REPORT ON
POTENTIAL HEASURES TO ALLEVIATE PROBLEMS
CREATED BY CURRENT HIGH LAKE LEVELS
TASK S
ST. CLAIR/DETRQIT RIVERS
TO THE
.- INTERNATIONAL JOINT CQMHISS9QN
FROM
TASK GROUP MEMBERS
REG- GOLDING RONALD W ILSHAW DAVE SHlTH FRANK QUINN BENJAHIN DE C06)KE TQH HARTIN
OCTOBER 1987 As a result of record high Great Lakes water levels in 1985 and 1986, the Governments of Canada and the United States issued in August, 1986, a Reference to the International Joint Commission for a comprehensive multi-year study of methods to alleviate the adverse consequences of fluctuating Great Lakes water levels. The Governments asked for an - interim report in one year and a final report by Hay 1, 1969. This report on the 'St. Clair/Detroit Rivers' forms part of the documentation which may be used in the preparation of the Commission's Interim Report and deals with measures which can be taken in the short-term to alleviate some of the high water problems. The work reported on herein, has been divided into three areas; the first objective denls with an analysis and review of historic information to determine the effect of the dredging and compensation that has been placed in the St. Clair/Detroit Rivers; the second section deals with the physical and environmental impacts and the cost of removal of the compensation, which has been placed in the Detroit River; the third section deals with the physical and environmental impacts and cost of placing additional compensation to offset the effect of dredging in the St. Clair River.
In its natural state, the Detroit River had limited navigation due to a rock ledge located in the lower river. This ledge, known as the Limekiln Crossing, was partially removed to a depth of 13 feet in 1876. Since that date, there have been numerous projects of both dredging and the placing of compensetion to offset the effect of deepening the river. The last project (known as the 27 foot navigation project) was completed in 1962. This project provides for depths that would allow 25.5 foot safe draft for vessels navigating the river. It also included the placing of compensation to offset the effect of this and post projects. The work on placement of these works was completed in 1959. The net impact on lake levels of this work is to raise Lake Michigan-Huron levels 0.0 1 foot and Lake St. Clair 0.02 foot.
Work on deepening the St. Clair River began in 1855 and provided minimum navigation depths throughout the river of 20 feet. As in the case of the Detroit River, navigation improvements have continued over the years (1 920- 1922; 1930; 1956). The last project provided for a safe draft for navigation of 25.5 feet. In addition to that dredging, there has been periodic dredging for the removal of sand and gravel from the river bed (1908; 1925). In general, no compensation was provided in connection wlth this work, except to dump spoil material in the deeper sections of the river. Some compensation, however, resulted from the sinking of the Steamers Fontana and Martin in 1900, which raised the levels of Lake Huron by 0.1 1 foot. The net effect of the dredging and compensation for the 25 and 27 foot navigation projects was a lowering of Lake Michigan- Huron by 0.59 foot. Work prior to the dredging for the 25 foot project lowered Lake Hichigan-Huron an additional 0.69 foot, which was partially offset by the sinking of the two steamlers. The net effect of all dredging and compensation placed to date, is a lowering of Lake Huron and Lake Hichigan by approximately 1.17 feet and Lake St. Clair by 0.15 foot.
The work in these two rivers over the years has also affected the ice retardation of the flow. This subject was dealt with in the report'on 'Ice Hanagement.' The net effect on lake levels resulting from the change in retardation is to lower the mean levels of Lake Michigan-Huron, St. Clalr and Erie by 0.10 foot, 0.07 foot and 0.05 foot respectively.
Removal of the compensation placed in the Detroit River to offset the effect of the 27 foot navigation project would cost in excess of sixty million dollars. Such a project would take approximately five gears to complete and result in a lowering of Lakes Michigan-Huron and St. Clair by 0.15 foot and 0.10 foot respectively. The effect on Lake Erie would be substantially dissipated inless than three years. A lowering of this magnitude would be beneficial to shoreline interests on Lakes Superior and Michigan-Huron by reducing erosion and inundation. There would also be a benefit to recreational users of these lakes. However, during the transition period, Lake Erie would experience a higher rate of erosion, inundation of low lying areas and loss of beach area. The removal of the Detroit River compensation works would have little effect on power productian on the Welland Canal or the Niagara and St. Lawrence Rivers. Some benefit to power would accrue to the plants located on the St. Glary's River. The removal of the compensating works would disrupt the Detroit River navigation profile and have a negative impact on commercial navigation users throughout the system. The environmental effect can be classified into two periods; the construction phase and; second, the long-term effect of lower levels. During the construction phase there would be a stirring of the bottom material and sediments col~ldcause the covering of spawning areas and disrupt growing vegetation. The Detroit River bottom material is known to contain excessive pollutants which will require special handling. The removal of the compensation works would change flow patterns and could interfere with the migration af fish. The Detroit River receives industrial discharge and municipal sewage. The current structure tends to pool water and promote Increases in fecal coliforms. Removal of the existing structures would tend to improve this situation.
