REPORT ON
POTENTIAL MEASURES TO ALLEVIATE PROBLEMS
CREATED BY CURRENT HIGH LAKE LEVELS
TASK 4
NIAGARA RIVER
TO
INTERNATIONAL JOINT COMMISSION
FROM
TASK GROUP MEMBERS
PETER YEE TONY EBERHARDT DAVE STRELCHUK FRANK QUINN BILL DALEY
OCTOBER 1987 Niagara River, 1925. EXECUTIVE SUMMARY
The Niagara River is the natural outlet of Lake Erie. It is also a bottleneck in the Great Lakes system with the problem compounded to some extent by placement of structures in the river. This study examines a number of potential short-term measures to increase the Niagara River flows in order to lower Lake Erie's water levels at times of extreme high water supplies.
Construction of a Squaw Island diversion channel, equipped with a control gate, would increase the river's flow carrying capacity by about 10,000 cubic feet per record (cf s) . Similarly, a channel deepening in the vicinity of the Peace Bridge would also bring about the same capacity increase. A twoyear construction period would be required for either project. Maximum lowering impact' on Lake Erie due to either measure is about 0.4 foot.
The operation of the existing butterfly valves and culverts at the Black Rock Lock would increase the Niagara River flow by about 1,300 cfs, which would correspond to a maximum lowering impact on Lake Erie of about 0.06 foot.
The control structure in the Chippawa-Grass Island Pool can be operated to maintain a slightly lower level when compared with the present operating procedure. Computer modelling and field measurements indicate that about 3,000 cfs flow increase may be possible if the Pool water level is lowered one foot. The estimated lowering impact on Lake Erie is about 0.13 foot.
Both sides of the upper Niagara River have been infilled repeatedly in the past. The construction of the Peace Bridge, International Railway Bridge, the old water intake, etc, have caused further restriction to the flows.
Of all the major obstructions examined in this study, it appears that the removal of the old intake structure and part of the filled area at Fort Erie just downstream of the Peace Bridge would be most practical and effective. Breaching the Bird Island Pier to allow a 100-foot opening would also increase the flow by about 2500 cfs. but this could adversely affect naviga- tion in the Black Rock Canal. Removal of the other obstructions would further increase the capacity of the river. However, these are not considered viable due to high costs and the extended time frame required. REPORT ON POTENTIAL MEASURES TO ALLEVIATE PROBLEMS CREATED BY CURRENT HIGH LAKE LEVELS
Inside Cover: Energy, Mines and Resources (Canada), National Air Photo Library, 1925, "Image of the Upper Niagara River,"
TABLE OF CONTENTS Page EXECUTIVE SUMMARY
Section 1
INTRODUCTION 1
Authority
Membership
Purpose and Scope
Section 2
EMERGENCY MEASURES
Squaw Island Diversion
Description of Diversion
Operational Constraints
Cost Estimates
Construction Schedule
Niagara River Excavation
Description of Excavation
Operational Constraints
Cost Estimates
Construction Schedule
Construktion Constraints TABLE OF CONTENTS (cont.) Page
Black Rock Lock Culverts and Valves
Operation of the Control Structure of the Chippawa - Grass Island Pool Description of Operations
Operational Constraints Hydraulic Analysis
Removal/Modification of Obstructions
Identification of Obstructions
Evaluation of Impacts
Section 3
HYDROLOGIC IMPACT ON LAKE ERIE LEVELS
Squaw Island Diversion
Niagara River Excavation
Black Rock Lock Culverts and Valves
Operation of the Control Structure of the Chippawa - Grass Island Pool Removal/Modification of Obstructions
Section 4 ENVIRONMENTAL, SOCIAL, AND OTHER CONSIDERATIONS
Squaw Island Diversion
Niagara River Excavation
Black Rock Lock Culverts and Valves
Operation of the Control Structure of the Chippawa - Grass Island Pool Removal/Modification of Obstructions
Regulatory Considerations
Section 5 FINDINGS
BIBLIOGRAPHY
LIST OF TABLES
Flow Increases for Squaw Island Diversion Structure
Flow Increases for Niagara River Excavation
Estimated Impacts on Lake Erie due to Removal/Modification of Obstructions
Hydrologic Impacts of Squaw Island Diversion
LIST OF FIGURES Black Rock Canal-Squaw Island Diversion Structure Black Rock Canal-Squaw Island Diversion Cross Sections of Diversion Channel
Black Rock Canal-Squaw Island Diversion Centerline Profile of Control Structure
Location of Niagara.River Excavation
Cross Section of Niagara River Excavation
Obstructions in the Niagara River
iii Section I
Introduction
1.1 Authority
On 1 August 1986, the governments of Canada and the United States requested the International Joint Commission (IJC) to examine and report on the subject of the record high Great Lakes water levels. The IJC subsequently established the Great Lakes Water Levels Task Force to investigate a number of emergency measures which could be taken within one year or less to reduce extremely high water levels. Eight task groups were established to examine the various aspects. Task Group No. 4 - Niagara River was assigned the investigation of possible emergency measures that could be taken in the Niagara River to increase its flows. This report is a summary of the findings of.the group.
The investigations which were initiated in January 1987 were to be cmpleted by September of that year. Funding was limited to in-house appropriations by the participating agencies.
1.2 Membership Membership of Task Group No. 4 - Niagara River consists of: United States Canada
A. J. Eberhardt, Chairman P. P. Yee, Chairman U.S. Army Corps of Engineers, Environment Canada, Buffalo District, Buffalo, NY Burlington, Ontario
F. He Quinn; PhD Dm L. Strelchuk Great Lakes Environmental Research Ontario Natural Resources Laboratory Toronto, Ontario NOAA, Ann Arbor, Michigan
We Daley New York State Department of Environmental Conservation Albany, New York
W. P. Erdle (thru April 1987) U.S. Army Corps ,'of Engineers, Buffalo District, Buffalo, NY
1.3 Purpose and Scope
This report discusses several possible emergency measures which could be implemented in one year or less to increase Niagara River flows. It also outlines some preliminary cost estimates, time-frames for implementation, &d likely constraints, associated wlth these emergency measures. The ' evaluation of hydrologic impacts does not include the implementation of other possible emergency measures being examined by other task groups. Task Group No. 8 will car:yout systemic evaluations which will take into account the Niagara River measres along with other concurrent measures.
