UTAH GEOLOGICAL AND MINERAL SURVEY

REPORT OF INVESTIGATION

NO. 197

DAM FAILURE INUNDATION STUDY FOR DEER CREEK DAM, UT~H COUNTY

by William F. Case

Applied Geology Group

March 1985

Work performed as part of the Earthquake Hazard,Reduction Program of the Utah Geological and Mineral Survey

FORWARD

A principal objective of the Utah Geological and Mineral Survey is the

identification of areas of Utah that are exposed to geologic hazards.

Geologic events such as earthquakes, landslides, and debris flows can cause

dams to fail and produce flooding downstream. Inundation mapping is thus an

essential ingredient.in any comprehensive hazard mapping effort. Deer Creek

Dam was chosen for this inundation study, the first by the Utah Geological and

Mineral Survey (UGMS), because of special interest expressed by the State

Division of Comprehensive Emergency Management and the Utah County Office of

Emergency Preparedness. The reservoir is one of the more significant water

impoundments along the Wasatch Front and would impact a considerable

population if it were to fail. Because topographic maps of Provo River

Canyon, downstream from the dam, are exceptional in scale and contour

interval, a more accurate inundation map can be produced here than would be

possible in most areas.

This report is intended to present the results of the inundation study and

to document the procedures adopted by the UGMS in the preparation of

inundation area maps. A byproduct of this study is the travel time of the

released reservoir water as it moves downstream. With this information,

emergency preparedness personnel may estimate time available for escape along

evacuation routes. Shelter zones can be established when the potential

inundation zone is determined. Potential inundation is but one hazard that

must be considered in the siting of critical facilities. It is one hazard,

however, that is commonly ignored by both public and private sectors.

I join Mr. Case in extending our gratitude to the U. S. Bureau of

Reclamation for their kind assistance with this study.

Bruce N. Kaliser

State Hazard Geologist

CONTENTS

Forward • • • •

Acknowledgments • •

Introduction

Hydrodynamic analysis • •

Discussion

Cited references

Appendix

ILLUSTRATIONS

Plate 1. Inundated area resulting from a postulated worst-case scenario: Deer Creek Dam failure Provo River, Utah •••••••••••••

Figure 1. Index and location map of Provo River Basin

Figure 2. Diagrammatic longitudinal profile of

• front

1

1

7

• 14

•• 20

• 21

.12-13

• . • .2

Provo River • . • • • • • • • • • • • • • • • • • • .6

TABLES

Table 1. List of Provo River flood obstructions •

Table A-I. Cross-section data • • • • • • • • • •

• 16-17

•• 22-23

ACKNOWLEDGMENTS

I would like to thank the Utah County Flood Control office and the Utah

State Department of Transportation. for the use of their large-scale maps of

the study area. The Utah State Department of Comprehensive Emergency

Management has provided necessary support and assistance. The Bureau of

Reclamation, specifically Brent D. Taylor, has provided technical assistance

which has made this report possible. Any errors, conceptuai or arithmetic,

are the author's.

INTRODUCTION

Deer Creek Dam is an earthfill dam on the Provo River in the Wasatch Range

east of Utah Valley. The Provo River originates in the western part of Unita

Mountains and flows in a northwesterly direction to Utah Lake. The natural

flow of the Provo River is augmented by water diverted from the North Fork of

the Duchesne River and the Weber River. The Deer Creek Dam is part of the

Provo River Project, which delivers Provo River water to metropolitan areas of

Utah and Salt Lake Counties. Deer Creek Reservoir, formed by the dam, has a

capacity of 152,000 acre-feet. Downstream from the dam the Provo River flows

through Orem and Provo. The dam provides flood protection for these

communities, but if the dam should fail and release water from Deer Creek

Reservoir into the Provo River, parts of these communities would be

inundated. The purpose of the study reported here was to determine the area

that would be inundated by an instantaneous failure of Deer Creek Dam with the

reservoir filled to capacity--the worst-case scenario.

The study area extends from Deer Creek Dam to Utah Lake, 20.3 river miles

(mileage along streambed, from dam) downstream along the Provo River (fig. 1).

