelevation of the water surface near the entrance which is affected by the curvature of the bend, width of channel , and current velocities during the range of stage and discharge. In general, shoaling will tend to be less with the entrance located downstream of the point bar or axis of the bend. (F.) Shoaling in harbor entrances located in straight reaches will depend on the harbor entrance location with respect to the channel over the crossing and the tendency for the channel to be unstable. Channels in long straight reaches will tend to meander between banks and are affected by changes in stages and discharge and the alignment of the channel with respect to the bend upstream. (G.) Some reduction in shoaling in harbor entrances can be accomplished by modification of the bank line or with structures near the entrance designed to increase the water level near the entrance, or by structures designed to prevent bottom currents from moving toward the entrance. (H.) L-head dikes and in some cases wing dikes, can be used to prevent bottom currents from moving toward the entrance by permitting surface flow over the top of the dikes toward the entrance. The effectiveness of these dikes would depend on their location, length, elevation, and alignment with respect to the entrance and stream channel.

Source: https://erdc-library.erdc.dren.mil/jspui/ The Walter Bouldin Lock will be the first navigation lock proposed for development of navigation on the Coosa River Waterway. The lock will be located in the left overbank area of Walter Bouldin Dam. The model investigation was concerned with navigation conditions in the reach, including the Jordan Reservoir, the intake diversion canal, the Walter Bouldin Reservoir, and the Walter Bouldin tailrace. Three fixed models were constructed to an undistorted scale of 1:100 to study navigation conditions at three locations in the reach where navigation difficulties were anticipated. Model A reproduced the Walter Bouldin Lock and Dam, Reservoir, and tailrace. Model B reproduced the Jordan Reservoir and entrance to the intake diversion canal. Model C reproduced the confluence of the Walter Bouldin tailrace and the Alabama River. Results of the investigation indicated the following: (A.) No serious navigation difficulties should be experienced through the Jordan Reservoir and in the entrance to the diversion canal. (B.) Because of high velocities and crosscurrents, navigation conditions could be hazardous through the Bouldin Reservoir when the pool is below el 248.0 even with a 220-ft-wide channel and the bottom at el 233.0. No serious navigation difficulties were indicated with a pool at el 252.0 and a 220-ft-wide channel. (C.) With a steady powerhouse flow of 27,000 cfs and low tailwater, tows with sufficient power to overcome the high-velocity currents could negotiate the powerhouse tailrace and lower lock approach channel without serious difficulties. However, lock emptying and start of powerhouse units would create surges that would be hazardous to navigation within the lock approach channel and in the reach downstream to below the confluence of the tailrace and the Alabama River, particularly with low tailwater. (D.) Hazardous conditions in the lower reach at the entrance to the lock canal could be reduced from 30 min to about 10 min after approach of the surge by increasing lock emptying time to at least 15 min and start of Bouldin powerhouse units at intervals of at least 10 min or by maintaining a high tailwater elevation. Surges hazardous to navigation could also develop when closing down one or more powerhouse units. NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ This study is concerned with a short reach of the Cumberland River just downstream of Barkley Lock and Dam. The reach is narrow and of irregular alignment with some very sharp bends and two fixed-span highway bridges, one located just downstream of the lower lock appr oach and the other located just downstream of a sharp bend. Currents in the reach are affected by continuous changes in powerhouse releases and changes in stages on the Ohio River located about 30 miles downstream of the dam. The model investigation was primarily concerned with navigation conditions in the lower lock approach and in the reach downstream and with the development of plans as required to provide satisfactory navigation conditions for both upbound and downbound traffic. A fixed-bed model reproducing Barkley Dam, the powerhouse, the portion of the lock downstream of the dam, and about 7.3 miles of the Cumberland River to an undistorted scale of 1:120 was used for the investigation. Results of the investigation indicated that with existing conditions navigation conditions are difficult and hazardous for large tows and are affected by changes in powerhouse releases, eddy currents, high velocities , and sharp bends. Conditions could be improved by increasing the interval between the increase or decrease of the number of powerhouse units in operation, adding dikes downstream of the powerhouse and lower lock guard wall, and increasing the width of channel and realignment of the banks in the sharp bends. Increasing the tailwater elevation with control structures would produce only limited navigation benefits, particularly during higher flows, and would substantially decrease the head available at the powerhouse.