The nature and scope of this report is limited by resources and due to the short time frame necessitated by the emergency nature of the situation. As such previous studies were used wherever possible, (see "Bibliography"). No socio-economic evaluation was carried out regarding the impacts of changing levels on Great Lakes interests due to these measures. Findings of the group are intended to serve as an indicator of the viability of the measures. Before any measure is to be implemented, a more extensive review as well as a more detailed design and plan of operation would be required. For a description of the Niagara River and the Great Lakes system, readers are referred to the recent IJC report on the subject of lake levels.
Section 2
Emergency Measures
2.1 Squaw Island Diversion
2.1.1 Description of Diversion
The structure considered is a slight modification of the Plan S2-75 structure studied in the Lake Erie Water Level Study, and is herein referred to in this report as the Modified S2-75 Control Structure. The structure would consist of 3 - 25' wide fixed-wheel roller gates. Plan and section views of the diversion channel and a detail of the gates are shown on Figures 1 through 3. The depth of concrete into bedrock and the overall structural dimensions have been updated compared to the original design in the Lake Erie Study.
2.1.2 Operational Constraints
It is assumed that the operating schedule of the diversion structure to accommodate operation of the Black Rock Canal and Lock would be the same as that used in the Lake Erie Water Level Study for S-alternatives. The schedule was developed to permit usage of the lock and canal by boats and commercial vessels. The operating schedule results in the effective flow being 62.5% of the design flow. For the Modified S2-75 Structure, the design and effective flows increase with Lake Erie outflow as shown in Table 1.
Table 1 - Flow Increases for Squaw Island Diversion Structure
Lake Erie Increased Discharge (cfs) Outflow ( cf s) Design Effective- R : 200,000 . 15,400 9,620
248,000 18,500 11,560 2.1.3 Cost Estimates
The construction cost of the Modified S2-75 Structure is $20.9 million based on October 1986 price levels. The-cost components are essentially the same as those incorporated in the Lake Erie Water Levels Study with the following exceptions:
a. where applicable, an Engineering News Record (EM) index factor of 1.632 was applied to bring component values up from December 1977 to current price levels;
b. the quantity of concrete required increased by 1,700 cubic yards due to the addition of piers between gates;
c. the quantity of rock excavation required decreased by 4,500 cubic yards due to the smaller structure size and higher foundation elevation;
d. current cost of 3 - fixed-wheel roller gates is slightly less than 1979 cost of single tainter gate; and
e. "damage" factors have been eliminated (real estate values were retained and assumed to be the same). In the Lake Erie Study estimate, "damages due to the project were assessed to compensate the City of Buffalo for the additional costs that would be incurred to dispose of a volume of material equal to the disposal area volume lost during the remaining 10-year life of the affected area". The city no longer uses this land for disposal purposes.
The estimate includes $2.7 million in indirect costs which consist of the cost of detailed design, field investigations including geotechnical and environmental evaluations, environmental impact statements, and miscellaneous actions related to project implementation.
2.1.4 Construction Schedule
Construction of the diversion.channe1 and control structure could be accomplished in 2 years assuming 2 shifts per day during 9 month construction seasons. Construction would begin, optimistically, 12 months after initiation of detailed design. An emergency designation could shorten this period by concurrent review and contracting procedures.
2.2 Niagara River Excavation
2.2.1 Description of Excavation
The dredging scheme considered in the report is similar to the dredging scheme in .Lake Erie water levels study, plan N3-75, but without a control structure and having a smaller capacity hd is herein referred to as N3-No Gates. The required width of excavation is about 225 feet and would extend 1000 feet upstream and 2300 feet downstream from the Peace Bridge. A plan view of the dredged channel is shown on Figure 4. The dredging consists of rock excavation varying in depth from 1 to 16 feet.with an average depth of cut of approximately 9.4 feet. Figure 5 shows the dredging required at the Peace Bridge cross-section. The channel excavation would increase the river's capacity by almost 10,000 cfs. Shore Protection works along the Canadian shoreline is not required since there would be no gates at the site which might be closed thereby temporarily raising levels and compounding problems along the Canadian shoreline. The increased channel capacity due to dredging the river, would most likely offset some of the effect of storms at this site.
Excavation near and along the Canadian shore is also a possibility. The type of dredged material is expected to be similar to that along the United States shore. The dredging operation along the Canadian shore would be somewhat easier since the equipment could in some areas be operated from shore. The quantity to be dredged could be somewhat' higher, however, since the channel along the Candian shore ia generally shallower.
2.2.2 Operational Constraints
The implementation of Plan N3-No Gates would not require a restrictive operating plan. The design increase in discharge capacity would be available annually on a 24-hour basis. For the plan, the design flow increases with various Lake Erie outflows are shown in Table 2. This plan would not have any known adverse impacts on either commercial and recreational navigation in the Black Rock Canal or recreational navigation in the Niagara River. However, during future low water periods either a control structure or a temporary rock fill would have to be constructed in the Niagara River in order to restore preproject conditions. Table 2 - Flow Increases for Niagara River Excavation
Lake Erie Outflow Increased Discharge (cfs) (cfs)
2 00,000 9,890 248,000 9,910 265,000 9,920
2.2.3 Cost Estimates
The excavation cost is $23.6 million based on October 1986 price levels. The components are essentially the same as those incorporated in the Lake Erie Water Level Study with the following exceptions: a. An ENR index factor of 1.632 was applied to bring component values up from December 1977 to current price levels;
b. The quantity of rock excavation required decreased by 186,600 cubic yards due to the deletion of the control structure and the reduction in channel width;
c. All other work items associated with the control structure were deleted; and
d. Shore protection along the Canadian shoreline was deleted. The estimate includes $1.2 million for liability insurance which the contractor would likely purchase and $2.9 million in indirect costs which consist of the cost of 'detailed design, field investigations including geotecknical and environmental evaluations, environmental impacts statements, and miscellaneous actions related to project implementation.
