FEASIBILITY STUDY OF REMOVING THE GRAND RAPIDS-PROVIDENCE DAMS, MAUMEE RIVER (NW OHIO) BASED ON HEC-RAS MODELS
Zachery P. Mueller
A Thesis
Submitted to the Graduate College of Bowling Green State University in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
December 2008
Committee:
James E. Evans, Advisor
Joseph P. Frizado
Enrique Gomezdelcampo
Sheila J. Roberts
ii
ABSTRACT
James E. Evans, Advisor
The Providence and Grand Rapids dams, located on the Maumee River at Grand Rapids,
Ohio are low-head dams built in 1840 as rock-crib dams that were subsequently bolstered with
concrete in 1907. The Providence dam is 362.1 m long and 2.6 m tall while the Grand Rapids
dam is 195.7 m long and 2.4 m tall. Both dams create a single reservoir with a normal pool
storage of 1233.5 m3 which is used for water supply and recreation. This study investigated the
impacts to the flood regime in the area associated with the removal of the two dams by
comparing HEC-RAS models of pre- and post-dam removal scenarios with 10-, 25-, 50-, 100-,
200-, 500-year flooding events. The model encompassed 30.6 river kilometers of the Maumee
River located in Henry, Lucas, and Wood County, Ohio using a total of 64 cross-sections
collected from HEC-GeoRAS and a 1998 HEC-6 sediment transport model along with 20 interpolated cross-sections created by HEC-RAS. The research also examined the potential release of sediment trapped behind the dams by performing grain-size analysis of sediment collected upstream of the dams.
The HEC-RAS results showed no significant change in the flood regime upstream of the
dams and no change at all downstream of the dams. Immediately upstream of the dams the water
surface elevation decreased from an initial elevation of 644.82 ft to 644.64 ft for the 10-year
flooding event, a difference of less than <1%. For the 500-year flooding event the water surface
elevation immediately upstream of the dams decreased from an initial elevation of 649.70 ft to
649.46 ft resulting in the same difference of <1%. The other flooding events resulted in similar iii differences. The differences in the areas inundated upstream of the dams due to these changes varied from no change to 0.01 mi2 for the 10-year and 500-year flooding events respectively.
The potential release of sediment trapped behind the dams was determined to be low due to the low trapping efficiency of the dams determined from observations of essentially no sediment accumulation in the reservoir. Along with the low trapping efficiency of the dams, the majority of the sediment being transported by the Maumee River was determined to be largely mud which is transported as suspended load and carried over the dams.
These results showed no significant changes in the flood regime near Grand Rapids, Ohio and no risk of releasing large quantities of sediment downstream after dam removal.
iv
ACKNOWLEDGMENTS
I would like to start by thanking Dr. James E. Evans, my thesis advisor, for guiding me through the process of conducting and writing this thesis. My sincere gratitude also goes to Dr.
Joseph P. Frizado, Dr. Enrique Gomezdelcampo, and Sheila J. Roberts, my thesis committee, for providing invaluable advice and a diverse knowledge base. I would also like to thank Nathan
Harris for the time he spent helping me collect sediment samples in the Maumee River. I am also indebted to Paul E. Murawski at the Army Corp of Engineers, and Tina Griffin and Pete
George at the ODNR Division of Water for their guidance and help in obtaining the data necessary to conduct my research. Finally, I would like to thank my family for their everlasting love and support. v
TABLE OF CONTENTS
Page
INTRODUCTION ...... 1
Dam Removal ...... 1
Effects of Dam Removal ...... 2
Purpose of Study ...... 5
BACKGROUND ...... 7
Hydrology...... 7
Bedrock Geology...... 10
Till ...... 11
Terraces ...... 17
Soils ...... 21
The Federal Emergency Management Agency ...... 23
Flood Insurance Studies ...... 25
Flood Insurance Rate Map ...... 26
INTRODUCTION TO THE HYDROLOGIC MODEL HEC-RAS ...... 27
Background ...... 27
One-Dimensional Flow Calculations ...... 29
Water Surface Profiles ...... 29
Cross-Section Conveyance ...... 29
Critical Depth ...... 31
Momentum Equation ...... 33
Weir Flow ...... 33
vi
Bridge Hydraulics ...... 35
Energy Method ...... 35
Momentum Method ...... 36
Yarnell Equation ...... 36
Floodplain Encroachment Analyses ...... 38
Computational Differences between HEC-2 and HEC-RAS ...... 44
Cross-Sectional Conveyance ...... 44
Critical Depth ...... 46
Bridge Hydraulic Computations ...... 47
Culvert Hydraulic Computations ...... 49
Floodway Encroachment Computations ...... 49
New Computational Features in HEC-RAS ...... 50
METHODS ...... 52
Field Methods ...... 52
Sediment ...... 52
Differential Global Positioning System ...... 56
Laboratory Methods ...... 61
Grain-Size Analysis ...... 61
Sediment Core ...... 62
GIS Analysis of Soils ...... 62
Hydrologic Modeling ...... 69
Data Sources ...... 69
Digital Elevation Model ...... 70 vii
Cross-Sections ...... 76
Dams ...... 82
Bridges ...... 85
Hydrologic Data ...... 87
Tolerance and Stability ...... 91
Conveyance Ratio Warning ...... 98
Energy Loss Warning ...... 102
Velocity Head Warning ...... 105
Divided Flow Warning ...... 105
Calibration Data ...... 105
Calibration ...... 106
Historical Verification ...... 108
Sensitivity Analysis ...... 108
Exceedance Probability Floods ...... 110
Encroachment ...... 110
FIRM Creation ...... 112
RESULTS ...... 113
Sediment Behind the Dam...... 113
Grain-Size Analysis ...... 113
Coarse Fraction ...... 113
Fine Fraction ...... 115
Core ...... 117
HEC-RAS Model ...... 117 viii
Calibration ...... 117
Historical Verification ...... 128
Sensitivity Analysis ...... 133
Exceedance Probability Floods ...... 133
Encroachment ...... 147
FIRM ...... 147
DISCUSSION ...... 157
CONCLUSION ...... 168
REFERENCES ...... 172
APPENDIX A GRAIN-SIZE STATISTICS ...... 181
APPENDIX B LASER PARTICLE SIZE ANALYSIS ...... 189
APPENDIX C HEC-RAS MODELS...... 199
APPENDIX D DIGITAL SOURCES ...... 236 ix
LIST OF FIGURES
Figure Page
1 Maumee River Basin extent ...... 8
2 Location of the Grand Rapids-Providence dams ...... 9
3 Extent of Devonian strata in Northwest Ohio and
Southeastern Michigan ...... 12
4 Stratigraphic column of Devonian strata in Northwest Ohio ...... 13
5 Locations of the Laurentide Ice Sheet through time ...... 16
6 Relationships between glacial-fluvial terraces in Northwest
Ohio...... 18
7 Energy relationships in rivers ...... 28
8 How HEC-RAS determines conveyance through a cross-
section ...... 30
9 Determination of critical depth ...... 32
10 Momentum principle in rivers ...... 34
11 Four key cross-sections required for bridge modeling ...... 37
12 Example of Encroachment Method 1 ...... 39
13 Example of Encroachment Method 2 ...... 40
14 Example of Encroachment Method 3 ...... 41
15 Example of Encroachment Method 4 ...... 42
16 Example of Encroachment Method 5 ...... 43
17 How HEC-2 sub-divides conveyance ...... 45
18 Locations of where samples were collected ...... 54
x
19 Sample locations upstream of the dams ...... 55
20 Location of the USGS benchmark and the elevation obtained
from the differential GPS ...... 57
21 Locations of where historical flood heights are recorded...... 58
22 Creation of soils maps ...... 64
23 Map Unit Legend generated by the NRCS SSURGO soil
survey of Paulding, Ohio ...... 65
24 Map Unit Description of the Rimer-Fulton complex soil ...... 67
25 Example query ...... 68
26 Stream centerline creation ...... 75
27 Cross-section modification ...... 77
28 Cross-section conversion from NGVD29 to NAVD88 ...... 79
29 The process by which the HEC-2 channel was merged with
the HEC-GeoRAS geometry ...... 80
30 LIDAR explanation ...... 81
31 Linear relationship assumed for the 2006 annual peak
discharge ...... 89
32 Linear relationships normalized to the 1982 annual peak
discharge for 8 annual peak discharges ...... 90
33 Slope determination ...... 92
34 Example of an unacceptable extrapolated cross-section ...... 97
35 Waterville gaging station modified rating curve ...... 107
36 Linear relationship assumed for the 100-year flood ...... 111 xi
37 Core photograph depicting homogeneous mud and fine sand
deposits ...... 118
38 Results of Sensitivity Analysis ...... 134
39 Grand Rapids FIRM overlayed over the FIRM created by the
HEC-RAS model ...... 156
40 Relationship between the percent submergence and the flow
reduction factor ...... 164
xii
LIST OF TABLES
Table Page
1 Names, elevations, and outlets of each ice-front lake that
existed in the Erie Basin during glaciation...... 15
2 Most prevalent soil textures present in the Maumee River
Basin...... 22
3 UTM coordinates of the samples taken during field work
along with how each sample was used in the study...... 52
4 Resulting flood stage elevations for the floods marked at
Providence and Grand Rapids, Ohio ...... 60
5 HEC-2 table of distances between cross-sections used to
determine the locations of cross-sections in HEC-GeoRAS...... 72
6 Notes for each cross-section used to determine the location
and geometry of dams and bridges...... 83
7 Locations and their corresponding drainage areas where
discharges were changed in the model...... 88
8 Cross-section locations of the warnings which occurred
before interpolated cross-sections were add to alleviate them...... 94
9 Cross-section locations of the warnings which occurred after
fixing the conveyance ratio warning...... 99
10 Cross-section locations of the warnings which occurred after
fixing the energy loss warning...... 103
xiii
11 Years and their accompanying discharges at the Defiance and
Waterville gaging stations used for historical verification...... 109
12 Statistical parameters of grain-size distribution of the coarse
fraction samples ...... 114
13 Statistical parameters of grain-size distribution of the fine
fraction samples ...... 116
14 Years used to calibrate the model with their accompanying
discharges at both the Defiance and Waterville gaging
stations...... 119
15 Original HEC-2 Manning numbers used as the basis to begin
calibration...... 121
16 Manning and contraction and expansion numbers used in the
calibrated model...... 124
17 Resulting differences between the modeled and actual gage
heights ...... 127
18 Historical verification comparing the gage height at the
Waterville gaging station...... 129
19 Heights of floods marked on the Isaac Ludwig Mill in
Providence, Ohio...... 131
20 Differences between the historical and modeled flood
elevations for each year at the Isaac Ludwig Mill in
Providence, Ohio with the calibrated model...... 132 xiv
21 HEC-RAS model runs simulating the discharges for the 10-
year flood...... 135
22 HEC-RAS model runs simulating the discharges for the 25-
year flood...... 136
23 HEC-RAS model runs simulating the discharges for the 50-
year flood...... 137
24 HEC-RAS model runs simulating the discharges for the 100-
year flood...... 138
25 HEC-RAS model runs simulating the discharges for the 200-
year flood...... 139
26 HEC-RAS model runs simulating the discharges for the 500-
year flood...... 140
27 Water surface elevations for the 10-year flood event for both
pre- and post-dam removal scenarios...... 141
28 Water surface elevations for the 25-year flood event for both
pre- and post-dam removal scenarios...... 142
29 Water surface elevations for the 50-year flood event for both
pre- and post-dam removal scenarios ...... 143
30 Water surface elevations for the 100-year flood event for
both pre- and post-dam removal scenarios...... 144
31 Water surface elevations for the 200-year flood event for
both pre- and post-dam removal scenarios...... 145 xv
32 Water surface elevations for the 500-year flood event for
both pre- and post-dam removal scenarios...... 146
33 Area inundated by each flood probability for both pre- and
post-dam removal scenarios ...... 148
34 Results from encroachment with the dams emplace ...... 149
35 Results from encroachment without the dams emplace ...... 152
36 Percent submergence of the two dams ...... 161
37 Differences in water surface elevations when different
conveyance methods are used ...... 165
1
INTRODUCTION
Dam Removal
There are more than 75,000 large dams (NID 2006) and approximately 2 million additional low-head dams in the United States (Graf 1993). Large dams are classified as dams greater than 2.0 m (6.6 ft) tall that impound more than 62,000 m3 (1,775 acre-ft) or are taller than
7.6 m (24.9 ft) and impound more than 18,500 m3 (530 acre-ft) (NID 2006). Dams are
constructed for different purposes, such as flood control, irrigation, navigation, and hydroelectric power (Graf 2003). During the interval from 1900-1960’s, construction of dams was widely
supported by both the federal government and the general public because of these benefits
(Doyle and Stanley 2003). Public attitudes toward dams have changed due to concerns about the
natural environment, because many dams no longer fulfill their intended purposes, the risk of
dam failures, and the effects of dams on fisheries (Heinz Center 2002). Though these are all
important reasons for dam removal, typically the strongest driving force for removing a dam is
financial, due to the increasing cost of maintenance and liability concerns for owners of dams
(Trout 2001).
Though dams have played an important role in the development of the United States they
also have had detrimental effects on river channels, on aquatic and riparian habitat, and to those
native species not adapted to lotic habitats created by the impoundment of water behind dams
(Graf 2003). Dams have been identified as one of the most significant impacts of humans on the
environment (Naiman et al. 1993). For more than 100 years the United States has been the
leader both in dam construction (Bowman 2002) and dam removal, although today little is
known about the result of removing these structures on the ecosystem of the river (Graf 2003).
This lack of knowledge demands scientific information to be gathered on both the effects of
2 dams and the effects of dam removals, in order to aid decision makers in deciding the most effective means of mitigating the effects of dams on river channels and ecosystems (Graf 2003).
Effects of Dam Removal
During the lifespan of a dam, sediment that would have otherwise traveled downstream ends up deposited behind the dam. The volume and grain size of this sediment is a characteristic of both the drainage basin geology and the trapping efficiency of the dam. The removal of the dam will cause a geomorphic change to an already quasi-adjusted fluvial system, from one that has adjusted to the hydraulics imposed by the dam to one where these imposed hydraulics no longer exist (Grant 2001). This change results in the erosion of sediment deposited behind the dam during its lifespan, increasing turbidity (Randle 2003), and deposition of sediment in pools and areas of reduced transport ability downstream (Rathburn and Wohl 2003). These changes may ultimately affect the vegetation, distribution of animals, and the morphology of the river
(LaPerriere et al. 1985; Wagener and LaPerriere 1985; Van Nieuwenhuyse and LaPerriere 1986;
McLeay et al. 1987; Miller et al. 1999; Stoughton and Marcus 2000).
In addition, deposition of reservoir sediment downstream can degrade or eliminate spawning grounds for various fish and mussels (Bogan 1993). Increased sediment loads can also abrade vegetation (Wood and Armitage 1997), insects, and algae and decrease areas for these organisms to attach to substrate due to a layer of fine silt and/or sand (Newcombe and
MacDonald 1991; Wood and Armitage 1997). Sediment can also completely cover leaf litter making it unusable for organisms (Doeg and Koehn 1994), as well as obstructing industrial and municipal water intake structures. 3
When estimating how much sediment will be transported after dam removal, an analysis
of the grain-size distribution should be mapped in the reservoir and critical shear stresses
determined for each grain size. The boundary shear stress should also be mapped, relative to
flow rates, along the river (Rathburn and Wohl 2003). With both the critical shear stress and
boundary shear stress measurements, an initial motion calculation can be made to determine
where the sediment will be eroded and deposited along the river (Evans et al. 2002). With this
information one can determine the length of travel for each class and plan the dam
dismantlement accordingly (Rathburn and Wohl 2003). This will aid in controlling the sediment
release in order to mitigate deposition in areas of interest such as key habitat sites and industrial
complexes.
According to Pizzuto (2002), geomorphic processes should evolve in an orderly fashion
after removal of a dam. Immediately after dam removal, incision of the reservoir sediment may
result in bank failure (Pizzuto 2002), depending on the material and mitigation measures
implemented. This sediment will be transported downstream and may be incorporated in
floodplains, the channel, and/or the river’s outlet (Pizzuto 2002). Current studies suggest the
initial removal of a dam will result in an immediate influx of fine-grained sediment, such as silt and clay, as suspended load, followed by coarser-grained sediment, such as sand, as bedload.
The fine-grained sediment will quickly move through the river system (Major et al. 2008) with short lived effects of increased turbidity, and siltation. The coarser-grained sediment though may take several years to propagate through the downstream river system (Evans 2007) and may have long term effects such as changes in stream morphology and flood hazards (Evans et al.
2007; Rumschlag and Peck 2007). The data that exists on channel morphology after dam removal indicates it may take years for a quasi-stable channel to develop in the former reservoir 4 site and the quasi-stable channel may be different than the one that existed before dam construction (Lenhart 2000; Doyle et al. 2002).
During incision of the reservoir sediment, different processes will take place depending on the grain-size of the impounded sediment (Pizzuto 2002). For the silt and clay sized sediment a short lived, hours to days, nickpoint will be produced which will move upstream as sediment is eroded (Doyle et al. 2002; Evans 2007). For sand-sized sediment, liquefaction and ground water sapping may play roles in the movement of the nick point (Pizzuto 2002).
In order to mitigate the effects of large dam removals where great amounts of sediment are stored, management practices should be incorporated into the dismantling process. These may include drawdown of the reservoir, timing of dismantlement, vegetating reservoir sediment, installation of rip-rap, and removal of contaminated sediment. These practices can reduce soil erosion, turbidity, deposition, and the related effects on the ecology of the river downstream of the dam.
Drawdown of the reservoir mitigates the effects of sediment erosion in the reservoir and later deposition of the sediment downstream. Drawing down the reservoir allows the sediment to consolidate and dewater, enabling it to stabilize and become more resistant to erosion (Kanehl et al. 1997).
The timing and the amount of dismantlement can play a key role in controlling the timing and amount of sediment released after dam removal. Varying processes should be modeled to determine the optimum dismantlement strategy (Randle 2003). It may be found through modeling that a dam should be removed during peak flow in order to flush out the reservoir in one sediment wave, or to remove it during low flow to slowly release sediment over a larger time span allowing it to be distributed throughout the channel downstream. 5
There are a variety of solutions ranging from cheap to costly. Vegetating the reservoir
sediment is a cost-effective way to stabilize the sediment and prevent further erosion of the reservoir (Harbor 1993; Kanehl et al. 1997). In some instances the installation of rip-rap may be
necessary to either control the path of the river or stabilize the banks of the river to prevent soil
erosion (Harbor 1993; Kanehl et al. 1997). This method is often expensive and it can be difficult
to choose the proper rip-rap size to use.
If contaminated sediment exists behind the dam, management practices should be
implemented to mitigate its effects downstream. Management practices include no action, river
erosion, mechanical removal, stabilization, dewatering or a combination of these practices
(Randle 2003; Evans and Gottgens 2007).
Purpose of Study
This study investigated the impacts associated with the removal of a single structure
consisting of a pair of dams, the Providence dam and the Grand Rapids dam, located on the
Maumee River at Grand Rapids, Ohio. The potential impacts associated with removal include
the effects on erosion upstream of the dams and deposition of sediment downstream of the dams,
as well as the changes in the flood regime near the site. It was determined from field work that
the two dams have a low trapping efficiency and there is essentially no sediment accumulation in
the reservoir. From this information it was determined that neither sediment loadings nor
contaminated sediment are issues associated with the potential removal of these two dams.
Therefore the focus of this study will be the potential hydrologic changes to the flood regime in
the area. This evaluation was done by constructing a model of the Maumee River for the reach
in question using the Hydrologic Engineering Centers River Analysis System (HEC-RAS) 6
model. Using HEC-RAS, hypothetical 10-, 25-, 50-, 100-, 200-, and 500-year floods were modeled both with existing conditions of the dams, and with the hypothetical conditions of the dams being removed. The model was calibrated using present conditions and historically verified using historical floods. The differences between pre- and post-removal results were examined to determine the feasibility of removing these dams.
7
BACKGROUND
Hydrology
The length of the Maumee River is about 209 river km (130 mi) between Fort Wayne,
Indiana, and Lake Erie. Its drainage area of 21,538 km2 (8,316 mi2) is the largest of any Great
Lakes river (EPA 2006). Figure 1 shows the Maumee River’s extent in Indiana, Michigan and
Ohio. The mean annual discharge at the Waterville gaging station between 1930 and 2007 was
145 m3/sec (5,136 cfs). The mean annual suspended sediment discharge, at the same location, was 3,214 metric ton/yr (3,543 English ton/yr) between 1951 and 2003 (USGS 2008b).
There are five dams that segment the Maumee River and its tributaries. These dams are:
(1) the Cedarville dam on the St. Joseph River near Fort Wayne, Indiana; (2) the Defiance Power
Company dam on the Auglaize River close to Defiance, Ohio; (3) the Grand Lake-St. Marys dam near Wapakoneta, Ohio, which collects water from the Wabash River and the St. Marys River;
(4) the Independence dam on the Maumee River at Independence, Ohio; and (5) the Providence dam and the Grand Rapids dam, which are a pair of dams on the Maumee River at Grand Rapids,
Ohio (ODNR 2006). Although the Providence dam and the Grand Rapids dam are separately named, they represent a single hydraulic structure and will be called the “Grand Rapids-
Providence dams” in this report. Of these, the Independence, Providence, and Grand Rapids dams are of canal-era vintage (ODNR 2006). The two dams located at Grand Rapids (the Grand
Rapids-Providence dams) are the topics of this report. Figure 2 shows the location of the two dams relative to state and county boundaries.
8
Figure 1: The Maumee River Basin extends into Michigan, Indiana, and Ohio. 9
Figure 2: The location of the Grand Rapids-Providence dams at Grand Rapids, Ohio. 10
Both dams were built originally in 1840 as rock-crib dams, that were subsequently
bolstered immediately downstream of the dams with concrete in 1907 with the rock-crib dams
still emplace (ODNR 2002a,b). Currently, both dams are owned and maintained by the Ohio
Department of Natural Resources, Division of Water. The Grand Rapids dam is 195.7 m (642.0
ft) long and has a structural and hydraulic height of 2.4 m (8.0 ft). The Providence Dam is 362.1
m (1,188.0 ft) long and has a structural and hydraulic height of 2.6 m (8.6 ft). Collectively, the
two dams create a single reservoir with a normal pool storage of 1,233.5 m3 (8,925.0 acre-feet)
(NID 2006). Both dams have not been inspected since August 15, 2002 and are ranked as Class
II, meaning the failure of the dams would result in a possible health hazard or probable loss of high-value property or damage to major highways, railroads, or other public utilities but loss of human life is not envisioned (ODNR 2002a,b; Ohio 1994). Currently their primary use is for
recreation and their secondary use is for water supply (ODNR 2002a,b).
Bedrock Geology
The distribution and exposure of bedrock in Northwest Ohio has been influenced by two
geologic structures, the Findlay Arch and the Bowling Green Fault. The Findlay Arch is a north-
eastern extension of the Cincinnati Arch extending about 32.2 km (20.0 mi) south west of
Findlay, Ohio to the Ontario Peninsula (Green 1957). The arch is a very gentle fold, having dips
of only one degree over most of its extent. The arch affected the lithology and thickness of
sediments deposited by influencing the environments present in the region during the Silurian
(Requarth 1978). The Bowling Green Fault cuts through the western arm of this fold, dissecting
it near Waterville, Ohio. The Bowling Green Fault is a near vertical, north-trending fault which 11 has uplifted the eastern block of the underlying Silurian Tymochtee Dolomite to lie next to the
Silurian Bass Islands Group to the west (Onasch and Kahle 1991).
The bedrock of Northwestern Ohio consists of a series of sedimentary rocks belonging to the Silurian and Devonian Periods resting upon Proterozoic (1.0 Ga) gneiss and schist (Onasch and Kahle 1991). Rocks of the Silurian Period include the Guelph Dolomite of the Lockport
Group, the Greenfield Dolomite, and Tymochtee Dolomite of the Salina Group, and the Put-in-
Bay Formation (Hull 1990, Kahle and Floyd 1971). Above these rocks are Devonian-age rocks which include the Sylvania Formation (Jeffs 1993), Amherstburg Dolomite, Lucas Dolomite, and
Anderdon Limestone of the Detroit River Group, and the Dundee, and Silica Formations (Hull
1990, Ehlers et al. 1951). Figure 3 shows the extent of Devonian strata in Northwest Ohio and
Southeastern Michigan while Figure 4 depicts the thicknesses of these rocks in Northwest Ohio.
Till
Above the eroded bedrock of Northwest Ohio lies unconsolidated till deposited during the latter part of the Ice Age, at approximately 10-25 ka (Forsyth 1968). Earlier ice advances and withdrawals eroded the bedrock and deposited till, filling the paleotopography on the bedrock surface. During glacial retreat, inundation by ice-front lakes further planed the landscape, resulting in the flat landscape we see today (Forsyth 1965). Of the numerous advancements and retreats of the glaciers, two distinct tills remain, separated by a cobble pavement in some locations and overlain by lacustrine and alluvial deposits (Forsyth 1960).
The two tills present in Northwest Ohio represent the entire interval of the Wisconsinan
(Forsyth 1960). The lower till is loamier and sandier when compared to the upper till which is 12
Figure 3: This is the extent of Devonian strata in Northwest Ohio and Southeastern Michigan (Modified from Ehlers et al. 1951). 13
Figure 4: This is the stratigraphic column of Devonian strata in Northwest Ohio showing thickness in feet (Modified from Ehlers et al. 1951). 14
rich in clay. The reason for this variance in composition is due to the substrate beneath the
advancing ice. The lower till is the result of ice advancing over weathered rock and older glacial
deposits, lending it to be loamy in composition. The upper till however is the result of ice
advancing over lake clays, which accumulated in temporary ice-front lakes during ice recession
(Forsyth 1965).
Overlying these two tills are lacustrine and alluvial deposits from temporary ice-front
lakes which fluctuated in their levels due to changes in elevation of available outlets as the
margin of the ice sheet fluctuated in its location (Forsyth 1965). A total of sixteen ice-front lakes
existed in the Erie Basin of the Great Lakes beginning 14.5 ka with Lake Maumee I, at 244.0 m
(800.5 ft) elevation and ending with the present Lake Erie at 174.0 m (570.9 ft) elevation
(Leverett and Taylor 1915, Prest 1970, Fullerton 1980, Mickelson et al. 1983). The history of
these ice-front lakes with their elevations and outlets is presented in Table 1. The extent of the
major lake stages is presented in Figure 5.
The deposition of lacustrine sediments occurred in regions where the lakes were deep and
turbulence low. In these regions a silty-clay was deposited. In most regions of Northwest Ohio
this silty-clay is only a few feet thick, but locally it can be as much as 1.8 to 2.4 m (5.9-7.9 ft)
thick (Forsyth 1965).
In more turbulent regions of these lakes, the silty-clay was kept in suspension and coarser
grained sediment was deposited, often as beaches, subaqueous dunes and glacial-lacustrine
deltas. The beaches represent wave action at the margin of the varying lake levels, while the subaqueous dunes, which are often found near bedrock highs, represent the currents which were present at the time. The thickness of these deposits varies by county due to the availability of
15
Table 1: These are the names, elevations, and outlets of each ice-front lake that existed in the Erie Basin during glaciation.
Lake Elevation Outlet Modern Lake Erie 174 m (570.9 ft) Niagra Early Lake Erie 128 m (419.9 ft) Niagra Lundy 189 m (620.1 ft) Marcellus-Cedarvale channels near Syracuse, New York Grassmere 195 m (639.8 ft) Marcellus-Cedarvale channels near Syracuse, New York Wayne 201 m (659.4 ft) Mohawk River Valley Warren III 204 m (669.3 ft) Grand Valley Warren II 206 m (675.9 ft) Grand Valley Warren I 209 m (685.7 ft) Grand Valley Whittlesey 226 m (741.5 ft) Ubly, Michigan Ypsilanti 166-122 m Hudson River Valley (544.6-400.3 ft) Arkona III 212 m (695.5 ft) Grand Valley Arkona II 213 m (698.8 ft) Grand Valley Arkona I 216 m (708.7) Grand Valley Maumee III 238 m (780.8 ft) Imlay, Michigan Maumee II 232 m (761.2 ft) North of the present Imlay, Michigan channel Maumee I 244 m (800.5 ft) Fort Wayne, Indiana
After Leverett and Taylor 1915, Hansel et al. 1985, Hough 1958, Hough 1966, Fullerton 1980, Coakley and Lewis 1985.
16
Figure 5: The locations of the Laurentide Ice Sheet through time along with corresponding lake stages (Larson and Schaetzl 2001). 17
sand. In Wood County these deposits are rarely more than 3.7 m (12.1 ft) thick while in Lucas
County deposits can locally be more than 9.1 m (29.9 ft). This variance is due to the erosion of
ancient moraines near Lucas County, composed of sandy till which occur in a very broad hilly
band that extends southwest from east-central Michigan near Pontiac (Forsyth 1965).
Terraces
There exist four terraces along the Maumee River in Northwest Ohio. These terraces, from oldest to youngest, are the Antwerp Terrace, Florida Terrace, Napoleon Terrace, and the
Grand Rapids Terrace (Klotz and Forsyth 1993). Figure 6 shows the locations and heights above the Maumee River of these terraces relative to one another. The elevation, morphology and soil composition of these terraces sheds light on the evolution of the Maumee River in the region and allows geologists to reconstruct the order of events that took place in northwest Ohio after glaciation.
The Antwerp Terrace, given by its elevation, is the oldest of the four terraces. The terrace has been split into two sections based on differences in morphology and soil composition.
The western section of the terrace extends from near the Indiana-Ohio state line to 1.0 km (0.6 mi) upstream of the Napoleon city limits and is characterized by constructional benches. These benches are capped by alluvial sands and silts which serve as parent materials for the Fulton
(sandy subsoil varian), Digby, Millgrove, and Haney soils. The eastern section of the terrace extends from 1.0 km (0.6 mi) upstream of the Napoleon city limits east to 4.2 km (2.6 mi) downstream of Napoleon and is represented by a broad (up to 1.6 km (1.0 mi) wide) belt of shallow anastomosing channels which cut 1.5 to 2.4 m (4.9-7.9 ft) into the till upland. Unlike the 18
Figure 6: Diagram showing the relationships between glacial-fluvial terraces in Northwest Ohio (Subsurface relationships inferred). The diagram shows the present day elevations of the terraces above the modern Maumee River floodplain (Modified from Klotz and Forsyth 1993).
19
western section, the eastern section is not capped by alluvial sediments. Soils present on this
terrace are the Hoytville and Millgrove soils (Klotz and Forsyth 1993).
The Florida Terrace lies 1.5 to 3.0 m (4.9-9.8 ft) below the Antwerp Terrace and 6.1 to
9.5 m (20.0-31.2 ft) above the present river level. This terrace is more distinct than the Antwerp
Terrace, exhibiting less erosion and slope-wash deposition. It contains soils which largely consist of sand with some silt which serve as parent materials for the Millgrove, Haskins, Haney, and Digby soils. These soils do not represent modern floodplain soils and presently the terrace itself does not experience flooding (Klotz and Forsyth 1993).
Just 1.5 m (4.9 ft) below the Florida Terrace lies the Napoleon Terrace which rests between 4.6 and 7.3 m (15.1-24.0 ft) above river level. This terrace converges with the river downstream standing 7.0 m (23.0 ft) above river level southeast of Florida and dropping to 4.6 m
(19.1 ft) above river level just west of Grand Rapids. This terrace shares the Digby and Haney soils with the Napoleon Terrace. Because no flood plain soils exist on this terrace, flooding does not reach this surface (Klotz and Forsyth 1993).
The final terrace on the Maumee River is the Grand Rapids Terrace, which starts at the north side of the river at Grand Rapids dam at an elevation of 195.4 m (641.1 ft) and extends downstream for 17.7 km (11.0 mi) diverging from the river until it reaches Waterville where it ends in an abandoned channel which cuts into the Tymochtee Dolomite at an elevation of 191.8 m (269.3 ft). Above the Grand Rapids dam, this terrace is at the same elevation as the current floodplain but just below the dam, it stands at 1.5 to 7.3 m (4.9-24.0 ft) above it. This change is further highlighted by the difference above the river level just below the dam and in Waterville.
Just below the dam, the terrace averages 4.3 m (14.1 ft) above river level while in Waterville it is
8.8 m (28.9 ft) above river level. This terrace is mostly silt with some sand and clay underlain by 20
shallow bedrock in places; the bedrock is typically the Dundee Limestone at the Grand Rapids
dam or the Tymochtee Dolomite at Waterville. The Dunbridge and Digby soils are found on this terrace. Flooding has occurred on upstream segments of this terrace where it is closer to the river. However it is uncommon for mean annual floods to submerge this terrace because it stands between 1.8 m (5.9 ft) and 7.3 m (24.0 ft) above the well-developed floodplain for most of
its length (Klotz and Forsyth 1993).
The Antwerp, Florida and Napoleon Terraces can be correlated to various ice-dammed
lakes during glaciations. However the Grand Rapids Terrace is interpreted to be a rock-defended
terrace and cannot be connected to any one event and may even not be considered a terrace due
to the lack of deposition. The Antwerp Terrace is correlated with Glacial Lakes Warren I and II
on the basis of these lakes elevation of 209.0 m (685.7 ft) and 206.0 m (675.9 ft) respectively.
The local terrace variations in the eastern part of the Antwerp Terrace may be due to lake
fluctuations from Glacial Lake Wayne. The Florida Terrace correlates best with Glacial Lake
Wayne which was quickly inundated by Lake Warren III and the Napoleon Terrace is tentatively correlated with Glacial Lake Grassmere (195.0 m or 639.8 ft). The Grand Rapids Terrace, since
its elevation is below that of the Napoleon Terrace, is thought to be post-Glacial Lake Grassmere
in age (Klotz and Forsyth 1993).
The terraces above could not be correlated with any of the first five ice-dammed lakes in the Erie Basin (Glacial Lake Maumee I, II, and III, Arkona and Whittlesey) since these lakes all occurred at elevations higher than the upland surrounding the Maumee River. It is possible that the western part of the Maumee Valley was exposed during the Glacial Lake Arkona phase (216-
212 .0 m or 708.7-695.5 ft) but this is interpreted to have been short lived (Calkin and Feenstra 21
1985), and would have been quickly inundated by Lake Whittlesey (226.0 m or 741.5 ft) which
extended almost to the state line (Klotz and Forsyth 1993).
Soils
Soils are a complex and ever evolving system which are shaped by past and present
processes. These processes alter the soil physically, biologically, and biochemically resulting in
continual change. To completely understand a soil and the processes that formed it, one most break it into its components. The components of a soil include color, porosity, bulk density, structure, consistence, profiles, soil micromorphology, and texture (Schaetzle and Anderson
2005). This study will focus on soil textures because of the implications for sediment loads in
the Maumee River.
Glaciation of the Maumee River Basin has increased the complexities of the soils which
have formed. Glaciation forms a unique environment where sediment is transported by both
water and ice making it one of the most complex soil landscapes. These transport agents sort and
compact sediment differently resulting in great variations from one region to another. Glacial
sediments can vary from unsorted, boulder-rich till to stratified lacustrine silts and clay
(Schaetzle and Anderson 2005). This variance is seen in the Maumee Basin because local sediment sources are either: (1) clay-rich glacial-lacustrine sediment, (2) clay-rich upper till unit, or (3) sand-rich lower till unit.
A determination of the most prevalent textures present in the Maumee River Basin was conducted and concluded the majority of the textures are fine-grained. Table 2 shows these
22
Table 2: These are the most prevalent soil textures present in the Maumee River Basin.
Texture Percentage of Area silt loam 25.3% silty clay loam 20.1% loam 17.3% silty clay 11.7% clay 9.6% clay loam 3.5% loamy fine sand 2.2% fine sandy loam 2.0% sandy loam 1.8% fine sand 1.0% muck 0.9%
23
textures along with the percentage of area they comprise in the basin. The most abundant texture is silt loam covering 25.3 % of the basin followed by silty-clay loam with 20.1 % and loam with
17.3 % coverage. The remaining textures comprise less and less of the basin but remain fine- grained in texture.
The Federal Emergency Management Agency
The Federal Emergency Management Agency (FEMA) was established in 1979. Before this time, emergency and disaster activities were fragmented over more than 100 federal agencies. The creation of FEMA merged many of the separate disaster-related responsibilities of these agencies into one, allowing for a more responsive agency. In March 2003, FEMA joined
22 other federal agencies in becoming part of the new Department of Homeland Security (FEMA
2002).