Source: https://erdc-library.erdc.dren.mil/jspui/ This investigation was concerned with the development of plans for the Smithland Locks and Dam located on the Ohio River at mile 918.5. The study indicated that satisfactory navigati on conditions could be developed with a 17-gate or 11-gate spillway and with a 600- and a 1,200- ft lock or with two adjacent 1,200-ft locks. With two 1,200-ft locks, a new concept in the arrangement of the lock auxiliary walls was developed that would improve navigation conditions, particularly for downbound tows. Ports will be required in the upper guard walls to reduce the tendency for crosscurrents near the ends of the walls. Shoaling in the lower lock approach will be a maintenance problem but could be minimized with the use of wing dikes along the lower end of the lower guard wall. Developments in the lower reach are affected by divided flow and intermittent flow from the Cumberland River. Dike structures will be required along the right bank downstream of the locks to prevent the channel from meandering and migrating toward the right bank. There will be a tendency for some shoaling in the channel between Cumberland and Towhead Islands approaching the mouth of the Cumberland River, particularly when there is flow to the left of Towhead Island, and reduction in flow in the channel to the left of Cumberland Island. There will tend to be a greater concentration of flow toward the gate bays near the fixed weir, particularly with the 11-gate spillway, causing a deep scour hole downstream of the gates and shoaling to the left downstream of the fixed weir. Flow through the gates near the fixed weir can be improved by moving the fixed weir about 160 ft upstream of the axis of the dam and tying into the left spillway abutment pier in a curve forming a guide wall. Scouring will occur near the upper corner and riverside face of the gated spillway cofferdam, but the scouring can be moved away from the cofferdam with a deflector developed during the study. Results also indicated conditions that will exist during various phases of construction._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ Locks and Dam 26 Replacement is proposed for construction on the Mississippi River about 2 miles downstream of the existing locks and dam at Alton, Illinois, as part of the program for the modernization of navigation facilities on the river. The project would replace the smaller existing structure with a large, modern structure designed to handle two-way traffic. The proposed structure would include two parallel locks separated by two 110-ft gate bays along the left bank and a dam consisting of a gated spillway and fixed overflow section. A fixed-bed model reproduced about 6.7 miles of the Mississippi River Channel, Ellis and Maple Islands, and the adjacent overbank areas to an undistorted scale of 1:120. The model study was concerned with the composition and configuration of the dam, arrangement and separation of the locks and lock walls, and navigation conditions in the lock approaches. The investigation has produced the following general results and conclusions: (A.) Satisfactory navigation conditions for two-way traffic could be developed at either the existing site or the proposed replacement site by providing gates between the locks. The number of gates in the proposed gated spillway could be reduced to seven without producing any significant changes affecting the movement of a tow approaching the locks. (B.) Currents in the upper approach to the landward lock at the alternate site would be affected by the eddy forming along the left overbank. Placing a fill along the overbank to an elevation above normal pool would reduce the effect of the eddy on navigation. (C.) Ports will be required in the upper guard walls to reduce the intensity of the crosscurrent near the end of the walls. The riverward lock guard wall should extend farther upstream than the landward guard wall. (D.) In the lower lock approaches, navigation conditions for two-way traffic could be improved with guard walls shorter than 1200 ft. (E.) With the locks separated, navigation conditions could be developed in both the upstream and downstream approaches with the locks used simultaneously without the operation of one interfering with the operation of the other. (F.) During construction of the project, adequate navigation conditions could be maintained by using a three- stage cofferdam with the first stage located on the Missouri side and the third stage along the Illinois side. (G.) Scouring of the bed can be expected along the upper corners of the cofferdams on the river side, particularly during long periods of extreme flow conditions. Along the main cofferdam, scouring can be eliminated or minimized with a deflector installed at the upstream corner on the river side of each cofferdam._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ In connection with the MRC Potamology Program, movable-bed model studies were conducted of seven of the most complex and troublesome reaches of the Mississippi River to obtain some quick general indications of the effectiveness of plans proposed for the improvement and stabilization of those reaches. Because of the limited time available, the studies were conducted in an existing facility with little or no adjustment of the models and in some cases without a base test. Because of the limited