Several methods of compensating in the St. Clair River to offset the lowering of Lake Hichigan-Huron, caused by the 25 and 27 foot navigation projects, have been studied over the years. These studies Indicete thet it is technically possible to place sills in the river to raise Lake Michigan- Huron levels by 0.59 foot (the effect of these two projects). The cost would be approximately 25 million dollars with e construction period of from 3 to 10 years. The placing of sills would also raise the levels of Lake Superior and have a lowering effect on Lake Erie. The raising of Lake Superior is caused by use of Plan 1977 for determining the release of water from Lake Superior. Plan 1977 atterrlpts to balance the levels on Lakes Superior and Michigan-Huron about their long-tern mean levels. Hence, higher levels on Lake Michigan-Huron will reduce the outflow from Lake Superior, causing higher levels on that lake. The increase in levels would have a negative effect on shoreline interests by increasing erosion and inundation of low lying areas. Loss would also occur to users of recreational beaches. A small benefit would result to cities which have lake water intakes through a reduction in pumping requirements. The raising of the Lake Michigan-Huron level would provide some benefits to commerical navigation, with little impact on power developments in the lower Great Lakes. However, the raising of the Lake Michigan-Huron levels would have e negetive impact on St. Mey's River power production. Environmegtly, the long-term etfect of the higher regime of levels on fishey and wildlife would be transitoy during the period of habitat adjustment. However, there would be further loss of wetland due to I inundation. I POTENTIAL HEASURES TO ALLEVIATE PROBLEtlS CREATED BY CURRENT H16H LAKE LEVELS ST. CLAIRIDETROIT RIVER
Executive Summary introduction
Objective A - Physical Effect of Works of Hen on the St. Clair and Detroit Rivers
Detroit River
St. Clair River
Detroit/St. Clair River Ice
Objective B - Removal of Compensating Works Detroit River
Impact on Users of System of Removal of Compensating Works
Construction Procedure and Cost
Objective C - Navigation Improvements St. Clair River
Compensation.
Impact and Cost to Users of the System of Placing Compensation in the St. Clair River FIGURES
Figure Wo. Title Page
Map of Detroit River 4
Flow Velocities - Detroit River 5
Map of St. Clair River 1 I
Flow Velocities - St. Clair River 12
Location of St. Clair 23 Cowrpensation (Sills) Works
TABLES
Table No. Title Page
Physical Effect of Regime 9 Changes in the Detroit River
*Physical Effect of Regime 14 Changes in the St. Clair River
REFERENCES
References REPORT OH POTENTIAL HEASURES TO ALLEVIATE PROBLEHS CREATED BV CURRENT H16H WAfER LEVELS
TASK 5
ST. CLAIR/DETROIT RIVERS
troduction
As a result of record high Great Lakes levels in 1985 and 1906, the Governments of Canada and the United States issued, in August 1986, a new reference to the lnternationa,doint Commission for a comprehensive mu1ti-year study of methods to alleviate the adverse consequences of fluctuating Great Lakes water levels. The Governments asked for an interim report in one year and a final report by May 1, 1989. This report en 'St. Clair/Detrei t Rivers' forms part of the documentation which may be used in the preparatian of the Commissions's Interim Report.
The work under this task has been subdivided into three objectives.
-Objective A
1. Determine, based on existing studies and analysis, the physical effects of channel dredging and subsequent compensating works in the Detroit River since 1900.
2. Determine, based on existing studies and analysis, the physical effects of sand and gravel removal and navigation dredging in the St. Clair River since 1900.
3. Prepare summary tables showing the physical effects of St. Cl air/Detroi t River dredging and compensating works. Objective B
1. Determine the technical possibilities of modifying the compensating works in the Detroit River and the resulting impacts on:
e. Upstream end downstream lakes Ib. Bower c. Navigation d. Environment
2. Identify the difficulties and remedies associated with the removal of any compensating works; identify refilling procedures or replacement of compensating devices and determine the cost and time frame to perform these actions as well as any associated environmental concerns.
-Objective C . .
1. Review previous reports by the Corps of Engineers of St. Clair River compensat ing works.
2. . Based on the review, determine the technical possibility of installing addi tione1 compensating works.
3. Identify difficulties associated with the construction of any compensating works; determine cost and time frame and any associated environmental concerns. PHYSICAL EFFECT OF THE WORKS OF HAW ON THE ST. CLAIRIDETROIT RIVERS
Petroit River .. -
The Detroit River, shown on Figure 1, is the natural channel which connects Lake St. Clair to Lake Erie. The river is approximately 32 miles + long from its head at the Windmill Point Light to its mouth at the Detroit River Light in Lake Erie. The river flows in a sol~therlydirection and falls about 3 feet between the two lakes. The river is characterized by two distinct reaches. The upper reach extends downstream from Lake St. Clair to the head of Fighting Island, about 13 miles. In this reach, the river consists of a single channel averaging about 2000 feet wide, except directly at its head, where it is divided by Peach Island and Belle Isle. The reach is generally deep; the bottom consisting of sand and clay and the channel banks are quite steep. Flow velocities, as shown on Figure 2, ere fairly uniform, ususally less than 2.5 feet per second (fps), even under high flow conditions. Higher velocities occur in the vicinity of the Ambassador Bridge, where the river constricts to a width of 1900 feet. Velocities in the center of the channel, in this one and one-half mile stretch, reach 3.5 to 4.0 fps during high flow conditions.