The purpose of FEMA is to guide America in the preparation for, prevention of, response to, and recovery from disasters. In the case of natural disasters, in order to serve its purpose the
Federal Insurance and Mitigation Administration (FIMA) within FEMA handles the National
Flood Insurance Program (NFIP) as well as programs that provide assistance for mitigating future damages from natural hazards (FEMA 2002).
Prior to 1968, before the implementation of the NFIP, the federal response to significant flooding events was to implement structural measures to control flooding. The large flood disasters of the 1920’s and 1930’s resulted in federal involvement in protecting life and property by the construction of structural flood-control projects authorized by the Flood Control Act of
1936. Prior to this point the only financial assistance provided by the federal government for flood victims was disaster assistance (FEMA 2002). 24
Despite the billions of dollars invested by the federal government in structural flood-
control projects and assistance, the loss of life and property continued to increase (FEMA 2002).
By the 1950’s it became apparent the federal government would need to provide financial assistance to flood victims due to the severity of flooding and the inability to develop an actuarial rate structure to reflect the risk of these disasters. Following a series of major floods, a major congressional report was written, entitled A Unified National Program for Managing Flood
Losses (U.S. House of Representatives 1966). This document and a prior feasibility study of a national flood insurance program constructed the foundation for the National Flood Insurance
Act of 1968. This act created the National Flood Insurance Program (NFIP), whose primary purposes are to improve the coverage of individuals for flood losses through insurance, to implement state and community floodplain management regulations to decrease future flood
damages and to mitigate federal expenditures related to disaster assistance and flood control
construction (FEMA 2002).
Section 1315 is a key provision in NFIP which stipulates that in order for FEMA to
provide flood insurance for a community, that community must adopt and enforce floodplain
management regulations that meet or exceed that of the criteria in Section 1361(c). By 2002,
over 19,700 communities had met these criteria in order to participate in NFIP (FEMA 2002).
Along with providing flood insurance and guidance in floodplain management, the NFIP
requires producing accurate floodplain maps called Flood Insurance Rate Maps (FIRMs).
FIRMs provide basic information for establishing the best floodplain management program and
are used as well to determine an actuary rate for flood insurance. FIRMs are used for community
floodplain management regulations, determining flood insurance premiums, and establishing if a
property owner is required by law to obtain flood insurance for obtaining mortgage loans or 25
other Federal or federally related financial assistance. They are also used by states and
communities for emergency management purposes and for land use planning or water resources
planning. Federal landowner agencies use FIRMs for floodplain management to determine if federal actions may affect a floodplain under the National Environmental Protection Act. The map boundary of the 100-year flood (or 1% exceedance probability) is used to determine the basis for risk assessment, insurance rating, and floodplain management. The 100-year flood was chosen as a compromise because it provides a higher level of protection while not inducing stringent requirements or excessive costs on property owners. The 100-year flood has a 26
percent chance of occurring during the extent of a 30-year mortgage (FEMA 2002).
Flood Insurance Studies
FEMA prepares Flood Insurance Study (FIS) reports to summarize the flood hazards in
any particular community (FEMA 2002). The FIS process includes preparation of a Flood
Insurance Rate Map (FIRM), which will be discussed later. The FIS is used to supplement the information presented in a FIRM.
The FIS report defines the region of study and gives a brief community description with background information pertaining to the regions geology, climate, hydrology, flooding, and structures in place. Along with this information are the engineering methods used to conduct the
FIS. This information covers how the peak discharges and cross-sections where obtained as well as how the hydrologic model was run to obtain flood elevations to be presented in graphs and the accompanying FIRM (FEMA 2002).
26
Flood Insurance Rate Map
Flood Insurance Rate Maps (FIRMs) are used by state and local governments to mitigate the effects of flooding in their community. Presented within a FIRM are common physical features, such as the boundaries of the 100- and 500-year floods, the 100-year and 500-year flood elevations, and flood insurance risk zones. These maps can be used to inform the public or government agencies of the location of the 100-year flood elevation at a specific site, magnitude of flood hazards in a specific area, location of regulatory floodways, or, in the case of coastal regions, areas where flood insurance is not available (FEMA 2003).
27
INTRODUCTION TO THE HYDROLOGIC MODEL HEC-RAS
Background
The Hydrologic Engineering Center, River Analysis System (HEC-RAS) model was
developed by the U.S. Army Corps of Engineers (USACE) as part of the Civil Works
Hydrologic Engineering Research and Development Program at the Hydrologic Engineering
Center (HEC), a division of the Institute for Water Resources (IWR). It was first released in
1995 and has been revised since then. The model supersedes HEC-2 both in computer science and hydraulic calculations (HEC 2002).
HEC-RAS is a one-dimensional model with the capability of performing both steady and unsteady flow river hydraulics calculations for natural and constructed channels. The steady flow, water surface profiles component is designed to model water surface profiles for steady or
horizontally gradually varied flow. This component of the program can handle situations
ranging from a single reach to a network of channels, in each case undergoing a range of
subcritical, supercritical, or mixed flow regime water surface profiles. The mathematical
procedures are based on the solution of the one-dimensional Bernoulli energy equation, where
energy losses are caused by friction and/or flow contraction or expansion (Figure 7). In
situations where the water surface profile rapidly changes, such as at bridges and weirs, the
momentum equation is used. The steady flow component is used for floodplain management and
flood insurance studies to evaluate floodway encroachments as well as the change in water
surface profiles due to channel improvements (HEC 2002).
28
Figure 7: Energy relationships in rivers, showing the relationship between two locations. Solution to the Bernoulli Equation is shown by the position potential (Z1, Z2), pressure potential 2 2 (Y1, Y2), momentum potential (αV1 /2g, αV2 /2g) and head loss (he) terms. (Modified from HEC 2002).
29
One-Dimensional Flow Calculations
Water Surface Profiles
HEC-RAS uses a form of the Bernoulli equation to determine the energy losses between
the upstream and downstream cross-section by evaluating the change in pressure, position, and
momentum (Eq. 1). This equation is solved through an iterative procedure called the standard
step method to arrive at a reasonable change in energy value (HEC 2002).
2 2 Δhe = (Y2-Y1) + (Z2-Z1) + (αV2 /2g – αV1 /2g) (1)
Where Y1 and Y2 represent the hydrostatic pressure potential at locations 1 and 2 (elevation of
the water at each cross-section), Z1 and Z2 represent the position potential at location 1 and 2
(the elevations of the bed at position 1 and 2), and V1 and V2 are the average velocities at
location 1 and 2, α is the velocity weighting coefficient, and g is the acceleration due to gravity.
These sum to equal Δhe, which is the energy head loss or change in total energy between locations 1 and 2 (HEC 2002). The relationship of these values is shown in Figure 7.
Cross-Section Conveyance
In order for HEC-RAS to determine conveyance for a cross-section, the flow must be subdivided into regions of uniform velocity. HEC-RAS does this by using break points for
Manning roughness coefficients as the basis for subdivision, as shown in Figure 8 (HEC 2002).
Within these subdivisions, conveyance is calculated by using the Manning’s equation (based on
English units) (Eq. 2).
v = (1.49R2/3S1/2)/n (2) 30
Figure 8: This is how HEC-RAS determines conveyance through a cross-section (HEC 2002).
31
Where v is the velocity, R is the hydraulic radius, S is the slope, and n is the Manning’s
roughness coefficient (HEC 2002).
Critical Depth
The user determines the need to calculate critical depth based on transitions from subcritical flow (Fr<1) to supercritical flow (Fr>1). The program may also require calculation of critical depth where the type of cross-section is an external boundary cross-section (cross-
sections at the beginning and end of the reach), in order to satisfy the boundary conditions to retain the correct flow regime. HEC-RAS may also find it necessary to calculate the critical depth if checking the Froude number reveals it is close to the critical value, or if the energy equation could not be balanced within the specified number of iterations. HEC-RAS determines critical depth in an iterative procedure where values of water surface elevations (Y1) are assumed
and the total energy head (H1) is determined until a minimum value of H1 is found. Figure 9
shows how the HEC-RAS determines H1 through multiple Y1 elevation values (HEC 2002).
The formula used to determine critical depth is presented in Equation 3.
2 H1 = Y1 + αV /2g (3)
2 Where H1 and Y1 are defined above and αV /2g is the velocity head (HEC 2002).
32
Figure 9: Determination of critical depth where the critical water surface elevation (WScrit) is the elevation where the total energy head (H4) is at a minimum (HEC 2002).
33
Momentum Equation
The momentum equation is used where the flow is changing spatially such as situations
where the flow transitions from subcritical to supercritical regimes (HEC 2002). The momentum
equation states that the sum of the forces in a particular direction are equal to the change in
momentum in that direction (Eq. 4).
(P1-P2) + (FT) - Rf = ρg(V2-V1) (4)
Where P1 and P2 are the hydrostatic pressure at cross-section 1 and 2, FT is the tangential force,
Rf is the frictional resistance, ρ is the density of water, g is the acceleration due to gravity, and
V1 and V2 are the velocities at cross-section 1 and 2 (HEC 2002). Figure 10 shows the
relationship between the terms of the momentum equation.
Weir Flow
The standard discharge equation for a straight-crested rectangular weir is used to
determine the discharge across a rectangular weir (Eq. 5).
Q = CLH3/2 (5)
Where Q is the discharge, C is the weir flow coefficient (dependent upon units and weir shape),
L is the length of the spillway crest, and H is the upstream energy head above the spillway crest.
If the weir is ogee shaped, having the shape of an elongated S, the program will automatically
adjust the coefficient when the upstream energy head is higher or lower than a user specified
design head (HEC 2002).
34
Figure 10: The momentum principle in rivers, showing the relationship between two locations. Solutions to the Momentum Equation is shown by the hydrostatic pressure (P1, P2), gravity force due to the weight of water (W), slope angle (θ), and velocity (V1, V2) terms (Modified from Haan et al. 1994).
35
Bridge Hydraulics
Bridges and their elements (piers, abutments, etc.) can act as obstructions to the natural
flow of water through them. Commonly these obstructions force the water surface elevation on
the upstream side of the bridge to be higher than they would be if the bridge were not present.
This effect can be translated upstream for some distance (Methods et al. 2003). In order to
model bridges and their effect on the water surface elevation correctly, HEC-RAS allows the
user to choose from four possible modeling approaches, the energy method, momentum method,
Yarnell equation, and the Water Surface Profile (WSPRO) method. The first three will be
discussed in the following paragraphs.
Energy Method
The energy method calculates energy loss using Equation 1 in a similar manner for
bridges (Fig. 11) as used for cross-sections (Fig. 7). The head loss is obtained from cross-section
2, the bridge upstream cross-section (BU), the bridge downstream cross-section (BD), and cross-
section 3, as if there were no obstructions and the friction losses between cross-sections and/or
losses due to expansion and contraction can be summed. If bridge piers are present, their lengths
are added to the channel’s wetted perimeter and their area subtracted from the cross-section of the channel at locations BD and BU (Methods et al. 2003).
36
Momentum Method
The momentum method is similar to the preceding method, using Equation 4, but a drag coefficient is added to account for the drag forces caused by the flow splitting around the piers and along the piers, and the creation of a downstream pier wake (Methods et al. 2003).
Yarnell Equation
The Yarnell equation is most applicable for bridges with many piers, with the piers
causing the majority of the energy losses through the bridge (Eq. 6). Figure 11 shows the
relationship between various locations used in the equation.
4 2 H3-2 = 2K (K+10ω-0.6) (α+15α ) (V2 /2g) (6)
Where H3-2 is the drop in the water surface elevation between cross-sections 3 to 2 near the
bridge, K is the Yarnell pier shape coefficient, ω is the ratio of the velocity head to the depth at
cross-section 2, α is the obstructed area of the piers divided by the total unobstructed area at
cross-section 2, V2 is the velocity at cross-section 2, and g is gravitational acceleration (Methods et al. 2003).
37
Figure 11: The four key cross-sections required for bridge modeling, where 1-4 represent user defined cross-sections while BU and BD define the upstream and downstream bridge cross- sections created by the program, respectively (Methods et al., 2003).
38
Floodplain Encroachment Analyses
The HEC-RAS floodplain encroachment analyses are important tools used by planners,
land developers, and engineers to conduct flood insurance studies. The tools allow interested parties to evaluate impacts of floodplain encroachment on water surface profiles. HEC-RAS offers five optional methods for determining floodplain encroachments, which are discussed below. The main difference between these is how the encroachments are established.
The first method requires the user to identify the exact location of the encroachment in each cross-section (Fig. 12). In the second method, the user only needs to define the width of the flow at flood stage. For the second method, the left and right encroachments are set at equal distances from the centerline of the channel (Fig. 13). The second method can also allow user- defined offset from the centerline. The third method is a more complex method in that it calculates encroachment stations for a specified percent reduction in the conveyance in each cross-section (Fig. 14). This method will make up any differences in conveyance on the left or right overbank if one-half of either overbank conveyance exceeds that of the other side. The fourth method determines encroachment stations by equaling the conveyance of the encroached cross-section to that of the natural cross-section at the natural water level (Fig. 15). The fourth method differs from the third method in that it bases the reduction in conveyance from the higher water surface while Method 3 uses the natural water surface. The final method, is similar to the fourth method except an optimization scheme is used to reach the target difference between natural and encroached conditions of the water surface elevation (Fig. 16) (HEC 2002).
39
Figure 12: This is an example of Encroachment Method 1 (HEC 2002).
40
Figure 13: This is an example of Encroachment Method 2 (HEC 2002).
41
Figure 14: This is an example of Encroachment Method 3 (HEC 2002).
42
Figure 15: This is an example of Encroachment Method 4 (HEC 2002).
43
Figure 16: This is an example of Encroachment Method 5 (HEC 2002).
44
Computational Differences between HEC-2 and HEC-RAS
The main goal of developing HEC-RAS was to better model river systems by improving the model’s computational capabilities. Thus, the HEC-RAS model carries none of the same computational routines used in its predecessor, HEC-2. The main differences are how the two models calculate cross-section conveyance, critical depth, bridge hydraulics, culvert hydraulics, and floodway encroachment. Along with these changes are additional computational features to the HEC-RAS model in order to improve its modeling capabilities (HEC 2002). These differences are discussed below.
Cross-Sectional Conveyance
The cross-section conveyance is a term that refers to the distribution of flow through cross-sections, the energy loss between cross-sections, and calculation of α (the velocity- weighing coefficient). The α-values are used to balance the energy equation, which is used in turn to determine a water surface elevation for each cross-section. Though both HEC-2 and
HEC-RAS use this calculation, they determine its value in two different fashions. HEC-2 determines cross-section conveyance by calculating it between coordinate points on each floodplain location as illustrated in Figure 17. The resulting numbers are then summed for the left and right floodplain to arrive at a conveyance value. The channel itself is not subdivided by coordinate points but between left and right floodplain points. Because this computational procedure is cumulative, it can lead to differences in conveyance values if new coordinate points are added, even when the geometry of the cross-section is not changed by the addition of these coordinate points. HEC-RAS overcomes this problem by determining conveyance between 45
Figure 17: This is how HEC-2 sub-divides conveyance (HEC 2002).
46
changes in Manning roughness coefficient values as shown in Figure 8 (HEC 2002). In HEC-
RAS, the Manning roughness coefficient only changes due to differences in roughness from
vegetation, sediment types, slope, and channel morphology.
Critical Depth
Though HEC-2 and HEC-RAS share common requirements to determine critical depth,
the two methods differ. HEC-RAS users have the choice of either using a “parabolic” method or
a “secant” method which may be determined either by the user or automatically by the program
in certain situations. HEC-2 uses only one method, similar to HEC-RAS’s parabolic method.
The HEC-RAS’s parabolic method finds the first minimum on the total energy curve. If this
method cannot converge on a value, the program will automatically switch to the secant method.
The secant method can also be chosen by the user as the primary method if multiple minimums
exist on the energy versus depth curve. This may occur where a cross-section has very wide and
flat overbanks or if levees and regions of ineffective flow exist. These levees and regions of
ineffective flow are user-defined in HEC-RAS. Levees are often used to constrain the flow
below a determined elevation and regions of ineffective flow are used to dictate areas where
water in the cross-section is not being actively conveyed (HEC 2002).
HEC-2 may select an incorrect critical depth because it is finding the first minimum value on the total energy curve. In contrast, HEC-RAS will automatically switch to the secant method when levees or ineffective flow regions are present. This difference makes HEC-RAS outputs more robust than HEC-2 outputs because HEC-RAS can detect problems while HEC-2 cannot
(HEC 2002).
Differences also exist between the two models for the precision of the parabolic method. 47
HEC-2 will calculate critical depth to a precision of 2.5 percent of the flow depth while HEC-
RAS calculates it to 0.01 ft. This difference in itself can lead to varying results between the two models (HEC 2002).
Bridge Hydraulic Computations
The largest difference between the two programs is how they model bridges. In HEC-
RAS, the user has the option of several different methods to model bridges while using the same bridge geometry. In contrast, HEC-2 requires the user to choose from two possible methods with two different data requirements, requiring the user to decide prior to inputting the data which method will be used. HEC-RAS will also create two cross-sections within the bridge geometry from the upstream and downstream bounding cross-sections. This addition allows the model to utilize four cross-sections, the two bounding cross-sections and the two cross-sections in the bridge geometry, as shown in Figure 11, to compute energy losses resulting from the bridge instead of HEC-2’s two cross-sections (HEC 2002).
The alternatives provided by the HEC-2 are the “special bridge” methodology and the
“normal bridge” methodology. Comparing the HEC-2 special bridge methodology with the
HEC-RAS methodology, the differences between the two models are as follows. First, the HEC-
2 model uses a trapezoidal approximation of the bridge opening for low-flow calculations while
HEC-RAS uses the actual geometry of the bridge opening. Second, the HEC-2 program compiles all the bridge piers into a single pier, which is placed in the middle of the bridge geometry. In contrast, HEC-RAS defines each pier separately and performs calculations by evaluating changes in the water surface and impact on each individual pier. Third, in order for
HEC-2 to calculate pressure flow values, the net flow area of the bridge opening must be 48
calculated by the user and inputted. HEC-RAS calculates this value from bridge and cross-
section data, decreasing the chance for human error. Fourth, HEC-RAS offers two alternatives to determine pressure flow. One is used when the bridge is completely submerged (also available in HEC-2), and the other is used when the bridge is partly submerged, acting as a sluice gate. The latter option is not available in the HEC-2 model. Fifth, HEC-2 does not require low chord height information (chord height refers to the elevation of the bridge deck) when using this methodology while HEC-RAS requires this information. This is because in HEC-2 the bridge opening is defined by a trapezoidal approximation while in HEC-RAS this opening needs to be completely defined. Finally, when defining the bridge in HEC-2, the stations of the bridge have to reflect stations of the cross-section. In contrast, HEC-RAS requires that the bridge only needs to reflect the additional blocked out area that is not part of the ground. This data then is automatically merged with the cross-section data (HEC 2002).
Comparing the normal bridge methodology of HEC-2 to HEC-RAS, the only difference is in how the data is transferred when importing HEC-2 data into HEC-RAS. For example, when piers are present and the user is using the energy based methods (Eq. 1) in HEC-RAS, the results should be comparable to HEC-2. If however the momentum (Eq. 4) or Yarnell (Eq. 6) methods are being used, the user must delete the pier information and re-enter it or else the model will not know about the pier information and incorrect values for losses through the bridge will result. In addition, in HEC-2 when the user may have created duplicate cross-sections when defining the bridge. If these cross-sections are different from those outside of the bridge, HEC-RAS will add cross-sections just outside the bridge. This results in two more cross-sections than were in the original data. These extra cross-sections are placed at the upstream and downstream ends of the bridge and could result in the model incorrectly calculating additional losses due to contraction 49
and expansion of flow. Finally, the HEC-2 model required the bridge stationing to match the ground station (stations that define the cross-section). HEC-RAS does not require this, and will interpolate any points that it requires (HEC 2002).
Culvert Hydraulic Computations
The two models adopted the culvert routines from the Federal Highway Administrations’
Hydraulic Design of Highway Culverts publication, HDS No. 5 (FHWA, 1985). Even so, the abilities and options of modeling culverts differ in the following manner. First, HEC-2 can evaluate box and circular culverts, while HEC-RAS can evaluate about a dozen shapes. Second,
HEC-RAS can combine different culvert shapes, sizes and all other parameters but HEC-2 cannot. Third, HEC-RAS allows the user to use two roughness coefficients inside the barrel to allow better modeling of culverts with natural bottoms but HEC-2 cannot. Fourth, HEC-RAS allows culverts to be partly filled with sediment to better model culverts that are buried, but
HEC-2 does not (HEC 2002).
Floodway Encroachment Computations
The computations for floodway encroachment in HEC-RAS were developed from those
in HEC-2 and for the most part are the same except for some minor differences. First, HEC-
RAS allows the user to specify a left and right encroachment offset applicable to methods 2-5
(Fig. 13-16). Second, the fourth method (Fig. 15) in HEC-RAS and HEC-2 are the same, except
HEC-RAS will measure the final encroachment to an accuracy of 0.01 ft while HEC-2 uses a parabolic interpolation between existing cross-section points. Third, HEC-RAS’s fifth method 50
(Fig. 16) is a combination of HEC-2’s methods 5 and 6, allowing the user to optimize a change
in water surface, a change in energy or both. Fourth, if bridges and/or culverts exist, the default
in HEC-RAS is to perform the encroachment while in HEC-2 the default is to not perform
encroachment. However, these parameters can be changed by the user. Fifth, if determining
encroachment at bridges where the energy based modeling is used, the HEC-RAS model will calculate encroachment for each cross-section through the bridge while HEC-2 will calculate it at a downstream cross-section, and then project those encroachment stations all the way through the bridge. Sixth, when importing HEC-2 data into HEC-RAS, if fixed encroachments are specified by the X3 record, anything on the user defined ET encroachment record will be overridden. The
X3, ET, and other record identifiers were used by the previous HEC-2 model to define user inputs and outputs due to the lack of a user interface. When this information is imported the X3 record is converted into a blocked obstruction. In the end any information found on the ET record will be used in addition to the blocked obstruction (HEC 2002).
New Computational Features in HEC-RAS
The development of HEC-RAS from HEC-2 has brought with it new computational features. First, HEC-RAS can calculate subcritical, supercritical, or mixed flow regime in a single step. If determining mixed flow regime calculations, HEC-RAS can locate the positions of hydraulic jumps. Second, HEC-RAS can calculate the effects of multiple bridge and/or culvert openings at a single cross-section. Third, in HEC-RAS one can solve the momentum equation when the flow is completely subcritical (class A), is either subcritical or supercritical
(class B), or when the flow is completely supercritical (class C), while in HEC-2 this could only be done for class B and C flow and required a trapezoidal channel. The momentum equation 51
used by HEC-RAS also takes into account frictional resistance and normal forces that HEC-2
does not. Fourth, HEC-2 can only perform modeling on a single reach with a limited number of
tributaries (a maximum of three stream orders), but HEC-RAS can model single reaches,
dendritic systems, or fully looped network systems. Fifth, HEC-RAS can use two different
modeling methods (energy based or momentum based) at stream junctions. While HEC-2 can only use the energy based method. Sixth, HEC-RAS can model blocked or ineffective flow areas, at any station in the cross-section, while HEC-2 users can only define blocked obstructions and specification of levees, limited to the main channel bank stations. Sixth, the number of points in any individual cross-section increases from 100 in HEC-2 to 500 in HEC-RAS.
Seventh, HEC-RAS can perform geometric cross-section interpolation between cross-sections while HEC-2 does so by a ratio of the current cross-section and a linear elevation adjustment.
Finally, HEC-RAS users can sub-divide the flow distribution calculation routine in the main channel and overbanks. HEC-2 users are constrained to the overbank areas and breaks at existing cross-section points (HEC 2002).
52
METHODS
Field Methods
Sediment
In order to determine the amount of sediment trapped behind the Grand Rapids-
Providence dams and the grain-sizes being transported by the Maumee River, field work was
conducted at the site. This was done by acquiring a boat to be used as a platform to collect
sediment from behind the dam and along the banks, upstream of the dam. Sediment was
collected using a push corer with a 2.0 m (6.6 ft) length extension for deep water regions.
Sediment collected from the corer were placed in a zip-lock bag, labeled, and the location
determined using a Garmin Global Positioning System (GPS) 12 Personal Navigator receiver with an accuracy of 15 meters (49 feet) (GARMIN 1999) using the 1983 North American Datum
(NAD83) geographic coordinate system, Universal Transverse Mercator (UTM) Zone 17N. A total of 11 samples were collected during field work with sample weights varying from approximately 25 g to 500 g. The coordinates of these samples and how they were used in the study are presented in Table 3 while Figure 18 shows the sample locations relative to the dams and the Maumee River. Samples shown as “Not Used” in Table 3 did not have enough sediment to conduct grain-size analysis. In some cases only bedrock existed and a small amount of gravel was present. These locations were also determined by the GPS receiver and the presence of
bedrock and gravel noted. The locations where this occurred are presented in Figure 19 relative to the dams. Along with the samples and notes, a 41 cm (16 in) long push core with a 6 cm (2
Table 3: The UTM coordinates of the samples taken during field work along with how each sample was used in the study.
53
Sample Northing Easting Grain-Size Analysis LPA Not Used Core 07ZM1 0259975 4589046 07ZM1A 0259975 4589046 07ZM2 0259521 4588654 07ZM3 0259517 4588577 07ZM4 0254995 4589415 07ZM5 0254805 4589480 07ZM6 0253822 4589821 07ZM7 0252235 4589611 07MR1 0251196 4589049 07MR2 0249752 4588113 07MR3 0249749 4588117 07MR4 0249749 4588117
54
Figure 18: These are the locations of where the samples were collected relative to the dams and the Maumee River.
55
Figure 19: These are the sample locations upstream of the dams. In all cases, the cores hit bedrock at the surface, and only a small amount of gravel was collected.
56 in) diameter was collected from the bank of the Maumee River, upstream of the dam. This core was later sectioned lengthwise in the lab, photographed, and interpreted.
Differential Global Positioning System
To determine the elevations of historical floods to be used in the HEC-RAS model for historical verification, differential GPS was utilized. This was done by using a Trimble GPS
Pathfinder Pro XR unit with a potential accuracy of 50 cm (20 in) (Trimble 2004) and first going to a United States Geological Survey benchmark located near Grand Rapids, Ohio to determine the vertical error associated with the unit relative to the benchmark as shown in Figure 20. This was done by taking the benchmark elevation of 199.3 m (654.0 ft) and subtracting the Trimble determined elevation 198.621 m (651.645 ft) at the same location. It was determined the
Trimble was arriving at a lower elevation than the benchmark elevation, a difference of 0.7 m
(2.4 ft).
Once the error associated with the GPS unit was determined, sites were visited at Grand
Rapids and Providence, Ohio, where historical flood elevations were marked. The locations of these sites relative to the Maumee River are shown in Figure 21. At Grand Rapids, Ohio the historical floods for the 1904, 1913, 1936, 1959, 1978, and 1982 floods were marked on a sign located at the corner of Front Street and Mill Street. The historical floods at Providence, Ohio were marked on the wall of the Isaac Ludwig Mill for the 1904, 1913, 1936, 1959, 1973, and
1982 floods. At these locations a tape-measure was used to obtain the stage height of each flood from the base of the structure. The stage height was then added to the elevation obtained from
57
Figure 20: This figure shows the location of the USGS benchmark and the elevation obtained from the differential GPS for the same location.
58
Figure 21: This shows the locations of the two sites, Grand Rapids sign and Isaac Ludwig Mill, where historical flood heights are recorded.
59
the backpack GPS unit for each location. This ultimately resulted in a water surface elevation
for each flooding event.
The base elevations obtained from the backpack GPS unit at the Grand Rapids, Ohio sign
and the Isaac Ludwig Mill wall were 193.393 m (634.492) and 196.485 m (644.635 ft)
respectively. These elevations were compared to elevations, at the same sites, obtained from the
TIN used in HEC-GeoRAS. From this comparison it was determined the two forms of elevation
determination differed by several feet. Elevations obtained from the TIN were 195.99 m (643.00
ft) at Grand Rapids, Ohio and 195.65 m (641.90 ft) at the Isaac Ludwig Mill, a difference from
the backpack GPS unit of 2.60 m (8.52 ft) and 0.84 m (2.74 ft) respectively.
In order to determine the correct elevation to base the stage heights upon at each site, the
TIN used in HEC-GeoRAS was referred to again by placing the Grand Rapids topographic map
(USGS 1977b) over the TIN and comparing the benchmark elevation to the TIN elevation at the same location. The result was the same elevation as the benchmark. From this it was determined the TIN was more accurate than the backpack GPS unit and the TIN elevations at each site would be used to base the stage heights upon. The resulting water surface elevations for each flood are presented in Table 4. This information was later used in historical verification.
Possible reasons for the difference in the elevations between the backpack GPS unit and the other sources, the TIN and the USGS benchmark, are attributed to user error while operating the backpack GPS unit and the inherent error associated with the unit. User error can offset the location and elevation determination of the unit by not allowing enough time for the unit to collect enough information from the various satellites to arrive at an accurate location and elevation. Furthermore this error is exacerbated by the error associated with the unit. It is
60
Table 4: These are the resulting flood stage elevations for the floods marked at the Isaac Ludwig Mill and at Grand Rapids which were used to historically verify the HEC-RAS model.
Location Date Datum Flood Sage Height Flood Stage Elevation Elevation (ft) (ft) (ft) Isaac Ludwig 3/2/1904 641.90 6.75 648.65 Mill Grand Rapids 3/3/1904 643.00 6.58 649.58 Isaac Ludwig 3/28/1913 641.90 5.25 647.15 Mill Grand Rapids 3/28/1913 643.00 5.17 648.17 Isaac Ludwig 2/28/1936 641.90 2.47 644.37 Mill Grand Rapids 2/28/1936 643.00 2.47 645.47 Isaac Ludwig 2/12/1959 641.90 4.33 646.23 Mill Grand Rapids 2/13/1959 643.00 4.17 647.17 Isaac Ludwig ?/?/1973 641.90 2.00 643.90 Mill Grand Rapids ?/?/1978 643.00 2.00 645.00 Isaac Ludwig 3/15/1982 641.90 2.79 644.69 Mill Grand Rapids 3/16/1982 643.00 2.67 645.67
61 common for the vertical error to be two times that of the horizontal error associated with the unit.
These two forms of error are the possible causes of the 0.7 m (2.4 ft) difference seen between the backpack GPS unit and the USGS benchmark.
Laboratory Methods
Grain-Size Analysis
Following standard practices, grain-size analysis was conducted by taking ~40.0 g of each sample collected during the field work and treating it with the aliquots of 3% H2O2
(hydrogen peroxide solution) until there was no reaction (typically within 24-hours). The ~40.0 g sample was then wet sieved through a +4.0 Ф sieve to separate the sand and mud fractions for analysis.
The sand fraction was oven dried overnight and then placed in a nest of sieves containing phi units of -2.0, -1.0, 0.0, +1.0, +2.0, +3.0, +4.0, and a pan to collect any sediment less than
+4.0 Ф. The nest of sieves was then shaken in a sieve shaker for 15 minutes. After the 15 minutes, the nest of sieves was separated and the sediment above each sieve was emptied into a newspaper and the sieve tapped on the counter to ensure all the sediment was collected. The sediment collected in the newspaper was then transferred to a beaker and weighed. The weight of the sample in each sieve was recorded and later compiled to arrive at the distribution of sediment for each sample. The results of each sample were collected and analyzed and later used to interpret the sediment being transported by the Maumee River.
The mud fraction was analyzed using a Laser Particle Size Analyzer (LPA). Following standard practices outlined by Spectrex (2005), the mud fraction was dispersed in a solution of 4 g/L Na6(PO3)6 (sodium hexametaphosphate) for 24-hours. After the 24-hours, the sample was 62 stirred to suspend any sediment that settled during the 24-hours and a very small amount of the sample was collected with a pipette and diluted in 100 ml of distilled water and placed in a jar to be used in the LPA.
While using the LPA, the default settings were used for each analysis. Each sample jar was placed in the LPA laser assembly for analysis. The Spectrex software converts the optical properties of the sediment dispersion into a grain size histogram, and further conducts standard statistical analysis for mean grain size and standard deviation.
Sediment Core
The sediment core collected during field work was split length wise, photographed, described, and one-half archived. The un-archived half was photographed using a digital camera and a 15 cm (6 in) ruler for scale. The core was then described, noting changes in composition and grain size. The other half was archived for possible future use.
GIS Analysis of Soils
ESRI’s ArcMap Geographical Information System (GIS) was used to determine the distribution and percentage of soils present within the Maumee River Basin. Shapefiles of soils maps for each county within the basin were downloaded from the Natural Resource
Conservation Service (NRCS), Soil Survey Geographic database (NRCS 2007). Once downloaded, these shapefiles were clipped by another shapefile depicting the Maumee River
Basin’s outer extent. This Maumee River Basin shapefile was made by combining sub-basin shapefiles obtained from the United States Department of Agriculture’s Geospatial Data 63
Gateway (USDA 2008). Once downloaded, these shapefiles were merged together using the merge tool in ArcMap, resulting in a shapefile depicting the outer extent of the Maumee River
Basin. The resulting soils map for each county ultimately only contained soils present within the
Maumee River Basin. Figure 22 shows the resulting soils map of Wood County after being clipped by the Maumee River Basin shapefile. It can be seen in Figure 22C and 22D that the extents of soils, represented by various colors, differ. This is because Figure 22C shows an unmodified Wood County soils map, while Figure 22D shows a modified county soils map. The process of how and why this was done is explained in the following paragraph.
Each county soils map was further simplified by changing the map unit names (e.g. Barry sandy loam) to the texture of the map unit name (e.g. sandy loam). This was done because soil names, with the same compositions, varied from county to county as well as state to state. This made it impossible to determine the distribution and percentage of each soil. By identifying each soil by its texture, the distribution and percentage of each texture could be calculated. An example of how the texture was determined for each map unit name for Paulding County, Ohio is presented in Figure 23. Once the texture of each map unit name was determined the attribute table of each county was accessed and the search by attribute tool was used to find soils with the same texture. The soil unit name in each county was then replaced by a textural description. In the case of complex soils, where several soils existed within a map unit name, the SSURGO database was used to assess the textural properties for each complex soil. These soil unit names 64
Figure 22: Creation of soils maps solely within the Maumee River Basin: A. The location of the Maumee River Basin relative to state and county boundaries. B. County soils maps were clipped to the outer extent of the Maumee River Basin to obtain the soils present within the basin. C. Wood County soils map. D. The result of clipping the Wood County soils map.
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Map Unit Legend Paulding County, Ohio Map unit name Map Symbol BeB Belmore loam, till substratum, 2 to 6 percent slopes BkA Bixler loamy sand, clayey substratum, 0 to 2 percent slopes BrB2 Broughton silty clay loam, 2 to 6 percent slopes, eroded BrC2 Broughton silty clay loam, 6 to 12 percent slopes, eroded BrD2 Broughton silty clay loam, 12 to 18 percent slopes, eroded BrE2 Broughton silty clay loam, 18 to 35 percent slopes, eroded BsC3 Broughton silty clay, 6 to 12 percent slopes, severely eroded BsD3 Broughton silty clay, 12 to 18 percent slopes, severely eroded Db Defiance silty clay loam, occasionally flooded Dc Defiance silty clay loam, frequently flooded Fb Flatrock silt loam, occasionally flooded Fc Flatrock silt loam, frequently flooded FtA Fulton loam, 0 to 2 percent slopes FuA Fulton silty clay loam, 0 to 2 percent slopes FuB2 Fulton silty clay loam, 2 to 6 percent slopes, eroded FxA Fulton silty clay loam, loamy substratum, 0 to 2 percent slopes FxB Fulton silty clay loam, loamy substratum, 2 to 6 percent slopes Gr Granby loamy sand, clayey substratum HaA Haskins loamy sand, 0 to 2 percent slopes HkA Haskins loam, 0 to 2 percent slopes HkB Haskins loam, 2 to 6 percent slopes Hs Hoytville silty clay loam Ht Hoytville silty clay Kn Knoxdale silt loam, occasionally flooded La Landes loam, occasionally flooded Lb Latty silty clay loam Lc Latty silty clay LtA Lucas silt loam, loamy substratum, 0 to 2 percent slopes LuB2 Lucas silty clay loam, loamy substratum, 2 to 6 percent slopes, eroded LuC2 Lucas silty clay loam, loamy substratum, 6 to 12 percent slopes, eroded Md Medway silt loam, occasionally flooded Me Mermill loam Mg Millgrove loam, till substratum NnA Nappanee loam, 0 to 2 percent slopes NpA Nappanee silty clay loam, 0 to 2 percent slopes NpB Nappanee silty clay loam, 2 to 6 percent slopes NpB2 Nappanee silty clay loam, 2 to 6 percent slopes, eroded OsB Oshtemo sandy loam, till substratum, 2 to 6 percent slopes OtB Ottokee loamy sand, 0 to 6 percent slopes Pc Paulding clay Pt Pits, quarry RkA Rimer loamy sand, 0 to 2 percent slopes RkB Rimer loamy sand, 2 to 6 percent slopes RmA Rimer-Fulton complex, 0 to 2 percent slopes RnA Roselms loam, 0 to 2 percent slopes RoA Roselms silty clay loam, 0 to 2 percent slopes RoB Roselms silty clay loam, 2 to 6 percent slopes RpA Roselms silty clay, 0 to 2 percent slopes RpB2 Roselms silty clay, 2 to 6 percent slopes, eroded Rt Rossburg silt loam, occasionally flooded Survey Area Version: 8 Survey Area Version Date: 12/12/2007
Figure 23: This is page one of two pages of the Map Unit Legend generated by the NRCS SSURGO soil survey of Paulding, Ohio showing the map symbols and unit names of soils present within the county. Each map unit name was simplified to the texture of the soil represented by the yellow highlight. The green highlight shows were a complex soil is present and further investigation was necessary to determine the texture. An example of how this was done is shown in Figure 24 (NRCS 2007). 66 were replaced with the textures of the soils present (e.g. Blount-Jenera complex became loam, fine sandy loam). Figure 24 shows an example of a complex soil which was simplified to its component textures.