The cost of replacing excavated material during lowwater periods was not included in the estimate since the time and nature of such an undertaking were not identified; being beyond the scope of this study.
2.2.4 Construction Schedule
Excavation of the river channel could he accomplished in 2 years assuming 3 shifts per day during 9 month construction seasons. Construction would begin, optimistically, 12 months after initiation of detailed design. An emergency designation would shorten this period by concurrent review and contracting procedures.
2.2.5 Construction Constraints
Channel excavation would require the operation of marine plant in a reach of the Niagara River with water velocity of approximately 12 fps. Extraordinary and, as yet, undetermined construction procedures may be required. Hazardous working conditions, especially upstream of the Peace Bridge, and a recent accident in which marine plant hit the bridge during a salvage operation, make the feasibility of this alternative, questionable. The movement of each piece of marine plant would probably have to be controlled by upstream anchors in the river bottom and heavy tension cables. The transit of material barges up and down the river between the dredging operation and the selected disposal area ts not considered feasible. Some other unique method for the disposal of dredged material would have to be designed and constructed. A conveyer systen mounted on a deck barge could possibly rehandle dredged rock into material barges operating in the adjacent Black Rock Canal. Any construction procedure for drilling and blasting, bedrock excavation and disposal of dredged material from this high velocity reach of the Niagara River would be slow and tedious, prone to unforetold delays and very costly. Due to the above constraints the contingency factor used in the preliminary feasibility cost estimate was increased from the customary 25% to 50%. 2.3 Black Rock Lock Culverts and Valves
This scheme will require operating the existing lock culverts and butterfly valves of the Black Rock Lock. Preliminary analysis shows that these facilities can be operated to discharge.300 cfs and 1,000 cfs respectively. The lock is operated by the United States Army Corps of Engineers. Limited field observations have indicated no detrimental effects relative to the lock chamber structure. Eddies of various size were observed in the chamber, while no noticeable change was detected at the water surface upstream of the gate. Since the eddies and currents were obviously occurring below the upstream surface in the vicinity of the gate, warning signs would be required to advise small craft of the operations.
During the Lake Erie Water Level Study, a flow in the Black Rock Canal of 12,000 cfs was determined to be the maximum allowable without bank protection. Basea on those previous determinations, a flow of 1,300 cfs should not create erosion problems along the canal.
Vessel transits through the lock would reduce the flow slightly on an annual basis. Also, some very small backwater effects would be present in the main river thus reducing very slightly the overall actual increase. For all practical purposes, a net increase of 1,300 cfs is assumed in this study. 2.4 Operation of the Control Structure of the Chippawa - Grass Island Pool
2.4.1 Description of Operations The Chippawa - Grass Island Pool Control Structure is operated jointly by Ontario Hydro and New York Power Authority under the supervision of the IJC's International Niagara Board of Control. Present operation follows the procedure specified in the Niagara Board's Directive of 1973. Essentially, the directive requires that the Pool level be regulated so as to maintain its long-term average level of 561.0 feet, IGLD (1955). Departures from the target level are permitted, within limits, in order to cope with abnormally high or low river flows and ice problems in order to make the most beneficial use of the waters of the river for power purposes.
The 18 gates at the control structure are operated to ensure a minimum of 100,000 cfs over Niagara Falls during the tourist season daylight hours. The remainder of the river flow would be diverted by the power plants in Canada and the United States for power purposes as permitted by the Niagara Treaty of 1950. During the night and in the winter months, the Treaty requirement for the Falls is 50,000 cfs. As a result, power diversions from the Pool increase during this time. There is a constant daily fluctuation of the water level in the Pool.
The above paragraph gives a very simple description of the operation of the structure. Actual operations are complicated by factors such as: constantly changing Lake Erie levels and hence its outflow, ice (particularly ice runs) in the river, capacities of the power plants, Treaty requirements and the number of gates which are operational. 2.4.2 Operational Constraints
The regulation of the Pool level has a limited backwater effect in the upper Niagara River extending from the Pool to the upper part of the river. Past field tests have shown that even with the Pool lowered by two feet, the backwater effect has dissipated in the vicinity of the Peace Bridge. Therefore, in order to estimate the effect of Pool lowering on Lake Erie, it would be necessary to conduct field measurements and/or mathematical modelling to evaluate the impacts on the flows.
In this study, it was assumed that the Pool would be regulated at a target level of 560 feet, IGLD (1955) during the emergency period. Lowering the Pool level steepens the hydraulic gradient of the river and thus, increases the river's capacity to convey flows from Lake Erie. As mentioned above, other factors might cause short-term departures from this level, but it was assumed in this study that the Pool would be at a constant elevation of 560 feet throughout the emergency period. A more detailed plan would be required to establish the actual operation procedure which would be necessary to mair tain this level.
A large lowering of the Pool level was considered in this study. However, during extremely high Lake Erie levels which cause extreme high river flows (such as those in 1985 and 1986), it would not be possible to maintain such low Pool levels for any extended period of time. Even with all gates opened, the control structure and the diversion capacities of the power plants have their limits. When inflow to the Pool exceeds the total Pool outflow capaci- ties, levels in the Pool will rise until there is sufficient head at the control structure to discharge the higher flows.