The southerly or lower reach of the Detroit River is broad with several islands and a shallow expanse. In the upper part of this reach, the channel banks rise with d gentle slope and the bottom consists of sand, clay, boulders and rock. In the six mile stretch from just downstream of Fighting Island to the south end of Bois Blanc Island, the bottom is mainly bedrock and boulders. The natural formation of the lower river bed has required very extensive rock excavation and dredging, to provide navigation channels of suitable width and depth for the large vessels engaged in lake commerce.
The major dredged navigation channels are located in the lower Detroit River. From the head of Fighting Island, the Trenton channel branches west from the navigation route and separates Gross lle from the U.S. Mainland. River depths at the south end of the Trenton Charmel are less than 10 feet and do not pennit through navigetion of deep-draft vessels. Further upstream, at the head of Stony Island, the main navigation route (8allards Reef Channel) divides into the Livingstone - - -- -. DETROIT RIVER ..
......
NU 8OUQL
- - .. -. ..
DETROIT RIVER AVERAGE VELOCITIES
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Q= su,omihY Q = [email protected] eta h Channel to accomodate downbound traffic (west of Bois Blanc Island) and the Amherstburg Channel, to accomodate upbound traffic (between Boic Blaric Island and the Canadian mainland).
Water depths in the river vary in accordance with the seasonal levels on Lakes St. Clair and Erie. Fluctuations of several feet, lasting over periods of several hours, occur as a result of the effects of meteorologic disturbances on Lake Erie. Such fluctuations are produced by high easterly or westerly winds, which cause the water levels to vacillate (seiche) in the western end of Lake Erie. These changes have been as great as eight feet within a five-hour period (April 6, 1979).
In .its natural state, the Detroit River limited early navigation by the presence of a rock ledge known as the Limekiln Crossing, extending east from Stony Island, at a depth of about 13 feet. Deepening of the Limekiln Crossing Channel began in 1876 and provided for a curved channel 20 feet deep by 300 feet wide. In 1884, during the progress of clonstruction, this was changed to a straight channel with the same dimensions. The work on this charmel was completed in 1686. In the same year, further work began on widening the channel to 440 feet. This work was completed in 1090. Between 190 1 and 1904, the channel was widened to 600 feet. In 1906, the United States removed an additional 2,632 cubic yards of rock to provide a 20 foot deep channel.
The Great Lakes Ship Canal project was adopted in 1892 and provided for a 2 1-foot channel having a minimum width of 300 feet. Under this - project a 20-foot channel was constructed through Ballerds Reef, just upstream of Limekiln Crossing with construction of a 2 1 by 800 foot channel through the shoal at the mouth of the Detroit River. In 1902, further wwk in the lower Detroit River was authorized, consisting of widening of the Ballards Reef to 600 feet with a depth of 21 feet and construction of the Amherstburg Channel (21 feet deep by 500 feet wide). From that date through 1908 the following occurred; further enlargements of the navigation channel occurred at the Limekiln Crossing location; and removal of islolated shoals in the navigation channel through the lower Detroit River and in Lake St. Clair at the head of the Detroit River. These improvements permitted 2 1 foot navigation through the entire river. There is no indication in any of the authorization documents of any attempt to balance the effect of this dredging with any form of
\_ 1 compensation. Review of the authorizing documents related to the above projects, and those discussed later, related to work'in the St. Clair River, does not provide a clear indication of the separate net effect on upstream lake levels of the deepening of, and compensation placed *inthese rivers. However, Horlon and Grunsky (1927) did ascertain what the net effect of work in the St. ClairIDetroit Rivers had on the levels of Lake Michigan- Huron. They compared conditions which existed between 1860 to 1685 with those for the period 1697 to 1922. This comparison indicated that the levels during the latter period (1697 to 1922) were from 0.35 foot to 0.70 foot lower than they would have been had natural conditions (1 860 to 1865) in the StClair and Detroit Rivers been left undisturbed. The Report of the Chief of Engineers, for 1904, makes a similar determination. The effect determined was 0.8 foot. Construction of the Livingstone Channel began in 1908 and was completed in 19 12. The channel had a width of 200 feet and a depth of 22 feet. Between 1920 and 1922, the channel was widened to 450 feet. To compensate for this deepening of the river, two dlkes were placed. One dike extended downstream from the Upper Entrance light along the west side of Amherstburg Channel for a distance of 10,000 feet. The other dike extended downstream from the lower end of Bois Blanc Island to, and 100 feet westerly, from the Amherstburg Channel for a distance of 6,200 feet. In addition, some dumping of dredged material was performed on the west side of the Limekiln Crossing Channel, see Figure 1.
Between 1932 and 1936, the Livingstone Channel was further deepened, to provide for 25 foot navigation through the river. After completion of the work in September 1936, it was found that the dike system placed as compensation for the earlier project had raised water levels upstream more than necessary to offset the effect of the channel improvements.