Once all the soil unit names were replaced with their corresponding texture, the county shapefile was simplified even more by dissolving neighboring polygons with the same texture.
This was done by using the “Dissolve by Attributes” tool in ArcMap. Once completed, each county shapefile with neighboring polygons consisting of the same texture were combined to better spatially show the distribution of textures in each county and to decrease the processing time for ArcMap to load each county. Once this task was complete, the clipped county soils maps were imported into a geodatabase to allow manipulation in Microsoft Access. Microsoft
Access was used to construct queries upon the data to determine the representative area of each texture and determine the percentage of the basin each texture comprised. An example of this process is shown in Figure 25. Microsoft Access was used for this step instead of ArcMap because Microsoft Access allows easy manipulation of tables from which queries can be constructed to gather specific information such as the coverage of specific textures.
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Map Unit Description Paulding County, Ohio RmA Rimer-Fulton complex, 0 to 2 percent slopes Setting Elevation: 500 to 1000 feet Mean annual precipitation: 27 to 42 inches Mean annual air temperature: 45 to 55 degrees F Frost-free period: 140 to 180 days Composition Rimer and similar soils: 64 percent Fulton and similar soils: 30 percent Minor components: 6 percent Description of Rimer Setting Landform: Lake plains, till plains Landform position (two-dimensional): Shoulder, summit Down-slope shape: Convex Across-slope shape: Linear Parent material: Sandy glaciolacustrine deposits over till Properties and Qualities Slope: 0 to 2 percent Drainage class: Somewhat poorly drained Capacity of the most limiting layer to transmit water (Ksat): Low or moderately high (0.01 to 0.20 in/hr) Depth to water table: About 12 to 30 inches Frequency of flooding: None Frequency of ponding: None Available water capacity: Moderate (about 6.6 inches) Interpretive Groups Land capability (non irrigated): 2w Typical Profile 0 to 8 inches: loamy sand 8 to 21 inches: loamy sand 21 to 38 inches: sandy loam 38 to 80 inches: clay Description of Fulton Setting Landform: Lake plains Landform position (two-dimensional): Shoulder, summit Down-slope shape: Convex Across-slope shape: Convex Parent material: Glaciolacustrine deposits Properties and Qualities Slope: 0 to 2 percent Drainage class: Somewhat poorly drained Capacity of the most limiting layer to transmit water (Ksat): Low or moderately low (0.01 to 0.06 in/hr) Depth to water table: About 12 to 30 inches Frequency of flooding: None Frequency of ponding: None Available water capacity: Moderate (about 7.2 inches) Interpretive Groups Land capability (non irrigated): 3w Typical Profile 0 to 8 inches: loam 8 to 33 inches: clay 33 to 80 inches: silty clay Tabular Data Version: 6 Tabular Data Version Date: 12/12/2007
Figure 24: This is the Map Unit Description of the Rimer-Fulton complex soil generated by the NRCS SSURGO soil survey of Paulding, Ohio showing the description of all the soils present within the complex and their properties. In this case the Rimer-Fulton complex texture was simplified to the surface texture of loamy sand, loam shown by the yellow highlight (NRCS 2007).
Figure 25: In this example Adams County, located in Indiana, was referenced within a query: A. The original table used in the query. B. The query used to determine the area each soil texture covered in the county. C. The area in km2 each soil texture covered in the county.
68 69
Hydrologic Modeling
Data Sources
In order to develop an accurate running model of the area of interest on the Maumee
River and interpret the output, data was collected from the Ohio Geographical Referenced
Information Program (OGRIP) website, Army Corps of Engineers (USACE), the United States
eologic Survey (USGS) website, and the ET Spatial Techniques website. The OGRIP website
was utilized to obtain Light Detection and Ranging (LiDAR) data with a 2.5 ft resolution of the
study area for use in HEC-GeoRAS (OGRIP 2006a, 2006c, 2006e) and topographic maps of the
area (USGS 19977ab, 1979, 1988). The USACE provided surveyed cross-sectional data in
HEC-2 format from a 1998 HEC-6 sediment transport model of which will be referred to as
“HEC-2” in this study (USACE 1998). These cross-sections were used to construct the channel
of the Maumee River in the study area. The USACE also provided the HEC-RAS model (HEC
2004), HEC-GeoRAS ArcMap extension (HEC 2006), and the Corpscon 6.0.1 program (TEC
2004), which is a vertical datum converter. The USGS website supplied annual peak flow data in National Water Data Storage and Retrieval System (WATSTORE) format for the two nearby gaging stations located in Defiance and Waterville, Ohio (USGS 2008ab). This data was used to calibrate and run various annual exceedance probability floods. These floods were determined from the PeakFQ program (USGS 2007a) also supplied by USGS. The ET Spatial Techniques website (ET 2008) was referred to in order to obtain a formula necessary to calculate areas of inundation in ArcMap.
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Digital Elevation Model
The LiDAR data from OGRIP was downloaded from the website in ASCII DEM tiled format for Henry, Lucas, and Wood Counties along with a feature class depicting the 1ft tile layout for each county (OGRIP 2006a,c,e). The 1ft tile layout feature class was used as a reference to choose each ASCII DEM tile in the area to use in HEC-GeoRAS. The downloaded tiles were then combined in ArcMap using the Mosaic tool. Using the tool options, the first tile was chosen as the elevation to be used in case two tiles overlapped during the mosaic. The other options were kept at their default settings. Once all the tiles were combined into one digital elevation model (DEM), a triangulated irregular network (TIN) was created using the raster-to-
TIN tool in ArcMap with a vertical tolerance of 0.30 m (1.00 ft). This vertical tolerance was chosen to retain the accuracy of the original LiDAR data.
The resulting TIN was used in conjunction with HEC-GeoRAS to retrieve data necessary for HEC-RAS to run. These data include the stream centerline layer, the left, right, and center flowpath centerline layers and the cross-section cut line layer. Within each of these layers information such as length and elevation was obtained from the TIN. Each layer also projects the coordinate system of the TIN, which is the 1983 North American Datum (NAD83), State
Plane Ohio, North FIPS 3401 with an elevation referenced to the 1988 North American Vertical
Datum (NAVD88). These datums were chosen because they were the datums used in the original LiDAR data.
Each of the above layers were created in ArcMap using the “create RAS layers” tool in the HEC-GeoRAS extension. The stream centerline was drawn along the center of the river by overlaying the Colton, Grand Rapids, Maumee, and Bowling Green North topographic maps of the area and tracing the stream centerline of the Maumee River depicted on them (USGS
71
1977a,b, 1979, 1988). This line was duplicated by HEC-GeoRAS to also represent the center
flowpath. The left and right flowpath centerlines were drawn in the center of flow for the left
and right sides of the river where the presupposed majority of flow during a flood would travel
when on the right or left side. These centerlines are used in the HEC-RAS model to determine respective left and right distances between each cross-section. Due to the complexities involved in combining the HEC-2 model’s channel cross-sections with those collected from HEC-
GeoRAS, the creation of the cross-section cut line layer took a more complex approach in how
the layer was created than the previous layers created in HEC-GeoRAS.
The locations and distances between each cross-section in the HEC-2 model had to be determined in order to construct cross-sections in HEC-GeoRAS that would accurately represent the same cross-section locations. This was done by referring to the table of reach lengths in the
HEC-2 model which was imported into HEC-RAS. This table, presented in Table 5, lists the distances in feet between each cross-section in the model for the left and right overbanks and the channel. The distances between cross-sections for the channel were used in HEC-GeoRAS to determine the location where a cross-section would be created. To begin creating cross-sections at these locations both a starting point to begin measuring from and a line to measure had to be determined. The State Route 109 bridge was chosen as the starting point due to its location being far upstream from the dams (41,201 ft) and its set location. The line chosen to be used was the stream centerline layer previously created. This layer was duplicated and split into distances between each cross-section previously determined from the HEC-2 table of reach lengths (Table
5). At each split in the line a cross-section was drawn across the channel and floodplain,
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Table 5: The HEC-2 table of distances between cross-sections in feet used to determine the locations of cross-sections in HEC-GeoRAS.
Distance Between Cross-Sections (ft) Cross-Section Station Cross-Section Left Overbank Channel Right Overbank STATION 2064+80 83 2750 3360 3180 STATION 2031+20 82 3200 3350 3320 STATION 1997+70 81 2980 2800 2550 STATION 1969+70 80 3100 2820 2170 STATION 1941+50 79 2820 2750 2530 STATION 1914+00 78 2800 2720 2700 STATION 1886+80 77 4050 4280 4260 STATION 1844+00 76 2490 2590 2740 STATION 1818+10 75 2780 2630 2460 STATION 1791+80 74 2800 2720 2540 STATION 1764+60 73 2440 2660 2940 STATION 1738+00 72 1860 1900 1840 STATION 1719+00* 71 770 880 180 STATION 1710+20 70 1170 694 10 STATION 1703+26** 69 10 10 10 STATION 1703+16** 68 20 20 20 STATION 1702+96** 67 30 30 30 STATION 1703+06 66 100 100 100 STATION 1702+66 65 1100 1100 1100 STATION 1701+66 64 1105 1105 1105 STATION 1690+66 63 97 97 97 STATION 1679+61 62 23 23 23 STATION 1678+64 61.5 Bridge STATION 1678+41 60 3 3 3 STATION 1678+38 59 97 97 97 STATION 1677+41 58 451 451 451 STATION 1672+90 57 97 97 97 STATION 1671+93 56 3 3 3 STATION 1671+90 55 50 50 50 STATION 1671+40 54 3 3 3
* = Grand Rapids Dam ** = Providence Dam
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Table 5 (con’t.)
STATION 1671+37 53 97 97 97 STATION 1670+40 52 562 562 562 STATION 1664+78 51 2006 2006 2006 STATION 1644+72 50 1848 1848 1848 STATION 1626+24 49 1690 1690 1690 STATION 1609+34 48 2006 2006 2006 STATION 1589+28 47 2059 2059 2059 STATION 1568+69 46 2165 2165 2165 STATION 1547+04 45 1954 1954 1954 STATION 1527+50 44 2112 2112 2112 STATION 1506+38 43 2164 2164 2164 STATION 1484+74 42 2007 2007 2007 STATION 1464+67 41 2059 2059 2059 STATION 1444+08 40 2059 2059 2059 STATION 1423+49 39 2218 2218 2218 STATION 1401+31 38 1214 1214 1214 STATION 1389+17 37 1957 1957 1957 STATION 1369+60 36 2308 2308 2308 STATION 1346+52 35 4000 4000 4000 STATION 1306+52 34 4000 4000 4000 STATION 1266+52 33 4000 4000 4000 STATION 1226+52 32 2000 2000 2000 STATION 1206+52 31 2500 2500 2500 STATION 1181+52 30 1550 1550 1550 STATION 1166+02 29 50 50 50 STATION 1165+52 28 40 40 40 STATION 1165+12 27 50 50 50 STATION 1164+62 26 1700 1700 1700 STATION 1147+62 25 2754 2754 2754 STATION 1120+08 24 2000 2000 2000 STATION 110+08 23 1700 1700 1700 STATION 1083+08 22 50 50 50 STATION 1082+58 21 35 35 35 STATION 1082+23 20 50 50 50 STATION 1081+73 19 2250 2250 2250 STATION 1059+23 18 2000 2000 2000 STATION 1039+23 17 39571 43771 39571
74 ensuring it was perpendicular to the flow for both average flow and above average flow (floods).
Because the stream center line chosen in this study to be split differed slightly than the one used by the engineers to measure the distance between cross-sections in the HEC-2 model, small differences in distances between known locations such as the dams and bridges existed in the
HEC-GeoRAS stream center line. To alleviate this problem and to ensure the correct location of cross-sections created in HEC-GeoRAS relative to the HEC-2 model’s cross-sections, the locations of these dams and bridges, shown in aerial photographs of Henry, Lucas, and Wood counties (OGRIP 2006b,d,f), as well as georeferenced FIRMs were used. The dams and bridges constrained the number of cross-sections that could be created between them, because the HEC-2 model had a specific number of cross-sections that could exist between these known locations.
Furthermore, the georeferenced FIRMs created from the same cross-sections used in the HEC-2 model, displayed some of these cross-sections. These cross-sections further constrained the locations of cross-sections in the same manner as the dams and bridges. Figure 26 shows an example of how the placement of each cross-section was determined. The ultimate result of this process was the correct placement and number of cross-sections in HEC-GeoRAS relative to the
HEC-2 model for the study area.
Once all the shapefiles were completed, the attribute table for each shapefile was populated by HEC-GeoRAS with (x, y, z) coordinates and distances relative to each cross- section in the model, all obtained from the TIN. This data was then exported to be used in HEC-
RAS by using the “Extract GIS Data” tool in the HEC-GeoRAS extension. Due to different identification schemes between the HEC-2 model and HEC-GeoRAS, the two models differed in how they identified each cross-section. The HEC-2 model identified its cross-sections by the
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Figure 26: This figure shows how the stream centerline was split to the correct distance between known locations such as bridges and a georefercenced FIRMs to obtain the correct location of each cross-section.
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distance in feet from the mouth of the Maumee River while HEC-GeoRAS did so by where the stream centerline began, also in feet. This difference was overcome by adding the HEC-2 identification into the notes section of the HEC-GeoRAS cross-sections in order to keep track of the HEC-2 cross-sections in the HEC-RAS model.
Cross-Sections
The data from HEC-GeoRAS was imported into HEC-RAS by creating a new project and using the “Import Geometry Data in GIS Format” tool in the Geometry Data window. Once imported, each cross-section was reviewed to ensure the data was imported correctly, checking for any unreasonably large or low elevation points, or expanses of missing elevation points. At no point in this study did these errors occur. After review, cross-sections were modified by deleting elevation points which depicted tributaries as shown in Figure 27. These points were deleted because tributaries do not represent the gradient of the main channel and HEC-RAS would have considered these areas as regions of flow (altering the actual cross-sectional area and slope). Further modifications were made to the imported cross-sections by addition of the channel depicted in HEC-2 model’s cross-sections. With these two sources combined, each cross-section contained a current and high resolution depiction of the floodplain as well as channel information, which could not be supplied by HEC-GeoRAS, of the Maumee River in the study area.
In order for the HEC-2 cross-sections to be used in HEC-RAS they needed to be imported into the program from their original HEC-2 format. This was done by creating a new geometric data file within the same project as above and using the “Import Geometry in HEC-2
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Figure 27: This is how each cross-section with a tributary was modified: A. The HEC- GeoRAS cross-section with a tributary present. B. The same HEC-GeoRAS cross-section with the tributary deleted.
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format” tool in the Geometry Data window. The Corpscon program was utilized because the
cross-sections were referenced to the 1929 Nation Geodetic Vertical Datum (NGVD29) and the
TIN data was referenced to NAVD88. This program required locations to be in latitude and longitude and the elevation projection to be converted from NGVD29 to NAVD88. The coordinates used were that of the Waterville gaging station (Latitude 41°30'00", Longitude
83°42'46"). At this location, Corpscon determined that NAVD88 is lower than NGVD29 data.
All of the NGVD29 data was corrected adding 0.20 m (0.64 ft). This correction was done by accessing each cross-section in the HEC-2 model, cutting out the elevations for each coordinate defining the cross-section, pasting them into an Excel spreadsheet, and making the conversion.
Once converted, the elevations were cut from the Excel spreadsheet and pasted back into each respective cross-section. This elevation correction was done to each cross-section elevation point for all of the 54 cross-sections in the HEC-2 model present in the study area, prior to merging it with the cross-sections collected by HEC-GeoRAS and imported into HEC-RAS. The process of cross-section elevation conversion from NGVD29 to NAVD88 is shown in Figure 28.
The imported and converted HEC-2 data were then used to merge the channel geometry into the HEC-GeoRAS cross-sections by using the “Graphical Cross-Section Editor” tool as shown in Figure 29. This tool allows comparison and modification of two geometry files by overlaying them. In order to place the 54 HEC-2 channel cross-sections into the HEC-GeoRAS cross-sections, the elevation points depicted by the HEC-GeoRAS data for the channel were erased and replaced by those of the HEC-2 model cross-sections. Regions selected to be erased were determined by relative flatness, due to the limitations of LiDAR. The signal used by
LiDAR does not penetrate water but is reflected back to the sensor as depicted in Figure 30.
Figure 28: An example of a cross-section from the surveyed data referenced to NGVD 29 which was converted to NAVD88 to be merged into the GeoRAS data: A. The original cross-section XY coordinates were copied. B. The copied coordinates were placed in Excel where the conversion was conducted and copied. C. The copied coordinates from Excel were pasted back into HEC-RAS to arrive at a NAVD88 referenced cross-section.
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Figure 29: The process by which the channel was merged with the HEC-GeoRAS geometry: A: The Original HEC-GeoRAS geometry overlayed on the converted HEC-2 data showing the channel. B. The HEC-GeoRAS channel geometry married to the HEC-2 channel geometry.
Figure 30: LIDAR works by recording the amount of time a laser light takes to reflect off a surface back to the sensor. When the light reflects off of the ground an accurate representation of the topography can be collected. When the light reflects off of water, only the water’s surface can be recorded since the water’s surface reflects the majority of the light back to the sensor resulting in a flat topography at these locations being recorded.
81 82
This results in a relatively flat region when compared to the surrounding floodplain. Once the
channel was added to the HEC-GeoRAS cross-section profiles, the dams and bridges were
added.
Dams
The cross-section for the dams were chosen by referring to the notes of the HEC-2 model
and looking at the notes taken during the survey presented in Table 6. These notes relayed the
distance of various structures relative to a particular cross-section. The location of the dams
were determined by looking at these notes where cross-section station 170316 was noted to be 10
ft upstream of the dams. This cross-section corresponded to cross-section 65172.95 in the HEC-
RAS model. With this information the dams were added to HEC-RAS by using the “Inline
Structure” editor and were emplaced between 65172.95 and 64983.730 cross-sections. Both
dams were defined with a weir elevation of 2.44 m (8.00 ft), an ogee weir crest shape, and a
spillway approach height and design energy head of 0.61 m (2.00 ft), making the weir coefficient
3.95, as calculated by the HEC-RAS program. The distance from the proceeding cross-section
was determined to be 30.48 m (100.00 ft) by matching the location of the dams in HEC-RAS to
that of the dams in an aerial photograph of the area placed in the background of the Geometric
Data window. The thickness of the dams were determined to be 1.22 m (4.00 ft) from
engineering plans of the dam obtained from the Ohio Department of Natural Resources Division of Water (ODNR 2002a,b).
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Table 6: The notes for each cross-section used to determine the location and geometry of dams and bridges.
Cross-Section Cross- Note Station Section STATION 2064+80 83 STATION 2031+20 82 STATION 1997+70 81 STATION 1969+70 80 STATION 1941+50 79 STATION 1914+00 78 STATION 1886+80 77 STATION 1844+00 76 STATION 1818+10 75 STATION 1791+80 74 STATION 1764+60 73 STATION 1738+00 72 STATION 1719+00 71 GRAND RAPIDS DAM STATION 1710+20 70 STATION 1703+26 69 20 FT US PROVIDENCE DAM STATION 1703+16 68 10 FT US PROVIDENCE DAM STATION 1702+96 67 10 FT DS PROVIDENCE DAM STATION 1703+06 66 STATION 1702+66 65 40 FT DS PROVIDENCE DAM STATION 1701+66 64 STATION 1690+66 63 STATION 1679+61 62 STATION 1678+64 61.5 3 FT US N-W RR BR STATION 1678+41 60 STATION 1678+38 59 DWNST FACE N-W-RR BR STATION 1677+41 58 STATION 1672+90 57 100 FT DS N-W RR BR STATION 1671+93 56 100 FT US BRIDGE ST BR STATION 1671+90 55 3 FT US BRIDGE ST BR STATION 1671+40 54 UPST FACE BRIDGE DT BR, LS=656.2, RDWY=668.5, CL BR AT STA. 1671+70 STATION 1671+37 53 DWNST FACE BRIDGE ST BR STATION 1670+40 52 STATION 1664+78 51 100 FT DS BRIDGE ST BR
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Table 6 (con’t.)
STATION 1644+72 50 STATION 1626+24 49 STATION 1609+34 48 STATION 1589+28 47 STATION 1568+69 46 STATION 1547+04 45 STATION 1527+50 44 STATION 1506+38 43 STATION 1484+74 42 STATION 1464+67 41 STATION 1444+08 40 STATION 1423+49 39 STATION 1401+31 38 STATION 1389+17 37 STATION 1369+60 36 STATION 1346+52 35 STATION 1306+52 34 STATION 1266+52 33 STATION 1226+52 32 STATION 1206+52 31 STATION 1181+52 30 STATION 1166+02 29 STATION 1165+52 28 50 FT US ABANDONED BR STATION 1165+12 27 UPST FACE ABANDONED BR, LS=641.4, RDWY=646.6, CL BR AT STA 1165+32 STATION 1164+62 26 DWNST FACE ABANDONED BR STATION 1147+62 25 STATION 1120+08 24 STATION 110+08 23 STATION 1083+08 22 STATION 1082+58 21 50 FT US U.S. RTE. 64 BR STATION 1082+23 20 UPST FACE U.S. RTE. 64 BR, LS=622.2, RDWY=626.3, CL BR AT STA 1082+40 STATION 1081+73 19 DWNST FACE U.S.RTE. 64 BR STATION 1059+23 18 50 FT DS U.S.RTE. 64 BR STATION 1039+23 17
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Bridges
The locations of bridges were inputted into HEC-RAS in a similar fashion as that of the dams. The notes section (Table 6) in the HEC-2 model’s cross-section, which contains the distance of various structures relative to the particular cross-section, were referred to in order to determine the correct cross-section in the HEC-RAS model where a bridge would be emplaced.
Furthermore, aerial photographs of the study area were used to correctly align the bridge between the two cross-sections where the bridge would be created. The low chord and high chord elevations and width of the bridge, which define the geometry of the bridge, were obtained from the original cross-sectional data while pier data were obtained from field work where the number of piers were determined and the geometry and width of piers were visually estimated.
All bridges were modeled as broad-crested in shape, with a default maximum submergence of
0.95 and the default weir coefficient of 2.6. The energy modeling approach (Eq. 1) was used for all bridges in the model.
The railroad bridge, located downstream of the dams, within the village limits of Grand
Rapids, Ohio was determined to be between cross-section stations 167864 and 167841 in the
HEC-2 model, corresponding to cross-sections 62401.310 and 62302.870 in the HEC-RAS model. The low chord-height and high chord-height elevations of this bridge were defined as
200.13 m (656.60 ft) and 201.32 m (660.50 ft) respectively. The distance from the upstream cross-section was placed as 10.36 m (34.00 ft) with a bridge width of 6.10 m (20.00 ft). The number of piers were determined to be 7 with a 60.96 m (200.00 ft) centerline spacing and 1.83 m (6.00 ft) deck width.
The Grand Rapids road bridge (Route 578) immediately downstream of the railroad bridge, also within the village limits of Grand Rapids, Ohio was determined to be between cross-
86 section stations 167193 and 167137 in the HEC-2 model, corresponding to cross-sections
61742.770 and 61653.910 in the HEC-RAS model. The low chord-height and high chord-height elevations were determined to be 198.42 m (651.00 ft) and 203.76 m (668.50 ft) respectively.
The distance from the upstream cross-section was placed as 10.36 m (34.00 ft) with a bridge width of 15.24 m (50.00 ft). The number of piers were determined to be 3 with 60.96 m (200.00 ft) centerline and 1.22 m (4.00 ft) deck width.
Further downstream of the Grand Rapids road bridge is the Ohio Electric abandoned bridge. This bridge was determined to be between cross-section stations 116602 and 116462 in the HEC-2 model, corresponding to cross-sections 12293.430 and 12141.290 in the HEC-RAS model. The low chord-height and high chord-height elevations were determined to be 193.55 m
(635.00 ft) and 197.08 m (646.60 ft) respectively. The distance from the upstream cross-section was placed as 18.29 (60.00 ft) with a bridge width of 12.19 m (40.00 ft). The number of piers were determined to be 11 with 35.05 m (115.00 ft) centerline and 1.22 m (4.00 ft) deck width.
The final bridge within the area of study is the Route 64 bridge. This bridge was determined to be between cross-section stations 108258 and 108223 in the HEC-2 model, corresponding to cross-sections 4597.082 and 4534.834 in the HEC-RAS model. The low chord- height and high chord-height elevations varied due to the bridge geometry and were placed from
189.15-190.18 m (620.57-623.95 ft) and 190.34-191.40 m (624.46-627.96 ft) respectively. The distance from the upstream cross-section was placed as 8.23 m (27.00 ft) with a bridge width of
10.67 (35.00 ft). The number of piers were determined to be 4 with 60.96 m (200.00 ft) centerline and 1.83 m (6.00 ft) deck width.
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Hydrologic Data
Along with geometric data, flow data is necessary to run the HEC-RAS program. Steady flow analysis was chosen as the method to be used for this study. This method was chosen because the information of interest is the water surface elevation to show regions that may inundate by various flooding events. The locations of introduced discharge, such as tributaries,
were determined by referring to the Henry and Lucas County Flood Insurance Studies
Hydrologic Analysis section (FEMA 1995; FEMA 2000), and the drainage area of each tributary
was calculated (Table 7) in square miles. For each tributary the drainage area was used to
calculate discharge changes at subsequent downstream cross-sections in the model. The cross-
sections where these changes were made are also presented in Table 7. In each case, the rate of
flow at these locations was determined by plotting drainage basin area versus discharge using the
Defiance and Waterville gaging stations for various annual peak flows. Due to the lack of
discharge data between these two gaging stations, a linear relationship between drainage basin
area and discharge was assumed. The slope of this line on the graph was used to determine
discharge contribution of each tributary. Figure 31 shows this relationship for the 2006 annual
peak discharge with the contributing tributaries and their corresponding drainage areas. The
validity of this relationship is supported by Figure 32 which shows various annual peak
discharges normalized to the 1982 annual peak discharge with a small range of slopes varying
from a negative slope of -5x10-5 to a positive slope of 0.5x10-5.
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Table 7: The locations and their corresponding drainage areas in square miles where discharges where changed in the model.
Cross-Section Location Upstream Drainage Basin Area (mi2) 100470.700 North Turkeyfoot Creek 5846 93666.770 Dry Creek 5921 82448.640 Bad Creek 5948 78409.050 Big Creek 6022 61009.870 Beaver Creek 6058 21800.780 Tontogany Creek 6266 4642.747 At State Route 64 6330
Figure 31: This is the linear relationship assumed for the 2006 annual peak discharge connecting the Defiance gaging station at 5,545 mi2 and the Waterville gaging station at 6,330 mi2. The formula of the line connecting the two gaging stations was later used to determine the rate of flow at the locations of tributaries.
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Figure 32: These are the linear relationships normalized to the 1982 annual peak discharge for 8 annual peak discharges connecting the Defiance gaging station at 5,545 mi2 and the Waterville gaging station at 6,330 mi2 with their accompanying formulas validating the assumed linear relationship.
90 91
Along with discharge, the steady state analysis requires boundary conditions for each reach to be defined for HEC-RAS to begin its calculations. The reach boundary condition used was
“Normal Depth” where the downstream slope was defined as 10-3 (0.001). This slope was determined by referring to the Maumee topographic map (USGS 1979) and measuring a length of the Maumee River in that region and the change of elevation along the length to obtain a slope
(Fig. 33).
Tolerance and Stability
Before running the model the set calculation tolerances option was changed in the
“Perform a Steady Flow Simulation” window. The value changed under this option was the maximum number of iterations the program would perform before moving to the next cross- section. This value was changed from the default value of 20 to the maximum value of 40. This was done to elevate the number of warnings and errors due to the program not reaching an accepted value. The rest of the options were kept at their default settings. After this change the model was run to ensure it was stable.
To ensure the model was stable, a 100-year flood event was simulated. After running the model for the 100-year flood event, the errors, notes and warnings were reviewed by opening the cross-section output window from the program’s main window. After reviewing each cross- section it was determined there were no errors or notes present at any of the cross-sections, but warnings existed at some. A total of four warnings existed within the model at 39 cross-sections with some cross-sections having more than one of the four warnings. The four warnings and the number of their occurrences were (1) The conveyance ratio is less than 0.7 or greater than 1.4
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Figure 33: The slope to be used by HEC-RAS to begin its calculations was determined by measuring a distance between two known elevation changes and dividing that distance by the change in elevation.
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which occurred at 9 cross-sections, (2) The energy loss was greater than 1.0 ft (0.3 m) between
the current and previous cross-section occurring at 16 cross-sections, (3) The velocity head has
changed by more than 0.5 ft (0.15 m) occurred at 1 cross-section, and (4) Divided flow computed for this cross-section, occurring at 27 cross-sections. The cross-sections these warnings occurred at are presented in Table 8.
The warnings were fixed with interpolated cross-sections in the order they are listed above. In doing so other warnings were inadvertently fixed resulting in a decrease in the number of each warnings present after each warning was alleviated. Each interpolated cross-section was reviewed to ensure a realistic interpolation by checking for the location of overbank and cross- section points as well as the location of the cross-section relative to the background aerial photograph of the area. Figure 34 shows an example of an unacceptable interpolated cross- section due to the location of the bank stations not being at the banks of the river in the aerial photograph. A total of 20 interpolated cross-sections were added to the model’s 64 original cross-sections.
The need for interpolated cross-sections is often caused by cross-sections being too far apart. When this occurs between two cross-sections the program cannot accurately determine the change in the energy gradient between them. This change in the energy gradient is necessary to correctly model friction losses and contraction and expansion losses (HEC 2002). If interpolated cross-sections are not added, the model will arrive at an inaccurate water surface elevation at the cross-section containing the warning and surrounding cross-sections. After review and addition of the interpolated cross-sections, the model was determined stable and calibration could begin.
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Table 8: These are the cross-section locations of the warnings which occurred before interpolated cross-sections were add to alleviate them.
Cross-Section Warning(s) 100470.700 Divided flow computed for this cross-section. 93666.770 Divided flow computed for this cross-section. 82448.640 Divided flow computed for this cross-section. 75796.420 Divided flow computed for this cross-section. 73173.300 Divided flow computed for this cross-section. 64983.730 Divided flow computed for this cross-section. 64882.000 The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 62302.870 Divided flow computed for this cross-section. 61814.340 Divided flow computed for this cross-section. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 61742.770 Divided flow computed for this cross-section. 61653.910 Divided flow computed for this cross-section. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 61560.930 Divided flow computed for this cross-section. 61009.870 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 58997.110 Divided flow computed for this cross-section. 57098.980 Divided flow computed for this cross-section. 53452.280 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 51485.800 The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections.
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Table 8 (con’t.)
47213.910 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 45369.590 The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 42967.380 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 41145.120 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 39042.520 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. 37076.850 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 34679.000 Divided flow computed for this cross-section. 33352.630 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. 31129.330 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 29141.250 Divided flow computed for this cross-section. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 25207.210 Divided flow computed for this cross-section. 21800.780 Divided flow computed for this cross-section. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections.
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Table 8 (con’t)
16499.690 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 13827.330 The velocity head has changed by more than 0.5 ft (0.15 m). This may indicate the need for additional cross sections. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 12141.290 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 10614.250 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 7876.465 Divided flow computed for this cross-section. 6860.224 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 4642.747 Divided flow computed for this cross-section. 4534.834 The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 4492.006 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 2264.968 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections.
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Figure 34: This is an example of an unacceptable extrapolated cross-section due to the location of the bank stations not being at the banks of the river in the aerial photograph.
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The processes by which these warnings were reviewed and interpolated cross-sections added are discussed below.
Conveyance Ratio Warning
The first warning fixed with interpolated cross-sections was the conveyance ratio warning which exists when the total conveyance at a cross-section is less than 70 percent or more than 140 percent that of the previous cross-section. Changes outside these bounds could be the result of too large a difference in depth or velocity between cross-sections, which would violate the steady state or gradually varied flow assumptions (Methods et al. 2003). A total of 9 cross- sections initially contained this warning. In each case, the conveyance ratio was determined by dividing the conveyance at the cross-section containing the warning by the downstream cross- section conveyance. Any cross-section more than 10 percent outside the range of 70-140 percent conveyance, an interpolated cross-section was added to fix the problem. After review of each interpolated cross-section the model was run again with the same flow to check if the interpolated cross-section fixed the conveyance ratio warning. At cross-sections where the warning was not fixed by the interpolated cross-section, the interpolated cross-section was moved either further away or closer to the cross-section containing the warning and the model was run again until the warning was fixed. A total of 4 cross-sections were interpolated to fix this warning. Table 9 shows the warnings and their locations after these interpolated cross- sections were added.
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Table 9: These are the cross-section locations of the warnings which occurred after fixing the conveyance ratio warning.
Cross-Section Warning(s) 100470.700 Divided flow computed for this cross-section. 93666.770 Divided flow computed for this cross-section. 82448.640 Divided flow computed for this cross-section. 75796.420 Divided flow computed for this cross-section. 73173.300 Divided flow computed for this cross-section. 64983.730 Divided flow computed for this cross-section. 62302.870 Divided flow computed for this cross-section. 61814.340 Divided flow computed for this cross-section. 61778.500* Divided flow computed for this cross-section. 61742.770 Divided flow computed for this cross-section. 61653.910 Divided flow computed for this cross-section. 61607.400* Divided flow computed for this cross-section. 61560.930 Divided flow computed for this cross-section. 61009.870 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 58997.110 Divided flow computed for this cross-section. 57098.980 Divided flow computed for this cross-section. 50338.100* Divided flow computed for this cross-section. 47213.910 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 45369.590 The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 42967.380 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. * = Interpolated cross-section created by HEC-RAS
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Table 9 (con’t)
41145.120 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 39042.520 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 37076.850 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 34679.000 Divided flow computed for this cross-section. 33352.630 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 31129.330 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 29141.250 Divided flow computed for this cross-section. 27174.200* Divided flow computed for this cross-section. 25207.210 Divided flow computed for this cross-section. 21800.780 Divided flow computed for this cross-section. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 16499.690 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 13827.330 The velocity head has changed by more than 0.5 ft (0.15 m). This may indicate the need for additional cross sections. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. * = Interpolated cross-section created by HEC-RAS
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Table 9 (con’t.)
12141.290 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 10614.250 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 7876.465 Divided flow computed for this cross-section. 6860.224 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 4642.747 Divided flow computed for this cross-section. 4492.006 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 2264.968 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections.
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Energy Loss Warning
The second warning fixed was the energy loss warning. The energy loss warning appears
when the energy loss is greater than 1.0 ft (0.3 m) between two cross-sections. This warning often indicates that cross-sections are too far apart. After cross-sections were interpolated for the conveyance ratio warning, the energy loss warning existed at 15 cross-sections as shown in
Table 9. In all cross-sections this warning existed, interpolated cross-sections were used to alleviate it. After review of the added interpolated cross-sections the model was run again with the same flow to check if the interpolated cross-sections fixed the warning. In some cases it was found this warning could not be eliminate by interpolated cross-sections and the interpolated cross-sections themselves caused one or more of the four listed warnings above to appear at other cross-sections. These warnings were reviewed to determine the severity of each warning.