U.S. Highway 189 which connects Provo, Utah with Evanston, Wyoming (via

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A. Sal t Lake Aqueduct

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I. Duchesne Tunnel Figure I: INDEX & LOCATION MAP OF PROVO RIVER BASIN

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-3-

Interstate 80) runs parallel to the Provo River in the study area. Utah

Highway 92, the "Alpine Loop" from American Fork which terminates at Wildwood

and Highway 189 approximtely 4 miles below Deer Creek Dam, is the only other

transportation route out of the Provo River Canyon. The tributaries that flow

into the Provo River in the study area are as follows: A) Provo Deer Creek

(river mile 0.74) has an approximate maximum discharge on the order of 100

sec.-ft. (Butler, 1966); B) North Fork, which enters the Provo River at

Wildwood (river mile 3.95) has an approximate maximum discharge of about 225

sec.-ft. (Butler, 1966); and C) South Fork which enters the Provo River at

Vivian Park (river mile 5.32) has an approximate maximum discharge of 125

sec.-ft. (Butler, 1966).

The headlands of the Provo River are in the Uinta Mountains approximately

40 miles east of Deer Creek Dam. Water is transferred from the North Fork of

the Duchesne River to the Provo River through the Duchesne Tunnel (Ion fig.

1) and from the Weber River along the Weber-Provo canal (fig. 1). The

Duchesne Tunnel has a capacity of 600 sec.-ft. and the Weber-Provo canal can

route 1000 sec.-ft. The drainage area of the Provo River above the mouth of

Provo Canyon (river mile 11) to Deer Creek Dam (river mile 0.00) is 666 sq.

mi. (Corps of Engineers, 1971). The Corps of Engineers (1971) has defined the

peak discharge of the Intermediate Regional Flood (IOO-yr flood) to be 3000

sec.-ft. and the peak discharge of the Standard Project Flood ("The most

severe combination of meteorological conditions reasonably characteristic of

the geographical region, excluding extremely rare combinations") to be 5200

sec.-ft. at the mouth of Provo Canyon. Peak discharges of the Provo River

(Corps of 'Engineers, 1971) are approximtely 2200 sec.-ft. at Deer Creek Dam

3200 sec.-ft. at Vivian Park (river mile 5.32) and 2500 sec.-ft. at Provo,

1300 feet downstream from the bridge at Highway 114 (river mile 17.67).

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Most of the population that would be affected by a fiood on the Provo

River live in Utah County, downstream from the county line at Wildwood (river

mile 3.95). Canyon Meadows Sales Offices (river mile 1), Deer Creek Park

Campground (river mile 0.75), and residential buildings along Provo Deer Creek

are the only populated zones in Wasatch County, upstream from Wildwood, that

would be affected by a flood due to Deer Creek Dam failure. A flood along the

Provo River below Deer Creek Dam would affect people in the cities of Orem and

Provo which have a 1980 census population of 52,399 and 73,907 respectively,

and represent 58 percent of the population of Utah County. A flood of the

magnitude suggested by this report is expected to indirectly affect at least

100,000 people due to disruption of lifelines. The residential areas

downstream from the Utah County line to the canyon mouth include Wildwood

(river mile 3.95), Vivian Park (river 5.32), Canyon Glen (river mile 8.2) and

Springdell (river mile 8.6). Commercial facilities include River Bend Trailer

Park and a general store (riyer mile 5.05), Bridal Veil Falls tram, etc.

(river mile 7.15) and a cafe near Wicks (river mile 9.3). Industrial

facilities in the Provo River Canyon include a gravel pit (river mile 10.5 )

and Utah Power and Light hydropower plant at Olmstead in the mouth of the

canyon (river mile 10.8). A hydropower plant at the base of Deer Creek Dam

can release 1500 sec.-ft. into the Provo River, enough to cause slight

flooding damage in Provo River Canyon. The water transmission facilities

(fig. 1) within Provo River Canyon are the Salt Lake City (Deer Creek)

Aqueduct (A on fig. 1) which has a capacity of 150 sec.-ft. and routes water

from Deer Creek Dam to Salt Lake City, the Provo Reservoir Canal/Murdock Canal

(B on fig. 1) which routes water from Murdock/Olmstead diversion dam to the

west side of Jordan River Valley, and the Union Canal (not shown on fig. 1)

which provides Provo River water to the Olmstead hydropower plant. The

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Murdock/Olmstead dam is a gravity dam which diverts approximately 550 sec.-ft~

into the Jordan River Valley. Below the canyon mouth 6 canals distribute

water along the Wasatch Front (fig. 1), water is routed to the north by the

North Union (C on fig. 1), West Union (0 on fig. 1), and Lake Bottom (E on

fig. 1) canals, and to the south water is routed by the Lower Union (F on fig.