The ability to maintain low Pool levels also depends on ice conditions in the river. When heavy ice runs occur, it is necessary to raise the Pool level to assist in efficient passage of ice which otherwise could ground in the Pool and cause ice jams. Maintenance of low Pool levels hampers the power entities' ability to make the most beneficial use of the waters for power generation. The reduction of storage in the Pool, coupled with a reduced degree of freedom in manipulating the gates, means that there would be a high incidence of Falls flows less than 100,000 cfs.
Extended periods of low Pool levels would adversely affect local riparian interests who operate water intakes and/or boating facilities in the area.
2.4.3 Hydraulic Analysis
(a) Mathematical Modelling. The steady-state subcritical flow backwater model for the Niagara River developed by NOAA was used in this study. It was calibrated to generate a series of stage-discharge relationships for the Buffalo Harbor Gage. Three separate ratings have been prepared for Pool levels corresponding to 559, 560 and 561 feet, IGLD (1955). The relationships show that at a lake stage of 573.5 feet, lowering the Pool level from 561 to 560 feet increases the river flow by about 1,500 cfs, with another 1,300 cfs increase if lowered further to 559, thus making it a total of about 2,800 cfs increase for a 2 foot Pool lowering. They also point out that the flow increases also diminfsh-with higher lake stages, illustrating the increasing impacts of the lake stfges (and thus reducing Pool impact) on river flows.
The accuracy of resdts in modelling depend on a number of factors: the governing equations defining the hydraulics of the river, model parameters (such as Manning's n) estimation techniques, accuracy of field data, reliability of measured flows, calibration/verification techniques and experience of the modeler. Because of the short timeframe assigned for this study, it was not possible to conduct more thorough model calibration and sensitivity analyses, or to explore the use of other types of models.
(b) Field Measurements. During the period June 1-4, 1987, 19 discharge measurements were conducted at the International Railway Bridge in the upper Niagara River. The Pool level was held at 561 feet during 13 of these measurements and at 560 feet during the other 6 measurements. In addition, a number of moving-boat measurements were also taken at the same time.
Analysis of the field data suggests that there might have been some flow increases when the Pool level was maintained at a lower level. During the measurement Lake Erie Levels fluctuated somewhat, and together with the scatterness of the data, it is not possible to quantify precisely the effect on river flows. Comparison of several individual measurements revealed that there was apparently a flow increase of about 3,000 cfs at a lower Pool level. The river flow at the time was about 242,000 cfs. This represents about 1-1/4 percent increase in flows. The accuracy of discharge measure- ments depends on a number of factors including stability of the boats used during the measurement, the number of panels used and number of points measured in the vertical at each panel, the accuracy of the gauges used to measure lake level and cross-sectional area at the measurement site, the current meters used, and conditions in the lake and river. It is believed that the accuracy of measurements in the upper Niagara River is about + 5 percent, under ideal weather and flow conditions. Measurements at ideyl channels such at the Welland Canal have accuracies of -+ 3 percent.
2.5 Removal/Modif ication of Obstructions
2.5.1 Identification of Obstructions.
Obstructions in the study are defined as any artificial shoreline modification and structure or part of structures placed in the upper Niagara River that are considered to increase the channel roughness, reduce the channel cross-sectional area, etc, and thus affect river flow and Lake Erie's water level.
No title search was conducted of the obstruction sites or structures. Also, the study did not examine the legality of placement of these obstructions, the legal requirement or implications of removals of the obstructions. Regarding filled water lots in Canada, they are referred to according to the name of land owner or commercial establishment conducting business as referred to in a 1985 survey conducted by Ontario Ministry of Natural Resource. This study examines the impact associated with the removal of these obstructions. It serves as a guide of the degree of impact on the flows and hence impact on Lake Erie levels of the obstructions. No investigation was carried out to determine the effect due to further deepening at the filled sites once the obstructions were removed. Figures 6-8 show some of the obstructions in the upper Niagara River. The report inside cover is an air photo of the head of the Niagara River taken in 1925. It should be emphasized that the study cannot possibly identify and evaluate all the artificial obstructions in the river. A review of early maps and charts shows that both sides of the Niagara River have been in-filled extensively and repeatedly in the past. The shoreline features today are vastly different from those in 1820 as is the development along the entire shoreline of the Great Lakes with the progression of civilization. Since the objective of the study is to identify emergency measures to increase Lake Erie's outflow, the task group concentrated on those obstructions that can be physically removed within one year and did not assess the merit of each obstruction.
2.5.2 Evaluation of Impacts
Much of the infqrmation on the obstructions was obtained from the offices of Environment Canada and the Buffalo District of the Corps of Engineers. In addition, letters were sent requesting more detailed information on such factors as the Peace Bridge, the Niagara Parks Commission parklancl, several lots in Fort Erie, Ontario and the old Buffalo water intake.
Because of the hydraulic characteristics of the upper Niagara River, shoreline modifications and/or removal of obstructions would have the most impact on Lake Erie water levels if they are located in the fast moving reach of the Niagara River in the vicinity of the Peace Bridge. Therefore, the hydraulic analysis focused on the reach between Frenchman's Creek and the head of the Niagara River at Buffalo/Fort Erie. The line of obstruction was refined after a preliminary assessment of the potential impacts associated with their removals. Some were deleted from further analysis since their existence or removal: a) was not found to have any measurable impact, or b) would take considerable time and resources, and thus could not be considered as a "possible emergency measure".
Several approaches were taken in the evaluations of the impacts. These included: literature review, field investigation and when possible, detailed hydraulic analysis.
In the hydraulic analysis, the Hydrologic Engineering Center's backwater mathematical computer model (HEC-2) was used. Cross-sectional data used were . those obtained by hydrographic survey by Department of Fisheries and Oceans in 1982, supplemented with cross-sections measured in the vicinity of the Peace Bridge in ~ovember1973 by Water Survey of Canada, with a cross-section measured at the below Peace Bridge gauge in December 1970, and a cross-section measured at Nicholl's Marine (formerly Niagara Bardware and Lumber) in 1987. Model calibration was carried out using the same technique as in the calibration of the NOAA backwater model (see Section 2.4.3).