In the case of the conveyance warning, the same standard of 10 percent outside the range of 70-
140 percent was used while a maximum percent error was developed for any new energy loss warnings created by the new interpolated cross-sections. It was determined a 20 percent maximum error would be used as a standard so that not too many interpolated cross-sections would be added to the model. Any cross-section with this warning above 20 percent error in its energy loss would have interpolated cross-sections added to alleviate the problem. The degree of each cross-sections energy loss was determined by subtracting the energy gradeline elevation of the cross-section downstream of the cross-section with the warning by the cross-section’s energy gradeline elevation containing the warning. Table 10 presents the remaining cross-sections containing warnings after interpolated cross-sections were added to alleviate the energy loss warning.
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Table 10: These are the cross-section locations of the warnings which occurred after fixing the energy loss warning.
Cross-Sections Warning(s) 100470.700 Divided flow computed for this cross-section. 93666.770 Divided flow computed for this cross-section. 82448.640 Divided flow computed for this cross-section. 75796.420 Divided flow computed for this cross-section. 73173.300 Divided flow computed for this cross-section. 64983.730 Divided flow computed for this cross-section. 62302.870 Divided flow computed for this cross-section. 61814.340 Divided flow computed for this cross-section. 61778.500* Divided flow computed for this cross-section. 61742.770 Divided flow computed for this cross-section. 61653.910 Divided flow computed for this cross-section. 61607.400* Divided flow computed for this cross-section. 61560.930 Divided flow computed for this cross-section. 61009.870 Divided flow computed for this cross-section. 58997.110 Divided flow computed for this cross-section. 57098.980 Divided flow computed for this cross-section. 50338.100* Divided flow computed for this cross-section. 46291.700* Divided flow computed for this cross-section. 45369.590 The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 42967.380 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 41145.120 Divided flow computed for this cross-section. 39042.520 Divided flow computed for this cross-section. 37076.850 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 34679.000 Divided flow computed for this cross-section. 33352.630 Divided flow computed for this cross-section. * = Interpolated cross-section created by HEC-RAS
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Table 10 (con’t.)
32796.800* The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 31129.330 Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 29141.250 Divided flow computed for this cross-section. 27174.200* Divided flow computed for this cross-section. 25207.210 Divided flow computed for this cross-section. 21800.780 Divided flow computed for this cross-section. The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. 16499.690 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 12141.290 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 11377.700* The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 10614.250 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 6583.040* The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 5197.110* Divided flow computed for this cross-section. 4492.006 Divided flow computed for this cross-section. 3935.240* Divided flow computed for this cross-section. The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. 2264.968 The energy loss was greater than 1.0 ft (0.3 m) between the current and previous cross section. This may indicate the need for additional cross sections. * = Interpolated cross-section created by HEC-RAS
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Velocity Head Warning
The velocity head warning indicates a change of 0.5 ft (0.15 m) in the velocity head.
This is often the result of the channel widening or narrowing greatly between two cross-sections.
Additional cross-sections are not normally added unless the distance between the two cross- sections is very large (Methods et al. 2003). After alleviating the above warnings, this warning no longer appeared in any of the cross-sections as shown in Table 10.
Divided Flow Warning
The divided flow warning is displayed when the water surface is not continuous from one side of the cross-section to the other. This is the result of high ground within the cross-section profile (Methods et al. 2003). After the addition of interpolated cross-sections for the above warnings a total of 31 cross-sections contained this warning. Where this warning existed the cross-section was reviewed to ensure that error was not the cause. After review of all the cross- sections with this warning it was determined the cause was acceptable and the warning was ignored. The locations of this warning are presented in Table 10.
Calibration Data
A rating curve was constructed using yearly peak stream flows with their corresponding gage heights at the Waterville gaging station. The data were obtained from the USGS website
(USGS 2008b) in order to construct simulations in HEC-RAS to calibrate the model. Because gage heights varied with similar discharges, a graph was constructed with gage height versus discharge and a trend line was drawn to obtain a better rating curve (Fig. 35). The formula of the
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trend line was subsequently used to determine a gage height for each yearly peak discharge used
to be compared to the modeled gage height.
Calibration
Calibration of the model was done by running recent annual peak flows. The 2005 and
2006 annual peak flows were chosen to make sure the model could simulate current conditions
of the Maumee River accurately. The more recent 2007 and 2008 annual peak flows were not
used in the calibration because they have not yet been made available by USGS. After each
annual peak flow was run, the converted gage elevation of the Waterville gaging station was
subtracted from the simulated water surface elevation to obtain a gage height. This height was
compared to the gage height obtained from HEC-RAS using the formula of the trendline for the corresponding discharge for each annual peak flow to determine the difference between the modeled gage height and the actual gage height. A difference of ±0.30 m (±1.00 ft) from modeled and actual water surface elevation was chosen as a standard to calibrate the model because this value is used by the USACE for calibrating their models. In order to meet this criteria, the original Manning roughness values used in the HEC-2 model were raised or lowered to change the water surface elevation to meet that of the observed water surface elevation. Once the model was considered calibrated historical verification runs were made of past annual peak flows which were not used during the calibration to ensure the validity of the calibration.
Figure 35: This is a graph of various discharges on a logarithmic scale plotted with their corresponding gage heights at the Waterville gaging station with a logarithmic trend line plotted and the formula of the line used to determine gage heights for various discharges.
107 108
Historical Verification
Two forms of historical verification were performed on the HEC-RAS model. The first
form of verification used historical annual peak discharges where the gage height at the
Waterville gaging station was compared to the modeled results for the same discharge in the
same manner as was done during the initial calibration stage. The years chosen for this form of
historical verification are presented in Table 11 with their accompanying discharges at the
Defiance and Waterville gaging stations. These years were chosen for their variance in
discharges and because they could be used for the second form of verification.
The second form of verification used the 1936, 1959, and 1982 annual peak discharges to
compare to flood stage heights for the same years at Providence and Grand Rapids, Ohio.
Sensitivity Analysis
Sensitivity analysis is necessary to ensure the model is producing reasonable and defensible results. It is often conducted by altering values with the most uncertainty, such as
Manning numbers, contraction and expansion numbers, and slope (Methods et al. 2003).
The sensitivity analysis was conducted on the HEC-RAS model by increasing one parameter at a time by 10 and 50 percent then running the 100-year flood event and determining the change in the area inundated after each increase. The parameters chosen for this analysis were the Manning numbers, contraction and expansion numbers, and slope. The values of the calibrated HEC-RAS model for these parameters were used as the basis from which the alterations were made.
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Table 11: The years and their accompanying discharges at the Defiance and Waterville gaging stations.
Discharge (cfs) Year Defiance Waterville 1936 5.39x104 5.78 x104 1954 1.86 x104 2.41 x104 1959 7.65 x104 8.50 x104 1970 3.19 x104 3.52 x104 1974 6.12 x104 7.13 x104 1982 1.04x105 1.21 x105 2001 4.10 x104 4.48 x104
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Exceedance Probability Floods
Once the model was confirmed to be producing reasonable and defensible results,
exceedance probability floods were run. The 10-, 25-, 50-, 100-, 200-, and 500-year floods were used in the analysis and determined by the PeakFQ program (USGS 2007). The program takes the WASTORE formatted hydraulic data for a gaging station and performs an annual peak flow frequency analysis. This analysis was conducted separately for the Defiance and Waterville gaging stations. The resulting flow for each exceedance probability flood at each gaging station was then plotted on an area versus discharge graph in the same manner as was done to obtain the calibration data. The slope of the line for each exceedance probability flood was determined and used to construct the discharge data to be used in the model. Figure 36 shows how this was done for the 100-year flooding event. These floods were run for both pre- and post-dams scenarios and the resulting water surface elevations compared to determine the effects of removing the dams. This information was also used to determine the difference in the areas inundated for each scenario.
Encroachment
Once the exceedance probability floods were determined, the encroachment option was chosen in the “Steady Flow Analysis” window. Encroachment Method 4 was chosen as the best method to be used since it encroaches on both sides of the river at equal distances to ensure property owners on both sides of the river receive equal treatment and no one entity is limited more than the other in the use of their property.
Figure 36: This is the linear relationship assumed for the 100-year flood connecting the Defiance gaging station at 5,545 mi2 and the Waterville gaging station at 6,330 mi2. The formula of the line connecting the two gaging stations was later used to determine the rate of flow at the locations of tributaries.
111 112
A target value of 0.5 ft was chosen as the target rise in water elevation for all cross-
sections in the model since the Ohio Department of Natural Resources (ODNR) suggests such an increase of 0.5 ft limit, provided that hazardous velocities are not produced (FEMA 2000). The
model then ran a 100-year flood event for both pre- and post-dam removal scenarios. A
comparison was made of the results with encroachments compared to the results without
encroachments to evaluate if a rise near 0.5 ft occurred. At cross-sections where this was not the
case, the target value was altered by imputing a higher or lower target value and run again to
obtain the accepted target value of 0.5 ft at the cross-section.
FIRM Creation
FIRM maps were created for the area of study to visually and statistically show the
differences between the post-dam removal scenario the FIRMs created by FEMA. FIRMs were created by exporting the 100-, 500-flood events and encroachment analysis for the post-dam removal scenario from HEC-RAS into ArcMap using the “Export GIS data” tool in HEC-RAS and the “Import” tool in the ArcMap HEC-GeoRAS extension. From the imported data, a shapefile was created for each event and analysis for each scenario.
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RESULTS
Sediment Behind the Dam
Field work behind the Grand Rapids-Providence dam was done to determine the amount of sediment trapped behind the dam. Figure 19 shows the locations relative to the dams where
these observations were taken. At these locations the corer was utilized to collect samples for
further analysis. At all of these locations a distinct metal against rock vibration resonated
through the corer and a small amount of gravel was retrieved.
Grain-Size Analysis
Coarse Fraction
The granulometric results for the coarse fraction are presented in Table 12 while the
locations where they were collected are shown in Figure 18. Individual histograms of the
samples are presented in Appendix A. The grain-size distribution curves for the samples demonstrate both bimodal and unimodal characteristics. The bimodal samples (07MR2, 07MR3,
07ZM1A, and 07ZM2) are poorly to very poorly sorted and have a wide grain-size distribution range from pebbles to very fine sand (from -4 to +4 Ф). Samples 07MR2, 07MR3, and 07ZM2 have moderate kurtosis values around 2, while sample 07ZM1A has a kurtosis value similar to the single modal samples of 0.7. All the bimodal samples are negatively skewed corresponding to a coarse to strongly coarsely skewed distribution.
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Table 12: Statistical parameters of grain-size distribution of the coarse fraction of samples collected on the Maumee River above the Grand Rapids-Providence Dam (in phi units).
Sample Mean Mode Standard Deviation Skewness Kurtosis 07MR1 2.9 3.1 0.6 moderately well sorted 0.2 fine skewed 0.8 07MR2 0.4 2.1 2.5 very poorly sorted -0.6 strongly coarse skewed 1.9 07MR3 2.0 2.1 1.4 poorly sorted -0.2 coarse skewed 2.3 07ZM1A 0.2 -2.0 2.5 very poorly sorted -0.2 coarse skewed 0.7 07ZM2 1.2 2.0 1.2 poorly sorted -0.4 strongly coarse skewed 1.9 07ZM6 1.9 2.0 0.6 moderately well sorted 0.2 fine skewed 1.0 07ZM7 2.8 3.0 0.6 moderately well sorted -0.1 coarse skewed 1.1
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The unimodal samples, 07MR1, 07ZM6, and 07ZM7, are all moderately well sorted and have a smaller range of grain-size distributions than the bimodal samples. The grain size of
these samples range from medium sand (1-2 Ф) to the most common size found in the samples,
which is fine to very fine sand (2-4 Ф). All of these samples have similar kurtosis values of
around 1. Samples 07MR1 and 07ZM6 are positively skewed corresponding to a finely skewed
distribution while sample 07ZM7 is negatively skewed corresponding to a coarsely skewed
distribution.
Fine Fraction
The granulometric results for the fine fraction are presented in Table 13 and the locations
where the samples were obtained are presented in Figure 18. Individual histograms of the
samples are presented in Appendix B. Unlike the coarse fraction, the fine fraction grain-size
distribution curves are all unimodal. All the samples are moderately well sorted except 07ZM2
which is well sorted. The overall distribution of phi size fractions present in the samples are fine
silt (6-7.0 Ф), very fine silt (7.0-8.0 Ф) and the most common in the samples, clay (8.0-10.0 Ф).
All samples have kurtosis values around 1. The degree of skewness ranges from coarse, near
symmetrical, and finely skewed. Samples 07MR1, 07MR2, 07ZM2, 07ZM4, 07ZM6 are all
coarsely skewed. The samples which exhibit near symmetrical skewness include 07MR3,
07ZM1, and 07ZM1A while only one sample, 07ZM7, shows a finely skewed distribution.
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Table 13: Statistical parameters of grain-size distribution of the fine fraction of samples collected on the Maumee River above the Grand Rapids-Providence Dam (in phi units).
Sample Mean Mode Standard Deviation Skewness Kurtosis 07MR1 9.1 10.0 0.6 moderately well sorted -0.2 coarse skewed 0.8 07MR2 9.1 10.0 0.6 moderately well sorted -0.1 coarse skewed 0.9 07MR3 9.0 10.0 0.6 moderately well sorted 0.0 near symmetrical 0.8 07ZM1 8.4 9.0 0.6 moderately well sorted 0.0 near symmetrical 1.2 07ZM1A 8.9 9.0 0.6 moderately well sorted 0.0 near symmetrical 0.9 07ZM2 9.2 10.0 0.5 well sorted -0.3 coarse skewed 1.1 07ZM4 9.0 10.0 0.6 moderately well sorted -0.1 coarse skewed 0.9 07ZM6 9.0 9.4 0.6 moderately well sorted -0.1 coarse skewed 0.8 07ZM7 8.8 9.0 0.6 moderately well sorted 0.1 fine skewed 1.0
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Core
A 41 cm push core (07MR4) was collected along the banks of the Maumee River upstream of the Grand Rapids-Providence dams. The location of where the core was taken is
shown in Figure 18. Figure 37 shows the core stratigraphy which displays facies characteristics of floodplain deposits. Sediments in this core are predominantly mud with a small layer of sand.
The core is capped with a 5 cm thick homogeneous mud followed by a 12.5 cm thick discontinuous, wavy, nonparallel fine to very fine sand deposit with lenses of mud. Below this deposit is 36 cm of the previous homogeneous mud deposit. The sand layer is interpreted as a proximal flood deposit while the mud deposits are interpreted as floodplain deposits (Boggs
2006).
HEC-RAS Model
Calibration
Once the model was considered to be running properly, calibration runs were made. The years chosen for calibration are presented in Table 14 with their accompanying discharges at both the Defiance and Waterville gaging stations. The 2004 annual peak discharge was not used for calibration due to a negative difference in discharges between the Defiance and Waterville gaging stations for the same day. The Defiance gaging station which is upstream of the
Waterville gaging station had a higher discharge (55,100 cfs) than the Waterville gaging station
(53,100 cfs).
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Figure 37: Sediments in this core are predominantly mud with a small layer of sand. The core is capped with a 5 cm thick homogeneous mud followed by a 12.5 cm thick discontinuous, wavy, nonparallel fine to very fine sand deposit with lenses of mud. Below this deposit is 36 cm of homogeneous mud.
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Table 14: These are the years used to calibrate the model with their accompanying discharges at both the Defiance and Waterville gaging stations.
Discharge (cfs) Year Defiance Waterville 2005 8.31x104 9.41x104 2006 4.46x104 5.68x104
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The gage heights obtained from the model for each yearly peak stream flow and the
calculated gage heights obtained from the discharge versus gage height trend line formula (Fig.
35) were compared to determine the differences between the two. The original Manning numbers from the HEC-2 model, presented in Table 15, were altered until the differences between the model and calculated gage heights were within ± 1.00 ft. The altering of the
Manning numbers was done by multiplying the original HEC-2 channel Manning numbers by a factor. The factor that resulted in the best calibration was determined to be 0.9 which is a 10 percent difference between the original Manning numbers used in the HEC-2 model and the ones used in the HEC-RAS model. These Manning numbers were determined to be acceptable by comparing them against a table of accepted manning values by Chow (1959) for various substrates to determine if they were acceptable for the area they were used in the model. The expansion and contraction coefficients used in the calibrated model were kept the same from the original HEC-2 model and are presented in Table 15. The slope chosen for the calibrated model was determined to be 10-3 (0.001) from viewing a topographic map of the area previous
explained. The Manning and contraction and expansion numbers used in the calibrated model
are presented in Table 16. The resulting differences between the measured gage height and the
HEC-RAS gage height at cross-section 4534.834 are presented in Table 17.
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Table 15: These are the original HEC-2 Manning numbers used as the basis to begin calibration.
Manning Number Cross-Section Left Overbank Channel Right Overbank Contraction Expansion 100470.700 0.06 0.04 0.06 0.1 0.3 97118.950 0.06 0.04 0.06 0.1 0.3 93666.770 0.06 0.04 0.06 0.1 0.3 90930.670 0.06 0.04 0.06 0.1 0.3 88126.240 0.06 0.04 0.06 0.1 0.3 85328.650 0.06 0.04 0.06 0.1 0.3 82448.640 0.06 0.04 0.06 0.1 0.3 78409.050 0.06 0.04 0.06 0.1 0.3 75796.420 0.06 0.04 0.06 0.1 0.3 73173.300 0.06 0.04 0.06 0.1 0.3 70463.680 0.06 0.04 0.06 0.1 0.3 67747.290 0.08 0.03 0.08 0.1 0.3 66076.200 0.08 0.03 0.08 0.1 0.3 65172.950 0.08 0.03 0.08 0.3 0.5 65160.000 Dams 64983.730 0.08 0.04 0.08 0.3 0.5 64882.000 0.08 0.04 0.08 0.1 0.3 64284.300* 0.08 0.04 0.08 0.1 0.3 63686.660 0.08 0.04 0.08 0.1 0.3 62646.440 0.08 0.04 0.08 0.1 0.3 62481.520 0.08 0.04 0.08 0.1 0.3 62401.310 0.08 0.025 0.08 0.3 0.5 62401.000 Bridge 62302.870 0.08 0.025 0.08 0.3 0.5 62234.360 0.08 0.04 0.08 0.3 0.5 61814.340 0.08 0.04 0.08 0.3 0.5 61778.500* 0.06 0.04 0.06 0.3 0.5 61742.770 0.04 0.025 0.04 0.3 0.5 61700.000 Bridge 61653.910 0.04 0.025 0.04 0.3 0.5 61607.400* 0.05 0.04 0.05 0.1 0.3 61560.930 0.06 0.04 0.06 0.1 0.3 * = Interpolated cross-section created by HEC-RAS
122
Table 15 (con’t.)
61009.870 0.06 0.04 0.06 0.1 0.3 58997.110 0.06 0.04 0.06 0.1 0.3 57098.980 0.06 0.04 0.06 0.1 0.3 55424.150 0.06 0.04 0.06 0.1 0.3 53452.280 0.06 0.04 0.06 0.1 0.3 51485.800 0.06 0.04 0.06 0.1 0.3 50338.100* 0.06 0.04 0.06 0.1 0.3 49190.450 0.06 0.04 0.06 0.1 0.3 47213.910 0.06 0.04 0.06 0.1 0.3 46752.800* 0.06 0.04 0.06 0.1 0.3 46291.700* 0.06 0.04 0.06 0.1 0.3 45830.600* 0.06 0.04 0.06 0.1 0.3 45369.590 0.06 0.04 0.06 0.1 0.3 42967.380 0.06 0.04 0.06 0.1 0.3 41145.120 0.06 0.04 0.06 0.1 0.3 40093.800* 0.06 0.04 0.06 0.1 0.3 39042.520 0.06 0.04 0.06 0.1 0.3 38059.600* 0.06 0.04 0.06 0.1 0.3 37076.850 0.06 0.04 0.06 0.1 0.3 34679.000 0.06 0.04 0.06 0.1 0.3 33352.630 0.06 0.04 0.06 0.1 0.3 32796.800* 0.06 0.04 0.06 0.1 0.3 31129.330 0.06 0.04 0.06 0.1 0.3 29141.250 0.06 0.04 0.06 0.1 0.3 27174.200* 0.06 0.04 0.06 0.1 0.3 25207.210 0.06 0.04 0.06 0.1 0.3 21800.780 0.06 0.04 0.06 0.1 0.3 18507.370 0.06 0.04 0.06 0.1 0.3 16499.690 0.08 0.04 0.08 0.1 0.3 13827.330 0.08 0.04 0.08 0.1 0.3 13060.300* 0.08 0.04 0.08 0.1 0.3 12293.430 0.08 0.04 0.08 0.3 0.5 12220.000 Bridge 12141.290 0.08 0.04 0.08 0.3 0.5 11377.700* 0.08 0.04 0.08 0.1 0.3 * = Interpolated cross-section created by HEC-RAS
123
Table 15 (con’t.)
10614.250 0.08 0.04 0.08 0.1 0.3 7876.465 0.08 0.04 0.08 0.1 0.3 6860.224 0.08 0.04 0.08 0.1 0.3 6583.040* 0.08 0.04 0.08 0.1 0.3 5197.110* 0.08 0.04 0.08 0.1 0.3 4642.747 0.08 0.04 0.08 0.1 0.3 4597.082 0.07 0.025 0.08 0.3 0.5 4590.000 Bridge 4534.834 0.07 0.025 0.085 0.3 0.5 4513.42* 0.07 0.027 0.085 0.1 0.3 4492.006 0.07 0.027 0.085 0.1 0.3 3935.240* 0.07 0.027 0.085 0.1 0.3 2821.720* 0.07 0.027 0.085 0.1 0.3 2264.968 0.07 0.027 0.085 0.1 0.3 1331.230* 0.07 0.027 0.085 0.1 0.3 864.363* 0.07 0.027 0.085 0.1 0.3 397.495 0.07 0.027 0.085 0.1 0.3 * = Interpolated cross-section created by HEC-RAS
124
Table 16: These Manning and contraction and expansion numbers used in the calibrated model.
Manning Number Cross-Section Left Overbank Channel Right Overbank Contraction Expansion 100470.700 0.054 0.036 0.054 0.1 0.3 97118.950 0.054 0.036 0.054 0.1 0.3 93666.770 0.054 0.036 0.054 0.1 0.3 90930.670 0.054 0.036 0.054 0.1 0.3 88126.240 0.054 0.036 0.054 0.1 0.3 85328.650 0.054 0.036 0.054 0.1 0.3 82448.640 0.054 0.036 0.054 0.1 0.3 78409.050 0.054 0.036 0.054 0.1 0.3 75796.420 0.054 0.036 0.054 0.1 0.3 73173.300 0.054 0.036 0.054 0.1 0.3 70463.680 0.054 0.036 0.054 0.1 0.3 67747.290 0.072 0.027 0.072 0.1 0.3 66076.200 0.072 0.027 0.072 0.1 0.3 65172.950 0.072 0.027 0.072 0.3 0.5 65160.000 Dams 64983.730 0.072 0.036 0.072 0.3 0.5 64882.000 0.072 0.036 0.072 0.1 0.3 64284.300* 0.072 0.036 0.072 0.1 0.3 63686.660 0.072 0.036 0.072 0.1 0.3 62646.440 0.072 0.036 0.072 0.1 0.3 62481.520 0.072 0.036 0.072 0.1 0.3 62401.310 0.072 0.0225 0.072 0.3 0.5 62401.000 Bridge 62302.870 0.072 0.0225 0.072 0.3 0.5 62234.360 0.072 0.036 0.072 0.3 0.5 61814.340 0.072 0.036 0.072 0.3 0.5 61778.500* 0.054 0.036 0.054 0.3 0.5 61742.770 0.036 0.0225 0.036 0.3 0.5 61700.000 Bridge 61653.910 0.036 0.0225 0.036 0.3 0.5 61607.400* 0.045 0.036 0.045 0.1 0.3 61560.930 0.054 0.036 0.054 0.1 0.3 * = Interpolated cross-section created by HEC-RAS
125
Table 16 (con’t.)
61009.870 0.054 0.036 0.054 0.1 0.3 58997.110 0.054 0.036 0.054 0.1 0.3 57098.980 0.054 0.036 0.054 0.1 0.3 55424.150 0.054 0.036 0.054 0.1 0.3 53452.280 0.054 0.036 0.054 0.1 0.3 51485.800 0.054 0.036 0.054 0.1 0.3 50338.100* 0.054 0.036 0.054 0.1 0.3 49190.450 0.054 0.036 0.054 0.1 0.3 47213.910 0.054 0.036 0.054 0.1 0.3 46752.800* 0.054 0.036 0.054 0.1 0.3 46291.700* 0.054 0.036 0.054 0.1 0.3 45830.600* 0.054 0.036 0.054 0.1 0.3 45369.590 0.054 0.036 0.054 0.1 0.3 42967.380 0.054 0.036 0.054 0.1 0.3 41145.120 0.054 0.036 0.054 0.1 0.3 40093.800* 0.054 0.036 0.054 0.1 0.3 39042.520 0.054 0.036 0.054 0.1 0.3 38059.600* 0.054 0.036 0.054 0.1 0.3 37076.850 0.054 0.036 0.054 0.1 0.3 34679.000 0.054 0.036 0.054 0.1 0.3 33352.630 0.054 0.036 0.054 0.1 0.3 32796.800* 0.054 0.036 0.054 0.1 0.3 31129.330 0.054 0.036 0.054 0.1 0.3 29141.250 0.054 0.036 0.054 0.1 0.3 27174.200* 0.054 0.036 0.054 0.1 0.3 25207.210 0.054 0.036 0.054 0.1 0.3 21800.780 0.054 0.036 0.054 0.1 0.3 18507.370 0.054 0.036 0.054 0.1 0.3 16499.690 0.072 0.036 0.072 0.1 0.3 13827.330 0.072 0.036 0.072 0.1 0.3 13060.300* 0.072 0.036 0.072 0.1 0.3 12293.430 0.072 0.036 0.072 0.3 0.5 12220.000 Bridge 12141.290 0.072 0.036 0.072 0.3 0.5 11377.700* 0.072 0.036 0.072 0.1 0.3 * = Interpolated cross-section created by HEC-RAS
126
Table 16 (con’t.)
10614.250 0.072 0.036 0.072 0.1 0.3 7876.465 0.072 0.036 0.072 0.1 0.3 6860.224 0.072 0.036 0.072 0.1 0.3 6583.040* 0.072 0.036 0.072 0.1 0.3 5197.110* 0.072 0.036 0.072 0.1 0.3 4642.747 0.072 0.036 0.072 0.1 0.3 4597.082 0.063 0.0225 0.072 0.3 0.5 4590.000 Bridge 4534.834 0.063 0.0225 0.0765 0.3 0.5 4513.42* 0.063 0.0243 0.0765 0.1 0.3 4492.006 0.063 0.0243 0.0765 0.1 0.3 3935.240* 0.063 0.0243 0.0765 0.1 0.3 2821.720* 0.063 0.0243 0.0765 0.1 0.3 2264.968 0.063 0.0243 0.0765 0.1 0.3 1331.230* 0.063 0.0243 0.0765 0.1 0.3 864.363* 0.063 0.0243 0.0765 0.1 0.3 397.495 0.063 0.0243 0.0765 0.1 0.3 * = Interpolated cross-section created by HEC-RAS
127
Table 17: These are the resulting differences between the modeled and actual gage heights at cross-section 4534.843 and the Waterville gaging station, respectively, along with their corresponding percent difference for each year.
Gage Height (ft) Peak Flow Modeled Actual Difference (ft) % Difference 2005 15.34 14.37 0.97 6.73% 2006 11.96 11.85 0.11 0.91%
128
Historical Verification
Once the model was considered calibrated two forms of historical verification runs were
made using flows which were not used during the calibration to ensure the model could simulate
reality. The first form compared gage heights at the Waterville gaging station to gage heights at
cross-section 4534.834. The second form compared flood stage heights at the Isaac Ludwig Mill at Providence, Ohio to the modeled water surface elevation of the same area.
The first form of historical verification used the annual peak discharges of 1936, 1954,
1959, 1970, 1974, 1982, and 2001. The results of the historical verifications are shown in Table
18 where almost all the years are within the determined level of error (±1 ft) except the 1982 peak flow. This inaccuracy could have been the result of error at the gaging station during this peak flow and even if this is not the case, the model still was able to accurately model six other flows and is considered verified.
The second form of historical verification used the flood heights recorded at the Isaac
Ludwig Mill in Providence, Ohio. This location was chosen over using both the Isaac Ludwig
Mill and the Grand Rapids location because the Mill is located about 15 m (49 ft) from the bank of the Maumee River without any obstructions between the Mill and the river while record location in the village of Grand Rapids contains a number of obstructions which may cause variations in the recorded elevations at the site as well as because the distance from the river to the location is about 100 m (328 ft). The locations of the Ludwig Mill and Grand Rapids sign are shown in Figure 21.
In order to ensure the floods recorded at Providence, Ohio correlated with that of the peak discharges obtained from the USGS website, old newspaper articles were referenced from both
129
Table 18: Historical verification comparing the gage height at the Waterville gaging station.
Gage Height (ft) Peak Flow Modeled Actual Difference (ft) % Difference 1936 12.07 11.94 0.13 1.10 1954 7.97 7.57 0.40 5.29 1959 14.60 13.87 0.73 5.30 1970 9.48 9.46 0.02 0.19 1974 13.37 12.99 0.38 2.95 1982 17.27 15.63 1.64 10.50 2001 10.65 10.67 -0.02 -0.15
130
the Wood County and Grand Rapids Libraries. From these articles it was determined floods
which occurred in 1936, 1959, and 1982 matched the dates of the annual peak discharges for the
Defiance and Waterville gaging stations, so flow data could be constructed. The discharges for
each year are presented in Table 19 with their corresponding heights at the Isaac Ludwig Mill.
In the case of the other years marked at the site, the date of the 1973 flood could not be determined from newspaper articles, while both the 1904 and 1913 floods could be determined but the 1904 flow data was missing at both gaging stations, and the 1913 flow data was missing
at the Defiance gaging station and estimated at the Waterville gaging station.
When the 1936, 1959, and 1982 flow data were inputted and run in the calibrated model,
the water surface elevations differed by several feet as presented in Table 20. After review of
this information, it was determined that the various floods recorded on the mill wall had too
much variation.
This variance may have been due to ice jams on the river near Grand Rapids. It was
noted while reviewing newspaper articles for various floods that pictures referring to 1913 and
1904, had large amounts of ice in them and in the case of the 1936 and 1959 floods, both
occurred in late to mid February, possibly due to ice jams as well. The 1982 flood occurred in
March. Other explanations include inaccurate flood stage record and/or backwater effects at the
site.
131
Table 19: Heights of floods marked on the Isaac Ludwig Mill in Providence, Ohio and the corresponding flow at the Waterville gaging station.
Year Height (ft) Corresponding Flow (cfs) 1936 2.46 5.78x104 1959 4.33 8.50x104 1982 2.79 1.21x105
132
Table 20: The differences between the historical and modeled flood elevations for each year at the Isaac Ludwig Mill in Providence, Ohio with the calibrated model.
Water Surface Elevation (ft) Year Historical Modeled Difference (ft) % Difference 1936 2.46 -0.70 3.16 128% 1959 4.33 2.40 1.93 45% 1982 2.79 5.80 -3.01 -108%
133
Sensitivity Analysis
The amount each parameter changed the area inundated during the 100-year flood event
using the pre-dam scenario is presented in Figure 38. The basis from which the Manning, and
contraction and expansion values were altered from were from the calibrated HEC-RAS model.
The alteration of the Manning numbers resulted in the most change in the area inundated than
any of the other parameters, followed by contraction and expansion values and slope.
Exceedance Probability Floods
The flows used to simulate the 10-, 25-, 50-, 100-, 200-, and 500-year floods are displayed in Tables 21, 22, 23, 24, 25, and 26 respectively. The result of these floods for pre- and post-dam removal showed no significant change upstream of the dam and no change at all below the structure. The differences in water surface elevation for these two scenarios for each flooding event are presented in Tables 27, 28, 29, 30, 31, and 32 for the 10-, 25-, 50-, 100-, 200-, and 500-year floods respectively.
The largest difference in water surface elevation between the two scenarios is seen immediately upstream of the dams for every flooding event. For the 500-year flood event, the
water surface elevation went from 649.70 ft , with the dams in place, to 649.46 ft without the
dams, a difference <1%. Further upstream for the 500-year flood event, the water surface
elevation decreased from 655.14 ft, with the dams in place, to 655.06 ft without the dams.
Downstream of the dams there was no change in the water surface elevation. The result of
decreased water surface elevations without the dams resulted in a decrease in the areas which
were inundated for each flooding event.
Figure 38: Results of Sensitivity Analysis showing how each percent increase in each parameters value changed the area inudated.
134 135
Table 21: HEC-RAS model runs simulating the discharges for the 10-year flood.
Cross-Section Area (mi2) Discharge (cfs) 100470.700 6,330 74,408 93666.770 6,266 75,175 82448.640 6,058 75,451 78409.050 6,022 76,208 61009.870 5,948 76,576 21800.780 5,921 78,704 4642.747 5,846 79,359
136
Table 22: HEC-RAS model runs simulating the discharges for the 25-year flood.
Cross-Section Area (mi2) Discharge (cfs) 100470.700 6,330 86,325 93666.770 6,266 87,147 82448.640 6,058 87,442 78409.050 6,022 88,253 61009.870 5,948 88,647 21800.780 5,921 90,926 4642.747 5,846 91,627
137
Table 23: HEC-RAS model runs simulating the discharges for the 50-year flood.
Cross-Section Area (mi2) Discharge (cfs) 100470.700 6,330 94,846 93666.770 6,266 95,707 82448.640 6,058 96,017 78409.050 6,022 96,867 61009.870 5,948 97,280 21800.780 5,921 99,667 4642.747 5,846 100,402
138
Table 24: HEC-RAS model runs simulating the discharges for the 100-year flood.
Cross-Section Area (mi2) Discharge (cfs) 100470.700 6,330 103,061 93666.770 6,266 103,950 82448.640 6,058 104,270 78409.050 6,022 105,148 61009.870 5,948 105,575 21800.780 5,921 108,042 4642.747 5,846 108,801
139
Table 25: HEC-RAS model runs simulating the discharges for the 200-year flood.
Cross-Section Area (mi2) Discharge (cfs) 100470.700 6,330 111,080 93666.770 6,266 111,997 82448.640 6,058 112,327 78409.050 6,022 113,232 61009.870 5,948 113,672 21800.780 5,921 116,216 4642.747 5,846 116,999
140
Table 26: HEC-RAS model runs simulating the discharges for the 500-year flood.
Cross-Section Area (mi2) Discharge (cfs) 100470.700 6,330 121,493 93666.770 6,266 122,439 82448.640 6,058 122,779 78409.050 6,022 123,712 61009.870 5,948 124,166 21800.780 5,921 126,790 4642.747 5,846 127,597
141
Table 27: The water surface elevations for the 10-year flood event for both pre- and post-dam removal scenarios.
Conditions Cross- Pre-Dam Removal Post-Dam Removal Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 650.40 650.35 0.05 <1% 97118.950 649.95 649.90 0.05 <1% 93666.770 649.42 649.37 0.05 <1% 90930.670 649.09 649.03 0.06 <1% 88126.240 648.78 648.71 0.07 <1% 85328.650 648.42 648.35 0.07 <1% 82448.640 647.89 647.81 0.08 <1% 78409.050 647.15 647.05 0.10 <1% 75796.420 646.71 646.60 0.11 <1% 73173.300 646.18 646.05 0.13 <1% 70463.680 645.49 645.34 0.15 <1% 67747.290 645.03 644.86 0.17 <1% 66076.200 644.87 644.69 0.18 <1% 65172.950 644.82 644.64 0.18 <1% 65160.000 Dams
142
Table 28: The water surface elevations for the 25-year flood event for both pre- and post-dam removal scenarios.