1), Upper Union (G on fig. 1), and Timpanogos (H on fig. 1) canals. The Provo

River, after leaving the canyon, passes through the communities of Orem,

Caryhurst, Edgemont, Pleasant View, and Provo on its way to Utah Lake State

Park. The elevation range of the study area is from 5425 feet at Deer Creek

Dam crest to about 4490 feet at Utah Lake.

The geology of Provo River Canyon in the study area is examined to

estimate the resistance to hydraulic erosion of the streambed and valley

walls. Erosion as defined for the purpose of this report consists of removal

of sediment and bedrock by 1) abrasion by transported materials within flood

waters such as sand, trees, boulders, etc.; 2) hydraulic plucking or

dislodging of sediment and bedrock by flood water pressure; and 3) solution of

geologic units by water. Three age groups are represented in the canyon:

A) Quaternary-age sediments, which are less than 1.8 million years old;

B) Pennsylvanian-age sedimentary rocks (320 to 280 million years old); and

C) Mississippian-age sedimentary rocks that were deposited before the

Pennsylvanian rocks but after 345 million years ago. The geologic formations

in the study area are Great Blue Limestone (Mississippian age), Manning Canyon

Shale (late Mississippian or early Pennsylvanian age) and Oquirrh Formation of

Pennsylvanian age which is basically sandstone with Bridal Veil Limestone

Member.

The Quaternary sediments are unconsolidated or semiconsolidated and are

classified by the agent that deposited them (fig. 2): Qal is alluvium/valley

-6-

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fill (stream deposit), Qow is glacial outwash (glacial sediments deposited by

meltwater), and Qls is a landslide deposit. The first letter or symbol is an

abbreviation for the age of the unit, i.e., Q = Quaternary, M = Mississippian,

P = Pennsylvanian, PM = Late Mississippian/Early Pennsylvanian.

The erosion resistance of geologic units is a function of: 1) age, younger

sediments or rocks are normally less lithified and thus more easily eroded; 2)

rock type, in a semi-arid climate (the average annual precipitation at Deer

Creek Dam is 23 inches, and at Provo and Utah Lake is 16 inches) limestone is

very resistant, and will erode into massive blocks the size of which may be

controlled by "joints" (fractures in rock caused by similar tectonic forces

that produce faults but which do not result in the slippage characteristic of

faults), sandstone has moderate resistance, and shale is relatively soft; and

3) density of faulting, an area of intense faulting will have more crushed

rock which is easier to erode. The geologic units,shown on figure 2 are in • the immediate vicinity of the streambed. It is not known how thick the

streambed (Quaternary) deposits are in the channel but for a dam failure flood

discharge, such as described in this report, the channel in Provo River Canyon

is likely to be scoured to bedrock throughout its length. Shroba (1979)

reports that the Big Thompson Canyon flood of July 31, 1976 scoured the creeks

to bedrock for the length of the canyon, with a flood discharge only 4 percent

(31,200 sec.-ft.) of the discharge postulated in this report (845,619

sec.-ft.). Silt, sand, and gravel will be available for flood transport in

varying proportions from all the Quaternary deposits along Provo River

Canyon. Larger blocks will come from bedrock, with limestone yielding the

largest blocks.

HYDRODYNAMIC ANALYSIS

Potential causes of dam failure include overtopping of flood waters over

-8-

the dam crest, damage to the structure or foundation due to earthquake

shaking, or foundation failure due to piping. Earth dams, such as Deer Creek

Dam, may develop a breach that enlarges gradually due to overtopping or

piping. The time required for the enlargement of the breach to its maximum

size (resulting in the peak flood discharge) may be a few minutes or several

hours depending on a multitude of factors including reservoir storage and

depth of water behind the dam at the time of failure. Peak depth of flood

waters and time to peak discharge just below the dam depend on the breach

size, shape, and development time among other factors.

In order to produce an inundation overlay and data layer for a seismic

hazard zonation model a worst-case scenario is assumed. The maximum inundated

area along the Provo River due to a failure of Deer Creek Dam is utilized.

The dam breach is equal to the size of the dam. The reservoir is assumed to

be full. Inflow to the reservoir will not be considered because it is minor

(less than 1 percent) compared to the magnitude of the dam failure flood

discharge. Butler (1966) gives the maximum discharge for the Provo River

directly upstream from the reservoir to be approx~mately 1700 sec.-ft., 0.2

percent of the calculated flood-wave discharge at the dam (845,619 sec.-ft.)

due to a hypothetical dam failure. Tributary inflow downstream from·the dam

was not considered because it, also, is minor (less than 0.1 percent) compared

to the calculated dam failure flood discharge.