The following paragraphs describe the results of the evaluations. The estimated impacts on Lake Erie levels due to removal or modifications of the obstructions are summarized in Table 3. a) Lake Erie-Niagara River Ice Boom
The Lake Erie-Niagara River Ice Boom is installed every winter (usually in late December), by Ontario Hydro and New York Power Authority. The timing of its removal depends on the severity of the winter and the extent of the ice coverage on the lake. Current'IJC Orders require that the boom be removed by April 1 unless more than 250 square miles of ice is present in the eastern portion of Lake Erie. The purpose of the ice boom is to reduce the frequency and duration of ice runs and/or jams in the river' which can block the power intakes at Niagara Falls.
A review of the operation of the ice boom since the winter of 1964-65 identified no adverse effect on river flow. Rather, severe ice runs of the type that occurred prior to the use of the boom have been reduced or eliminated. It should be noted that a natural ice arch normally forms at the site of the boom with or without the boom present. The placement of the boom strengthens this ice arch and thus reduces considerably, the potential of the arch breaking and subsequently prevents heavy ice runs during storms. The incidence of ice jams, which would potentially restrict river flows, has been decreased.
A review of the data on measured flows for both the open water season and ice season, has shown that there has been no noticeable reduction in the flows out of Lake Erie during the winter months since,l964. Thus, the group concludes that the. boom does not have a retarding effect on the flows out of Lake Erie and is not considered an obstruction.
b) Bird Island Pier and Black Rock Canal
Construction of the Black Rock Lock and Canal in the United States occurred at various times, with much of the latest activity concentrated in 1930-31 and 1944-45.
The canal allows for passage of commercial vessels around this shallow and fast moving portion of the river. The canal is separated from the river by the Bird Island Pier and Squaw Island. Construction of the Bird Island Pier reduces the width of the river, particularly, at the point where the channel is rather narrow. Thus, removal of the Bird Island Pier, would increase the flow capacity of the river. The increase would be limited by the presence of Squaw Island which is located,immediately downstream of the Pier.
An extensive rehabilitation program of the Pier was undertaken between 1985 and 1987. The program which raised the pier to provide safe access for recreational fishermen, included the installation of 150 culverts, so that the preproject flow of water from the Canal to the river would be maintained. As such, the rehabilitation does not cause any further restriction on the flows out of Lake Erie. Hydraulic backwater calculations were carried out to evaluate the impacts of removing portions of the Bird Island Pier for river flow conditions of 220,000 cfs, 250,000 cfs, and 280,000 cfs. The results are shown in Table 3. The table also shows the estimated impact of breaching 100 feet of the pier. Breaching any portion of the Pier would adversely affect navigation within the Black Rock Canal. The cost of removal of the entire pier and timeframe have not been evaluated. However, such an extensive undertaking would eliminate its consideration as an emergency measure.
c) Mather Park (Niagara Parks Commission Parkland)
In the 1930's and 19401s, construction of Mather Park at Fort Erie, Ontario took place along the Canadian shore of the Niagara River in the vicinity of the Peace Bridge and upstream thereof. he park construction involved placement of fill material in the Niagara River and a seawall. Early photos and cross-sections show that the river channel in the filled area was fairly shallow, particularly under low lake level conditions. In fact, a large area of land near the Peace Bridge was above water prior to filling. A return to pre-fill conditions is not expected to increase significantly the flow capacity. Thus, hydraulic evaluations were carried out assuming various degrees of shoreline modifications. Alternative 1 assumed removal of about 150 feet of the parkland, returning the area to its original depth with the high land near the Peace Bridge removed. Since the original depth was quite shallow, Alternative 2 was formulated which assumed further deepening of the excavated parkland area. Alternative 3 assumes the removal of part of the fill upstream of the Peace Bridge to streamline the flows. This alternative would require further deepening of the excavated parkland and near-shore areas. The effect of each of these alternatives are shown in Table 3. Note that the scenarios selected are for comparison purposes only and further detailed analysis would be required for any proposed work.
d) City of Buffalo Water Intakes
The intake presently in use by the City is located fairly close to the site of the ice boom. No adverse impacts on flows are present since the. intake is located very close to the lake where the channel is wide and fairly deep.
A second intake built in the 1880's is located just downstream of the Peace Bridge. It was last used in 1963, and is at present used as a back-up intake during emergencies. Removal of the intake structure while retaining the intake pipes will have a slight lowering effect on Lake Erie's water levels (Table 3).
e) Peace Bridge
Constructed in 1925, the Peace Bridge with its piers acts as an obstruction to flow. A complete removal of the bridge will lower Lake Erie's level by a small amount. As the Peace Bridge is a vital transportation link between Canada and the United States, a replacement bridge would have to be erected at or adjacent to the site of the Peace 'Bridge. A new three span cable stayed bridge, with a center span of about 1525 feet and side span of 600 feet is considered the best solution. The new bridge would require one pier instead of the present five. The hydraulic analysis assumed that the new bridge was in place. (Table 3). . The Peace Bridge piers raise the level of Lake Erie by 0.1 foot. The raising is due to reduction in river cross-section by the width of the piers and not to their lack of a streamlined design. Therefore, additional streamlining was not considered.
f) Nichollls Marine and other adjacent fill sites
Placement of fills at the Nichollls Marine and its adjacent areas at Fort Erie, Ontario took place at various times until the early 1970's. Several commercial establishments (Agrettes Ltd. and Ming Teh Restaurant) occupy the filled water lots, with buildings erected on their properties. These fills are located in the river at its narrowest point and thus, have a relatively significant impact on Lake Erie levels compared to other fills in the area.