Conditions Cross- Pre-Dam Removal Post-Dam Removal Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 651.71 651.66 0.05 <1% 97118.950 651.28 651.22 0.06 <1% 93666.770 650.72 650.66 0.06 <1% 90930.670 650.38 650.31 0.07 <1% 88126.240 650.08 650.00 0.08 <1% 85328.650 649.72 649.64 0.08 <1% 82448.640 649.17 649.08 0.09 <1% 78409.050 648.44 648.33 0.11 <1% 75796.420 648.00 647.87 0.13 <1% 73173.300 647.47 647.33 0.14 <1% 70463.680 646.81 646.65 0.16 <1% 67747.290 646.36 646.18 0.18 <1% 66076.200 646.22 646.03 0.19 <1% 65172.950 646.18 645.98 0.20 <1% 65160.000 Dams
143
Table 29: The water surface elevations for the 50-year flood event for both pre- and post- dam removal scenarios.
Conditions Cross- Pre-Dam Removal Post-Dam Removal Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 652.60 652.54 0.06 <1% 97118.950 652.18 652.11 0.07 <1% 93666.770 651.61 651.53 0.08 <1% 90930.670 651.26 651.18 0.08 <1% 88126.240 650.95 650.87 0.08 <1% 85328.650 650.60 650.51 0.09 <1% 82448.640 650.04 649.94 0.10 <1% 78409.050 649.32 649.19 0.13 <1% 75796.420 648.87 648.74 0.13 <1% 73173.300 648.35 648.20 0.15 <1% 70463.680 647.70 647.53 0.17 <1% 67747.290 647.27 647.07 0.20 <1% 66076.200 647.13 646.92 0.21 <1% 65172.950 647.10 646.89 0.21 <1% 65160.000 Dams
144
Table 30: The water surface elevations for the 100-year flood event for both pre- and post-dam removal scenarios.
Conditions Cross- Pre-Dam Removal Post-Dam Removal Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 653.42 653.35 0.07 <1% 97118.950 653.00 652.93 0.07 <1% 93666.770 652.42 652.33 0.09 <1% 90930.670 652.08 651.99 0.09 <1% 88126.240 651.77 651.67 0.10 <1% 85328.650 651.42 651.31 0.11 <1% 82448.640 650.85 650.74 0.11 <1% 78409.050 650.13 650.00 0.13 <1% 75796.420 649.69 649.54 0.15 <1% 73173.300 649.16 649.00 0.16 <1% 70463.680 648.53 648.34 0.19 <1% 67747.290 648.11 647.90 0.21 <1% 66076.200 647.97 647.75 0.22 <1% 65172.950 647.95 647.73 0.22 <1% 65160.000 Dams
145
Table 31: The water surface elevations for the 200-year flood event for both pre- and post-dam removal scenarios.
Conditions Cross- Pre-Dam Removal Post-Dam Removal Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 654.18 654.11 0.07 <1% 97118.950 653.77 653.69 0.08 <1% 93666.770 653.17 653.08 0.09 <1% 90930.670 652.84 652.74 0.10 <1% 88126.240 652.53 652.43 0.10 <1% 85328.650 652.17 652.06 0.11 <1% 82448.640 651.60 651.48 0.12 <1% 78409.050 650.88 650.74 0.14 <1% 75796.420 650.43 650.28 0.15 <1% 73173.300 649.91 649.74 0.17 <1% 70463.680 649.29 649.09 0.20 <1% 67747.290 648.86 648.65 0.21 <1% 66076.200 648.73 648.51 0.22 <1% 65172.950 648.71 648.49 0.22 <1% 65160.000 Dams
146
Table 32: The water surface elevations for the 500-year flood event for both pre- and post-dam removal scenarios.
Conditions Cross- Pre-Dam Removal Post-Dam Removal Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 655.14 655.06 0.08 <1% 97118.950 654.73 654.65 0.08 <1% 93666.770 654.12 654.02 0.10 <1% 90930.670 653.78 653.68 0.10 <1% 88126.240 653.48 653.37 0.11 <1% 85328.650 653.12 653.00 0.12 <1% 82448.640 652.54 652.41 0.13 <1% 78409.050 651.84 651.68 0.16 <1% 75796.420 651.38 651.22 0.16 <1% 73173.300 650.86 650.68 0.18 <1% 70463.680 650.25 650.04 0.21 <1% 67747.290 649.83 649.61 0.22 <1% 66076.200 649.71 649.47 0.24 <1% 65172.950 649.70 649.46 0.24 <1% 65160.000 Dams
147
The extent of flooding for each flood probability is shown in Table 33. It can be seen in
this table the small differences in water surface elevation also resulted in very small changes in
the area which was inundated by water. The removal of the dams resulted in a decreased
inundation area upstream of the dams, ranging from no change to 0.01 mi2 (0.03 km2).
Encroachment
The encroachment values used in the encroachment analysis are presented in Table 34 and 35 for both pre- and post-dam removal respectively. It is seen in these tables that some cross-sections have a much smaller water surface change than the target value of 0.5 ft (0.15 m).
This is because the encroachment will only encroach upon the river until it reaches the banks of
the river. Further encroachment is not deemed reasonable as it would result in encroachment
into the river.
FIRM
Due to the negligible changes in water surface elevation between the pre- and post-dam
removal scenarios, the difference in areas inundated for each scenario were also negligible. This
resulted in FIRMs with similar floodways and flooding extents as the FEMA created FIRMs.
The pre- and post-dam removal FIRMs created from the HEC-RAS model matched those created by FEMA except that of Grand Rapids, Ohio. The Grand Rapids, Ohio FIRM showed differences for both the 100- and 500-year flood events. Floodway differences could not be determined due to the lack of a floodway in the FEMA FIRM of the Grand Rapids area.
148
Table 33: The area inundated by each flood probability for both pre- and post-dam removal scenarios and the difference.
Conditions Year Floods Pre-Dam Removal Post-Dam Removal Difference (mi2) % Difference Area (mi2) Area (mi2) 10 7.27 7.27 0.00 0% 25 7.44 7.44 0.00 0% 50 7.55 7.55 0.00 0% 100 7.64 7.64 0.00 0% 200 7.72 7.72 0.00 0% 500 7.82 7.81 0.01 <1%
149
Table 34: These are the results from encroachment with the dams emplace showing each cross- sections floodway width, area, and mean velocity. The base flood water surface elevations are also presented showing the water surface level before encroachment and after encroachment with the increase in water surface elevation which occurred relative to the unencroached water surface elevation.
Cross-Section Without Floodway With Floodway Increase 100470.700 653.56 654.07 0.51 97118.950 653.12 653.64 0.52 93666.770 652.54 653.06 0.52 90930.670 652.19 652.72 0.53 88126.240 651.88 652.40 0.52 85328.650 651.51 652.04 0.53 82448.640 650.94 651.48 0.54 78409.050 650.22 650.78 0.56 75796.420 649.78 650.34 0.56 73173.300 649.26 649.83 0.57 70463.680 648.64 649.22 0.58 67747.290 648.22 648.82 0.60 66076.200 648.09 648.70 0.61 65172.950 648.06 648.68 0.62 65160.000 Bridge 64983.730 647.84 648.39 0.55 64882.000 647.78 648.33 0.55 64284.300* 647.60 648.15 0.55 63686.660 647.18 647.72 0.54 62646.440 646.45 646.99 0.54 62481.520 646.41 646.95 0.54 62401.310 646.23 646.77 0.54 62401.000 Bridge 62302.870 645.98 646.56 0.58 62234.360 646.00 646.56 0.56 61814.340 645.66 646.21 0.55 61778.500* 645.61 646.17 0.56 61742.770 645.59 646.18 0.59 61700.000 Bridge 61653.910 645.40 645.86 0.46 * = Interpolated cross-section created by HEC-RAS
150
Table 34 (con’t.)
61607.400* 645.29 645.74 0.45 61560.930 645.36 645.81 0.45 61009.870 645.21 645.67 0.46 58997.110 644.22 644.63 0.41 57098.980 643.60 644.02 0.42 55424.150 643.05 643.45 0.40 53452.280 642.20 642.64 0.44 51485.800 641.23 641.61 0.38 50338.100* 641.01 641.39 0.38 49190.450 640.93 641.31 0.38 47213.910 640.52 640.87 0.35 46752.800* 640.06 640.46 0.40 46291.700* 639.43 639.88 0.45 45830.600* 638.65 639.15 0.50 45369.590 637.79 638.34 0.55 42967.380 636.79 637.32 0.53 41145.120 635.61 636.12 0.51 40093.800* 634.82 635.31 0.49 39042.520 633.85 634.32 0.47 38059.600* 632.97 633.44 0.47 37076.850 632.24 632.72 0.48 34679.000 630.81 631.24 0.43 33352.630 629.71 630.03 0.32 32796.800* 629.21 629.61 0.40 31129.330 628.25 628.62 0.37 29141.250 627.14 627.43 0.29 27174.200* 626.55 626.91 0.36 25207.210 626.15 626.55 0.40 21800.780 625.64 626.05 0.41 18507.370 624.59 624.95 0.36 16499.690 623.55 623.87 0.32 13827.330 621.96 622.39 0.43 13060.300* 621.20 621.70 0.50 12293.430 619.98 620.52 0.54 12220.000 Bridge * = Interpolated cross-section created by HEC-RAS
151
Table 34 (con’t.)
12141.290 619.69 620.28 0.59 11377.700* 618.51 619.00 0.49 10614.250 617.72 618.17 0.45 7876.465 615.27 615.50 0.23 6860.224 614.58 614.84 0.26 6583.040* 614.33 614.61 0.28 5197.110* 612.91 613.29 0.38 4642.747 612.26 612.66 0.40 4597.082 611.90 612.37 0.47 4590.000 Bridge 4534.834 611.46 611.97 0.51 4513.420* 611.44 611.96 0.52 4492.006 611.49 611.96 0.47 3935.240* 610.65 611.19 0.54 2821.720* 609.15 610.01 0.86 2264.968 608.21 608.52 0.31 1331.230* 606.99 607.22 0.23 864.363* 606.49 606.77 0.28 397.495 606.04 606.38 0.34 * = Interpolated cross-section created by HEC-RAS
152
Table 35: These are the results from encroachment without the dams emplace showing each cross-sections floodway width, area, and mean velocity. The base flood water surface elevations are also presented showing the water surface level before encroachment and after encroachment with the increase in water surface elevation which occurred relative to the unencroached water surface elevation.
Cross- Without With Increase Section Floodway Floodway 100470.700 653.49 653.98 0.49 97118.950 653.05 653.54 0.49 93666.770 652.45 652.95 0.50 90930.670 652.10 652.60 0.50 88126.240 651.78 652.28 0.50 85328.650 651.41 651.91 0.50 82448.640 650.83 651.33 0.50 78409.050 650.10 650.61 0.51 75796.420 649.64 650.16 0.52 73173.300 649.11 649.63 0.52 70463.680 648.46 648.99 0.53 67747.290 648.02 648.56 0.54 66076.200 647.88 648.43 0.55 65172.950 647.86 648.41 0.55 64983.730 647.84 648.39 0.55 64882.000 647.78 648.33 0.55 64284.300* 647.60 648.15 0.55 63686.660 647.18 647.72 0.54 62646.440 646.45 646.99 0.54 62481.520 646.41 646.95 0.54 62401.310 646.23 646.77 0.54 62401.000 Bridge 62302.870 645.98 646.56 0.58 62234.360 646.00 646.56 0.56 61814.340 645.66 646.21 0.55 61778.500* 645.61 646.17 0.56 61742.770 645.59 646.18 0.59 61700.000 Bridge 61653.910 645.40 645.86 0.46 * = Interpolated cross-section created by HEC-RAS
153
Table 35 (con’t.)
61607.400* 645.29 645.74 0.45 61560.930 645.36 645.81 0.45 61009.870 645.21 645.67 0.46 58997.110 644.22 644.63 0.41 57098.980 643.60 644.02 0.42 55424.150 643.05 643.45 0.40 53452.280 642.20 642.64 0.44 51485.800 641.23 641.61 0.38 50338.100* 641.01 641.39 0.38 49190.450 640.93 641.31 0.38 47213.910 640.52 640.87 0.35 46752.800* 640.06 640.46 0.40 46291.700* 639.43 639.88 0.45 45830.600* 638.65 639.15 0.50 45369.590 637.79 638.34 0.55 42967.380 636.79 637.32 0.53 41145.120 635.61 636.12 0.51 40093.800* 634.82 635.31 0.49 39042.520 633.85 634.32 0.47 38059.600* 632.97 633.44 0.47 37076.850 632.24 632.72 0.48 34679.000 630.81 631.24 0.43 33352.630 629.71 630.03 0.32 32796.800* 629.21 629.61 0.40 31129.330 628.25 628.62 0.37 29141.250 627.14 627.43 0.29 27174.200* 626.55 626.91 0.36 25207.210 626.15 626.55 0.40 21800.780 625.64 626.05 0.41 18507.370 624.59 624.95 0.36 16499.690 623.55 623.87 0.32 13827.330 621.96 622.39 0.43 13060.300* 621.20 621.70 0.50 12293.430 619.98 620.52 0.54 12220.000 Bridge * = Interpolated cross-section created by HEC-RAS
154
Table 35 (con’t.)
12141.290 619.69 620.28 0.59 11377.70* 618.51 619.00 0.49 10614.250 617.72 618.17 0.45 7876.465 615.27 615.50 0.23 6860.224 614.58 614.84 0.26 6583.040* 614.33 614.61 0.28 5197.110* 612.91 613.29 0.38 4642.747 612.26 612.66 0.40 4597.082 611.90 612.37 0.47 4590.000 Bridge 4534.834 611.46 611.97 0.51 4513.420* 611.44 611.96 0.52 4492.006 611.49 611.96 0.47 3935.240* 610.65 611.19 0.54 2821.720* 609.15 610.01 0.86 2264.968 608.21 608.52 0.31 1331.230* 606.99 607.22 0.23 864.363* 606.49 606.77 0.28 397.495 606.04 606.38 0.34
155
The difference between the FEMA FIRM and the FIRM created by the model for the
post-dam removal scenario is presented in Figure 39. Since the pre- and post-dam removal
FIRMs showed no differences at this location, the post-dam removal FIRM was used to represent both scenarios. The HEC-RAS model FIRM resulted in a flooding increase of 6.37 acres
(25,774 m2) where previously no flooding was predicted in the FEMA FIRM. The 100-year
flood event for the model inundated regions where once the 500-year flood event was predicted
to inundate. This resulted in an increase of 9.72 acres (39,316 m2) for the area inundated by the
100-year flood event when compared to the FEMA FIRM. The total difference between the
FEMA FIRM and the HEC-RAS model FIRM for the 100- and 500-year flood event inundation resulted in an increase of 16.08 acres (65,090 m2) in the areas inundated.
Figure 39: This is a figure of the Grand Rapids FIRM overlayed over the FIRM created by the HEC-RAS model. Zone A4 represents the 100-year flood event while Zone B represents the 500-year flood event determined by FEMA in 1983. The 100-year flood event is represented by the grey region while the dark grey represents the 500-year flood event determined by the HEC-RAS model.
156 157
DISCUSSION
The removal of dams has become an important topic in the United States due to the potential changes on the hydrology and flood regime. This has led to the need for feasibility studies to anticipate what changes may occur to a river after removal of a dam. Typically the issues related to this problem would be the release of sediment trapped behind the dams, contaminated sediment, and potential changes in the flood regime. This study focused on the
Grand Rapids-Providence dams in hopes to broaden knowledge of these issues.
Field work conducted behind the dams helped identify the absence of sediment behind the dam and the sediment being transported in the Maumee River. The lack of sediment collected behind the dams and the observation of exposed bedrock underlying the reservoir reveals that these dams have very low trapping efficiencies. This is attributed to both the hydraulics of the dams and the characteristics of the sediment being transported in the Maumee
River. The dams in this study are low-head weirs which facilitate high flow energies near the dams and minimal stagnant conditions behind the dam. This characteristic does not allow any suspended sediment to come out of suspension, and promotes transport over the dams and downstream to likely depositional sites where the Maumee River meets Lake Erie. It was also determined by grain-size analysis of sediment collected on the banks of the Maumee River, upstream of the dams, that the sediment being transported is bimodal, with a gravel fraction and a mud (very-fine sand to clay) fraction. While some of the gravel fraction accumulates above the bedrock surface near the dams, the much larger mud fraction is transported as suspended load and carried over the dams.
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The bimodal texture of Maumee River sediment is most likely due to characteristics of
the drainage basin and its history. The advance and retreat of glaciers brought together a small
fraction of coarse grained sediment (pebble clasts) with reworked glacial-lacustrine sediments
(very-fine sand, silt, and clay). Local studies on soils in the drainage basin suggest source areas
are typically 10% gravel and coarse-grained sand, 10% fine-grained sand, 50% silt, and 30%
clay (Evans, unpublished data). In conclusion, removing these dams would not create problems
related to the release of reservoir sediment because these are minimal.
When the differences between the 10-year and 500-year flooding events are compared to
historical records located at the Isaac Ludwig Mill, discrepancies existed. The 500-year flooding
event used a discharge of 127,597 ft3/sec at the same location as the Waterville gaging station
and resulted in a 5 ft increase in the water surface elevation when compared to the 10-year
flooding event. While at the Isaac Ludwig Mill a discharge of only 85,000 ft3/sec, recorded at
the same location, resulted in a 4.33 ft stage height. From this it appears the model is incorrectly modeling the Maumee River. This discrepancy is believed to be caused by ice jams near the
Isaac Ludwig Mill resulting in an inaccurate record at the site. As was previously discussed, it was noted while reviewing newspaper articles for various floods that pictures referring to the
1913 and 1904 floods, had large amounts of ice in them and in the case of the 1936 and 1959 floods, both occurred in late to mid February, possibly due to ice jams as well.
When looking at the effects of removing the dams on the flood regime of the river by
comparing the modeled pre- and post-dam scenarios for various floods, models indicate no
significant change (<1%) in water surface elevation. The reason for such small differences is
due to the amount the weir is submerged during floods. A weir is considered submerged when
the water level below the dams is high enough to affect the discharge (USDI 1976). The degree
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of this submergence is determined by dividing the depth of water above the minimum weir
elevation on the downstream side by the height of the energy gradeline above the minimum weir
elevation on the upstream side (HEC 2002). The increase in submergence results in a reduced
weir coefficient used in the standard weir equation (Eq. 5) to determine the discharge over the
weir. This new value is determined by multiplying the weir coefficient by a submergence factor
determined from Figure 40. As can be seen from this figure, the tailwater does not affect the
weir until the weir is greater than 76% submerged. As can be seen from Table 36 which shows
the degree of submergence with the dams present for all floods used in this study, the percent
submergence for all floods is ≥95% submergence. This indicates that water surface elevations
would be similar in both pre-removal and post-removal scenarios.
The similar water surface elevations for the pre- and post-dam removal scenarios resulted in similar inundation areas for the various flooding events. Of these events the 100-year and
500-year flooding events for the post-dam removal scenario were used to create FIRMs of the study area. When these were compared to those created by FEMA of the same area, they all matched except the Grand Rapids FIRM. The FEMA FIRM for the Grand Rapids area had smaller inundation areas for both the 100- and 500-year floods while the FIRM created from the model had larger inundation areas for the same floods. This difference is attributed to the increase in discharges for the 100-year and 500-year flooding events since 1983. The discharges used in the FEMA FIRM for the 100-year and 500-year flooding events were 92,400 ft3/sec and
105,000 ft3/sec respectively, while the discharges used in the FIRM created from the model were
105,574 ft3/sec and 124,160 ft3/sec for the 100-year and 500-year flooding events respectively.
Figure 40: This Figure shows the relationship between the percent submergence and the flow reduction factor (Bradley 1978).
160 161
Table 36: These are the percent submergence of the two dams determined by dividing the depth of water above the minimum weir elevation on the downstream side by the height of the energy gradeline above the minimum weir elevation on the upstream side
Year Floods % Submergence 10 95% 25 96% 50 96% 100 96% 200 97% 500 97%
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The differences in the discharges used, for each exceedance probability flood, are
attributed to the availability of data at the time the FIRM was completed. The FEMA FIRM
used a data set of annual peak discharges prior to 1983, possibly going back as far as 1900, to
construct exceedance probability flood discharges, while the model FIRM used annual peak
discharges from 1925 to 2006. Since 1983, the annual peak discharges have increased at both
the Defiance and Waterville gaging stations. This has resulted in an increase in the discharges
for the various annual exceedance probability floods. The increase in annual peak discharges,
since 1983, is possibly due to (1) increases in urbanized areas within the Maumee River Basin
between 1983-2007, (2) climate change (3) and/or changes in farming practices. Furthermore, the creation of FIRMs carries with it errors associated with the model used and the determination of exceedance flood boundaries, all of which maybe coupled with the differences in the areas inundated by each exceedance probability flood.
The increase in urbanized areas within the Maumee River Basin between 1984 and 1999 has increased by 3% in Northwest Ohio (Vincent et al. 2002). This increase may have resulted in a decrease in the amount of time runoff takes to arrive in the Maumee River. This could result in larger annual peak discharges observed at each gaging station since 1983.
Climate change also maybe a contributing factor for the increase in annual peak discharges observed since 1983. Over the contiguous United States, annual precipitation has increased on average 6% per century from 1901 to 2005. In the East North Central United
States, the region of study, this increase has been 12% per century (NOAA 2008). Furthermore, the increase in heavy precipitation events during the last three decades of the 20th century have
increased by 14% and 20% for heavy precipitation and very heavy precipitation respectively
(Kunkel et al. 2003, Groisman et al. 2004).
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Changes in farming practices such as the increase in the installation of tile and intensive
cultivation practices during the twentieth century are other possible reasons for the increase in
annual peak discharges. The widespread installation of tile can enhance peak flows by inhibiting
water flow and storage within the soil (Howe et al 1967). Intensive cultivation practices also
increases peak flows by deteriorating the soil structure resulting in conditions which favors soil
sealing and crusting resulting in reduced infiltration and soil storage (Reed 1979, Robinson 1990,
Boardman and FavisMortlock 1993, De Roo 1993).
The computational differences between the HEC-2 and HEC-RAS models are not
attributed to the differences between the FEMA FIRM and the HEC-RAS FIRM of the same area
because these differences are believed to be small. The differences between the two models are
how they calculate cross-section conveyance, bridge hydraulics, culvert hydraulics, and
floodway encroachment (HEC 2002). Of these differences, the calculation of cross-section
conveyance and bridge hydraulics would be where the differences in water surface elevation could exist between the two FIRMs (FEMA and modeled). Critical depth cannot be attributed to
the differences in the area inundated because it was only calculated at the dams and bridges
where the flow was constricted and not at any of the cross-sections crossing Grand Rapids.
Culverts were not present within the study area and the floodway encroachment is not connected
to the 100-year and 500-year flood determination, so these differences in the models cannot be associated with the increase in water surface elevation.
The differences between how the two models calculate cross-section conveyance are
HEC-2 calculates it between coordinate points on the floodplain and between the left and right floodplain points for the channel while HEC-RAS does so by changes in Manning roughness coefficient values (HEC 2002). To determine how this difference would translate into the water
164
surface elevation, the model was run using the HEC-2 method of conveyance for the 100-year
flood with the dams in place and comparing the results to the same flood and scenario using the
HEC-RAS method. The resulting differences are seen in Table 37. From this table it can be
seen the different methods result in changes in the water surface elevations but these differences
are small, the largest being 0.25 ft which is not near Grand Rapids.
The major difference between the two models is how they model piers and the number of
cross-sections used while performing bridge hydraulics. The HEC-2 model compiles the piers
into one pier at the center of the bridge while HEC-RAS defines each pier separately and performs calculations by evaluating changes in water surface and impact on each individual pier.
Furthermore HEC-2 models bridges using two cross-sections while HEC-RAS uses four cross- sections (HEC 2002). The results of these differences are dissimilar losses due to contraction and expansion, and friction between the two models. These differences though are believed to be small and would trivially effect the water surface elevation immediately upstream and downstream of a bridge.
The technique used for mapping the inundation area for each exceedance probability flood for each FIRM carries with it error as well (Merwade et al. 2008). The flood boundary for the FEMA FIRM used the water surface elevation at each cross-section. Between cross-sections the flood boundary was interpolated using a topographic map at a scale of 1:24,000 with a contour interval of 5 feet (FEMA 1982). The model FIRM used the same process but with high resolution LiDAR data to construct the flood boundaries. These differences can result in differences in the location of each boundary for each exceedance probability flood.
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Table 37: The differences in water surface elevations when different conveyance calculations are used using the pre-dam scenario with the 100-year flood event
Calculation of Conveyance Cross- HEC-RAS HEC-2 Section Water Surface Elevation Water Surface Elevation Difference % (ft) (ft) (ft) Difference 100470.700 653.42 653.33 0.09 <1% 97118.950 653.00 652.92 0.08 <1% 93666.770 652.42 652.33 0.09 <1% 90930.670 652.08 652.00 0.08 <1% 88126.240 651.77 651.69 0.08 <1% 85328.650 651.42 651.34 0.08 <1% 82448.640 650.85 650.77 0.08 <1% 78409.050 650.13 650.04 0.09 <1% 75796.420 649.69 649.59 0.10 <1% 73173.300 649.16 649.05 0.11 <1% 70463.680 648.53 648.41 0.12 <1% 67747.290 648.11 647.97 0.14 <1% 66076.200 647.97 647.83 0.14 <1% 65172.950 647.95 647.81 0.14 <1% 65160.000 Dams 64983.730 647.71 647.57 0.14 <1% 64882.000 647.65 647.51 0.14 <1% 64284.300* 647.46 647.32 0.14 <1% 63686.660 647.05 646.93 0.12 <1% 62646.440 646.33 646.20 0.13 <1% 62481.520 646.28 646.14 0.14 <1% 62401.310 646.10 645.95 0.15 <1% 62401.000 Bridge 62302.870 645.84 645.69 0.15 <1% 62234.360 645.87 645.72 0.15 <1% 61814.340 645.52 645.37 0.15 <1% 61778.500* 645.47 645.34 0.13 <1% 61742.770 645.44 645.29 0.15 <1% * = Interpolated cross-section created by HEC-RAS
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Table 37 (con’t.)
61700.000 Bridge 61653.910 645.28 645.16 0.12 <1% 61607.400* 645.14 645.07 0.07 <1% 61560.930 645.22 645.13 0.09 <1% 61009.870 645.07 644.95 0.12 <1% 58997.110 644.10 644.02 0.08 <1% 57098.980 643.48 643.40 0.08 <1% 55424.150 642.93 642.85 0.08 <1% 53452.280 642.06 641.96 0.10 <1% 51485.800 641.11 641.00 0.11 <1% 50338.100* 640.89 640.79 0.10 <1% 49190.450 640.81 640.71 0.10 <1% 47213.910 640.41 640.33 0.08 <1% 46752.800* 639.96 639.88 0.08 <1% 46291.700* 639.32 639.23 0.09 <1% 45830.600* 638.54 638.46 0.08 <1% 45369.590 637.69 637.62 0.07 <1% 42967.380 636.72 636.69 0.03 <1% 41145.120 635.55 635.51 0.04 <1% 40093.800* 634.76 634.72 0.04 <1% 39042.520 633.79 633.74 0.05 <1% 38059.600* 632.91 632.85 0.06 <1% 37076.850 632.18 632.10 0.08 <1% 34679.000 630.74 630.65 0.09 <1% 33352.630 629.64 629.54 0.10 <1% 32796.800* 629.13 629.01 0.12 <1% 31129.330 628.17 628.03 0.14 <1% 29141.250 627.06 626.90 0.16 <1% 27174.200* 626.45 626.25 0.20 <1% 25207.210 626.05 625.83 0.22 <1% 21800.780 625.53 625.28 0.25 <1% 18507.370 624.50 624.34 0.16 <1% 16499.690 623.51 623.45 0.06 <1% 13827.330 621.91 621.86 0.05 <1% 13060.300* 621.14 621.08 0.06 <1% * = Interpolated cross-section created by HEC-RAS
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Table 37 (con’t.)
12293.430 619.92 619.89 0.03 <1% 12220.000 Bridge 12141.290 619.63 619.57 0.06 <1% 11377.700* 618.45 618.41 0.04 <1% 10614.250 617.66 617.62 0.04 <1% 7876.465 615.25 615.21 0.04 <1% 6860.224 614.56 614.51 0.05 <1% 6583.040* 614.31 614.25 0.06 <1% 5197.110* 612.88 612.79 0.09 <1% 4642.747 612.24 612.14 0.10 <1% 4597.082 611.87 611.76 0.11 <1% 4590.000 Bridge 4534.834 611.42 611.30 0.12 <1% 4513.42* 611.40 611.28 0.12 <1% 4492.006 611.45 611.34 0.11 <1% 3935.240* 610.62 610.51 0.11 <1% 2821.720* 609.19 609.16 0.03 <1% 2264.968 608.38 608.43 -0.05 <1% 1331.230* 607.26 607.25 0.01 <1% 864.363* 606.8 606.78 0.02 <1% 397.495 606.41 606.38 0.03 <1% * = Interpolated cross-section created by HEC-RAS
168
CONCLUSION
This study presents a quantitative comparison of pre- and post-dam removal scenarios to determine the changes in flood regime upstream and downstream of the dams. To conduct this analysis, previously surveyed cross-sections obtained from a HEC-2 format sediment transport study were combined with cross-sections created by HEC-GeoRAS to construct a new HEC-
RAS model of the area. With this information combined, accurate cross-sections were constructed representing the channel topography along with the present floodplain conditions.
The information obtained from the model was then exported into ArcMap to construct FIRMs of the area to compare to pre-dam removal FIRMs constructed by FEMA.
The study showed there would be minimal significant change (<1%) in the flood regime for the various flooding events when the dams are removed. This was attributed to the degree of submergence of the dams due to the large discharges of the flooding events. The submergence resulted in smaller discharge coefficients used in the standard weir equation (Eq. 5) which in turn
resulted in similar water surface elevations upstream and downstream of the dams for the pre-
dam removal scenario and the post-dam removal scenario.
The information obtained from the model for the different scenarios was exported
into ArcMap and used to create FIRMs of the area. Due to the small differences between the two
scenarios, the FIRMs created for each flooding event matched. These FIRMs were then
compared to the FIRMs created by FEMA to see if any differences existed between them. No
differences existed except for the FIRM for the Grand Rapids area. The FEMA FIRM for this
area had smaller flooding extents for the 100-year and 500-year flooding events when compared
to the FIRM of the same area created from the model. This difference was believed to be
possibly due to (1) increases in urbanized areas within the Maumee River Basin between 1983-
169
2007, (2) climate change (3) and/or changes in farming practices. Differences between the HEC-
2 and HEC-RAS models and FIRM creation were also possible causes of the differences seen
between the FEMA FIRM and model FIRM.
During this study, field work was conducted to determine if sediment existed behind the
dams and to see what type of sediment was being transported in the Maumee River Basin. It was
found very little sediment existed behind the dams from the lack of sediment collected and the
observation of exposed bedrock underlying the reservoir. This revealed the dams had low trapping efficiencies which was attributed to both the hydraulics of the dams and the characteristics of the sediment being transported in the Maumee River. Due to the design of the dams being low-head weirs, they facilitated high flow energies near them and minimal stagnant
conditions behind them. The result of this characteristic was the promotion of sediment transport
over the dams and downstream to likely depositional sites where the Maumee River meets Lake
Erie. It was also determined during grain-size analysis that the sediment being transported was bimodal with a gravel and mud (very fine sand and clay) fraction. While some of the gravel fraction accumulates above the bedrock surface near the dams, the much larger mud fraction is transported as suspended load over the dams.
When projects such as dam removal are proposed, a cost benefit analysis is commonly done to determine if the benefits outweigh the costs. The benefits associated with removing the dams are reconnecting the aquatic habitat, gaining lentic fisheries, and restoring the sediment budget downstream. While the costs associated with removing them, beyond the initial cost of removal, are the loss of water supply, recreation, a barrier to the spread of exotics, and an historical interpretive site.
170
By removing the dams, the aquatic habitat would be reconnected and restored to its
original state. This would result in the reintroduction of species adapted to lentic environments
which would increase the area of lentic fisheries near Grand Rapids. This in turn could bring
more business into the Grand Rapids community as the number of fisherman fishing for these
species increases. Furthermore, the removal of the dams would result in restoring the sediment
budget downstream which could restore habitats for native fish by the creation of gravel bars and
substrates to which they are adapted to.
Currently the reservoir created by the dams is used for water supply (ODNR 2002ab) and
if removed this resource would be lost. Furthermore the reservoir is used as a recreation (ODNR
2002ab) site for boaters and fisherman fishing for species adapted to lotic environments. The
removal in this case would result in the loss of these pastimes and may result in financial losses
for the Grand Rapids community from the decrease of people traveling through. The dams also
act as a barrier to the spread of exotic species. The removal could result in the propagation of
these species further upstream, endangering the existence of native species. Finally, the draining
of the reservoir would result in the dewatering of the canal system in Providence, Ohio. This
canal system is used as an historical interpretation site where tourist can visit an operating canal.
If the canal in Providence, Ohio were dewatered, it could no longer operate and the number of
people visiting the site may decline resulting in decreased funds to maintain the historic canal
which may result in the closure of the site.
This study has shown the removal of the Grand Rapids-Providence Dams would not alter
the flood regimes for the 10-, 25, 50-, 100-, 200-, and 500-year floods or release large amounts of sediment downstream.
172
REFERENCES
Boardman, J., and D.T. Favis-Mortlock. 1993. Climate change and soil erosion in Britain. Geographical Journal, 159:179-183.
Bogan, A. E. 1993. Freshwater bivalve extinctions (Mollusca: Unionoida): A search for causes. American Zoologist, 33(6):599-609.
Boggs, S. Jr. 2006. Principles of sedimentary and stratigraphy, fourth edition. P. Lynch (Ed.), Upper Saddle River, NJ: Pearson Education, Inc. pp. 662.
Bowman, M. B. 2002. Legal perspective on dam removal. BioScience, 52(8):739-747.
Calkin, P.E. and B.H. Feenstra. 1985. Evolution of the Erie-Basin Great Lakes. In P.F. Karrow and P.E. Calkin (Eds), Quaternary evolution of the Great Lakes. Geological Survey of Canada Special Paper 30. pp. 149-170.
Coakley, J.P. and C.F.M. Lewis. 1985. Postglacial lake levels in the Erie Basin. In: P.F. Karrow and P.E. Calkin (Eds), Quaternary evolution of the Great Lakes. Geological Survey of Canada Special Paper 30. pp. 195-212.
Chow, V.T. 1959. Open-channel hydraulics. New York, NY: McGraw Hill Book Co. pp. 680.
De Roo, A.P.J. 1993. Modelling surface runoff and soil erosion in catchments using geographical information systems. Netherlands: Utrecht.
Doeg, T. J. and J. D. Koehn. 1994. Effects of draining and desilting a small weir on downstream fish and macroinvertebrates. Regulated Rivers: Research and Management, 9(4):263- 277.
Doyle, M. W., E. H. Stanley, and J. M. Harbor, 2002. Geomorphic Analogies for Assessing Probable Channel Response to Dam Removal. American Water Resource Association, 38(6):1567-1579.
Doyle, M. W. and E. M. Stanley. 2003. Toward policies and decision-making for dam removal. Environmental Management, 31(4):453-465.
Ehlers, G.M., E.C. Stumm, and R.V. Kesling. 1951. Devonian rocks of southeastern Michigan and northwestern Ohio. Guidebook Geological Society of America. Field trip, Detroit Meeting.
EPA (Environmental Protection Agency). 2006. Maumee River area of concern. Available from http://www.epa.gov/glnpo/aoc/maumee.html (accessed March 18, 2007)
173
ET Spatial Techniques. 2008. Easy Calculate 5.0. Available from http://www.ian-ko .com/ (accessed May 20, 2008).
Evans, J. E., N.S. Levine, S.J. Roberts, J.F. Gottgens, and D.M. Newman. 2002. Assessment using GIS and sediment routing of the proposed removal of Ballville dam, Sandusky River, Ohio. Journal of the American Water Resources Association, 38(6):1549-1565.
Evans, J. E. 2007. Sediment impacts of the 1994 failure of IVEX dam (Chargrin River, NE Ohio): a test of channel evolution models. Journal of Great Lakes Resources, 33 (Special Issue 2):90-102.
Evans, J.E., J.M. Huxley, and R.K. Vincent. 2007. Upstream channel changes following dam construction and removal using a GIS/remote sensing approach. Journal of the American Water Resources Association, 43(3):1-15.
Evans, J.E., J.F. Gottgens. 2007. Contaminant stratigraphy of the Ballville reservoir, Sandusky River, NW Ohio: implications for dam removal. Journal of Great Lakes Resources, 33(Special Issue 2):182-193.