Further deepening of the Detroit River was authorized on March 2 1, 1956 and is commonly known as the 27 foot navigation project. The approved project provided for depths that would allow 25.5 feet of safe draft for vessels when Lakes St. Clair and Erie are at Low Water Datum. To make such drafts possible, additional depth was provided to allow for vessel squat, clearance for exposed hard or soft bottom areas, clearance for she1tered hard bottom areas, and for lake level variations with respect to Low Water Datum. The project provided for further constriction of the flow in the upper reach of the Amherstburg Channel and the Construction of an additional dike downstream from Bois Blanc Island. This work was completed in 1959. The work on deepening of the channels was completed in 1962. P The deepening of the Trenton Channel began in 1940 (See Figure 1). The project provided for a tuming basin 1,700 feet below the lower Grosse Ile Bridge and a 250 feet wide, 2 1 foot-deep channel from the main pavigation channel to the tuming basin. In 1964, additional dredging was completed to provide for a 300 footwide, 27 foot-deep channel from the. main navigation channel to the Upper Grosse Ile Bridge; and for a 300 foot wide and 28 foot deep channel extending about 6,000 feet below the bridge, to and including, en upper turning basin 28 feet deep and 15 acres in area, outside the channel limits.
The net effect of the latter and all the work described above is shown inTable I. ,.
TABLE 1
PHYSICAL EFFECT OF REGIME CHANGES IN THE DETROIT RIVER IN FEET
Lake Huron Lake St. Clais Deepening of Limekiln Crossing Channel -0.35 to -0.70( 1 ) 1876- 1908
Construction of Livingstone Channel 1908- 1922
Compensation for Construction 0 +0.06 (2) of Livingstone Channel 1922
Construction of 25-font Navigation Channel and Compensation +0.04 (3) +0.07 (3) 1932-36
Cons?ruction of 27-foot Navigation Channel and Compensation -0.03 (3) -0.05 (3) 1959- 1962
Deepening of Trenton Channel 0 1940- 1964
NET EFFECT +O.O 1 (4) +0.02
Negative velues indicate a lowering of levels; Positive values indicate a raising of levels.
(1) Combined effect of work on St. Clair- Detroit Rivers. (2) U.S. Lake Survey File Report 3-3083 March 1946. (3) Misc. Paper 65- 1 US ~ake'surve~,October 65. (4) Disregarding corr~binedeffect of work on St. Clair-Detroit Rivers. St. Clair River
The St. Clair River, shown on Figure 3, is the natural channel which connects Lake Huron to Lake St. Clair. The river is approximately 39 miles long, flows in a southerly direction and falls approximately 5 feet between the two lakes. The St. Clair River has three distinct reaches. The upper reach, extending downstream from Lake Huron to a point about three miles below the International Blue Water Bridge, is about 800 feet wide at Its narrowest point and has mid-channel depths varying from about 30 to. 70 feet. The river in this reach is a single channel with maximum velocities of 5 to 6 fps occurring near the Blue Water Bridge. The middle reach, extending downstream another 27 miles, is about one-ha1 f mile. wideand has channel depths varying from 27 to 50 feet. Velocities in this reach vary between 1 to 3 fps. Located in this reach are Stag and Fawn Islands and a middle round shoal opposite the City of St. Clair, Michigan. The lower reach extends downstream for the remaining 9 miles of the river to Lake St. Clair where it divides into a number of channels which flow across a delta called the St. Clair Flats. The average velocity in this area is generally about 1 fps except in the upper North and Cut-Off channels, where it may exceed 2 fps. Flow velocities for the entire river are shown in Figure 4.
In its natural state, the St. Clair River had depths of 20 feet or more throughout most of its length, excluding is1olated shoals. However, near its mouth, at Lake St. Clair, the natural depth was only four to six feet. Deepening of the South Channel of the St. Clair Rlver, where this channel joins Lake St. Clair, began in 1855. The opening of the East and West channels through the Flats occurred in 1906. These improvements, which provide minimum navigation depths throughout the river of 20 feet, had an effect on levels. As noted under the Detroit River discussion, there has been no determination of individual effects, however the combined effect as determined by Horton and Grunsky 1927 and the Corps of Engineers (1 904) is shown on Table 2.
On August 4, 1900, the Steamer Fontana was wrecked in the narrows at the head of the St. Clair River and on September 22 of the same year, the Steamer Martin was wrecked at the same point. Only the superstructures and machinery of these vessels were removed. Their hulls still lie on the river bottom near the west shore buried'in the sand. These wrecks have decreased the cross sectional area of the river at its narrowest point causing a reduction in the capacity of the river, and in ST. CWR RIVER .AVERAGE VELOCITIES (Baaed rn .St. Clalr Rlver Model 1981 Callbratlon)
.-. .. .--,
-. ---A_. _. --
...... - - ......
.-- . ,...... -... turn hove raised the levelsof Lake Michigan-Huron. The effect of the obstruction is shown in Table 2.