Emergency plans for evacuation and shelter require not only the

geographical extent of flooding but also the minimum amount of time available

for evacuation. Because the maximum flood and minimum travel time is desired

for this analysis the entire Deer Creek Dam is assumed to fail

instantaneously. This postulated event is believed to be extremely

improbable. The following analysis will attempt to show the maximum

inundation area along the Provo River from Deer Creek Dam to Utah Lake and the

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expected flood-wave arrival time at various localities assuming the worst

conceivable scenario.

The procedures used for estimating peak discharge at the dam and the

attenuation of the flood-wave discharge as it moves downstream are based on

Bureau of Reclamation 'Guidelines for Defining Inundated Areas Downstream from

Bureau of Reclamation Dams' (1982). The Bureau of Reclamation equation for

estimating peak discharge at the dam, in sec.-ft., is: Q = 75(0)1.85, where

Q is the peak discharge and D is the depth of the water in feet behind the dam

at the time of failure which, in this study, is equal to the design hydraulic

height of Deer Creek Dam, 155 feet. The calculated peak discharge, Q, using

this equation is 845,619 sec.-ft. The equation for estimating downstream

discharge attenuation, Qx, is: Qx = 10 (log Q-O.OlXY, where Qx is the

calculated peak discharge in sec.-ft., x miles below the dam. The equations

for Q and Qxare empirical and were derived from data compiled by the Bureau

of Reclamation (1982).

Cross-sections were drawn at intervals along the valley to characterize

the hydraulic properties of the valley, for example at constrictions or change

in slope, in order to accurately determine the inundated areas along the river

and to determine the extent of potential flood water encroachment on geologic

hazards such as landslides. The shape of each cross-section was approximated

by trapezoidal sub-sections to simplify determination of cross-sectional area

and wetted-perimeter (cumulative length of channel sides and. bottom in contact

with floodwater). Many analyses assume the wetted perimeter is basically the

same as the width of the channel, however, because of the large-scale maps

that were available the channel sides were considered as part of the wetted

perimeter. Each trapezoidal sub-section was defined by a top- and

bottom-width and their respective elevations. The bottom-width of the initial

trapezoidal sub-section for each cross-section is the width of the streambed.

-10-

The discharge for each trapezoidal cross-section was calculated using Man~ings

equation for open-channel flow. The depth in the cross-section approximation

is increased until the calculated discharge is contained.

Mannings equation calculates cross-sectional discharge (Qs) as a function

of: A) n, a parameter characterizing net channel roughness, which is assumed

to be 0.035 in this study, the average value for natural channels according to

Linsley (1975); B) s, the topographical gradient of the streambed from the

closest upstream cross-section in vertical feet/horizontal feet; C) A, the

area of the cross-section in square feet; and D) R, the hydraulic radius of

the cross-section, in feet (the cross-sectional area A, divided by the

wetted-perimeter of the cross-section). The discharge through the

cross-section, Qs, is calculated from Mannings equation where Qs = (1.49/n)

(s)1/2(R)2/3(A), in sec.-ft. Code for a hand-held calculator used to

compute the peak flood-level elevation at each cross-section. Results

compared favorably with the National Weather Service (NWS) Simplified Dambreak

Program (SMPOBK). This elevation defines the maximum inundation at the

cross-section.

The peak flood elevations and inundated areas between cross-sections is

subject to interpretation and must be interpolated using hydraulic logic from

values calculated at cross-sections. In a straight channel the water surface

is relatively level, i.e., the water surface is at the same elevation on both

banks. A curved pathway such as in a natural meander introduces a centrifugal

force on the flowing water mass resulting in higher water on the outside of

the bend and lower water on the inside of the bend than would occur with a

straight channel. Flood waters tend to back upstream as a result of valley

constrictions. Increased channel-bottom resistance also increases depth of

flood waters due to the fact that vegetation or buildings reduce the velocity

of flood waters.

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The average yelocity of flow at the cross-section, in feet/second, is

equal to the discharge, Qs, divided by the area, A. Travel times of the flood

crest are estimated because of the number of variables that can influence

velocity.

The topographic base maps used are from the Utah State Department of

Transportation (UDOT) and Utah County. Flood Control Office. The UDOT maps are

at a scale 1 inch'= 100 feet with a contour interval of 2 feet and cover the

Provo River Canyon from Deer Creek Dam to the canyon mouth, about 11 river

miles. The Utah County maps have a contour interval of 5 feet, a scale 1 inch

= 500 feet, and cover the drainage area from the canyon mouth to Utah Lake,

about 9 river miles. It should be noted that the topographic maps used were

drafted before the recent (1983-84) increase in precipitation in the Provo

River area, therefore the topography of the river valley may have changed

slightly.