FEMA (Federal Emergency Management Agency). 1995. Flood insurance study, Henry County, Ohio (unincorporated areas). Washington, D.C.
FEMA (Federal Emergency Management Agency). 2000. Flood insurance study, Lucas County, Ohio and incorporated areas. Washington, D.C.
FEMA (Federal Emergency Management Agency). 1982. Flood insurance study, village of Grand Rapids, Wood County, Ohio. Washington, D.C.
FEMA (Federal Emergency Management Agency). 2002. National flood insurance program: program description. Washington, D.C. pp. 37.
FEMA (Federal Emergency Management Agency). 2003. How to read a flood insurance rate map tutorial. Washington, D.C. pp. 54.
FHWA (Federal Highway Administration). 1985. Hydraulic design of highway culverts, hydraulic design Series No. 5, U.S. Department of Transportation, September 1985, Washington D.C.
Forsyth, J.L. 1960. Correlation of tills exposed in Toledo Edison Dam cut, Ohio. Ohio Journal of Science, 60(2): 94.
Forsyth, J.L. 1965. Water-modified till of the lake plain of northwestern Ohio. Ohio Journal of Science, 65: 96.
Forsyth, J.L. 1968. A study of physical features for the Toledo regional area. Toledo Regional Area Plan for Action. pp. 111.
174
Fullerton, D.S. 1980. Preliminary correlation of Post-Erie interstadial events (16000-10000 radiocarbon years before present), central and eastern Great Lakes region and Hudson, Champlain, and St. Lawrence lowlands, United States and Canada. U.S. Geological Survey Professional Paper 1089.
GARMIN Corporation. 1999. GARMIN GPS 12 handheld products. Olathe, KA. pp.2.
Graf, W. L. 1993. Landscapes, commodities, and ecosystems: The relationship between policy and science for American rivers. pp. 11-42 in Sustaining Our Water Resources, National Academy Press, Washington, D.C.
Graf, W. L. 2003. Summary and perspective. In W. L. Graf (Ed), Dam Removal Research: Status and Prospects (pp. 1-21). Washington D.C.: The H. John Heinz III Center for Science, Economics, and the Environment.
Grant, G. 2001. Dam removal: panacea or Pandora for rivers? Hydrologic Processes, 15(8):1531-1532.
Green, D.A. 1957. Trenton structure in Ohio, Indiana, and northern Illinois. American Association of Petroleum Geologist Bulletin, 41:627-642.
Groisman, P.Y., R.W. Knight, T.R. Karl, D.R. Easterling, B. Sun, and J.M. Lawrimore, 2004: Contemporary changes of the hydrological cycle over the contiguous United States: Trends derived from in-situ observations. Journal of Hydrometeorology, 5, 64-85.
Hann, C.T., B.J. Barfield, and J.C. Hayes. 1994. Design hydrology and sedimentology for small catchments. San Diego, CA: Academic Press, Inc. pp. 588.
Hansel, A.K., D.M. Mickelson, A.F. Schneider, and C.E. Larsen. 1985. Late Wisconsinan and Holocene History of the Lake Michigan Basin: In: P.F. Karrow and P.E. Calkin (Eds.), Quaternary evolution of the Great Lakes. Geological Survey of Canada Special Paper 30. pp. 39-53.
Harbor, J. M. 1993. Proposed measures to alleviate the environmental impacts of hydroelectric dams on the Elwha River, Washington, U.S.A. In Y. Eckstein and A. Zaporozec (Eds.), Industrial and Agricultural Impacts on the Hydrologic Environment: Proceedings of the Second USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology (pp. 199–214). St. Paul, MN: American Institute of Hydrology.
HEC (Hydrologic Engineering Center). 2002. HEC-RAS river analysis system: hydraulic reference manual. Davis, CA: U.S. Army Corps of Engineers. pp. 377.
HEC (Hydrologic Engineering Center). 2004. HEC-RAS (Hydrologic Engineering Centers River Analysis System), Version 3.1.3, U.S. Army Corps of Engineers, Davis, California. Available from www.hec.usace.army.mil (accessed November 1, 2007).
175
HEC (Hydrologic Engineering Center). 2006. HEC-GeoRAS (Hydrologic Engineering Centers Geographical River Analysis System), Version 4.1.1 . U.S. Army Corps of Engineers, Davis, California. Available from www.hec.usace.army.mil (accessed November 1, 2007).
Heinz Center. 2002. Dam removal: Science and decision making. The Heinz Center for Science, Economics, and the Environment, Washington, D.C., 221 pp.
Hough, J.L. 1958. Geology of the Great Lakes. Urbana, IL: University Illinois Press. pp. 313.
Hough, J.L. 1966. Correlation of glacial lake stages in the Huron-Erie Basins. Journal of Geology, 74:62-77.
Howe, G.M., H.O. Slaymaker, D.M. Harding. 1967. Some aspects of the flood hydrology of the upper catchments of the Severn and Wye. Transcript of the Institute of British Geographers, 41: 33-58.
Hull, D. N., 1990. Generalized column of bedrock units in Ohio. Ohio Department of Natural Resources, Division of Geological Survey, 1 sheet.
Jeffs, B.G. 1993. Stratigraphic and petrographic investigation of the Sylvania Sandstone (Middle Devonian) in the subsurface of the Michigan Basin. M.S. Thesis, Bowling Green State University, Bowling Green, Ohio. pp. 79.
Kahle, C.F., J.C. Floyd. 1971. Stratigraphic and environmental significance of sedimentary structures in Cayugan (Silurian) tidal flat carbonates, northwestern Ohio. Geological Society of America Bulletin, 82:2071-2098.
Kanehl, P. D., J. Lyons and J. E. Nelson. 1997. Changes in the habitat and fish community of the Milwaukee River, Wisconsin, following removal of the Woolen Mills Dam. North American Journal of Fisheries Management, 17(2): 387-400.
Klotz, J.A., and J.L. Forsyth. 1993. Late glacial origin of the Maumee Valley terraces, northwestern Ohio. Ohio Journal of Science, 93(5):126-133.
Kunkel, K.E., D.R. Easterling, K. Redmond, and K. Hubbard, 2003: Temporal variations of extreme precipitation events in the United States: 1895–2000. Geophysical Research Letters, 30, 1900, doi:10.1029/2003GL018052.
LaPerriere, J. D., S. M. Wagener, and D. M. Bjerklie. 1985. Gold-mining effects on heavy metals in streams, Circle Quadrangle, Alaska. Water Resources Bulletin, 21(2):245-252.
Larson, G., and R. Schaetzl. 2001. Origin and evolution of the Great Lakes. Journal of Great Lakes Resources, 27(4): 518-546.
176
Lenhart, C. F. 2000. The vegetation and hydrology of impoundments after dam removal in southern Wisconsin. M S thesis. Univeristy of Wisconsin, Madison, Wisconsin.
Leverett, F., and F.B. Taylor. 1915. The Pleistocene of Indiana and Michigan and the history of the Great Lakes. U.S. Geological Survey Monograph 53.
Major, J.J, J. E. O’Connor, G. E. Grant, K.R. Spicer, H.M Bragg, A. Rhode, D. Q. Tanner, C. W. Anderson, and J. R. Wallick. 2008. Initial fluvial response to the removal of Oregon’s Marmot Dam. Electronic Supplement (EOS), Transactions, American Geophysical Union, 89(27): 241-242.
McLeay, D. J., I. K. Birtwell, G. F. Hartman, and G. L. Ennis. 1987. Response of Artic grayling (Thymallus arcticus) to acute and prolonged exposure to Yukon placer mining sediment. Canadian Journal of Fisheries and Aquatic Sciences, 44:658-673.
Merwade, V., F. Olivera, M. Arabi, and S. Edleman. 2008. Uncertainty in flood inundation mapping: current issues and future directions. Journal of Hydrologic Engineering, 13(7):608-620.
Methods, H., G. Dyhouse, J. Hatchett, and J. Benn. 2003. Floodplain modeling using HEC-RAS. Waterbury, CT: Haested Methods, Inc. pp. 696.
Mickelson, D.M., L. Clayton, D.D. Fullerton, and H.W. Jr. Borns. 1983. The Late Wisconsin glacial record of the Laurentide Ice Sheet in the United States. In Late Quaternary Environments of the United States, Volume 1. The Late Pleistocene, University Minnesota Press, Minneapolis. pp. 3-37.
Miller, J., R. Barr, D. Grow, P. Lechler, D. Richardson, K. Waltman, and J. Warwick. 1999. Effects of the 1997 flood on the transport and storage of sediment and mercury within the Carson River Valley, west-central Nevada. Journal of Geology, 107:313-327.
Naiman, R. J., H. Decamps, and M. Pollock. 1993. The Role of Riparian Corridors in Maintaining Regional Biodiversity. Ecological Applications, 3(2):209-212.
Newcombe, C. P., and D. D. MacDonald. 1991. Effects of suspended sediments on aquatic ecosystems. North American Journal of Fisheries Management, 11:72-82.
NID (National Inventory of Dams). 2006. Available from http://crunch.tec.army.mil/nid/webpag es/nid.cfm (accessed March 18, 2007)
NOAA (National Oceanic and Atmospheric Administration). 2008. United States Historical Climatology Network (USHCN): Version 1. National Oceanic and Atmospheric Administration, National Climate Data Center. U.S. Department of Commerce. www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html (accessed June 20, 2008)
177
NRCS (Natural Resources Conservation Service). 2007. SSURGO (Soil Survey Geographic) database, Soil Data Mart. Available from http://soils.usda.gov/survey/ geography/ssurgo/ (accessed May 2, 2008).
ODNR (Ohio Department of Natural Resources: Division of Water). 2002a. Dam safety inspection report: Grand Rapids Dam, Class I, Wood County, Grand Rapids Township. pp. 12.
ODNR (Ohio Department of Natural Resources: Division of Water). 2002b. Dam safety inspection report: Providence Dam, Class I, Wood County, Grand Rapids Township. pp. 14.
ODNR (Ohio Department of Natural Resources: Division of Wildlife). 2006 Ohio comprehensive wildlife conservation strategy. pp. 980.
OGRIP (Ohio Geographically Referenced Information Program). 2006a. Henry County, Ohio ASCII DEM tiled. Available from http://gis1.oit.ohio.gov/geodatadownload/osip.aspx (accessed February 10, 2008).
OGRIP (Ohio Geographically Referenced Information Program). 2006b. Henry County, Ohio Mr. Sid mosaic aerial photograph. Available from http://gis1.oit.ohio.gov/geodatadownl oad/osip.aspx (accessed February 10, 2008).
OGRIP (Ohio Geographically Referenced Information Program). 2006c. Lucas County, Ohio ASCII DEM tiled. Available from http://gis1.oit.ohio.gov/geodatadownload/osip.aspx (accessed February 10, 2008).
OGRIP (Ohio Geographically Referenced Information Program). 2006d. Lucas County, Ohio Mr. Sid mosaic aerial photograph. Available from http://gis1.oit.ohio.gov/geodatadownl oad/osip.aspx (accessed February 10, 2008).
OGRIP (Ohio Geographically Referenced Information Program). 2006e. Wood County, Ohio ASCII DEM tiled. Available from http://gis1.oit.ohio.gov/geodatadownload/osip.aspx (accessed February 10, 2008).
OGRIP (Ohio Geographically Referenced Information Program). 2006f. Wood County, Ohio Mr. Sid mosaic aerial photograph. Available from http://gis1.oit.ohio.gov/geodatadownl oad/osip.aspx (accessed February 10, 2008).
Ohio Administration Code. 1994. 1501: 21-13-01.
Onasch, C.M., and C.F. Kahle. 1991. Recurrent tectonics in cratonic setting: An example from northwestern Ohio. Geological Society of America Bulletin, 103:1259-1269.
Pizzuto, J. 2002. Effects of dam removal on river form and process. BioScience, 52(8):683-691.
178
Prest, V.K. 1970. Quaternary geology of Canada. In Geology and Economic Mineral of Canada: Geological Survey of Canada, Economic Geology Report 1, 5th ed., pp. 675-794.
Randle, T. J. 2003. Dam removal and sediment management. In W. L. Graf (Ed), Dam Removal Research: Status and Prospects. Washington D.C.: The H. John Heinz III Center for Science, Economics, and the Environment. pp. 81-104.
Rathburn, S. L., E. E. Wohl. 2003. Sedimentation hazards downstream from reservoirs. In W. L. Graf (Ed), Dam Removal Research: Status and Prospects (pp. 105-118). Washington D.C.: The H. John Heinz III Center for Science, Economics, and the Environment.
Reed, A. 1970. Accelerated erosion of arable soils in the United Kingdom by rainfall and runoff. Outlood on Agriculture, 10:41-47.
Requarth, J.S. 1978. The evolution of Guelph (Silurian) Dolomite multistory reefs, White Rock Quarry, Clay Center, Ohio. M.S. Thesis, Bowling Green State University, Bowling Green, Ohio. pp. 221.
Robinson, M. 1990. Impact of improved drainage on river flows. Institute of Hydrology Report No. 113. Oxon, U.K.
Rumschlag, J. H. and J.A. Peck. 2007. Short-term sediment and morphologic response of the Middle Cuyahoga River to the removal of the Munroe Falls Dam, Summit County, Ohio. Journal of Great Lakes Resources, 33(Special Issue 2):142-153.
Schaetzl, R., and S. Anderson. 2005. Soils: genesis and geomorphology. New York, NY: Cambridge University Press. pp. 817.
Spectrex Corporation. 2005. Spectrex Laser Particle Counter Model PC-2300 instruction manual. Redwood, CA. pp. 21.
Stoughton, J. A. and W. A. Marcus. 2000. Persistent impacts of trace metals from mining on floodplain grass communities along Soda Butte Creek, Yellowstone National Park. Environmental Management, 25(3):305-320.
TEC (Topographic Engineering Center). 2004. Corpscon, Version 6.0.1. U.S. Army Corps of Engineers, Alexandria, Virginia. Available from http://crunch.tec.army.mil/softw are/corpscon/corpscon.html (accessed May 5, 2008).
Trimble. 2004. GPS Pathfinder Pro XR specifications. Westminster, CO. pp. 2.
Trout Unlimited. 2001. Small dam removal: A review of potential economic benefits. Arlington, VA.
USACE (United States Army Corp of Engineers). 1998. HEC-6 sediment transport model, conducted by P. Muraski. Buffalo, NY.
179
USDA (United States Department of Agriculture). 2008. Geospatial Data Gateway. Available from http://datagateway.nrcs.usda.gov/ (accessed May 2, 2008).
USDI (United State Department of the Interior). 1976. Design of gravity dams, design manual for concrete gravity dams. Denver, CO: United States Government Printing Office. pp. 553. USGS (United States Geologic Survey). 1977a. Colton quadrangle, Ohio [map]. 1:24,000. 7.5 Minute Series. Available from http://ogrip.oit.ohio.gov/ (accessed April 25, 2008)
USGS (United States Geologic Survey). 1977b. Grand Rapids quadrangle, Ohio [map]. 1:24,000. 7.5 Minute Series. Available from http://ogrip.oit.ohio.gov/ (accessed April 25, 2008)
USGS (United States Geologic Survey). 1979. Maumee quadrangle, Ohio [map]. 1:24,000. 7.5 Minute Series. Available from http://ogrip.oit.ohio.gov/ (accessed April 25, 2008)
USGS (United States Geologic Survey). 1988. Bowling Green North quadrangle, Ohio [map]. 1:24,000. 7.5 Minute Series. Available from http://ogrip.oit.ohio.gov/ (accessed April 25, 2008)
USGS (United States Geologic Survey). 2007a. PeakFQ, Version 5.2. Available from http://water.usgs.gov/software/PeakFQ/ (accessed April 15, 2008).
USGS (United States Geologic Survey). 2008a. Streamflow data: Maumee River at Station 04193500. Available from ttp://waterdata.usgs.gov/nwis/nwisman/?site_no=04193500 &agency_cd= USGS (accessed January 18, 2008)
USGS (United States Geologic Survey). 2008b. Streamflow data: Maumee River at Station 04192500. Available from ttp://waterdata.usgs.gov/nwis/nwisman/?site_no=04192500 &agency_cd= USGS (accessed January 18, 2008)
U.S. House of Representatives. 1966. A unified national program for managing flood losses. House Document No. 465. 89th Congress, 2d Session. Washington, D.C.: U.S. Government Printing Office. pp. 47.
Van Nieuwenhuyse, E. E. and J. D. LaPerriere. 1986. Effects of placer gold mining on primary production in subarctic streams of Alaska. Water Resources Bulletin, 22(1):91-99.
Vincent, R.K, G.M. Baquero, N.S. Levine. 2002. Landsat TM assessment of cropland loss due to urbanization in N.W. Ohio. Presented at the Annual Meeting of the American Society for Photogrametry and Remote Sensing (ASPRS).
Wagener, S. M. and J. D. LaPerriere. 1985. Effects of placer mining on the invertebrate communities of interior Alaska streams. Freshwater Invertebrate Biology, 4:208-214.
Wood, P. J. and P. D. Armitage. 1997. Biological effects of fine sediment in the lotic environment. Environmental Management, 21(2):203-217.
180
APPENDICES
181
APPENDIX A
GRAIN-SIZE STATISTICS
182
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size -3.4 -2.8 -2.4 0.8 2.2 2.7 4.1
Mode Median Mean SD S K Φ Size -2.0 0.8 0.2 2.5 -0.2 0.7
183
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size -2.3 0.1 0.7 1.4 1.8 2.0 2.7
Mode Median Mean SD S K Φ Size 2.0 1.4 1.2 1.2 -0.4 1.9
184
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 1.0 1.3 1.5 1.8 2.4 2.6 3.1
Mode Median Mean SD S K Φ Size 2.0 1.8 1.9 0.6 0.2 1.0
185
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 1.6 2.1 2.4 2.8 3.2 3.4 3.7
Mode Median Mean SD S K Φ Size 3.0 2.8 2.8 0.6 -0.1 1.1
186
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 2.1 2.3 2.4 2.8 3.3 3.5 3.9
Mode Median Mean SD S K Φ Size 3.0 2.8 2.9 0.6 0.2 0.8
187
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size -3.8 -3.0 0.8 1.6 2.3 2.6 3.2
Mode Median Mean SD S K Φ Size 2.0 1.6 0.4 2.5 -0.6 1.9
188
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size -3.3 1.2 1.4 1.9 2.6 2.9 3.4
Mode Median Mean SD S K Φ Size 2.0 1.9 2.0 1.4 -0.2 2.3
189
APPENDIX B
LASER PARTICLE SIZE ANALYSIS
190
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 7.4 7.8 8.1 8.4 8.8 9.0 9.5
Mode Median Mean SD S K Φ Size 9.0 8.4 8.4 0.6 0.0 1.2
191
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 7.9 8.3 8.5 8.9 9.4 9.6 9.8
Mode Median Mean SD S K Φ Size 9.0 8.9 8.9 0.6 0.0 0.9
192
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 8.1 8.6 8.9 9.3 9.6 9.7 9.9
Mode Median Mean SD S K Φ Size 10.0 9.3 9.2 0.5 -0.3 1.1
193
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 7.8 8.3 8.5 9.0 9.4 9.6 9.8
Mode Median Mean SD S K Φ Size 10.0 9.0 9.0 0.6 -0.1 0.9
194
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 8.0 8.3 8.5 9.0 9.4 9.6 9.8
Mode Median Mean SD S K Φ Size 9.0 9.0 9.0 0.6 -0.1 0.8
195
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 7.7 8.2 8.4 8.7 9.3 9.5 9.8
Mode Median Mean SD S K Φ Size 9.0 8.7 8.8 0.6 0.1 1.0
196
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 8.1 8.4 8.7 9.2 9.6 9.7 9.9
Mode Median Mean SD S K Φ Size 10.0 9.2 9.1 0.6 -0.2 0.8
197
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 8.0 8.4 8.7 9.1 9.6 9.7 9.9
Mode Median Mean SD S K Φ Size 10.0 9.1 9.1 0.6 -0.1 0.9
198
Φ % Φ 5 Φ 16 Φ 25 Φ 50 Φ 75 Φ 84 Φ 95 Φ Size 8.0 8.4 8.5 9.0 9.5 9.7 9.9
Mode Median Mean SD S K Φ Size 10.0 9.0 9.0 0.6 0.0 0.8
199
APPENDIX C
HEC-RAS MODELS
200
Pre-dam removal: 10-year flood
River Profile Q Min Ch W.S. Crit E.G. E.G. Vel Froude # Sta Total El Elev W.S. Elev Slope Chnl Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 10 74408 623.5 650.4 650.55 0.000114 3.34 0.13 97118.95 10 74408 626 649.95 650.11 0.000171 3.67 0.15 93666.77 10 75175 628.5 649.42 649.59 0.000136 3.35 0.14 90930.67 10 75175 626.8 649.09 649.23 0.000122 3.17 0.13 88126.24 10 75175 622.6 648.78 648.92 0.00011 3.24 0.13 85328.65 10 75175 626.7 648.42 648.57 0.000143 3.34 0.14 82448.64 10 75451 627.9 647.89 648.09 0.000196 3.69 0.16 78409.05 10 76208 629 647.15 647.32 0.000181 3.37 0.15 75796.42 10 76208 628 646.71 646.87 0.000158 3.31 0.15 73173.3 10 76208 628.1 646.18 646.37 0.000232 3.6 0.17 70463.68 10 76208 628.5 645.49 645.71 0.000259 3.76 0.18 67747.29 10 76208 628.3 645.03 645.22 0.000128 3.57 0.17 66076.2 10 76208 628.3 644.87 645.02 0.0001 3.09 0.15 65172.95 10 76208 630.9 644.82 635.1 644.92 0.000094 2.56 0.14 65160 Inl Struct 64983.73 10 76208 630.9 644.61 644.71 0.000189 2.69 0.15 64882 10 76208 629.2 644.55 644.68 0.000229 3.01 0.16 64284.3* 10 76208 628.1 644.34 644.53 0.000256 3.62 0.18 63686.66 10 76208 627 643.97 644.33 0.000427 5.13 0.23 62646.44 10 76208 622.8 643.31 643.84 0.000478 6.08 0.26 62481.52 10 76208 623.1 643.26 643.76 0.000448 5.73 0.25 62401.31 10 76208 623.1 643.12 633.22 643.72 0.000233 6.29 0.28 62401 Bridge 62302.87 10 76208 623.1 642.96 643.64 0.000233 6.63 0.28 62234.36 10 76208 624.5 642.95 643.6 0.000622 6.55 0.29 61814.34 10 76208 622.3 642.69 643.35 0.000566 6.56 0.28 61778.5* 10 76208 622.75 642.65 643.32 0.000585 6.65 0.28 61742.77 10 76208 623.2 642.64 632.58 643.31 0.000223 6.64 0.28 61700 Bridge 61653.91 10 76208 623.2 642.5 643.24 0.000257 7.22 0.3 61607.4* 10 76208 623.35 642.38 643.2 0.000719 7.37 0.31 61560.93 10 76208 623.5 642.43 643.15 0.000664 6.91 0.3 61009.87 10 76576 621.3 642.24 642.79 0.000462 6.14 0.25 58997.11 10 76576 622.59 641.2 641.77 0.00061 6.43 0.28 * = Interpolated cross-section created by HEC-RAS
201
Pre-dam removal: 10-year flood (con’t.)
57098.98 10 76576 620 640.61 640.94 0.000288 4.85 0.2 55424.15 10 76576 621.07 640.08 640.43 0.000334 5.05 0.21 53452.28 10 76576 622.74 639.2 639.59 0.000555 5.1 0.26 51485.8 10 76576 617.87 638.26 638.67 0.000397 5.5 0.23 50338.1* 10 76576 617.99 638.03 638.29 0.000241 4.34 0.18 49190.45 10 76576 618.11 637.93 638.06 0.000125 3.2 0.13 47213.91 10 76576 614.39 637.56 637.74 0.000169 3.9 0.15 46752.8* 10 76576 615.17 637.19 637.44 0.000246 4.46 0.18 46291.7* 10 76576 615.95 636.7 636.92 0.000254 4.33 0.19 45830.6* 10 76576 616.72 636.1 636.29 0.000231 4 0.18 45369.59 10 76576 617.5 635.45 635.6 0.000199 3.66 0.16 42967.38 10 76576 621.97 634.57 634.88 0.000487 4.73 0.24 41145.12 10 76576 618.6 633.44 633.86 0.00063 5.34 0.28 40093.8* 10 76576 620.3 632.65 633.11 0.000789 5.59 0.3 39042.52 10 76576 622 631.6 632.14 0.00109 6.03 0.35 38059.6* 10 76576 619.93 630.6 631.12 0.000962 5.89 0.33 37076.85 10 76576 617.87 629.79 630.25 0.000769 5.59 0.3 34679 10 76576 610.18 628.19 628.61 0.00062 5.23 0.27 33352.63 10 76576 612.38 627.08 627.68 0.000791 6.3 0.31 32796.8* 10 76576 609.98 626.62 627.24 0.000763 6.33 0.31 31129.33 10 76576 602.77 625.67 626.16 0.000524 5.74 0.26 29141.25 10 76576 604.74 624.58 625.11 0.000547 5.94 0.27 27174.2* 10 76576 603.95 624.01 624.26 0.000294 3.99 0.19 25207.21 10 76576 603.16 623.61 623.76 0.0002 3.06 0.16 21800.78 10 78704 601.49 623.03 623.12 0.000164 2.45 0.14 18507.37 10 78704 602.01 622.03 622.31 0.000406 4.94 0.23 16499.69 10 78704 603.84 621.12 621.44 0.000429 5.11 0.24 13827.33 10 78704 606.59 619.5 619.92 0.000753 5.17 0.29 13060.3* 10 78704 605.33 618.76 619.3 0.000845 5.89 0.31 12293.43 10 78704 604.06 617.63 612.32 618.47 0.001297 7.53 0.39 12220 Bridge 12141.29 10 78704 603.84 617.34 618.14 0.001387 7.21 0.4 11377.7* 10 78704 603.11 616.24 617.1 0.001293 7.58 0.39 10614.25 10 78704 602.38 615.42 616.16 0.001089 7.06 0.36 7876.465 10 78704 599.15 612.94 613.56 0.000832 6.55 0.32 6860.224 10 78704 596.62 612.12 612.63 0.00097 5.73 0.33 6583.04* 10 78704 596.52 611.84 612.36 0.000941 5.78 0.33 5197.11* 10 78704 596 610.41 611.04 0.000945 6.41 0.33 4642.747 10 79359 595.79 609.73 610.47 0.001075 6.99 0.36 * = Interpolated cross-section created by HEC-RAS
202
Pre-dam removal: 10-year flood (con’t.)
4597.082 10 79359 595.76 609.52 603.8 610.43 0.000494 7.69 0.39 4590 Bridge 4534.834 10 79359 595.76 609.15 610.21 0.000632 8.27 0.44 4513.42* 10 79359 595.87 609.13 610.2 0.000737 8.29 0.44 4492.006 10 79359 595.98 609.14 610.18 0.00071 8.19 0.43 3935.24* 10 79359 595.12 608.45 609.72 0.000836 9.15 0.47 2821.72* 10 79359 593.41 607.12 608.65 0.001055 10.17 0.53 2264.968 10 79359 592.56 606.18 607.98 0.001306 11.21 0.58 1331.23* 10 79359 591.92 605.02 606.79 0.001221 10.82 0.56 864.363* 10 79359 591.6 604.56 606.21 0.001118 10.39 0.54 397.4951 10 79359 591.28 604.17 600.04 605.67 0.001001 9.89 0.51 * = Interpolated cross-section created by HEC-RAS
203
Pre-dam removal: 25-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 25 86325 623.5 651.71 651.88 0.000118 3.54 0.13 97118.95 25 86325 626 651.28 651.44 0.000165 3.78 0.15 93666.77 25 87147 628.5 650.72 650.91 0.000143 3.59 0.14 90930.67 25 87147 626.8 650.38 650.54 0.000124 3.34 0.13 88126.24 25 87147 622.6 650.08 650.22 0.000112 3.4 0.13 85328.65 25 87147 626.7 649.72 649.88 0.000142 3.49 0.14 82448.64 25 87442 627.9 649.17 649.39 0.000198 3.9 0.16 78409.05 25 88253 629 648.44 648.62 0.000179 3.54 0.15 75796.42 25 88253 628 648 648.18 0.000161 3.51 0.15 73173.3 25 88253 628.1 647.47 647.68 0.000226 3.77 0.17 70463.68 25 88253 628.5 646.81 647.04 0.000248 3.91 0.18 67747.29 25 88253 628.3 646.36 646.57 0.000123 3.73 0.17 66076.2 25 88253 628.3 646.22 646.37 0.000096 3.23 0.15 65172.95 25 88253 630.9 646.18 635.45 646.28 0.000083 2.61 0.13 65160 Inl Struct 64983.73 25 88253 630.9 645.96 646.07 0.000164 2.71 0.14 64882 25 88253 629.2 645.91 646.04 0.0002 3.05 0.16 64284.3* 25 88253 628.1 645.71 645.9 0.000234 3.7 0.17 63686.66 25 88253 627 645.31 645.71 0.000423 5.41 0.24 62646.44 25 88253 622.8 644.62 645.22 0.000492 6.47 0.26 62481.52 25 88253 623.1 644.58 645.12 0.000457 6.08 0.25 62401.31 25 88253 623.1 644.41 634.03 645.09 0.000242 6.67 0.29 62401 Bridge 62302.87 25 88253 623.1 644.22 644.99 0.000244 7.11 0.29 62234.36 25 88253 624.5 644.22 644.94 0.000629 6.93 0.29 61814.34 25 88253 622.3 643.92 644.67 0.000596 7.05 0.29 61778.5* 25 88253 622.75 643.88 644.64 0.000613 7.13 0.29 61742.77 25 88253 623.2 643.85 633.39 644.62 0.000236 7.14 0.29 61700 Bridge 61653.91 25 88253 623.2 643.71 644.55 0.000272 7.74 0.31 61607.4* 25 88253 623.35 643.6 644.51 0.000747 7.86 0.32 61560.93 25 88253 623.5 643.65 644.45 0.000688 7.37 0.31 61009.87 25 88647 621.3 643.47 644.08 0.000478 6.53 0.26 58997.11 25 88647 622.59 642.46 643.06 0.000596 6.69 0.28 * = Interpolated cross-section created by HEC-RAS
204
Pre-dam removal: 25-year flood (con’t.)
57098.98 25 88647 620 641.86 642.22 0.000297 5.15 0.21 55424.15 25 88647 621.07 641.32 641.71 0.00034 5.34 0.22 53452.28 25 88647 622.74 640.44 640.88 0.000533 5.34 0.26 51485.8 25 88647 617.87 639.5 639.97 0.000406 5.82 0.24 50338.1* 25 88647 617.99 639.28 639.57 0.000249 4.61 0.19 49190.45 25 88647 618.11 639.19 639.33 0.000128 3.38 0.13 47213.91 25 88647 614.39 638.81 639 0.000173 4.11 0.16 46752.8* 25 88647 615.17 638.4 638.66 0.000246 4.65 0.19 46291.7* 25 88647 615.95 637.84 638.09 0.000261 4.58 0.19 45830.6* 25 88647 616.72 637.16 637.37 0.000241 4.26 0.18 45369.59 25 88647 617.5 636.42 636.59 0.000213 3.93 0.17 42967.38 25 88647 621.97 635.5 635.84 0.000488 4.98 0.25 41145.12 25 88647 618.6 634.36 634.81 0.000638 5.65 0.28 40093.8* 25 88647 620.3 633.56 634.07 0.000785 5.89 0.31 39042.52 25 88647 622 632.54 633.12 0.001029 6.25 0.34 38059.6* 25 88647 619.93 631.6 632.15 0.000913 6.12 0.33 37076.85 25 88647 617.87 630.83 631.32 0.000738 5.81 0.3 34679 25 88647 610.18 629.3 629.75 0.000594 5.45 0.27 33352.63 25 88647 612.38 628.19 628.85 0.000781 6.62 0.31 32796.8* 25 88647 609.98 627.72 628.41 0.000772 6.72 0.31 31129.33 25 88647 602.77 626.76 627.3 0.000536 6.07 0.27 29141.25 25 88647 604.74 625.66 626.24 0.000562 6.29 0.27 27174.2* 25 88647 603.95 625.07 625.36 0.000309 4.28 0.2 25207.21 25 88647 603.16 624.67 624.83 0.000203 3.26 0.16 21800.78 25 90926 601.49 624.12 624.21 0.000153 2.54 0.13 18507.37 25 90926 602.01 623.12 623.43 0.000408 5.19 0.23 16499.69 25 90926 603.84 622.16 622.53 0.000454 5.51 0.24 13827.33 25 90926 606.59 620.54 620.99 0.000718 5.4 0.29 13060.3* 25 90926 605.33 619.79 620.39 0.000834 6.22 0.32 12293.43 25 90926 604.06 618.63 613 619.57 0.001308 7.95 0.4 12220 Bridge 12141.29 25 90926 603.84 618.33 619.22 0.001362 7.58 0.4 11377.7* 25 90926 603.11 617.2 618.18 0.001311 8.05 0.4 10614.25 25 90926 602.38 616.39 617.22 0.001094 7.46 0.37 7876.465 25 90926 599.15 613.94 614.61 0.000831 6.88 0.33 6860.224 25 90926 596.62 613.18 613.71 0.000895 5.9 0.32 6583.04* 25 90926 596.52 612.91 613.46 0.000881 5.99 0.32 5197.11* 25 90926 596 611.49 612.19 0.000928 6.75 0.34 * = Interpolated cross-section created by HEC-RAS
205
Pre-dam removal: 25-year flood (con’t.)
4642.747 25 91627 595.79 610.83 611.64 0.001044 7.31 0.36 4597.082 25 91627 595.76 610.56 604.46 611.59 0.000502 8.18 0.4 4590 Bridge 4534.834 25 91627 595.76 610.15 611.35 0.000637 8.76 0.44 4513.42* 25 91627 595.87 610.14 611.33 0.00074 8.78 0.44 4492.006 25 91627 595.98 610.16 611.31 0.000701 8.62 0.43 3935.24* 25 91627 595.12 609.42 610.85 0.000845 9.7 0.48 2821.72* 25 91627 593.41 608.03 609.76 0.001084 10.84 0.54 2264.968 25 91627 592.56 607.14 609.08 0.001284 11.73 0.59 1331.23* 25 91627 591.92 606.01 607.91 0.001195 11.31 0.57 864.363* 25 91627 591.6 605.56 607.34 0.001102 10.9 0.54 397.4951 25 91627 591.28 605.16 600.78 606.81 0.001 10.44 0.52 * = Interpolated cross-section created by HEC-RAS
206
Pre-dam removal: 50-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 50 94846 623.5 652.6 652.77 0.000118 3.63 0.13 97118.95 50 94846 626 652.18 652.34 0.000161 3.85 0.15 93666.77 50 95707 628.5 651.61 651.81 0.000147 3.75 0.15 90930.67 50 95707 626.8 651.26 651.43 0.000127 3.48 0.14 88126.24 50 95707 622.6 650.95 651.11 0.000112 3.5 0.13 85328.65 50 95707 626.7 650.6 650.76 0.000141 3.59 0.14 82448.64 50 96017 627.9 650.04 650.28 0.000198 4.03 0.17 78409.05 50 96867 629 649.32 649.51 0.000177 3.64 0.16 75796.42 50 96867 628 648.87 649.07 0.000162 3.64 0.15 73173.3 50 96867 628.1 648.35 648.57 0.000222 3.88 0.17 70463.68 50 96867 628.5 647.7 647.94 0.000241 4.01 0.18 67747.29 50 96867 628.3 647.27 647.48 0.000121 3.84 0.17 66076.2 50 96867 628.3 647.13 647.29 0.000094 3.32 0.15 65172.95 50 96867 630.9 647.1 635.7 647.2 0.000077 2.64 0.13 65160 Inl Struct 64983.73 50 96867 630.9 646.87 646.98 0.000151 2.74 0.14 64882 50 96867 629.2 646.81 646.95 0.000185 3.08 0.15 64284.3* 50 96867 628.1 646.62 646.82 0.000222 3.76 0.17 63686.66 50 96867 627 646.21 646.63 0.000418 5.57 0.24 62646.44 50 96867 622.8 645.51 646.14 0.000497 6.71 0.27 62481.52 50 96867 623.1 645.46 646.05 0.000462 6.31 0.26 62401.31 50 96867 623.1 645.29 634.58 646.01 0.000245 6.92 0.29 62401 Bridge 62302.87 50 96867 623.1 645.06 645.9 0.000251 7.43 0.3 62234.36 50 96867 624.5 645.08 645.84 0.000636 7.19 0.3 61814.34 50 96867 622.3 644.75 645.56 0.000613 7.36 0.29 61778.5* 50 96867 622.75 644.7 645.53 0.000632 7.45 0.3 61742.77 50 96867 623.2 644.67 633.96 645.51 0.000244 7.47 0.3 61700 Bridge 61653.91 50 96867 623.2 644.53 645.44 0.000282 8.09 0.32 61607.4* 50 96867 623.35 644.41 645.4 0.000765 8.18 0.33 61560.93 50 96867 623.5 644.47 645.34 0.000703 7.68 0.31 61009.87 50 97280 621.3 644.3 644.95 0.000486 6.76 0.26 58997.11 50 97280 622.59 643.32 643.93 0.000589 6.87 0.28 57098.98 50 97280 620 642.71 643.09 0.000303 5.34 0.21 * = Interpolated cross-section created by HEC-RAS
207
Pre-dam removal: 50-year flood (con’t.)