size and shape of the facility available, only a relatively short reach of the river including the problem could be reproduced in each model with little or no overbank areas . The horizontal scales varied with each reach depending on its size and shape and were much smaller with a higher distortion of the linear scales than was considered desirable for studies of this type. An analysis of the model results compared with developments in the river based on an evaluation of considerable prototype data indicated that the types of models used predicted, at least qualitatively , most of the principal trends that actually occurred in the river with the plans tested. The degree of accuracy of the models varied and depended to a considerable extent on the model adjustment, characteristics of the reach, flow conditions, and similarity between plan tested and actual construction. The analysis of model and prototype data permitted an evaluation of the performance of various types of dikes and dike systems and some of the principles involved in the developments within alluvial streams._x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ The need for locks and dams for the development of navigation on some streams and the problems that could be encountered are discussed in this report. Satisfactory navigation conditions depend on the site selected, characteristics of the stream, orientation and arrangement of the structure and related facilities, and type of traffic anticipated. Tows approaching the locks could be affected by adverse currents that could be hazardous or cause delays. The lock arrangement should consider the currents to be caused by the completed structure and the effects of these currents on the movement of tows. Model studies can be invaluable in determining the adequacy of a proposed structure and modifications required to eliminate any undesirable conditions. New concepts in lock arrangements should be considered to improve safety and efficiency. Shoaling in the lock approaches can present serious problems but can be eliminated or minimized with special structures. Cofferdam plans should consider maintenance of navigation during construction and the effect of scour on its stability. Deflectors can be used to move the scour area away from the main cofferdam.

Source: https://erdc-library.erdc.dren.mil/jspui/ McAlpine Locks and Dam are located on the Ohio River near Louisville, Kentucky, 606.8 miles below Pittsburgh, Pennsylvania. The locks are located in a bypass canal on the left overbank landward of Shippingport Island. A powerhouse is located along the left bank adjacent to the downstream end of Shippingport Island, and a four-gated spillway section is located adjacent to the powerhouse. A fixed-crest weir extends from the four-gated spillway section upstream 6,600 ft generally parallel to the right bank to an upper five-gated spillway section which is connected to the right bank with a 1,200-ft-long fixed-crest weir just upstream of the Pennsylvania Railroad bridge. The structures, designed to maintain a minimum upper pool during low flows extending about 75 miles upstream to Markland Locks and Dam near Warsaw, Kentucky, include a navigation lock with clear chambers dimensions of 110 ft wide by 1,200 ft long located at the lower end of a 1.75-mile-long canal along the left bank and two auxiliary locks between the main lock and left bank that are out of service. A fixed-bed model reproduced about 8.5 miles of the Ohio River channel, the lock approach canal, and adjacent overbank areas to an undistorted scale of 1:120. The model investigation was concerned with improving navigation conditions at the entrance to the lock approach canal; developing modifications required to remove shoaling along the right bank just downstream of the fixed weir at the upper gates; determining the effectiveness of dam modifications on reducing swellhead at the dams; determining the effect of a proposed dike design to reduce scouring along the Indiana bank opposite the lower tainter gates; investigating the effect of an additional 1,200-ft lock on navigation; and investigating the effect of lock filling on surge within the lock approach canal with the proposed additional lock. Results of the investigation revealed that of the plans tested, the greatest improvement in the canal was obtained with a 600-ft long low dike forming an extension to Shippingport Island. Increasing the number of gate bays and gates to the right of the upper gated spillway or lowering the elevation of the overflow fixed-crest weir would increase the range of controlled flows. Deposition along the right bank downstream of the Pennsylvania Railroad bridge could be reduced with the addition of gates to the right of the existing upper gated spillway or by construction of a training dike to divert flow from the existing upper spillway toward the deposition area. Scouring along the right bank opposite the lower gated spillway could be reduced by construction of a deflector dike between the spillway and the right bank; however, velocities would tend to be increased farther downstream. Velocities impinging on the right bank could also be reduced with flow through the upper gated spillway during lower flows. Surges created by lock filling can vary appreciably, depending on the surge remaining after a previous filling and other factors such as traffic, wind, river