In 1908, commerical interests began to remove sand and gravel from the bed of the river. It was estimated that between that date and 1925, three and one-half million cubic yards of sand and gravel were removed, most of it in the upper portion of the river. During the period 1920- 1922, dredging was performed in the interest of improving navigation. This work - general1y involved the removal of isolated shoals along the river. During this period commerical interests also removed large quantities of sand and gravel from the North Channel below Algonac, Michigan. In 1925, all sand and gravel dredging in the river was prohibited. TABLE 2
PHYSICAL EFFECT OF REGIME CHANGES IN THE ST. CLAlR RIVER IN FEET
Lake Huron* Lake St. Clair* Deepening of River For 20-Foot Navigation -0.35 to -0.7( 1 ) ** 1855- 1906-
Removal of Shoal in St. Clair Flats - 1906
Sinking of Steemer Fontana and Martin 1900
Send end Gravel Removal -0.30 (3) 1908- 1925
Construction of 25-Foot Nevigation -0.. 15 (4) Channels and Compensation 1933- 1937
Construction of 27-Foot Navigation -0.44 (5) Channels and Compensation 1960- 1962
Effect of Ice Retardation -0. 10 -0.07
NET EFFECT - t .17 to 1.52(6) -0.15 (6)
* Negative values indicste a lowering of levcls; Positive vslues indicate a raising of levels. **No effect available from historic literature.
1) Combined effect of work on St. Cleir-Detroit Rivers 2) Moore, S. U.SLS Inhouse Report File 3-2692 3) Report to IJC on "Regulation of Greet Lakes Water Levels," December 7, 1973. I I 4) Korkigian "ASCE" Vol 89, No WW2 Proc. Paper 351 1 May 1963 pp. 1-14 5) Obtained by taking difference between removal of shoal, St. Clair Flats and sinking of Steamers Fontana and Martin, and the reported total effects of 0.59 foot. 6) Does not include the effect of change in ice retardation.
The Rivers and Harbors Act of July 3, 1930, provided for deepening of the channels of the St. Clair River to a safe draft of 25 feet .in the downbound channels and 20 feet in the upbound channels when the levels of Lakes Huron, St. Clair and Erie are at their respective low water datums. Authorized project depths were deeper than the safe draft by one foot in soft bottom and two feet in hard bottom. This work was started in 1933 and was completed in 1937. No compensation was provided.in connection with the 25 foot project, except to dump spoil material from the dredging operatian into the deeper sections of the river.
The Rivers and Harbors Act of March 2 1, 1956, provided for a safe draft navigation channel of 25.5 feet in the downbound and two-way channel of the St. Clair/Detroit Rivers system when Lakes Huron, St. Clair and Erie are at their respective low-water datums. Project depths authorized ranged from 27 to 30 feet. Work began in 1960 and was completed in 1962. The project involved significant excavation in conjunction with the dredging of a new cut-off channel. Project authorization also included the construction of submerged sills for compensation in the St. Clair River, b~~tthese have never beerr put in place. However, some compensation has resulted from the concentrated dumping of spoil material above Bag Point Light, and the random dumping of spoil material in other areas of the river.
The effect of the described actions on the levels of Lakes Michigan-Huron and St. Clair are shown in Table 2. Other researchers may have computed effects other than those shown.
Detroit/St. Clair River Ice I As reported under Task 6 'Ice Management" channel modifications over the years in the Detroit/St. Clair River have resulted in a change in the amount of retardation of flow caused by ice. Historical data indicates that these conditions are not predictable for any specific winter, either as to their severity or to the exact timing of their occurrence. Computation of the effect of ice retardation on the levels of Lakes Michigan-Huron, St. Clair and Erie indicates that the effect is dissipated before the following Ice season on Lake St. Clair, but some of the effect remains on Lakes Michigan-Huron and Erie. On the St. Clair River, navigation improvements (with some compensation) have reduced the effects of ice; while on the Detroit River, navigation improvements (because of compensation) have restored ice retardation to approximately that which occurred, prior to the 25 foot navigation project. The net effect is to lower the levels of Lakes Michigan-Huron and Erie by 0.90 foot and by 0.05 foot respectively. On Lake St. Clair an anomaly occurs in that the average levels during January through March are raised by approximately 0.33 foot. Following that date, a more normal relationship develops on the lake, reflecting conditions about the same as on Lakes Michigan-Huron end Erie and a lowering of the average level of 0.07 foot. For details on the effect of channels changes on ice retardation, see Task 6 'Ice Management.' TASK 5
OBJECTIVE B REMOVAL OF COMPENSATING WORKS - DETROIT RIVER
Senate Document No. 7 1,64th Congress, 1st Session 'Great Lakes Connecting Channels - 19 July 1955 - Committee on Public Works," indicates that without compensation the proposed deepening of the downbound channel to 27 foot in the lower Detroit River between the Livingstone Channel Upper Entrance Light and the lower end of the dike section of the Livingstone Channel, would lower water levels on Lakes St. Clair and Michigan-~uronby 0.15 and 0.10 foot, respectively. Such a lowering would result in an increase in flow through the St. Clair-Detroit Rivers of 1300 to 1500 cfs and cause a transitory effect to Lake Erie levels, with the maximum effect being an increase of 0.07 foot. The proposed compensation and deepening discussed in the cited document was accomplished during the period 1959- 1962. Similarly, removal of the compensation, which was placed to offset the construction of the original Livingstone Channel and the deepening of the river for 25 foot navigation, would lower Lake St. Clair by an additional 0.13 foot. The total effect of both of these projects would lower Lake St. Clair by 0.20 foot and Lakes Michigan-Huron by approximately 0.15 foot. The combined cited lowering would cause a temporary increase in the flow of the St. Clair - Detroit Rivers, of approximately 1900 to 2200 cfs. Such an increase in flow would further raise Lake Erie by approximately 0.10 foot. This rise would be transitory.