Sixteen cross-sections, tfrom #1 at the base of Deer Creek Dam spillway to

#16 at Utah Lake State Park, were drawn across the Provo River at specific

locations (plate 1). Flood-wave crest elevations have been calculated and

plotted on plate 1 for all cross-sections except 1 and 16. Cross-section 1

(river mile 0.00) is at the base of the dam 0.16 miles upstream from 2.

Cross-section 16 (river mile 20.14) extends from the Utah Lake shoreline on

one end to the shoreline on the other end of the section across the Provo

River delta. By the time the flood-wave. arrives at cross-section 16 it will

have exceeded the width of the section therefore the height cannot be

calculated. Cross-sections 2, 4, 5, 7, 12, 13, 14, 15 were located to

characterize Provo River Canyon hydraulic parameters. Populated areas in the

canyon and on the flood plain are covered by cross-sections 2, 3, 6, 8, 10,

11, 13, 14, and 15 (note: some cross-sections are multi-purpose). Cross-

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sections 9, 10, 11 are at locations of landslides and, glacial outwash.

Cross-section widths range from 419 feet (7) to 6464 feet (15) and the depth

of the flood-wave ranges from 25 feet at section 15 (the widest cross-section)

to 83 feet at cross-section 9 which has the most gentle channel-bed slope

along the study reach, 10 ft/mile. Just downstream, at cross-sections 10 and

11, the slopes are 83 ft/mile and 90 ft/mile, the steepest slopes.

Cross-section 10 will have the highest average velocity of flood waters, 36

mph (53 ft/s). All cross-section plots showing the flood-wave crest

elevation, geology, and diagrammatic topography are in appendix A. Table A-I

in appendix A is a compilation of relevant data used for calculations for each

cross-section'. All top-widths used in the hydraulic calculations were picked

at a topographic threshold if evident (where a channel suddenly widens as the

water level rises), or to characterize the slope of valley walls. The

smallest top-width and lowest elevation of the cross-section represent the

present channel width and streambed elevation as estimated within the contour

interval of the base maps.

DISCUSSION

Plate 1 shows the extent of the inundation of Deer Creek Reservoir waters

from Deer Creek Dam to Utah Lake. Table 1 lists known ob~tructians in the

study area, their height above the streambed, and the height of the expected

flood-wave above the obstruction. Examples of obstructions include: bridges

(foot, vehicle, or railroad), weirs, diversion dams, viaducts, and abutments

of dismantled structures. The only feature that would not be overtopped by

the calculated flood-wave is the bridge at West Center Street (river mile

20.05), however, if the flow velocity is greater than 3 mph (hydraulic

calculations indicate that flow velocities would be approximately 10 mph) the

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Table 1. List of Provo River Flood Obstructions (from Corps of Engineers, 1971 & 1972)

Top Approx. Flood Approx. Flood River Elev. -wave Crest Height Above

Obstruction Mile (ft. ) Elev. (ft.) Feature (ft.)

Vehicle bridge 0.40 5280 5330 50 Foot bridge 0.84 5261 5310 49 Foot bridge 0.88 5261 5310 49 Railroad bridge 2.77 5232 5310 78 yehicle bridge,

Vivian Park 5.15 5197 5220 23 Union Aqueduct

diversion 6.11 5194 5270 76 Foot bridge 6.55 5159 5220 61 Foot bridge, Bridal

Veil Falls 7.22 5110 5165 55 HWY 189 bridge 7.63 5060 5110 50 Foot bridge 7.76 5042 5080 38 Railroad bridge 8.35 4995 5020 25 Vehicle bridge . 9.88 4897 4910 13 Murdock diversion

dam 10.00 4886 4900 13 Railroad bridge,

abandoned 10.88 4827 4850 23 Timpanogos Canal

diversion 10.89 4820 4850 30 Upper Union Canal

diversion 10.90 4816 4850 34 North Union Canal

diversion 10.94 4815 4845 30 Unnamed canal

diversion 10.98 4820 4845 25 8th North, Orem

bridge 11.07 4821 4840 19 Railroad bridge 11.27 4800 4825 25 West Union canal

diversion 11.36 4791 4820 29 Carterville Road

bridge 11.54 4791 4810 19 Center St., Orem

abutment 12.21 4745 4770 25 3700 N, Provo

bridge 13.33 4701 4715 14 Riverside Golf

Course bridge 14.33 4650 4665 15 Lake Bottom canal

diversion 14.55 4630 4655 25 Lower Union Canal

diversion & bridge 14.75 4623 4645 22 BYU diagonal: east 14.96 4620 4635 15 BYU diagonal: west 14.98 4619 4635 16 HWY 89-91 bridge 15.60 4590 4605 15

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Table 1. List of Provo River Flood Obstructions - Continued.