Hydraulic analyses were carried out ranging from a small alteration of the shoreline to complete removal of all fills to align the shoreline with the upstream and downstream shoreline approaches. Alternative 1 assumed removing about 70 feet of the fill with the shoreline protected by vertical sheet pile wall. Under this alternative, there is no need to remove any existing above ground buildings. Alternative 2 assumed a return to the 1959 shoreline condition and would require removing some of the existing buildings. Alternative 3 would require removing all existing fills, but this alternative is effective only when combined with removal of the fill upstream at Mather Park.
Removal of the obstructions at these sites will increase the flow carrying capacity of the river and thus have a lowering impact on Lake ~rie's-water level.
g) Squaw Islarid
A review of some early maps and charts shows that the size and extent of Squaw Island have varied over time due to natural and man-made factors. The present island is the location of the Buffalo Sewage Treatment Plant.
Removal of portions of Squaw Island would have some lowering impact on Lake Erie levels. Removal of part of the island or setting back its entire existing shoreline would be a major and costly undertaking. Thus, no detailed hydraulic analysis was carried out on this alternative. An earlier Environment Canada study found that removing portions of Squaw Island could have an impact of about 0.05 feet on Lake Erie. This relatively small magni- tude is mainly due to the fact that much of the filled area was at one time marshland and thus, had little carrying capacities except during high flow periods. Based on ' hydraulic analysis, removal of the bulkheads at the Sewage Treatment Plant would not have any measurable impact on Lake Erie's levels. h) International Railway Bridge
Completed in 1872, the International Railway Bridge with its numerous massive support piers, has a considerable retarding impact on river flows. The impact on Lake Erie's water levels is about the same order of magnitude as that of the Peace Bridge. Removal of the Railway Bridge is considered extremely costly and impractical, since it is a major route of rail traffic between the United States and Canada.
i) Utvich, Customs Dock, Parsero and Other Adjacent Fills
A number of establishments occupy the properties located just below the International Railway Bridge in Canada. Some of the properties have been filled to almost the limits of their water lots. Hydraulic analyses show that complete removal of these fills would have a slight lowering effect on Lake Erie levels. ,However, the impacts are relatively small when compared to other obstructions and fill sites upstream, at, or near the Peace Bridge.
(j) South and North Grand Island Bridges
These structures are located a fairly long distance downstream from the head of the Niagara River. A field investigation of the sites shows that the bridge piers do not have any noticeable impacts on flows. Thus, removal of these bridges would not bring about any measurable impact on Lake Erie's water levels.
(k) Buckhorn Island Flow Control Dikes
The Buckhorn Island Flow Control Dikes were constructed by the New York Power Authority to improve flow conditions at its water intakes in order to maximize power diversions. During periods of heavy ice runs, the dikes accelerate passage of ice and thus help prevent ice grounding that could lead to ice jams. A review of recent literature could not identify any cause of ice jamming attributed to the presence of, the dikes, and thus they were considered to have no adverse impact on flows. Table 3 -Estimated Tmpacts on Lake Erie due to Removal/Modification of
Obstructions. / ' \I - Estimated Lowering-Impacts (feet) Obstructions :220 TCFS : 250 TCFS .: 280 TCFS 1. Bird Island Pier . . 1.1 Removing 100 f t . : 0.11 : 1.2 Complete Removal : 0.35 :
2. Mather Park 2.1 Removing up to 150 ft. of Parkland : * 2.2 'Removing up to 150 f t. plus Deepening 0.04 : 2.3 Streamlining Constriction above : 0.07 : Peace Bridge plus Deepening
3. Old Buffalo Water Intake Structure *
4. Peace Bridge (one pier retained) : 0.09 : 5. Nicholl's Marine and Adjacent Fills : . 5.1 Removing 70 ft. at Nicholl's Marine: 0.03 : 5.2 Returning to 1959 Shoreline : 0.04 : Condition 5.3 Complete Removal : 0.04 :
6. Buffalo Sewage Treatment Plant Bulkhead: *
7. International Railway Bridge : 0.05 :
8. Utvich and Adjacent Fills *
9. Options 3 and 5.1 : 0.04 :
10. Options 3 and 2.2 and 5.2 : 0.09 :
11. Options1.2,2.1,3,4, 5.3, 6, 7, : 0.53 : and 8 --- Note: (1) Except where stated, all values are determined assuming only one obstruction removed while retaining all other obstructions in place.
(2) An asterisk (*) indicates a calculated lowering impact less than 0.01 foot.
(3) Several obstructions listed above such as removal of the Bird Island Pier or any of the international bridges would require time exceeding the one-year emergency timeframe specified.
(4) The removal of the Bird Island Pier would have a greater impact than preproject conditions since the added capacity of the Black-Rock Canal would be present and the Canal did not exist prior to construction of the Pier. Section 3
Hydrologic Impact on Lake Erie Levels
3.1 Squaw Island Diversion
The operation of the Modified S2-75 Structure would follow the procedures specified by Regulation Plan 15s which was developed in the Lake Erie Water Level Study. Table 4 is a summary of the hydrologic impact of this diversion on the Great Lakes, The Basis-Of-Comparison (BOC) used is based on the period 1900 through 1976 and is the same as that wed in the previous study. Considering the high levels which have prevailed since 1976, the BOC'and the levels attributed to the Squaw Island diversion dl1 be higher. The differences, however, should be about the same magnitude. , , Table 4 Hydrologic Impacts of Squaw Island Diversion
------ma---. Basis-of- : ~oiified ~omDariso& :S2-75 ~tructur&/: Mf fereoce : (IG~D,1955) :.-.-a (IGLD,- 1955) : (feet) Lake Superior Mean 600.44 600.41 -0.03 Maximum 601.93 601.93 0.00 Minimum 598.69 598.65 -0.04 Range 3.24 3.28 +Om04 Lakes Michigan-Huron : . Mean . 578.27 . 578.18 -0.09 Maximum 581.15 580.99 -0.16 Minimum 575.47 575.42 -0.05 Range 5.68 . 5.57 -0.11 Lake Erie Mean 570.76 . 570.53 -0.23 -- Maximum 573.60 . 573.18 -0.42 Minimum 568.09 568.02 -0.07 Range . 5.51 . 5.16 . -0.35 Lake Ontario (with deviation) Mean 244.61 . 244.65 W. 04 Maximum 247.37 . 247.56 W.19 Minimum 241.81 241.59 -0.22 Range 5.56 5.97 M.41 - -- -l/BOC for the period 1900-1976. -2/Diversion structure to be operated in accordance with Regulation Plan 15s 3.2 Niagara River Excavation
Dredging in the Niagara River would result in increases in Lake Erie outflow of approximately 10,000 cfs. This outflow increase is essentially equal to that which would result with the Squaw Island diversion structure.. Therefore, the hydrologic impact displayed in Table 4 for the Modified S2-75 Structure could similarly be expected with the Niagara Biver excavation scheme.