ItlPACT ON USERS OF SYST En OF REMOVAL OF COMPENSAT IN6 WORKS
Shoreline Interests - The permanent removal of the compensation . - placed in the St. Clair-Detroi t Rivers to offset navigation improvements, would have a positive long-term effect on shoreline interests upstream, and negative short-term shoreline effects downstream of the rivers. The lowering of the Lake Michigan-Huron levels will result in less storage being placed on Lake Superior during high water periods under Plan 1977, thus providing, in general, benefits to shoreline interests on both these lakes by reducing erosion and inundation. On those lakes where shoreline protective structures are expected to be built, a benefit would also res~rlt based on the reduced structure crest elevation. It should be noted that, for the Canadian shoreline of Lake Superior, little effect on erosion rates would result from the lowering because of the generally higher rocky shoreline. Downstream from the St. Clair-Detroi t Rivers, the reverse of the upstream conditions would prevail. Lake Erie would be somewhat higher, thus increasing erosion and inundation during the period when it is adjusting to the temporary increase in flow.
From the standpoint of marine structures and recreational use of the upstream lake, the removal of the compensating works would have a small positi ve effect, inthat lower levels would prevent overtopping of docks and provide slightly more beach area. On the downstream lake a slight negative impact would be felt, since the reverse would result.
Based on the data available, it is concluded that for all lakes there would be no significant benefits or losses to water intakes or sewer outfalls resulting from the proposed action.
Power - Hydroelectric installations on the outlet rivers that could be affected by the changes in water levels and flows indicated above, are those existing on the St. Mary's River, Niagara River, the Welland Canal and the St. Lawrence River. The installations on the St. Clair-Detroit Rivers would not be affected since these are steam plants and do not generate hydro-power.
The plants located on the St. Mery's River would benefit from the lowering of Lake Michigan-Huron 1evels by increasing the amount of head at these plants. In addition, as a result of the lower Lake Michigan-Huron water levels, the flow' out of Lake Superior would increose during periods of normal to above normal water supplies. The increase in flow results from regulation of Lake Superior under Plan 1977, which is based on the balancing of the storage on the two lakes.
The resulting change in the levels of Lake Erie would have no effect on power production on plants located on the Welland Canal, nor on the plants located on the Niagars River. This is due to the fac't that the water utilized, approximately 7200 cfs by plants located on the Welland Canal, is allocated first from the Canadian entitlement of the Lake Erie diversion of water for power production in accordance with Article II I of the 1950 Niagara Treaty. Hence, there would be no change in their water allocation. Plants located on the Niagera River would not benefit since the proposed removal of the compensation would occur during o high water period. 1 3 Review of information contained in the Lake Erie Regulation Study indicates that flow in the high range (240,000 cfs and above) cannot be fully utilized for power production but must be discharged over the fells or passed through less efficient plants. However, some small benefits may accrue to these plants if the water supply would return to a more normal range and the Lake Erie levels were still in the transition period. It would appear from this brief analysis that there would be no overall benefit to Niagara River power production from the proposed action. - The increase inflow from Lake Erie would impact on the St. Lawrence Power plants in a similar manner to that cited for the Niagara Plants. As a result of the moderating effect of Lake Erie, the increase in flow could be accomodated by the present operating plan on Lake Ontario. The Increased flow during the transitory period would be passed downstream during a period of generally high flow, resulting in less effective use of the water for power production and little or no benefit.
-Navigation Interests - Commercial navigation evaluation-is based on - the concept that ships will take advantage of every inch of draft over the /:-j 1 J route traveled. As previously noted, by removal of the compensation there 'J would be a lowering of the levels of Lakes Superior and Michigan-Huron and a slight raising of the levels of Lake Erie. Since vessels will load to the least depth over the navigation route, the lowering on the upper lakes will be detrimental to this interest. The compensation which was placed in the river was also placed to provide a profile for 27 foot navigation. The removal of these works will disrupt this profile. Overall, the proposed action will hpve a negative impact on commercial navigation.
The area in question is extensive1y used for recreational boating. The removal of the dikes will enhance the full use of the river by providing for more safe passage and direct routes.
Environmental Effects - The enviromental effects can be-classifed --.... .-.. -... . into two periods; one, the construction phase and the second, the long-term effect of lower levels. Due to the small level change, which would result from the proposed action, in comparison to the total range in lake levels, no quantification of effects on fisheries nnd wildlife is possible with presently available data. However, during the estimated two years of dredging there would be a stirring of bottom material and sediments, which could cause the covering of spawning areas and disrupt vegetation growing in the affected areas. The dredging would also disrupt fish and invertebrates inhabiting the area. In addition, the dredge site is known to contain excessive pollutants which will require special handling. As a result of the removal of the compensation, flow patterns in the area will be changed and could interfer with the migration of fish between bakes Erie and St. Clair. There will also be a small fedl~ctionin Lakes flichigan-Huron and St. Clair wetlands caused by the lowering of levels on these lakes.
The Detroit River receives industrial discharge and municipal sewage. he present compensating structures in the river serve to pool water and promote increases in fecal coliforrns. Removal of the existing structures would tend to improve this situation. However, during the removal process there would be an increase in turbidity and a redistribution of the polluted bottom sediments. The water quality would be degraded with an increased hazard to human health. In addition, the removal of the dikes would also change the flow patterns which could alter distribution of pollutants and contaminants.