55424.15 50 97280 621.07 642.16 642.57 0.000343 5.53 0.22 53452.28 50 97280 622.74 641.29 641.75 0.000521 5.5 0.26 51485.8 50 97280 617.87 640.34 640.84 0.000412 6.04 0.24 50338.1* 50 97280 617.99 640.12 640.43 0.000253 4.78 0.19 49190.45 50 97280 618.11 640.04 640.19 0.00013 3.5 0.14 47213.91 50 97280 614.39 639.65 639.85 0.000175 4.25 0.16 46752.8* 50 97280 615.17 639.22 639.48 0.000245 4.78 0.19 46291.7* 50 97280 615.95 638.61 638.87 0.000265 4.75 0.19 45830.6* 50 97280 616.72 637.88 638.1 0.000247 4.44 0.18 45369.59 50 97280 617.5 637.09 637.27 0.000221 4.11 0.17 42967.38 50 97280 621.97 636.14 636.5 0.000491 5.15 0.25 41145.12 50 97280 618.6 634.98 635.47 0.000641 5.85 0.28 40093.8* 50 97280 620.3 634.19 634.72 0.000777 6.07 0.31 39042.52 50 97280 622 633.19 633.79 0.000991 6.39 0.34 38059.6* 50 97280 619.93 632.28 632.86 0.000882 6.27 0.32 37076.85 50 97280 617.87 631.54 632.05 0.000719 5.96 0.3 34679 50 97280 610.18 630.06 630.52 0.000579 5.58 0.27 33352.63 50 97280 612.38 628.96 629.64 0.00077 6.81 0.31 32796.8* 50 97280 609.98 628.47 629.21 0.000776 6.97 0.32 31129.33 50 97280 602.77 627.51 628.08 0.000543 6.29 0.27 29141.25 50 97280 604.74 626.41 627.02 0.000567 6.5 0.28 27174.2* 50 97280 603.95 625.81 626.12 0.000316 4.47 0.2 25207.21 50 97280 603.16 625.41 625.59 0.000204 3.38 0.16 21800.78 50 99667 601.49 624.88 624.98 0.000146 2.59 0.13 18507.37 50 99667 602.01 623.84 624.19 0.000438 5.53 0.24 16499.69 50 99667 603.84 622.86 623.25 0.000458 5.7 0.25 13827.33 50 99667 606.59 621.25 621.73 0.000697 5.55 0.29 13060.3* 50 99667 605.33 620.49 621.13 0.000828 6.43 0.32 12293.43 50 99667 604.06 619.29 613.44 620.31 0.001323 8.25 0.4 12220 Bridge 12141.29 50 99667 603.84 619.01 619.95 0.001349 7.82 0.4 11377.7* 50 99667 603.11 617.85 618.9 0.001325 8.37 0.41 10614.25 50 99667 602.38 617.06 617.93 0.001096 7.72 0.37 7876.465 50 99667 599.15 614.62 615.33 0.000829 7.09 0.33 6860.224 50 99667 596.62 613.9 614.45 0.00085 6 0.32 6583.04* 50 99667 596.52 613.64 614.21 0.000843 6.11 0.32 5197.11* 50 99667 596 612.22 612.97 0.00092 6.98 0.34 4642.747 50 100402 595.79 611.57 612.42 0.001026 7.52 0.36 4597.082 50 100402 595.76 611.25 604.91 612.37 0.000509 8.51 0.4 * = Interpolated cross-section created by HEC-RAS
208
Pre-dam removal: 50-year flood (con’t.)
4590 Bridge 4534.834 50 100402 595.76 610.82 612.11 0.000642 9.1 0.45 4513.42* 50 100402 595.87 610.81 612.1 0.000746 9.11 0.45 4492.006 50 100402 595.98 610.85 612.06 0.000698 8.92 0.44 3935.24* 50 100402 595.12 610.06 611.6 0.000858 10.1 0.49 2821.72* 50 100402 593.41 608.62 610.49 0.001106 11.29 0.55 2264.968 50 100402 592.56 607.79 609.81 0.001266 12.05 0.59 1331.23* 50 100402 591.92 606.66 608.66 0.001185 11.66 0.57 864.363* 50 100402 591.6 606.21 608.1 0.001098 11.25 0.55 397.4951 50 100402 591.28 605.81 601.3 607.57 0.001 10.79 0.52 * = Interpolated cross-section created by HEC-RAS
209
Pre-dam removal: 100-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 100 103061 623.5 653.42 653.6 0.000117 3.7 0.13 97118.95 100 103061 626 653 653.17 0.000158 3.92 0.15 93666.77 100 103950 628.5 652.42 652.63 0.000151 3.9 0.15 90930.67 100 103950 626.8 652.08 652.25 0.000126 3.57 0.14 88126.24 100 103950 622.6 651.77 651.93 0.000113 3.58 0.13 85328.65 100 103950 626.7 651.42 651.58 0.00014 3.67 0.14 82448.64 100 104270 627.9 650.85 651.1 0.000199 4.15 0.17 78409.05 100 105148 629 650.13 650.33 0.000175 3.74 0.16 75796.42 100 105148 628 649.69 649.89 0.000163 3.75 0.15 73173.3 100 105148 628.1 649.16 649.4 0.000218 3.99 0.17 70463.68 100 105148 628.5 648.53 648.78 0.000236 4.11 0.18 67747.29 100 105148 628.3 648.11 648.33 0.000118 3.93 0.17 66076.2 100 105148 628.3 647.97 648.14 0.000092 3.4 0.15 65172.95 100 105148 630.9 647.95 635.91 648.05 0.000073 2.67 0.13 65160 Inl Struct 64983.73 100 105148 630.9 647.71 647.82 0.000141 2.76 0.13 64882 100 105148 629.2 647.65 647.79 0.000174 3.12 0.15 64284.3* 100 105148 628.1 647.46 647.67 0.000213 3.82 0.17 63686.66 100 105148 627 647.05 647.48 0.000406 5.67 0.24 62646.44 100 105148 622.8 646.33 646.99 0.000501 6.92 0.27 62481.52 100 105148 623.1 646.28 646.9 0.000466 6.52 0.26 62401.31 100 105148 623.1 646.1 635.08 646.86 0.000245 7.14 0.29 62401 Bridge 62302.87 100 105148 623.1 645.84 646.75 0.000256 7.72 0.31 62234.36 100 105148 624.5 645.87 646.67 0.000638 7.41 0.3 61814.34 100 105148 622.3 645.52 646.38 0.000628 7.64 0.3 61778.5* 100 105148 622.75 645.47 646.35 0.000646 7.73 0.3 61742.77 100 105148 623.2 645.44 634.49 646.34 0.000249 7.75 0.3 61700 Bridge 61653.91 100 105148 623.2 645.28 646.26 0.000289 8.41 0.32 61607.4* 100 105148 623.35 645.14 646.21 0.000794 8.54 0.34 61560.93 100 105148 623.5 645.22 646.14 0.000712 7.93 0.32 61009.87 100 105575 621.3 645.07 645.75 0.00049 6.96 0.27 58997.11 100 105575 622.59 644.1 644.73 0.000584 7.03 0.29 * = Interpolated cross-section created by HEC-RAS
210
Pre-dam removal: 100-year flood
57098.98 100 105575 620 643.48 643.89 0.000308 5.52 0.21 55424.15 100 105575 621.07 642.93 643.37 0.000347 5.7 0.22 53452.28 100 105575 622.74 642.06 642.54 0.000512 5.64 0.26 51485.8 100 105575 617.87 641.11 641.63 0.000418 6.24 0.24 50338.1* 100 105575 617.99 640.89 641.22 0.000257 4.95 0.19 49190.45 100 105575 618.11 640.81 640.97 0.000132 3.61 0.14 47213.91 100 105575 614.39 640.41 640.63 0.000177 4.37 0.16 46752.8* 100 105575 615.17 639.96 640.24 0.000245 4.89 0.19 46291.7* 100 105575 615.95 639.32 639.59 0.000269 4.9 0.2 45830.6* 100 105575 616.72 638.54 638.77 0.000253 4.6 0.19 45369.59 100 105575 617.5 637.69 637.89 0.000228 4.27 0.18 42967.38 100 105575 621.97 636.72 637.11 0.00049 5.3 0.25 41145.12 100 105575 618.6 635.55 636.07 0.000644 6.03 0.29 40093.8* 100 105575 620.3 634.76 635.32 0.000771 6.24 0.31 39042.52 100 105575 622 633.79 634.41 0.000962 6.52 0.34 38059.6* 100 105575 619.93 632.91 633.5 0.000856 6.39 0.32 37076.85 100 105575 617.87 632.18 632.71 0.000706 6.1 0.3 34679 100 105575 610.18 630.74 631.22 0.000566 5.71 0.27 33352.63 100 105575 612.38 629.64 630.36 0.000764 7 0.32 32796.8* 100 105575 609.98 629.13 629.92 0.000783 7.21 0.32 31129.33 100 105575 602.77 628.17 628.78 0.000549 6.48 0.27 29141.25 100 105575 604.74 627.06 627.71 0.000574 6.7 0.28 27174.2* 100 105575 603.95 626.45 626.79 0.000325 4.65 0.21 25207.21 100 105575 603.16 626.05 626.24 0.000207 3.51 0.16 21800.78 100 108042 601.49 625.53 625.63 0.000143 2.66 0.13 18507.37 100 108042 602.01 624.5 624.86 0.000432 5.64 0.24 16499.69 100 108042 603.84 623.51 623.92 0.000462 5.87 0.25 13827.33 100 108042 606.59 621.91 622.41 0.000681 5.69 0.29 13060.3* 100 108042 605.33 621.14 621.82 0.000823 6.63 0.32 12293.43 100 108042 604.06 619.92 613.84 621 0.001326 8.5 0.41 12220 Bridge 12141.29 100 108042 603.84 619.63 620.63 0.001336 8.04 0.4 11377.7* 100 108042 603.11 618.45 619.58 0.00134 8.67 0.41 10614.25 100 108042 602.38 617.66 618.59 0.001099 7.96 0.37 7876.465 100 108042 599.15 615.25 615.99 0.000827 7.29 0.33 6860.224 100 108042 596.62 614.56 615.12 0.000816 6.1 0.31 6583.04* 100 108042 596.52 614.31 614.89 0.000813 6.22 0.31 5197.11* 100 108042 596 612.88 613.68 0.000918 7.2 0.34 4642.747 100 108801 595.79 612.24 613.13 0.001016 7.73 0.36 * = Interpolated cross-section created by HEC-RAS
211
Pre-dam removal: 100-year flood (con’t.)
4597.082 100 108801 595.76 611.87 605.33 613.08 0.000518 8.83 0.41 4590 Bridge 4534.834 100 108801 595.76 611.42 612.79 0.00065 9.42 0.45 4513.42* 100 108801 595.87 611.4 612.78 0.000755 9.44 0.45 4492.006 100 108801 595.98 611.45 612.74 0.000699 9.2 0.44 3935.24* 100 108801 595.12 610.62 612.27 0.000873 10.47 0.49 2821.72* 100 108801 593.41 609.19 611.15 0.001106 11.62 0.55 2264.968 100 108801 592.56 608.38 610.48 0.001252 12.35 0.59 1331.23* 100 108801 591.92 607.26 609.35 0.001178 11.97 0.57 864.363* 100 108801 591.6 606.8 608.79 0.001094 11.57 0.55 397.4951 100 108801 591.28 606.41 601.81 608.26 0.001 11.11 0.53 * = Interpolated cross-section created by HEC-RAS
212
Pre-dam removal: 200-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 200 111080 623.5 654.18 654.36 0.000116 3.77 0.13 97118.95 200 111080 626 653.77 653.94 0.000155 3.98 0.15 93666.77 200 111997 628.5 653.17 653.41 0.000154 4.03 0.15 90930.67 200 111997 626.8 652.84 653.01 0.000126 3.65 0.14 88126.24 200 111997 622.6 652.53 652.69 0.000113 3.67 0.13 85328.65 200 111997 626.7 652.17 652.35 0.000142 3.8 0.14 82448.64 200 112327 627.9 651.6 651.86 0.000199 4.27 0.17 78409.05 200 113232 629 650.88 651.09 0.000174 3.83 0.16 75796.42 200 113232 628 650.43 650.65 0.000164 3.87 0.15 73173.3 200 113232 628.1 649.91 650.15 0.000217 4.09 0.17 70463.68 200 113232 628.5 649.29 649.55 0.000232 4.2 0.18 67747.29 200 113232 628.3 648.86 649.1 0.000118 4.03 0.17 66076.2 200 113232 628.3 648.73 648.91 0.000091 3.49 0.15 65172.95 200 113232 630.9 648.71 636.15 648.82 0.00007 2.72 0.13 65160 Inl Struct 64983.73 200 113232 630.9 648.47 648.58 0.000134 2.79 0.13 64882 200 113232 629.2 648.42 648.56 0.000166 3.16 0.15 64284.3* 200 113232 628.1 648.23 648.44 0.000207 3.89 0.17 63686.66 200 113232 627 647.82 648.26 0.000399 5.77 0.23 62646.44 200 113232 622.8 647.07 647.77 0.000508 7.13 0.27 62481.52 200 113232 623.1 647.02 647.67 0.000472 6.72 0.26 62401.31 200 113232 623.1 646.82 635.57 647.63 0.000247 7.36 0.3 62401 Bridge 62302.87 200 113232 623.1 646.54 647.51 0.000263 8.01 0.31 62234.36 200 113232 624.5 646.58 647.42 0.000645 7.64 0.3 61814.34 200 113232 622.3 646.19 647.12 0.000649 7.94 0.31 61778.5* 200 113232 622.75 646.16 647.1 0.000658 7.98 0.31 61742.77 200 113232 623.2 646.13 635.02 647.08 0.000255 8.02 0.31 61700 Bridge 61653.91 200 113232 623.2 645.92 646.99 0.000303 8.78 0.33 61607.4* 200 113232 623.35 645.85 646.96 0.000795 8.75 0.34 61560.93 200 113232 623.5 645.92 646.89 0.000728 8.21 0.32 61009.87 200 113672 621.3 645.78 646.48 0.000492 7.13 0.27 58997.11 200 113672 622.59 644.83 645.48 0.000576 7.16 0.29 * = Interpolated cross-section created by HEC-RAS
213
Pre-dam removal: 200-year flood (con’t.)
57098.98 200 113672 620 644.21 644.64 0.000313 5.7 0.21 55424.15 200 113672 621.07 643.65 644.11 0.00035 5.86 0.22 53452.28 200 113672 622.74 642.78 643.29 0.000505 5.78 0.26 51485.8 200 113672 617.87 641.82 642.38 0.000424 6.43 0.25 50338.1* 200 113672 617.99 641.61 641.95 0.000261 5.11 0.2 49190.45 200 113672 618.11 641.53 641.7 0.000133 3.72 0.14 47213.91 200 113672 614.39 641.13 641.35 0.000179 4.49 0.16 46752.8* 200 113672 615.17 640.66 640.94 0.000245 5 0.19 46291.7* 200 113672 615.95 639.97 640.27 0.000273 5.05 0.2 45830.6* 200 113672 616.72 639.15 639.41 0.000261 4.77 0.19 45369.59 200 113672 617.5 638.26 638.48 0.000235 4.42 0.18 42967.38 200 113672 621.97 637.28 637.68 0.000489 5.43 0.25 41145.12 200 113672 618.6 636.1 636.64 0.000646 6.2 0.29 40093.8* 200 113672 620.3 635.31 635.9 0.000765 6.39 0.31 39042.52 200 113672 622 634.36 635 0.000937 6.65 0.34 38059.6* 200 113672 619.93 633.5 634.11 0.000834 6.51 0.32 37076.85 200 113672 617.87 632.78 633.34 0.000695 6.23 0.3 34679 200 113672 610.18 631.38 631.87 0.000556 5.82 0.27 33352.63 200 113672 612.38 630.28 631.02 0.000758 7.16 0.32 32796.8* 200 113672 609.98 629.75 630.58 0.00079 7.43 0.32 31129.33 200 113672 602.77 628.8 629.43 0.000554 6.66 0.28 29141.25 200 113672 604.74 627.68 628.36 0.00058 6.89 0.28 27174.2* 200 113672 603.95 627.06 627.42 0.000334 4.82 0.21 25207.21 200 113672 603.16 626.66 626.86 0.000209 3.62 0.16 21800.78 200 116216 601.49 626.15 626.25 0.00014 2.71 0.13 18507.37 200 116216 602.01 625.13 625.5 0.000427 5.73 0.24 16499.69 200 116216 603.84 624.13 624.56 0.000464 6.02 0.25 13827.33 200 116216 606.59 622.53 623.05 0.000667 5.83 0.29 13060.3* 200 116216 605.33 621.75 622.47 0.000819 6.82 0.32 12293.43 200 116216 604.06 620.52 614.22 621.65 0.001325 8.74 0.41 12220 Bridge 12141.29 200 116216 603.84 620.23 621.28 0.001321 8.25 0.4 11377.7* 200 116216 603.11 619.01 620.21 0.001359 8.97 0.42 10614.25 200 116216 602.38 618.24 619.21 0.001097 8.17 0.38 7876.465 200 116216 599.15 615.85 616.61 0.000822 7.46 0.33 6860.224 200 116216 596.62 615.19 615.77 0.000786 6.19 0.31 6583.04* 200 116216 596.52 614.94 615.55 0.000786 6.33 0.31 5197.11* 200 116216 596 613.5 614.35 0.000915 7.4 0.34 4642.747 200 116999 595.79 612.87 613.8 0.001007 7.92 0.36 * = Interpolated cross-section created by HEC-RAS
214
Pre-dam removal: 200-year flood (con’t.)
4597.082 200 116999 595.76 612.46 605.73 613.75 0.000526 9.12 0.41 4590 Bridge 4534.834 200 116999 595.76 611.98 613.45 0.000657 9.72 0.46 4513.42* 200 116999 595.87 611.96 613.43 0.000763 9.74 0.46 4492.006 200 116999 595.98 612.03 613.39 0.000698 9.45 0.44 3935.24* 200 116999 595.12 611.14 612.91 0.000892 10.84 0.5 2821.72* 200 116999 593.41 609.73 611.78 0.001102 11.91 0.56 2264.968 200 116999 592.56 608.94 611.12 0.001241 12.62 0.59 1331.23* 200 116999 591.92 607.81 609.99 0.001172 12.26 0.57 864.363* 200 116999 591.6 607.36 609.43 0.001092 11.87 0.55 397.4951 200 116999 591.28 606.96 602.29 608.9 0.001001 11.42 0.53 * = Interpolated cross-section created by HEC-RAS
215
Pre-dam removal: 500-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 500 121493 623.5 655.14 655.32 0.000116 3.87 0.13 97118.95 500 121493 626 654.73 654.91 0.000152 4.06 0.15 93666.77 500 122439 628.5 654.12 654.37 0.000158 4.2 0.15 90930.67 500 122439 626.8 653.78 653.97 0.000125 3.74 0.14 88126.24 500 122439 622.6 653.48 653.65 0.000113 3.77 0.13 85328.65 500 122439 626.7 653.12 653.31 0.000141 3.89 0.14 82448.64 500 122779 627.9 652.54 652.82 0.000199 4.4 0.17 78409.05 500 123712 629 651.84 652.06 0.000172 3.94 0.16 75796.42 500 123712 628 651.38 651.61 0.000165 4 0.15 73173.3 500 123712 628.1 650.86 651.12 0.000214 4.21 0.17 70463.68 500 123712 628.5 650.25 650.52 0.000228 4.31 0.18 67747.29 500 123712 628.3 649.83 650.09 0.000116 4.15 0.17 66076.2 500 123712 628.3 649.71 649.9 0.00009 3.59 0.15 65172.95 500 123712 630.9 649.7 636.41 649.81 0.000066 2.76 0.12 65160 Inl Struct 64983.73 500 123712 630.9 649.44 649.56 0.000127 2.84 0.13 64882 500 123712 629.2 649.39 649.53 0.000157 3.21 0.14 64284.3* 500 123712 628.1 649.2 649.42 0.0002 3.96 0.17 63686.66 500 123712 627 648.79 649.24 0.000388 5.89 0.23 62646.44 500 123712 622.8 648.01 648.76 0.000514 7.38 0.28 62481.52 500 123712 623.1 647.96 648.66 0.000477 6.97 0.26 62401.31 500 123712 623.1 647.75 636.17 648.62 0.000249 7.63 0.3 62401 Bridge 62302.87 500 123712 623.1 647.44 648.49 0.00027 8.35 0.32 62234.36 500 123712 624.5 647.49 648.38 0.000651 7.9 0.31 61814.34 500 123712 622.3 647.07 648.07 0.000664 8.26 0.31 61778.5* 500 123712 622.75 647.05 648.05 0.000666 8.26 0.31 61742.77 500 123712 623.2 647.01 635.65 648.03 0.000259 8.3 0.31 61700 Bridge 61653.91 500 123712 623.2 646.81 647.94 0.000308 9.09 0.34 61607.4* 500 123712 623.35 646.77 647.92 0.000788 8.97 0.34 61560.93 500 123712 623.5 646.84 647.85 0.000724 8.43 0.32 61009.87 500 124166 621.3 646.72 647.44 0.000488 7.31 0.27 58997.11 500 124166 622.59 645.78 646.46 0.000573 7.37 0.29 57098.98 500 124166 620 645.11 645.6 0.000333 6.04 0.22 * = Interpolated cross-section created by HEC-RAS
216
Pre-dam removal: 500-year flood (con’t.)
55424.15 500 124166 621.07 644.57 645.05 0.000353 6.05 0.23 53452.28 500 124166 622.74 643.7 644.23 0.000495 5.95 0.26 51485.8 500 124166 617.87 642.73 643.32 0.000429 6.66 0.25 50338.1* 500 124166 617.99 642.48 642.88 0.000286 5.49 0.21 49190.45 500 124166 618.11 642.43 642.61 0.000136 3.85 0.14 47213.91 500 124166 614.39 642.02 642.26 0.000182 4.64 0.17 46752.8* 500 124166 615.17 641.52 641.82 0.000245 5.13 0.19 46291.7* 500 124166 615.95 640.8 641.11 0.000277 5.22 0.2 45830.6* 500 124166 616.72 639.93 640.2 0.000269 4.97 0.2 45369.59 500 124166 617.5 638.98 639.21 0.000242 4.61 0.18 42967.38 500 124166 621.97 637.98 638.4 0.000487 5.6 0.25 41145.12 500 124166 618.6 636.78 637.36 0.00065 6.41 0.29 40093.8* 500 124166 620.3 636 636.62 0.000757 6.58 0.31 39042.52 500 124166 622 635.07 635.74 0.000909 6.8 0.34 38059.6* 500 124166 619.93 634.24 634.87 0.00081 6.66 0.32 37076.85 500 124166 617.87 633.54 634.12 0.000683 6.4 0.3 34679 500 124166 610.18 632.17 632.68 0.000543 5.96 0.27 33352.63 500 124166 612.38 631.07 631.85 0.00075 7.36 0.32 32796.8* 500 124166 609.98 630.52 631.41 0.000798 7.7 0.33 31129.33 500 124166 602.77 629.57 630.24 0.000559 6.87 0.28 29141.25 500 124166 604.74 628.46 629.17 0.000585 7.1 0.29 27174.2* 500 124166 603.95 627.82 628.21 0.000344 5.03 0.22 25207.21 500 124166 603.16 627.42 627.64 0.000212 3.77 0.17 21800.78 500 126790 601.49 626.92 627.03 0.000136 2.78 0.13 18507.37 500 126790 602.01 625.91 626.29 0.000421 5.85 0.24 16499.69 500 126790 603.84 624.9 625.35 0.000468 6.22 0.26 13827.33 500 126790 606.59 623.29 623.85 0.000654 5.99 0.29 13060.3* 500 126790 605.33 622.5 623.27 0.000817 7.05 0.32 12293.43 500 126790 604.06 621.24 614.7 622.45 0.001327 9.04 0.41 12220 Bridge 12141.29 500 126790 603.84 620.95 622.07 0.001309 8.52 0.41 11377.7* 500 126790 603.11 619.71 620.99 0.001373 9.3 0.42 10614.25 500 126790 602.38 618.96 619.98 0.001094 8.43 0.38 7876.465 500 126790 599.15 616.6 617.4 0.000818 7.67 0.33 6860.224 500 126790 596.62 615.97 616.57 0.000751 6.3 0.31 6583.04* 500 126790 596.52 615.73 616.35 0.000755 6.45 0.31 5197.11* 500 126790 596 614.28 615.18 0.000909 7.64 0.34 4642.747 500 127597 595.79 613.65 614.64 0.001 8.16 0.36 4597.082 500 127597 595.76 613.18 606.22 614.58 0.000536 9.49 0.42 * = Interpolated cross-section created by HEC-RAS
217
Pre-dam removal: 500-year flood (con’t.)
4590 Bridge 4534.834 500 127597 595.76 612.67 614.25 0.000665 10.09 0.47 4513.42* 500 127597 595.87 612.65 614.24 0.000774 10.12 0.47 4492.006 500 127597 595.98 612.74 614.18 0.000699 9.77 0.45 3935.24* 500 127597 595.12 611.79 613.7 0.00091 11.27 0.51 2821.72* 500 127597 593.41 610.43 612.57 0.001092 12.24 0.56 2264.968 500 127597 592.56 609.64 611.91 0.001226 12.96 0.59 1331.23* 500 127597 591.92 608.51 610.79 0.001164 12.62 0.58 864.363* 500 127597 591.6 608.06 610.24 0.001088 12.23 0.56 397.4951 500 127597 591.28 607.66 602.96 609.71 0.001001 11.78 0.53 * = Interpolated cross-section created by HEC-RAS
218
Post-dam removal: 10-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 10 74408 623.5 650.35 650.51 0.000115 3.35 0.13 97118.95 10 74408 626 649.9 650.06 0.000174 3.69 0.15 93666.77 10 75175 628.5 649.37 649.53 0.000138 3.37 0.14 90930.67 10 75175 626.8 649.03 649.17 0.000124 3.18 0.13 88126.24 10 75175 622.6 648.71 648.85 0.000112 3.25 0.13 85328.65 10 75175 626.7 648.35 648.5 0.000145 3.36 0.14 82448.64 10 75451 627.9 647.81 648.01 0.000199 3.71 0.16 78409.05 10 76208 629 647.05 647.22 0.000186 3.4 0.16 75796.42 10 76208 628 646.6 646.77 0.000162 3.34 0.15 73173.3 10 76208 628.1 646.05 646.25 0.00024 3.64 0.17 70463.68 10 76208 628.5 645.34 645.56 0.00027 3.8 0.18 67747.29 10 76208 628.3 644.86 645.05 0.000133 3.62 0.17 66076.2 10 76208 628.3 644.69 644.84 0.000104 3.13 0.15 65172.95 10 76208 630.9 644.64 644.74 0.0001 2.61 0.14 64983.73 10 76208 630.9 644.61 644.71 0.000189 2.69 0.15 64882 10 76208 629.2 644.55 644.68 0.000229 3.01 0.16 64284.3* 10 76208 628.1 644.34 644.53 0.000256 3.62 0.18 63686.66 10 76208 627 643.97 644.33 0.000427 5.13 0.23 62646.44 10 76208 622.8 643.31 643.84 0.000478 6.08 0.26 62481.52 10 76208 623.1 643.26 643.76 0.000448 5.73 0.25 62401.31 10 76208 623.1 643.12 633.22 643.72 0.000233 6.29 0.28 62401 Bridge 62302.87 10 76208 623.1 642.96 643.64 0.000233 6.63 0.28 62234.36 10 76208 624.5 642.95 643.6 0.000622 6.55 0.29 61814.34 10 76208 622.3 642.69 643.35 0.000566 6.56 0.28 61778.5* 10 76208 622.75 642.65 643.32 0.000585 6.65 0.28 61742.77 10 76208 623.2 642.64 632.58 643.31 0.000223 6.64 0.28 61700 Bridge 61653.91 10 76208 623.2 642.5 643.24 0.000257 7.22 0.3 61607.4* 10 76208 623.35 642.38 643.2 0.000719 7.37 0.31 61560.93 10 76208 623.5 642.43 643.15 0.000664 6.91 0.3 61009.87 10 76576 621.3 642.24 642.79 0.000462 6.14 0.25 58997.11 10 76576 622.59 641.2 641.77 0.00061 6.43 0.28 57098.98 10 76576 620 640.61 640.94 0.000288 4.85 0.2 55424.15 10 76576 621.07 640.08 640.43 0.000334 5.05 0.21 53452.28 10 76576 622.74 639.2 639.59 0.000555 5.1 0.26 * = Interpolated cross-section created by HEC-RAS
219
Post-dam removal: 10-year flood (con’t.)
51485.8 10 76576 617.87 638.26 638.67 0.000397 5.5 0.23 50338.1* 10 76576 617.99 638.03 638.29 0.000241 4.34 0.18 49190.45 10 76576 618.11 637.93 638.06 0.000125 3.2 0.13 47213.91 10 76576 614.39 637.56 637.74 0.000169 3.9 0.15 46752.8* 10 76576 615.17 637.19 637.44 0.000246 4.46 0.18 46291.7* 10 76576 615.95 636.7 636.92 0.000254 4.33 0.19 45830.6* 10 76576 616.72 636.1 636.29 0.000231 4 0.18 45369.59 10 76576 617.5 635.45 635.6 0.000199 3.66 0.16 42967.38 10 76576 621.97 634.57 634.88 0.000487 4.73 0.24 41145.12 10 76576 618.6 633.44 633.86 0.00063 5.34 0.28 40093.8* 10 76576 620.3 632.65 633.11 0.000789 5.59 0.3 39042.52 10 76576 622 631.6 632.14 0.00109 6.03 0.35 38059.6* 10 76576 619.93 630.6 631.12 0.000962 5.89 0.33 37076.85 10 76576 617.87 629.79 630.25 0.000769 5.59 0.3 34679 10 76576 610.18 628.19 628.61 0.00062 5.23 0.27 33352.63 10 76576 612.38 627.08 627.68 0.000791 6.3 0.31 32796.8* 10 76576 609.98 626.62 627.24 0.000763 6.33 0.31 31129.33 10 76576 602.77 625.67 626.16 0.000524 5.74 0.26 29141.25 10 76576 604.74 624.58 625.11 0.000547 5.94 0.27 27174.2* 10 76576 603.95 624.01 624.26 0.000294 3.99 0.19 25207.21 10 76576 603.16 623.61 623.76 0.0002 3.06 0.16 21800.78 10 78704 601.49 623.03 623.12 0.000164 2.45 0.14 18507.37 10 78704 602.01 622.03 622.31 0.000406 4.94 0.23 16499.69 10 78704 603.84 621.12 621.44 0.000429 5.11 0.24 13827.33 10 78704 606.59 619.5 619.92 0.000753 5.17 0.29 13060.3* 10 78704 605.33 618.76 619.3 0.000845 5.89 0.31 12293.43 10 78704 604.06 617.63 612.32 618.47 0.001297 7.53 0.39 12220 Bridge 12141.29 10 78704 603.84 617.34 618.14 0.001387 7.21 0.4 11377.7* 10 78704 603.11 616.24 617.1 0.001293 7.58 0.39 10614.25 10 78704 602.38 615.42 616.16 0.001089 7.06 0.36 7876.465 10 78704 599.15 612.94 613.56 0.000832 6.55 0.32 6860.224 10 78704 596.62 612.12 612.63 0.00097 5.73 0.33 6583.04* 10 78704 596.52 611.84 612.36 0.000941 5.78 0.33 5197.11* 10 78704 596 610.41 611.04 0.000945 6.41 0.33 4642.747 10 79359 595.79 609.73 610.47 0.001075 6.99 0.36 4597.082 10 79359 595.76 609.52 603.8 610.43 0.000494 7.69 0.39 4590 Bridge 4534.834 10 79359 595.76 609.15 610.21 0.000632 8.27 0.44 * = Interpolated cross-section created by HEC-RAS
220
Post-dam removal: 10-year flood (con’t.)
4513.42* 10 79359 595.87 609.13 610.2 0.000737 8.29 0.44 4492.006 10 79359 595.98 609.14 610.18 0.00071 8.19 0.43 3935.24* 10 79359 595.12 608.45 609.72 0.000836 9.15 0.47 2821.72* 10 79359 593.41 607.12 608.65 0.001055 10.17 0.53 2264.968 10 79359 592.56 606.18 607.98 0.001306 11.21 0.58 1331.23* 10 79359 591.92 605.02 606.79 0.001221 10.82 0.56 864.363* 10 79359 591.6 604.56 606.21 0.001118 10.39 0.54 397.4951 10 79359 591.28 604.17 600.04 605.67 0.001001 9.89 0.51 * = Interpolated cross-section created by HEC-RAS
221
Post-dam removal: 25-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 25 86325 623.5 651.66 651.83 0.000119 3.55 0.13 97118.95 25 86325 626 651.22 651.38 0.000167 3.8 0.15 93666.77 25 87147 628.5 650.66 650.85 0.000145 3.61 0.14 90930.67 25 87147 626.8 650.31 650.47 0.000125 3.35 0.13 88126.24 25 87147 622.6 650 650.15 0.000114 3.42 0.13 85328.65 25 87147 626.7 649.64 649.8 0.000144 3.52 0.14 82448.64 25 87442 627.9 649.08 649.3 0.000202 3.92 0.17 78409.05 25 88253 629 648.33 648.52 0.000183 3.57 0.16 75796.42 25 88253 628 647.87 648.06 0.000165 3.54 0.15 73173.3 25 88253 628.1 647.33 647.55 0.000233 3.81 0.17 70463.68 25 88253 628.5 646.65 646.88 0.000258 3.96 0.18 67747.29 25 88253 628.3 646.18 646.39 0.000129 3.78 0.17 66076.2 25 88253 628.3 646.03 646.19 0.000101 3.28 0.15 65172.95 25 88253 630.9 645.98 646.09 0.000088 2.65 0.14 64983.73 25 88253 630.9 645.96 646.07 0.000164 2.71 0.14 64882 25 88253 629.2 645.91 646.04 0.0002 3.05 0.16 64284.3* 25 88253 628.1 645.71 645.9 0.000234 3.7 0.17 63686.66 25 88253 627 645.31 645.71 0.000423 5.41 0.24 62646.44 25 88253 622.8 644.62 645.22 0.000492 6.47 0.26 62481.52 25 88253 623.1 644.58 645.12 0.000457 6.08 0.25 62401.31 25 88253 623.1 644.41 634.03 645.09 0.000242 6.67 0.29 62401 Bridge 62302.87 25 88253 623.1 644.22 644.99 0.000244 7.11 0.29 62234.36 25 88253 624.5 644.22 644.94 0.000629 6.93 0.29 61814.34 25 88253 622.3 643.92 644.67 0.000596 7.05 0.29 61778.5* 25 88253 622.75 643.88 644.64 0.000613 7.13 0.29 61742.77 25 88253 623.2 643.85 633.39 644.62 0.000236 7.14 0.29 61700 Bridge 61653.91 25 88253 623.2 643.71 644.55 0.000272 7.74 0.31 61607.4* 25 88253 623.35 643.6 644.51 0.000747 7.86 0.32 61560.93 25 88253 623.5 643.65 644.45 0.000688 7.37 0.31 61009.87 25 88647 621.3 643.47 644.08 0.000478 6.53 0.26 58997.11 25 88647 622.59 642.46 643.06 0.000596 6.69 0.28 57098.98 25 88647 620 641.86 642.22 0.000297 5.15 0.21 55424.15 25 88647 621.07 641.32 641.71 0.00034 5.34 0.22 53452.28 25 88647 622.74 640.44 640.88 0.000533 5.34 0.26 * = Interpolated cross-section created by HEC-RAS
222
Post-dam removal: 25-year flood (con’t.)