discharge, and rate of filling. Proper phasing of the filling of the second lock can reduce the surge produced to heights equal to or less than those produced by filling the first lock. Satisfactory navigation conditions could be developed with two 1,200-ft locks arranged as tested. When emptying the two 1,200-ft locks simultaneously on the riverside of both locks, erosion along Sand Island could be increased to a point that it might have some effect on navigation in the lower approach. _x000D_ _x000D_ NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ The Red River between miles 68.6 and 79.2 was selected as a typical troublesome reach in which to determine the general channel realignment, training, and stabilization structures necessary to provide a navigation channel of adequate depth and width that would be stable and require minimum dredging. The movable-bed model was built to a horizontal scale of 1:150 and a vertical scale of 1:100. The following conclusions were indicated by the model investigation: (A.) The natural channel of the Red River and typical cross sections proposed for cutoffs were too wide to provide adequate navigation channel depths without contraction and stabilization structures. (B.) Considerably more length of dike was required to maintain an adequate navigation channel when the existing river alignment was followed than when an improved channel alignment was used. (C.) Preservation of old bendways created by channel realignment was substantially improved by a closure of the upper end to top bank elevation and the construction of structures designed to block movement of sediment-carrying bottom currents entering the lower end of the channel.

Source: https://erdc-library.erdc.dren.mil/jspui/ Alexandria Reach is a section of the Red River approximately 87.3 miles upstream of the junction of the Red and Mississippi Rivers. The reach is included in the Red River Navigation Project and will be about 14 miles upstream of Lock and Dam No. 2. There are five bridges in the reach within a distance of less than 2 miles . A fixed- bed model reproducing about 3.5 miles of the river in the vicinity of Alexandria, Louisiana, to an undistorted scale of 1:100 was used to determine navigation conditions through the reach and to develop modifications required to eliminate any adverse conditions indicated. The model investigation was concerned principally with navigation conditions approaching and through the bridges. Results of the investigation indicated the following: (1.) With existing conditions, navigation through the reach will tend to be hazardous, particularly for downbound tows because of the arrangement and limited width of the navigation spans, the channel and current alignment approaching the bridges, and the high-velocity currents. (2.) The high-velocity currents with the water-surface elevations anticipated in the reach indicate that some scouring of the channel bed and changes in channel cross section can be expected with the completed project. (3.) Navigation conditions through the reach with the existing bridges can be improved by modification of the revetment along the left bank in the cutoff and just downstream of the cutoff, excavation of the right bank between the two upper bridges, excavation and addition of a dike along the left bank upstream of the U.S. Highway 165 Bridge, and addition of submerged dikes along the right bank. (4.) Navigation conditions in the lower reach would be considerably better with the replacement of the U.S. Highway 165 Bridge. (5.) Navigation through the reach will tend to be hazardous because of the limited widths of spans divided by a center pier, alignment of the channel and bridge spans, and short distance between some of the spans. Satisfactory navigation conditions would require the use of tows with sufficient power and maneuverability to maintain control and alignment and widths of tows limited to 35 ft.

Source: https://erdc-library.erdc.dren.mil/jspui/ This investigation was concerned with the development of parameters that could be used as a guide in the layout and design of shallow-draft waterways, particularly bends and straight reaches between bends. Results are based largely on model studies using different linear scales and some limited prototype tests. In negotiating a bend or making a turn, tows occupy a greater channel width than in straight reaches. The width of channel required depends on the deflection or drift angle which varies with the size of tow, radius of the bend or turn, length of the bend up to about 90 deg, alignment and velocity of currents, weather conditions, direction of travel (upstream or downstream), draft of tow with respect to channel depth, alignment and location of the tow when entering the bend, and maneuverability of the tow. If the deflection angle assumed by a tow in negotiating a bend is known, the width of channel required can be computed using one of the equations from this study. Results include curves showing the deflection angle assumed by tows of various sizes in bends of different curvatures with and without currents. Also covered are bends consisting of compound curves, bends with irregular bank lines, and lengths of straight reaches required between alternate bends. Principal results have been included in OCE Engineer Manual EM 1110-2-1611, Layout and Design of Shallow-Draft Waterways, 31 December 1980.