CONSTRUCT l ON PROCEDURE AND COST
Senate Document No. 7 1,84th Congress indicates that compensation for construction of the 27-foot navigetilon project was obtained by construction of:
a) A dike extending downriver from the upper entrance light along the west side of Amherstburg Channel for a distance of 10,000 feet.
b) A dike extending downstream from the lower end of Bois Blanc Island to and 100 feet westerly from the Amherstburg Channel for a distance of 6,200 feet.
A detailed procedure for removal of these works has not been developed, nor has the holding area for the removed material been located. However, it has been estimated that such a project would take approximately five years to complete and cost in excess of sixty-million dollars. The cost of replacing the material after the current high water has receded has not been estimated. TASK 5 .
OBJECTIVE C IYAVIGATIOH IHPROVHENTS - ST. CLAlR RIVER
Two major navigation improvements on the St. Clair River have been made since 1933. The first, which was completed in October 1936, deepened the river for 25 foot navigation. The second project, completed in 1962, provided for 27 foot navigation throughout the system. In both projects, spoil material was dumped in deeper sections of the river. No other compensation was provided in connection with the 25 foot project,. but provisions for additional compensation works were proposed in connection with the 27 foot project. Because of the deepening, the river channels became more efficient and required less slope than required prior to deepening, to discharge the same amount of water from Lake Michigan-Huron to Lake St. Clair. The effect of this deepening on the levels of Lake Michigan Huron has been studied both by the Corps of Engineers and the International Joint Commission (International Great Lakes Levels Board). Results of those investigations indicate that the net uncompensated lowering of Lake Michigan-Huron for the 25 and 27 foot projects has been 0.59 foot. The net effect of these two projects on Lake St. Cleir has been a lowering of 0.14 foot.
Several methods of compensation, to offset the above noted lowering, have been studied. ~hesestudies date back to 1926 when a report of a joint board of United States and Canadian engineers proposed the placing I of submerged sills in the river. The effect and feasibility of placing sills in the river was model tested at the Waterways Experiment Station (WES) in 1934 and 1964. The requirements specified for these model tests were - that the crests of the sills be located 30 foot below low water datum so as not to interfere with navigation, and that the cross-sectional areas . over the sills be 40,000 square feet or greater so that objection01 high velocities would not occur. These model tests indicate that it was technically possible to place these sills to satisfy the given requirement, and that using eight sills would raise the level of Lake Michigan-Huron approximately 0.50 foot at mean flow (see Figure 5 for suggested location). Additional studies and model tests have been made since that date to determine more effective sill placement and shapes. Each of these studies concluded that 1t was technicslly possible tooffset theef fect of this dredging and that as little as three sills could be used.
Other methods to obtain the necessary compensation have also been studied. These methods include (1) closure of the North Channel in the St. Clair River delta; (2) closure of channels east of Stag and Fawn Islands;. (3) parallel snd longitudinal dikes extending into Lake Huron; and (4) construction of a longitudinal dike extending downstream f mm Bay Point Light several miles (location shown on Figure 5).
Each of these a1 ternatives is technically feasible as a means of 'I offsetting the lowering of Lake Michigan-Huron caused by the navigation 1 improvement projects. However, each of the proposals would require construction in an area of the river used extensively by deep-draft navigation and for fishing and recreational boats. The reports indicated that these alternatives were more costly than the placing of sills and were unacceptable to the navigation and recreational interests and would not be recommended without further study.
(-j Shore1ine Interests - The lnternati onal Great Lakes Levels Board evaluated the impact of placing compensation in the St. Clair River for the restoration of Lake Michigan-Huron levels to those which would have occurred had the dredging for the 25 foot and 27 foot channels not been accomplished. The report indicated that there would be no impact on lakes I other than on Lake Michigan-Huron. However, the evaluation assumed that regulation-of Lake Superior would be conducted under the 1955 Modified Rule of 1949. Current regulation of that lake is under Plan 1977, which gave consideration to the levels of Lake Michigan-Huron in determining releases from Lake Superior. With placement of compensation in the St. Clair River, and under Plan 1977, the level of Lake Michigan-Huron would be higher, resulting in more water being stored on Lake Superior during high water supply periods. The Levels Board report indicated that as a result of the higher levels on Lakes Michigan-Huron (with compensation in place) there would be a detrimental impact on the shoreline interests on that lake due to an increase in erosion and inundation. A loss would also occur to the users of recreational beaches on Lake Michigan-Huron. With regulation under Plan 1977, these statements will also be true for Lake RLOULATORK STRUCTURE AT PORT HURON REQUlATORY STRUCTURE AT STAO ISLAND REOIJlAfORY SfRUCIURt IN NURT H' & MIDDLE CHANNLLS Superior. Downstream from Lake Michigan-Huron there should be some 3 benefits due to the reprogramming