51485.8 25 88647 617.87 639.5 639.97 0.000406 5.82 0.24 50338.1* 25 88647 617.99 639.28 639.57 0.000249 4.61 0.19 49190.45 25 88647 618.11 639.19 639.33 0.000128 3.38 0.13 47213.91 25 88647 614.39 638.81 639 0.000173 4.11 0.16 46752.8* 25 88647 615.17 638.4 638.66 0.000246 4.65 0.19 46291.7* 25 88647 615.95 637.84 638.09 0.000261 4.58 0.19 45830.6* 25 88647 616.72 637.16 637.37 0.000241 4.26 0.18 45369.59 25 88647 617.5 636.42 636.59 0.000213 3.93 0.17 42967.38 25 88647 621.97 635.5 635.84 0.000488 4.98 0.25 41145.12 25 88647 618.6 634.36 634.81 0.000638 5.65 0.28 40093.8* 25 88647 620.3 633.56 634.07 0.000785 5.89 0.31 39042.52 25 88647 622 632.54 633.12 0.001029 6.25 0.34 38059.6* 25 88647 619.93 631.6 632.15 0.000913 6.12 0.33 37076.85 25 88647 617.87 630.83 631.32 0.000738 5.81 0.3 34679 25 88647 610.18 629.3 629.75 0.000594 5.45 0.27 33352.63 25 88647 612.38 628.19 628.85 0.000781 6.62 0.31 32796.8* 25 88647 609.98 627.72 628.41 0.000772 6.72 0.31 31129.33 25 88647 602.77 626.76 627.3 0.000536 6.07 0.27 29141.25 25 88647 604.74 625.66 626.24 0.000562 6.29 0.27 27174.2* 25 88647 603.95 625.07 625.36 0.000309 4.28 0.2 25207.21 25 88647 603.16 624.67 624.83 0.000203 3.26 0.16 21800.78 25 90926 601.49 624.12 624.21 0.000153 2.54 0.13 18507.37 25 90926 602.01 623.12 623.43 0.000408 5.19 0.23 16499.69 25 90926 603.84 622.16 622.53 0.000454 5.51 0.24 13827.33 25 90926 606.59 620.54 620.99 0.000718 5.4 0.29 13060.3* 25 90926 605.33 619.79 620.39 0.000834 6.22 0.32 12293.43 25 90926 604.06 618.63 613 619.57 0.001308 7.95 0.4 12220 Bridge 12141.29 25 90926 603.84 618.33 619.22 0.001362 7.58 0.4 11377.7* 25 90926 603.11 617.2 618.18 0.001311 8.05 0.4 10614.25 25 90926 602.38 616.39 617.22 0.001094 7.46 0.37 7876.465 25 90926 599.15 613.94 614.61 0.000831 6.88 0.33 6860.224 25 90926 596.62 613.18 613.71 0.000895 5.9 0.32 6583.04* 25 90926 596.52 612.91 613.46 0.000881 5.99 0.32 5197.11* 25 90926 596 611.49 612.19 0.000928 6.75 0.34 4642.747 25 91627 595.79 610.83 611.64 0.001044 7.31 0.36 4597.082 25 91627 595.76 610.56 604.46 611.59 0.000502 8.18 0.4 4590 Bridge 4534.834 25 91627 595.76 610.15 611.35 0.000637 8.76 0.44 * = Interpolated cross-section created by HEC-RAS
223
Post-dam removal: 25-year flood (con’t.)
4513.42* 25 91627 595.87 610.14 611.33 0.00074 8.78 0.44 4492.006 25 91627 595.98 610.16 611.31 0.000701 8.62 0.43 3935.24* 25 91627 595.12 609.42 610.85 0.000845 9.7 0.48 2821.72* 25 91627 593.41 608.03 609.76 0.001084 10.84 0.54 2264.968 25 91627 592.56 607.14 609.08 0.001284 11.73 0.59 1331.23* 25 91627 591.92 606.01 607.91 0.001195 11.31 0.57 864.363* 25 91627 591.6 605.56 607.34 0.001102 10.9 0.54 397.4951 25 91627 591.28 605.16 600.8 606.81 0.001 10.44 0.52 * = Interpolated cross-section created by HEC-RAS
224
Post-dam removal: 50-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 50 94846 623.5 652.54 652.72 0.000119 3.64 0.13 97118.95 50 94846 626 652.11 652.28 0.000163 3.87 0.15 93666.77 50 95707 628.5 651.53 651.74 0.000149 3.77 0.15 90930.67 50 95707 626.8 651.18 651.35 0.000129 3.5 0.14 88126.24 50 95707 622.6 650.87 651.02 0.000114 3.52 0.13 85328.65 50 95707 626.7 650.51 650.67 0.000143 3.61 0.14 82448.64 50 96017 627.9 649.94 650.18 0.000203 4.06 0.17 78409.05 50 96867 629 649.19 649.39 0.000181 3.67 0.16 75796.42 50 96867 628 648.74 648.94 0.000166 3.67 0.15 73173.3 50 96867 628.1 648.2 648.43 0.000229 3.93 0.17 70463.68 50 96867 628.5 647.53 647.77 0.000251 4.07 0.18 67747.29 50 96867 628.3 647.07 647.3 0.000126 3.89 0.17 66076.2 50 96867 628.3 646.92 647.09 0.000098 3.37 0.15 65172.95 50 96867 630.9 646.89 647 0.000082 2.69 0.13 64983.73 50 96867 630.9 646.87 646.98 0.000151 2.74 0.14 64882 50 96867 629.2 646.81 646.95 0.000185 3.08 0.15 64284.3* 50 96867 628.1 646.62 646.82 0.000222 3.76 0.17 63686.66 50 96867 627 646.21 646.63 0.000418 5.57 0.24 62646.44 50 96867 622.8 645.51 646.14 0.000497 6.71 0.27 62481.52 50 96867 623.1 645.46 646.05 0.000462 6.31 0.26 62401.31 50 96867 623.1 645.29 634.58 646.01 0.000245 6.92 0.29 62401 Bridge 62302.87 50 96867 623.1 645.06 645.9 0.000251 7.43 0.3 62234.36 50 96867 624.5 645.08 645.84 0.000636 7.19 0.3 61814.34 50 96867 622.3 644.75 645.56 0.000613 7.36 0.29 61778.5* 50 96867 622.75 644.7 645.53 0.000632 7.45 0.3 61742.77 50 96867 623.2 644.67 633.96 645.51 0.000244 7.47 0.3 61700 Bridge 61653.91 50 96867 623.2 644.53 645.44 0.000282 8.09 0.32 61607.4* 50 96867 623.35 644.41 645.4 0.000765 8.18 0.33 61560.93 50 96867 623.5 644.47 645.34 0.000703 7.68 0.31 61009.87 50 97280 621.3 644.3 644.95 0.000486 6.76 0.26 58997.11 50 97280 622.59 643.32 643.93 0.000589 6.87 0.28 57098.98 50 97280 620 642.71 643.09 0.000303 5.34 0.21 55424.15 50 97280 621.07 642.16 642.57 0.000343 5.53 0.22 * = Interpolated cross-section created by HEC-RAS
225
Post-dam removal: 50-year flood (con’t.)
53452.28 50 97280 622.74 641.29 641.75 0.000521 5.5 0.26 51485.8 50 97280 617.87 640.34 640.84 0.000412 6.04 0.24 50338.1* 50 97280 617.99 640.12 640.43 0.000253 4.78 0.19 49190.45 50 97280 618.11 640.04 640.19 0.00013 3.5 0.14 47213.91 50 97280 614.39 639.65 639.85 0.000175 4.25 0.16 46752.8* 50 97280 615.17 639.22 639.48 0.000245 4.78 0.19 46291.7* 50 97280 615.95 638.61 638.87 0.000265 4.75 0.19 45830.6* 50 97280 616.72 637.88 638.1 0.000247 4.44 0.18 45369.59 50 97280 617.5 637.09 637.27 0.000221 4.11 0.17 42967.38 50 97280 621.97 636.14 636.5 0.000491 5.15 0.25 41145.12 50 97280 618.6 634.98 635.47 0.000641 5.85 0.28 40093.8* 50 97280 620.3 634.19 634.72 0.000777 6.07 0.31 39042.52 50 97280 622 633.19 633.79 0.000991 6.39 0.34 38059.6* 50 97280 619.93 632.28 632.86 0.000882 6.27 0.32 37076.85 50 97280 617.87 631.54 632.05 0.000719 5.96 0.3 34679 50 97280 610.18 630.06 630.52 0.000579 5.58 0.27 33352.63 50 97280 612.38 628.96 629.64 0.00077 6.81 0.31 32796.8* 50 97280 609.98 628.47 629.21 0.000776 6.97 0.32 31129.33 50 97280 602.77 627.51 628.08 0.000543 6.29 0.27 29141.25 50 97280 604.74 626.41 627.02 0.000567 6.5 0.28 27174.2* 50 97280 603.95 625.81 626.12 0.000316 4.47 0.2 25207.21 50 97280 603.16 625.41 625.59 0.000204 3.38 0.16 21800.78 50 99667 601.49 624.88 624.98 0.000146 2.59 0.13 18507.37 50 99667 602.01 623.84 624.19 0.000438 5.53 0.24 16499.69 50 99667 603.84 622.86 623.25 0.000458 5.7 0.25 13827.33 50 99667 606.59 621.25 621.73 0.000697 5.55 0.29 13060.3* 50 99667 605.33 620.49 621.13 0.000828 6.43 0.32 12293.43 50 99667 604.06 619.29 613.44 620.31 0.001323 8.25 0.4 12220 Bridge 12141.29 50 99667 603.84 619.01 619.95 0.001349 7.82 0.4 11377.7* 50 99667 603.11 617.85 618.9 0.001325 8.37 0.41 10614.25 50 99667 602.38 617.06 617.93 0.001096 7.72 0.37 7876.465 50 99667 599.15 614.62 615.33 0.000829 7.09 0.33 6860.224 50 99667 596.62 613.9 614.45 0.00085 6 0.32 6583.04* 50 99667 596.52 613.64 614.21 0.000843 6.11 0.32 5197.11* 50 99667 596 612.22 612.97 0.00092 6.98 0.34 4642.747 50 100402 595.79 611.57 612.42 0.001026 7.52 0.36 4597.082 50 100402 595.76 611.25 604.91 612.37 0.000509 8.51 0.4 4590 Bridge * = Interpolated cross-section created by HEC-RAS
226
Post-dam removal: 50-year flood (con’t.)
4534.834 50 100402 595.76 610.82 612.11 0.000642 9.1 0.45 4513.42* 50 100402 595.87 610.81 612.1 0.000746 9.11 0.45 4492.006 50 100402 595.98 610.85 612.06 0.000698 8.92 0.44 3935.24* 50 100402 595.12 610.06 611.6 0.000858 10.1 0.49 2821.72* 50 100402 593.41 608.62 610.49 0.001106 11.29 0.55 2264.968 50 100402 592.56 607.79 609.81 0.001266 12.05 0.59 1331.23* 50 100402 591.92 606.66 608.66 0.001185 11.66 0.57 864.363* 50 100402 591.6 606.21 608.1 0.001098 11.25 0.55 397.4951 50 100402 591.28 605.81 601.3 607.57 0.001 10.79 0.52 * = Interpolated cross-section created by HEC-RAS
227
Post-dam removal: 100-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 100 103061 623.5 653.35 653.53 0.000119 3.72 0.13 97118.95 100 103061 626 652.93 653.1 0.000161 3.95 0.15 93666.77 100 103950 628.5 652.33 652.55 0.000153 3.92 0.15 90930.67 100 103950 626.8 651.99 652.16 0.000129 3.59 0.14 88126.24 100 103950 622.6 651.67 651.83 0.000115 3.61 0.13 85328.65 100 103950 626.7 651.31 651.48 0.000143 3.7 0.14 82448.64 100 104270 627.9 650.74 650.99 0.000203 4.18 0.17 78409.05 100 105148 629 650 650.2 0.00018 3.77 0.16 75796.42 100 105148 628 649.54 649.75 0.000167 3.79 0.15 73173.3 100 105148 628.1 649 649.24 0.000226 4.03 0.17 70463.68 100 105148 628.5 648.34 648.6 0.000246 4.16 0.18 67747.29 100 105148 628.3 647.9 648.13 0.000124 3.99 0.17 66076.2 100 105148 628.3 647.75 647.93 0.000096 3.45 0.15 65172.95 100 105148 630.9 647.73 647.84 0.000077 2.72 0.13 64983.73 100 105148 630.9 647.71 647.82 0.000141 2.76 0.13 64882 100 105148 629.2 647.65 647.79 0.000174 3.12 0.15 64284.3* 100 105148 628.1 647.46 647.67 0.000213 3.82 0.17 63686.66 100 105148 627 647.05 647.48 0.000406 5.67 0.24 62646.44 100 105148 622.8 646.33 646.99 0.000501 6.92 0.27 62481.52 100 105148 623.1 646.28 646.9 0.000466 6.52 0.26 62401.31 100 105148 623.1 646.1 635.08 646.86 0.000245 7.14 0.29 62401 Bridge 62302.87 100 105148 623.1 645.84 646.75 0.000256 7.72 0.31 62234.36 100 105148 624.5 645.87 646.67 0.000638 7.41 0.3 61814.34 100 105148 622.3 645.52 646.38 0.000628 7.64 0.3 61778.5* 100 105148 622.75 645.47 646.35 0.000646 7.73 0.3 61742.77 100 105148 623.2 645.44 634.49 646.34 0.000249 7.75 0.3 61700 Bridge 61653.91 100 105148 623.2 645.28 646.26 0.000289 8.41 0.32 61607.4* 100 105148 623.35 645.14 646.21 0.000794 8.54 0.34 61560.93 100 105148 623.5 645.22 646.14 0.000712 7.93 0.32 61009.87 100 105575 621.3 645.07 645.75 0.00049 6.96 0.27 58997.11 100 105575 622.59 644.1 644.73 0.000584 7.03 0.29 57098.98 100 105575 620 643.48 643.89 0.000308 5.52 0.21 55424.15 100 105575 621.07 642.93 643.37 0.000347 5.7 0.22 53452.28 100 105575 622.74 642.06 642.54 0.000512 5.64 0.26 * = Interpolated cross-section created by HEC-RAS
228
Post-dam removal: 100-year flood (con’t.)
51485.8 100 105575 617.87 641.11 641.63 0.000418 6.24 0.24 50338.1* 100 105575 617.99 640.89 641.22 0.000257 4.95 0.19 49190.45 100 105575 618.11 640.81 640.97 0.000132 3.61 0.14 47213.91 100 105575 614.39 640.41 640.63 0.000177 4.37 0.16 46752.8* 100 105575 615.17 639.96 640.24 0.000245 4.89 0.19 46291.7* 100 105575 615.95 639.32 639.59 0.000269 4.9 0.2 45830.6* 100 105575 616.72 638.54 638.77 0.000253 4.6 0.19 45369.59 100 105575 617.5 637.69 637.89 0.000228 4.27 0.18 42967.38 100 105575 621.97 636.72 637.11 0.00049 5.3 0.25 41145.12 100 105575 618.6 635.55 636.07 0.000644 6.03 0.29 40093.8* 100 105575 620.3 634.76 635.32 0.000771 6.24 0.31 39042.52 100 105575 622 633.79 634.41 0.000962 6.52 0.34 38059.6* 100 105575 619.93 632.91 633.5 0.000856 6.39 0.32 37076.85 100 105575 617.87 632.18 632.71 0.000706 6.1 0.3 34679 100 105575 610.18 630.74 631.22 0.000566 5.71 0.27 33352.63 100 105575 612.38 629.64 630.36 0.000764 7 0.32 32796.8* 100 105575 609.98 629.13 629.92 0.000783 7.21 0.32 31129.33 100 105575 602.77 628.17 628.78 0.000549 6.48 0.27 29141.25 100 105575 604.74 627.06 627.71 0.000574 6.7 0.28 27174.2* 100 105575 603.95 626.45 626.79 0.000325 4.65 0.21 25207.21 100 105575 603.16 626.05 626.24 0.000207 3.51 0.16 21800.78 100 108042 601.49 625.53 625.63 0.000143 2.66 0.13 18507.37 100 108042 602.01 624.5 624.86 0.000432 5.64 0.24 16499.69 100 108042 603.84 623.51 623.92 0.000462 5.87 0.25 13827.33 100 108042 606.59 621.91 622.41 0.000681 5.69 0.29 13060.3* 100 108042 605.33 621.14 621.82 0.000823 6.63 0.32 12293.43 100 108042 604.06 619.92 613.84 621 0.001326 8.5 0.41 12220 Bridge 12141.29 100 108042 603.84 619.63 620.63 0.001336 8.04 0.4 11377.7* 100 108042 603.11 618.45 619.58 0.00134 8.67 0.41 10614.25 100 108042 602.38 617.66 618.59 0.001099 7.96 0.37 7876.465 100 108042 599.15 615.25 615.99 0.000827 7.29 0.33 6860.224 100 108042 596.62 614.56 615.12 0.000816 6.1 0.31 6583.04* 100 108042 596.52 614.31 614.89 0.000813 6.22 0.31 5197.11* 100 108042 596 612.88 613.68 0.000918 7.2 0.34 4642.747 100 108801 595.79 612.24 613.13 0.001016 7.73 0.36 4597.082 100 108801 595.76 611.87 605.33 613.08 0.000518 8.83 0.41 4590 Bridge 4534.834 100 108801 595.76 611.42 612.79 0.00065 9.42 0.45 * = Interpolated cross-section created by HEC-RAS
229
Post-dam removal: 100-year flood (con’t.)
4513.42* 100 108801 595.87 611.4 612.78 0.000755 9.44 0.45 4492.006 100 108801 595.98 611.45 612.74 0.000699 9.2 0.44 3935.24* 100 108801 595.12 610.62 612.27 0.000873 10.47 0.49 2821.72* 100 108801 593.41 609.19 611.15 0.001106 11.62 0.55 2264.968 100 108801 592.56 608.38 610.48 0.001252 12.35 0.59 1331.23* 100 108801 591.92 607.26 609.35 0.001178 11.97 0.57 864.363* 100 108801 591.6 606.8 608.79 0.001094 11.57 0.55 397.4951 100 108801 591.28 606.41 601.81 608.26 0.001 11.11 0.53 * = Interpolated cross-section created by HEC-RAS
230
Post-dam removal: 200-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 200 111080 623.5 654.11 654.29 0.000118 3.79 0.13 97118.95 200 111080 626 653.69 653.86 0.000158 4 0.15 93666.77 200 111997 628.5 653.08 653.32 0.000156 4.05 0.15 90930.67 200 111997 626.8 652.74 652.92 0.000128 3.67 0.14 88126.24 200 111997 622.6 652.43 652.59 0.000115 3.69 0.13 85328.65 200 111997 626.7 652.06 652.24 0.000144 3.81 0.15 82448.64 200 112327 627.9 651.48 651.74 0.000204 4.3 0.17 78409.05 200 113232 629 650.74 650.96 0.000179 3.87 0.16 75796.42 200 113232 628 650.28 650.5 0.000169 3.9 0.15 73173.3 200 113232 628.1 649.74 649.99 0.000224 4.13 0.18 70463.68 200 113232 628.5 649.09 649.36 0.000242 4.25 0.18 67747.29 200 113232 628.3 648.65 648.9 0.000123 4.09 0.17 66076.2 200 113232 628.3 648.51 648.7 0.000096 3.54 0.15 65172.95 200 113232 630.9 648.49 648.6 0.000074 2.76 0.13 64983.73 200 113232 630.9 648.47 648.58 0.000134 2.79 0.13 64882 200 113232 629.2 648.42 648.56 0.000166 3.16 0.15 64284.3* 200 113232 628.1 648.23 648.44 0.000207 3.89 0.17 63686.66 200 113232 627 647.82 648.26 0.000399 5.77 0.23 62646.44 200 113232 622.8 647.07 647.77 0.000508 7.13 0.27 62481.52 200 113232 623.1 647.02 647.67 0.000472 6.72 0.26 62401.31 200 113232 623.1 646.82 635.57 647.63 0.000247 7.36 0.3 62401 Bridge 62302.87 200 113232 623.1 646.54 647.51 0.000263 8.01 0.31 62234.36 200 113232 624.5 646.58 647.42 0.000645 7.64 0.3 61814.34 200 113232 622.3 646.19 647.12 0.000649 7.94 0.31 61778.5* 200 113232 622.75 646.16 647.1 0.000658 7.98 0.31 61742.77 200 113232 623.2 646.13 635.02 647.08 0.000255 8.02 0.31 61700 Bridge 61653.91 200 113232 623.2 645.92 646.99 0.000303 8.78 0.33 61607.4* 200 113232 623.35 645.85 646.96 0.000795 8.75 0.34 61560.93 200 113232 623.5 645.92 646.89 0.000728 8.21 0.32 61009.87 200 113672 621.3 645.78 646.48 0.000492 7.13 0.27 58997.11 200 113672 622.59 644.83 645.48 0.000576 7.16 0.29 57098.98 200 113672 620 644.21 644.64 0.000313 5.7 0.21 55424.15 200 113672 621.07 643.65 644.11 0.00035 5.86 0.22 53452.28 200 113672 622.74 642.78 643.29 0.000505 5.78 0.26 * = Interpolated cross-section created by HEC-RAS
231
Post-dam removal: 200-year flood (con’t.)
51485.8 200 113672 617.87 641.82 642.38 0.000424 6.43 0.25 50338.1* 200 113672 617.99 641.61 641.95 0.000261 5.11 0.2 49190.45 200 113672 618.11 641.53 641.7 0.000133 3.72 0.14 47213.91 200 113672 614.39 641.13 641.35 0.000179 4.49 0.16 46752.8* 200 113672 615.17 640.66 640.94 0.000245 5 0.19 46291.7* 200 113672 615.95 639.97 640.27 0.000273 5.05 0.2 45830.6* 200 113672 616.72 639.15 639.41 0.000261 4.77 0.19 45369.59 200 113672 617.5 638.26 638.48 0.000235 4.42 0.18 42967.38 200 113672 621.97 637.28 637.68 0.000489 5.43 0.25 41145.12 200 113672 618.6 636.1 636.64 0.000646 6.2 0.29 40093.8* 200 113672 620.3 635.31 635.9 0.000765 6.39 0.31 39042.52 200 113672 622 634.36 635 0.000937 6.65 0.34 38059.6* 200 113672 619.93 633.5 634.11 0.000834 6.51 0.32 37076.85 200 113672 617.87 632.78 633.34 0.000695 6.23 0.3 34679 200 113672 610.18 631.38 631.87 0.000556 5.82 0.27 33352.63 200 113672 612.38 630.28 631.02 0.000758 7.16 0.32 32796.8* 200 113672 609.98 629.75 630.58 0.00079 7.43 0.32 31129.33 200 113672 602.77 628.8 629.43 0.000554 6.66 0.28 29141.25 200 113672 604.74 627.68 628.36 0.00058 6.89 0.28 27174.2* 200 113672 603.95 627.06 627.42 0.000334 4.82 0.21 25207.21 200 113672 603.16 626.66 626.86 0.000209 3.62 0.16 21800.78 200 116216 601.49 626.15 626.25 0.00014 2.71 0.13 18507.37 200 116216 602.01 625.13 625.5 0.000427 5.73 0.24 16499.69 200 116216 603.84 624.13 624.56 0.000464 6.02 0.25 13827.33 200 116216 606.59 622.53 623.05 0.000667 5.83 0.29 13060.3* 200 116216 605.33 621.75 622.47 0.000819 6.82 0.32 12293.43 200 116216 604.06 620.52 614.22 621.65 0.001325 8.74 0.41 12220 Bridge 12141.29 200 116216 603.84 620.23 621.28 0.001321 8.25 0.4 11377.7* 200 116216 603.11 619.01 620.21 0.001359 8.97 0.42 10614.25 200 116216 602.38 618.24 619.21 0.001097 8.17 0.38 7876.465 200 116216 599.15 615.85 616.61 0.000822 7.46 0.33 6860.224 200 116216 596.62 615.19 615.77 0.000786 6.19 0.31 6583.04* 200 116216 596.52 614.94 615.55 0.000786 6.33 0.31 5197.11* 200 116216 596 613.5 614.35 0.000915 7.4 0.34 4642.747 200 116999 595.79 612.87 613.8 0.001007 7.92 0.36 4597.082 200 116999 595.76 612.46 605.73 613.75 0.000526 9.12 0.41 4590 Bridge 4534.834 200 116999 595.76 611.98 613.45 0.000657 9.72 0.46 * = Interpolated cross-section created by HEC-RAS
232
Post-dam removal: 200-year flood (con’t.)
4513.42* 200 116999 595.87 611.96 613.43 0.000763 9.74 0.46 4492.006 200 116999 595.98 612.03 613.39 0.000698 9.45 0.44 3935.24* 200 116999 595.12 611.14 612.91 0.000892 10.84 0.5 2821.72* 200 116999 593.41 609.73 611.78 0.001102 11.91 0.56 2264.968 200 116999 592.56 608.94 611.12 0.001241 12.62 0.59 1331.23* 200 116999 591.92 607.81 609.99 0.001172 12.26 0.57 864.363* 200 116999 591.6 607.36 609.43 0.001092 11.87 0.55 397.4951 200 116999 591.28 606.96 602.29 608.9 0.001001 11.42 0.53 * = Interpolated cross-section created by HEC-RAS
233
Post-dam removal: 500-year flood
River Profile Q Total Min Ch W.S. Crit E.G. E.G. Vel Froude Sta El Elev W.S. Elev Slope Chnl # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) 100470.7 500 121493 623.5 655.06 655.24 0.000118 3.89 0.14 97118.95 500 121493 626 654.65 654.82 0.000155 4.08 0.15 93666.77 500 122439 628.5 654.02 654.27 0.00016 4.22 0.16 90930.67 500 122439 626.8 653.68 653.87 0.000128 3.77 0.14 88126.24 500 122439 622.6 653.37 653.54 0.000116 3.79 0.13 85328.65 500 122439 626.7 653 653.19 0.000144 3.92 0.15 82448.64 500 122779 627.9 652.41 652.69 0.000204 4.44 0.17 78409.05 500 123712 629 651.68 651.91 0.000177 3.98 0.16 75796.42 500 123712 628 651.22 651.45 0.00017 4.04 0.16 73173.3 500 123712 628.1 650.68 650.94 0.000222 4.25 0.18 70463.68 500 123712 628.5 650.04 650.32 0.000237 4.37 0.18 67747.29 500 123712 628.3 649.61 649.87 0.000121 4.21 0.17 66076.2 500 123712 628.3 649.47 649.67 0.000094 3.64 0.15 65172.95 500 123712 630.9 649.46 649.58 0.00007 2.81 0.13 64983.73 500 123712 630.9 649.44 649.56 0.000127 2.84 0.13 64882 500 123712 629.2 649.39 649.53 0.000157 3.21 0.14 64284.3* 500 123712 628.1 649.2 649.42 0.0002 3.96 0.17 63686.66 500 123712 627 648.79 649.24 0.000388 5.89 0.23 62646.44 500 123712 622.8 648.01 648.76 0.000514 7.38 0.28 62481.52 500 123712 623.1 647.96 648.66 0.000477 6.97 0.26 62401.31 500 123712 623.1 647.75 636.17 648.62 0.000249 7.63 0.3 62401 Bridge 62302.87 500 123712 623.1 647.44 648.49 0.00027 8.35 0.32 62234.36 500 123712 624.5 647.49 648.38 0.000651 7.9 0.31 61814.34 500 123712 622.3 647.07 648.07 0.000664 8.26 0.31 61778.5* 500 123712 622.75 647.05 648.05 0.000666 8.26 0.31 61742.77 500 123712 623.2 647.01 635.65 648.03 0.000259 8.3 0.31 61700 Bridge 61653.91 500 123712 623.2 646.81 647.94 0.000308 9.09 0.34 61607.4* 500 123712 623.35 646.77 647.92 0.000788 8.97 0.34 61560.93 500 123712 623.5 646.84 647.85 0.000724 8.43 0.32 61009.87 500 124166 621.3 646.72 647.44 0.000488 7.31 0.27 58997.11 500 124166 622.59 645.78 646.46 0.000573 7.37 0.29 57098.98 500 124166 620 645.11 645.6 0.000333 6.04 0.22 55424.15 500 124166 621.07 644.57 645.05 0.000353 6.05 0.23 53452.28 500 124166 622.74 643.7 644.23 0.000495 5.95 0.26 * = Interpolated cross-section created by HEC-RAS
234
Post-dam removal: 500-year flood (con’t.)
51485.8 500 124166 617.87 642.73 643.32 0.000429 6.66 0.25 50338.1* 500 124166 617.99 642.48 642.88 0.000286 5.49 0.21 49190.45 500 124166 618.11 642.43 642.61 0.000136 3.85 0.14 47213.91 500 124166 614.39 642.02 642.26 0.000182 4.64 0.17 46752.8* 500 124166 615.17 641.52 641.82 0.000245 5.13 0.19 46291.7* 500 124166 615.95 640.8 641.11 0.000277 5.22 0.2 45830.6* 500 124166 616.72 639.93 640.2 0.000269 4.97 0.2 45369.59 500 124166 617.5 638.98 639.21 0.000242 4.61 0.18 42967.38 500 124166 621.97 637.98 638.4 0.000487 5.6 0.25 41145.12 500 124166 618.6 636.78 637.36 0.00065 6.41 0.29 40093.8* 500 124166 620.3 636 636.62 0.000757 6.58 0.31 39042.52 500 124166 622 635.07 635.74 0.000909 6.8 0.34 38059.6* 500 124166 619.93 634.24 634.87 0.00081 6.66 0.32 37076.85 500 124166 617.87 633.54 634.12 0.000683 6.4 0.3 34679 500 124166 610.18 632.17 632.68 0.000543 5.96 0.27 33352.63 500 124166 612.38 631.07 631.85 0.00075 7.36 0.32 32796.8* 500 124166 609.98 630.52 631.41 0.000798 7.7 0.33 31129.33 500 124166 602.77 629.57 630.24 0.000559 6.87 0.28 29141.25 500 124166 604.74 628.46 629.17 0.000585 7.1 0.29 27174.2* 500 124166 603.95 627.82 628.21 0.000344 5.03 0.22 25207.21 500 124166 603.16 627.42 627.64 0.000212 3.77 0.17 21800.78 500 126790 601.49 626.92 627.03 0.000136 2.78 0.13 18507.37 500 126790 602.01 625.91 626.29 0.000421 5.85 0.24 16499.69 500 126790 603.84 624.9 625.35 0.000468 6.22 0.26 13827.33 500 126790 606.59 623.29 623.85 0.000654 5.99 0.29 13060.3* 500 126790 605.33 622.5 623.27 0.000817 7.05 0.32 12293.43 500 126790 604.06 621.24 614.7 622.45 0.001327 9.04 0.41 12220 Bridge 12141.29 500 126790 603.84 620.95 622.07 0.001309 8.52 0.41 11377.7* 500 126790 603.11 619.71 620.99 0.001373 9.3 0.42 10614.25 500 126790 602.38 618.96 619.98 0.001094 8.43 0.38 7876.465 500 126790 599.15 616.6 617.4 0.000818 7.67 0.33 6860.224 500 126790 596.62 615.97 616.57 0.000751 6.3 0.31 6583.04* 500 126790 596.52 615.73 616.35 0.000755 6.45 0.31 5197.11* 500 126790 596 614.28 615.18 0.000909 7.64 0.34 4642.747 500 127597 595.79 613.65 614.64 0.001 8.16 0.36 4597.082 500 127597 595.76 613.18 606.22 614.58 0.000536 9.49 0.42 4590 Bridge 4534.834 500 127597 595.76 612.67 614.25 0.000665 10.09 0.47 * = Interpolated cross-section created by HEC-RAS
235
Post-dam removal: 500-year flood (con’t.)
4513.42* 500 127597 595.87 612.65 614.24 0.000774 10.12 0.47 4492.006 500 127597 595.98 612.74 614.18 0.000699 9.77 0.45 3935.24* 500 127597 595.12 611.79 613.7 0.00091 11.27 0.51 2821.72* 500 127597 593.41 610.43 612.57 0.001092 12.24 0.56 2264.968 500 127597 592.56 609.64 611.91 0.001226 12.96 0.59 1331.23* 500 127597 591.92 608.51 610.79 0.001164 12.62 0.58 864.363* 500 127597 591.6 608.06 610.24 0.001088 12.23 0.56 397.4951 500 127597 591.28 607.66 602.96 609.71 0.001001 11.78 0.53 * = Interpolated cross-section created by HEC-RAS
236
APPENDIX D
DIGITAL SOURCES
Digital Sources
Information Type Collection Data Source Originating From Scale Publication USGS Note Resolution Agency Date Hydrologic Cataloging Code Soil Map NRCS Adams County, Indiana 1:24,000 2007 Allen County, Indiana 1:24,000 2007 Allen County, Ohio 1:24,000 2007 Auglaize County, Ohio 1:24,000 2007 Branch County, Michigan 1:24,000 2007 De Kalb County, Indiana 1:24,000 2007 Defiance County, Ohio 1:24,000 2007 Fulton County, Ohio 1:24,000 2007 Hancock County, Ohio 1:24,000 2007 Hardin County, Ohio 1:24,000 2007 Henry County, Ohio 1:24,000 2007 Hillsdale County, Michigan 1:24,000 2006 Lenawee County, Michigan 1:24,000 2006 Logan County, Ohio 1:24,000 2007 Lucas County, Ohio 1:24,000 2007 Mercer County, Ohio 1:24,000 2007 Noble County, Indiana 1:24,000 2007 Paulding County, Ohio 1:24,000 2007 Putnam County, Ohio 1:24,000 2007 Seneca County, Ohio 1:24,000 2007 Shelby County, Ohio 1:24,000 2007 Steuben County, Indiana 1:24,000 2007 Van Wert County, Ohio 1:24,000 2007 Wells County, Indiana 1:24,000 2007 Williams County, Ohio 1:24,000 2007 Wood County, Ohio 1:24,000 2007 Wyandot County, Ohio 1:24,000 2007 Watershed NRCS St. Joseph Watershed 1:24,000 1999 04100003 Boundary St. Marys Watershed 1:24,000 1999 04100004 Upper Maumee Watershed 1:24,000 1999 04100005
237
Digital Sources (con’t.)
Tiffin Watershed 1:24,000 1999 04100006 Auglaize Watershed 1:24,000 1999 04100007 Blanchard Watershed 1:24,000 1999 04100008 Lower Maumee Watershed 1:24,000 1999 04100009 Topographic Map USGS OGRIP Grand Rapids Quadrangle 1:24,000 1977 Colton Quadrangle 1:24,000 1977 Bowling Green North Quadrangle 1:24,000 1988 Maumee Quadrangle 1:24,000 1979 LiDAR OGRIP Henry County, Ohio Tiles: 2006 The flying 2.5 ft grid DEM N1545640, N1545635, N1550640, altitude N1550635, N1550630, N1555630, was 7,300- N1555635, N1555640, N1560640, feet AMT, N1560635, N1560630, N1565645, with the N1565640, N1565635, N1570635, targeted N1570640, N1570645, N1575645, flying N1575640, N1575635, N1580635, speed at N1580640, N1580645, N1585645, 170 knots. N1585640, N1585635 Collected Lucas County, Ohio Tiles: during the N1590635, N1590635, N1590640, months of N1590645, N1595645, N1595640, March and N1600640, N1600645, N1600650, April (leaf- N1605650, N1605645, N1605640, off N1610645, N1610650, N1610655, conditions). N1610660, N1615660, N1615655, N1615650, N1620655, N1620660, N1620665, N1625665, N1625660, N1625655, N1630660, N1630665, N1630670, N1635670, N1635665 Wood County, Ohio Tiles: N1600635, N1605635, N1610640, N1620650, N1625650, N1630655, N1640665, N1640670
238
Digital Sources (con’t.)
Aerial Photograph OGRIP Mosaic Mr.SID Format: Lucas, Wood, Henry 2006 Collected 1 ft pixel during the resolution months of March and April (leaf- off conditions).
239