3.3 Black Bock Lock Culverts and Valves
The use of the Black Rock Lock culverts and valves (1,300 cfs discharge capacity) would have a maximum lowering effect of about 0.06 foot on Lake Erie. Impacts on the upper lakes and Lake Ontario would be negligible.
3.4 Operation af the Control Structure of the Chippawa - Grass Island Pool
Estimated maximum lowering effects on Lake Erie due to a one-foot lowering of the Pool level is about 0.13 foot as estimated by recent discharge measurements.
Removal and/or modification of obstructions located in the vicinity of the Peace Bridge would have the most noticeable impacts on Lake Erie and water levels, Table 3 is a summary of the estimated impacts.
It should be noted that removing or modifying obstructions in the Niagara River improves its carrying capacity. There will initially be some flow increases at the time of the removal of these obstructions and for a sl~ort tiae thereafter. Once the lake has settled to a new and lower level regime, no further net increase in flow is possible and Lake Erie's outflow once again would depend on hydrologic conditions within the basin.
Section 4
Environmental, Social, and Other Considerations
4-1 Squaw Island Diversion
Squaw Island (about 60 acres in size), is owned by the City of Buffalo and has historically been used as a landfill by the City. Squaw Island was used for over three decades as a waste disposal site for foundry sand with phenolic binders, incinerator residue, street sweepings, debris and general refuse, From 1954-70, the island was used for disposal of waste foundry sand with insoluble metals compounds, trace oils, and resins. The estimated rate of disposal was 300,000 to 400,000 tons per year. In the mid-1970's much of the fill was excavated and transferred to the Tifft Farm site to allow for construction of the Buffalo Sewer Authority Wastewater Treatment Plant on Squaw Island. In addition, debris and dredged material from the Black Rock Lock has been disposed of on Squaw Island adjacent to the Black Rock Lock.
Squaw Island is listed as a non-point site along the Niagara River which has "a significant potential for contaminant migration along the Niagara River". As such, it is assumed that Squaw Island is "leaking" chemical contaminants to the Niagara River.
The area adjacent to the Black Rock Lock which would be excavated for channel construction currently has many small potholes (apparently mechanically excavated) that have developed into wetland areas. In addition, the downstream end of the proposed channel cut is currently occupied by a small pond, about 2 acres in size, which has been created out of the Niagara River by construction of a stone dike from the International Railroad Bridge to the downstream end of the island.
As discussed previously, Squaw Island had been used for many .years as a landfill. and disposal area. There is a high potential that the materials to be excavated for diversion channel construction are contaminated with numerous organic compounds. Considerable testing of the area to be excavated would be necessary to determine the exact nature and degree of contamination. It is likely, that special handling of the excavated materials will be necessary to prevent any contaminant migration to the Niagara River.
Strawberry Island is located about one mile downstream of the proposed outlet of the diversion channel. The island and adjacent areas, well known for their Muskellunge fishing, have been severely eroded in recent years. It would be necessary to determine if the increased outflow from the Squaw Is land Diversion Channel would further accelerate the erosion of Strawberry Island.
At least one prehistoric site is known on Squaw Island. It is likely that a cultural resources survey of the Squaw Island Diversion Channel area will be needed to determine if any prehistoric or historic relics exist in the area.
Due to its high potential for significant impacts, it is likely that preparation of Draft and Final Environmental Impact Statements (EIS) will be required prior to construction. EIS would likely take 1 year to develop. A Public Notice and Section 404(b)(l) Evaluation will definitely be required and the project will require 401 Certification from the New York State Department of Environmental Conservation.
4.2 Niagara River Excavation
The scheme calls for deepening the Niagara River channel adjacent to the Bird Island ~ierl~lackRock Canal and passing under the Peace Bridge. The channel would be deepened for about 3,300 feet of length, 225 feet of width and about 16 feet of maximum depth. Channel deepening would increase the capacity of the Niagara River by about 10,000 cfs. Blasting and excavation would be required through two construction seasons (each about 9 months). A total of about 260,000 cubic yards of rock would be generated by the project.
The Niagara River in the vicinity of Bird Island Pier is a significant fishery.resource in the Buffalo area. Large numbers of freshwater drum, rock bass, yellow perch, smallmouth bass and trout and salmon are caught from the pier, In 1977 the New York State Department of Environmental Conservation estimated that about 36,000 man-hours were spent fishing from the pier in a 13-week period from June to August. Blasting and excavation of the new channel would probably disrupt fishing activity during the S-month construction periods. Public opposition might be expected as the pier has been closed to fishing for most of the last two years while a new walkway was being constructed on the pier. Within a year or two after construction is completed, the fishery would probably return to preproj ect conditions.
It is not expected that any polluted dredged material will be encountered as the area of excavation is scoured to bedrock by the fast waters of, the Niagara River, The clean, broken stone, excavated from the riverbed, would provide excellent material for construction of a reef in Lake Erie for fish habitat. Such a measure would offset the adverse construction effects on fishery resources along the Bird Island Pier, As an alternative, the rock could be used for upland fill or other purposes with no major adverse environmental effects.