of the sutflows from Lake Superior and the decrease in the increased Lake Michigan-Huron levels due to the storage of water on Lake Superior. The higher levels on Lakes Michigan- Huron and Superior should provide some smell benefit to recreational boating and water intakes through a reduction in pumping requirements. The Levels Board report further indicates that since 1933, shoreline users and shoreline development have gradually adjusted themselves downward to the lower regime of water levels. This trend has continued since the Levels Board report was completed. Hence, the placing of compensation in the St. Clair River and the raising of levels on the upper lakes would compound the negative impacts noted above, which far outweigh the benefits derived for boating and at the water intakes. --Navigation - As far as navigation is concerned, the benefits derived as a result of the higher regime of levels would be small. Even with the higher levels on Lake Michigan-Huron, the percentage of time when channel and harbor depths on that lake and its connecting chennel, control navigation, is not significantly greater than under the 1962 conditions. Lake Superior is general1y the controlling lake for all intra-lake navigation. Power - The Levels Board report indicates thet since there. would only be a slight variation in the flow in the St. Mary's and Niagbra Rivers, caused by the change in regime, there would be little impact on power At the present time, this would still be true. Environment - Environmently, the effect of the change in-regime on fishery and wildlife would be transitory; for example, the habitat adjusted to the changed regime during the period 1930's to the 1960's. This adjustment would probably occur again with adjustment to the higher regimes. However, there could be a further loss due to inundation of existing wetlands. The 'life styles of individuals using the lake may also be somewhat altered due to the further loss of recreation areas and security associated with the lower levels. -Cost - Authorization for placement of the compensation sills was described in House Document No. 253,70th Congress Ist Session and in Senate Document No. 7 I,84th Congress Ist Session. Review ofthese documents and further study of the matter indicate that total compensation, which would offset the channel deepening and restore Lake - Michigan-Huron levels, can be accomplished by the placing of from three to eight sills. The exact number of sills required to produce the desired results cannot be foretold with assurance. The construction of the sills should be executed consecutive1y, their effectiveness determined by slope and discharge observation as the work proceeds, and stopped, when the desired results are secured. Under this procedure, the initinl sills would be placed in accordance with the studies made in 196 1, 1965 and 1972 a period of stabilization observed, and measurements made. Such a iconstruction sequence could take from 3 to 10 years. lnitial cost of placing three sills, as determined by the June 196 1 Design Memorandum, would be approximately $25 Million (1 987 Dollars). REFERENCES Coordinating Committee on Great Lakes Basic Hydrarllic and Hydrologic Data 'bakes Michigan-Huron O~~tflowsSt. Clair & Detroit Rivers 1900- 1978,' December 1982. Derecki, J.A. - 'Effect of Channel Changes in the St. Clair River during the Present Century,' J.Great Lakes Research 1 1 (3:20 1-20), International . . : Association Great bakes Research, 1985. Horton, R.E. and.Grunsky, C.E. 'Hydrology of the Great Lakes' Report to the Engineering Board of Review of the Sani tory District of Chicago 1927. lnternational Joint Commission 'Regulstion of Greet Lakes Water Levels' Report by lnternational Great Lakes Levels Board, December 1973. Korkigisn, I.M., 'Channel Changes in the St. Clair ~iverSince 1933," I Journal of Waternays and Harbors Division, ASCE, May 1963. U.S. Army Corps of Engineers District, Leke Survey, 'Effect of end Compensation for Deepening of the St. Clair River for 25 and 27 Foot Project,' 1 96 1 File No. 3-3898. U.S. Armg Corps of Engineers Distr!ct, Leke Survey, 'Study of Hydraulics of the Detroit l?i ver,' 1 946 File No. 3-3083. U.S. Army Corps of Engineers District, Lake Survey. 'flydrel~licDesign Memorandum Greet Lakes Connecting Channels - Effect of the Compensstion for Deepening af the St. Clair River of 25 and 27 Foot ~ro~ects,'196 1 File No. 3-3098. ... .- . - U.S..Army Corps of Engineers District, Lake Survey. 'Compensation for Navigation Improvements in St. Clair-Detroi t Rivers,' 1965 Miscellaneous Paper 65- 1. U.S. Army Corps of Engineers District, Lake Survey. 'Net Effect of Dredging and Compensation in the Detroit River,' August 1965 File 3-4228. U.S. Army Corps of Engineers District, Lake Survey. 'First Addendumto August 1965 Report on Net Effect of Dredging and Compensation in the Detroit River; and Additional Compensation for the Detroit River, July 1968. U.S. House of Representatives, 'Detroit River, Wyandotte Channel, Hichigan,' House Document 17,62nd Congress 1st Session, U.S. Government Printing Office Washington, D.C. Q U.S. Senate 'Improvements of the Trenton Channel Detroit River, Michigan' I Senate Document 30,8 1st Congress 1st Session, U.S. Government 1 Printing Office, Washington, D.C. I U.S. Senate, 'Great Lakes Connecting Channels' Senate Document 7 1, I 84th Congress, 1st Session, U.S. Government Printing Off ice, 1 Washington, D.C. I U.S. Waterways Experiment Station, 'Experiments to Determine the Backwater Effects of Submerged Sills in the St. Clair River,' Vicksburg, Miss. April 1934 U.S. Waterways Experiment Station, 'Effects of Submerged Sills in the St. Clair River,' Technical Report H-'72-4, Vicksburg, Miss. August 19'72.