Deepening of the Niagara River should not have any adverse effect on cultural resources.
It is likely that a Draft and Final Environmental Impact Statement would be required prior to construction of the project primarily due to significant public concern about high lake levels, fishery resources, contamination and other problems in the Niagara River. A Public Notice and Section 404(b)(l) Evaluation would be required for disposal of the rock if it is used .for reef building in Lake Erie. In addition, 401 Certification from the New York State Department of Environmental Conservation would be required.
4.3 Black Rock Lock Culverts and Valves
The use of the Black Rock Lock culverts and valves to increase the Niagara River flow is not expected to have any major environmental impacts. There would be minor interruption to recreational and commercial boating activi- ties, since its operation would be at night and during non-recreational seasons. 4.4 Operation of the Control Structure of the Chippawa - Grass Island Pool
A lowering of the Pool level from its present operating level would affect seriously the power diversion at Niagara Falls. A higher incidence of Falls flow dropping below 100,000 cfs is expected. Extended period of low levels in the Pool would also adversely affect local riparian interests. Maintenance of low Pool levels during ice runs in the winter could lead to ice jamming in the river. The modified operation should have no adverse environ- mental. impact.
I 4.5 Removal/Modification of Obstructions
Removing or replacing the Peace Bridge and the International Railway Bridge wuld cause major disruption to the traffic between Canada and the United States. During the construction/demolition, all traffic would have to be re-routed to Niagara Falls. Construction of a new bridge would create some local environmental problems along the shorelines (similar to those mentioned in Section 4.1 and 4.2) as well as temporarily increasing turbidity. Complete removal of the existing bridge and construction of new ones would take 2-4. years, depending on the exact type and location of the bridge.
Removal of the old water intake structure is not expected to cause any serious environmental problems because of its location in bedrock. The operation would be difficult, however, since it will take place in fast moving water.
Removal of the fills on Squaw Island will pose a serious environmental problem since it was once used as a landfill site (see Section 4.1). Removal of the Bird Island Pier will cause temporary localized problems, particularly increases in the turbidity level. It would make transits of large vessels impossible. Removal of a portion of the Pier would also make navigation difficult due to the resultant high velocity flow from the Canal to the River.
Removal .of the landfills along the Canadian shoreline will affect the business establishments at these sites. Complete removal of the fills will eliminate their operation altogether.
-Removal of the Niagara Parks Commission landfills at the Peace Bridge is not expected to cause any serious environmental problems. If further deepening is to be carried out upon completion of the removal of the fills, however, the expected problems encountered for Niagara River excavation (Section 4.2) would arise here also, although they would be of a smaller magnitude . 4.6 Regulatory Considerations
Since the flow from any of the emergency measures would impact inter national boundary waters, aspects of the Boundary Water Treaty of 1909, 1950 Niagara Treaty, and 1913 Directive of the Niagara Board, would need to be considered. Assessments of Lake Ontario Regulation Plan 1958D and the capa- city of the St. Lawrence River to accommodate additional water would also be required. ' ', Section 5 \. - Findings The following are findings of Task Group No. 4:
1. Construction of a Squaw Island Diversion channel with a control structure would increase the Niagara River flow capacity about 10,000 cfs. The project could be completed in two years at a cost of about $21 million. Estimated lowering impact on Lake Erie is about 0.4 foot.
2. Excavation of the Niagara River in the vicinity of the Peace Bridge would increase the river's flow capacity by about 10,000 cfs. The excavation could be completed in two years at a cost of about $24 million. Estimated lowering impact on Lake Erie is about 0.4 foot.
3. Breaching of a 100-ft section of the Bird Island Pier can be considered as a potential emergency measure and would lower Lake ~rieabout' 0.1 foot. Navigation in the Black Rock Canal would, however, be difficult.
4. Operation of the existing butterfly valves and culverts at the Black Rock Lock is also considered a potential measure and would increase the Niagara River flow capacity by 1,300 cfs, which would correspond to a maximum lowering impact of 0.06 foot on Lake Erie.
5. The water level in the Chippawa - Grass Island Pool can be lowered slightly relative to the present mode of operation. While it is not possible to quantify precisely the impact on the flows, limited field measurements conducted in 1987 suggest that some flow increases of about 3,000 cfs may be possible which would correspond to about a 0.13 foot lowering impact on Lake Erie. The value is qualified since it represents 1-1/4 percent of the flow and measurement accuracies are typically 5 percent.
6. Both sides of the upper Niagara River have been in-filled repeatedly in the past since 1820. The construction of the Peace Bridge and the International Railway Bridge further restrict the capacity of the river. Taken all together, these obstructions have a considerable cumulative impact on the flow of the Niagara River and Lake Erie's water level.
7, Removal of the old water. intake structure and part of the filled area at the Nicholl's Marine and adjacent sites would be most practical and would increase the carrying capacity of the Niagara River. Other obstructions could also be removed, although at a much higher cost and would also require a longer time span. BIBLIOGRAPHY
TASK GROUP f2 - NIAGARA RIVER
1. U.S. Amy Corps of Engineers, Buffalo District, "Letter Report: Design of Emergency Measures to Increase Lake Erie Outflow", December 1986.
2. International Lake Erie Regulation Study Board, "Lake Erie Water Level Study, Documentation of Software", July 1984.
3. U.S. Army Corps of Engineers, Hydrologic Engineering Center, "HEC-2, Water Surf ace ,Profiles, Comp. Prog. 723-~6-~202~",update May 1984.
4. Environment Canada, Inland Waters Directorate, Ontario Region, "The Effects of Landfills in the Niagara River on the Water Levels of Lake Erie", August 1983.
5. International Lake Erie Regulation Study Board, "Lake Erie Water Level Study, Main Report and Appendix B - Regulatory Works", July 1981.
6. International Great Lakes Levels Board, "Regulation of Great Lakes Water Levels, Report and Appendix G - Regulatory Works", 7 December 1973. SOUW
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