Columbia Lane bridge 15.72 4592 4595 3 Weir 15.73 4581 4595 14 9th No, Provo

bridge 16.10 4573 4585 12 8th No, Provo

bridge 16.19 4572 4580 8 D&RGW rail abut-

ments 16.94 4527 4555 28 D&RGW rail- bridge 16.98 4539 4550 11 U.P. railroad

bridge 17.04 4543 4550 7 1-15 HWY bridge 17.12 4537 4545 8 Weir 17.15 4518 4545 27 HWY 114 bridge 17.42 4523 4535 12 West Center st.

bridge 20.05 4497 4495 -3 Utah Lake State

Park bridge 20.17 4490 4495 5

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bridge piers could be washed out due to erosion of surrounding fill (Corps of

Engineers, 1972). Another type of obstruction that occurs in the study area

is the embankment of Interstate 15. Although it is estimated that the flood

waters may overtop the embankment (table 1) some water would back up on the

upslope side of the embankment and would flow to the northwest and southeast

(plate 1). Once this water reaches an overpass it would flow through the

overpass at a high velocity, particularly if the surface is paved. The

"breaks" in the 1-15 embankment through which flood waters would flow include

the overpass over the railroad tracks about 9th North in Provo, the Center

Street overpass, and the intersection of University Avenue and Interstate 15.

The ponding upslope of the 1-15 embankment would likely extend well into

Provo. Below the city and the embankment the flood waters would fan out and

deposit debris across the Utah Lake plain.

As a result of flood waters from a Deer Creek Dam failure, the water level

in Utah Lake may temporarily rise above an elevation of 4490 foot. The

projected maximum water surface elevation increase in Utah Lake would be about

8 inches. If the Jordan River gates were open it is likely that areas along

the Jordan River would be flooded although the consequent rise in the Great

Salt Lake would be minimal.

water flowing out of the canyon mouth below the constriction at

cross-section 12 would spread out between two bluffs and, as the flooded

'channel effectively widens below the mouth of Provo River Canyon, flow

velocities would steadily decrease. The average velocity of flood waters

through cross-section 12 (narrow canyon mouth) would be about 30 mph. As the

flooded channel widens the velocities would decrease progressively to 10 mph

at section 15 in Provo City. Once the flood waters leave cross-section 15

(river mile 15.63) they would spread out because they are no longer contained

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by the river'bluffs. Locally the velocity would be higher, for example, over

paved streets, through local constrictions, etc. The velocities in the bluff

area would be of the same magnitude as those in the steepest reaches of the

Big Thompson Canyon flood in Colorado in 1976 (Shroba, 1979). With such high

velocities one would expect similar damage, that is, vehicles smashed beyond

recognition, wood frame houses torn off foundations, masonry buildings

destroyed by debris acting as battering rams, deposition of very

large-diameter debris (natural and man made) in bars nearly 20 feet thick.

All transportation routes within the bluff area (cross-sections 12'to 15) and

within the Provo River Canyon (cross-sections 1 to 11) would be severed. The

bluffs themselves would be undercut and slopes would fail severing the canals

on top. The canals near the mouth of Provo River Canyon would probably be

breached early in the flood and therefore would not likely route flood water

beyond the postulated area of inundation. The Olmstead hydropower plant would

be taken out of service by the flood waters. It would take about one-half

hour, after dam failure for the flood-wave (a 38-foot-high wall of water

loaded with diverse debris) to reach the mouth of the canyon.

Upstream, within the Provo River Canyon, the flood waters would scour the

canyon to bedrock or below depending on local conditions. Sediment that has

been picked up is. usually deposited just downstream in the next area of slack

water, except for floating material that wasn't tangled up. The flood waters

would undercut most of·the highway fill and railroad fill, and near

cross-section 9, would sever the Salt Lake City Aqueduct and the Union

Aqueduct. All Provo River Canyon communities and facilities would be

flooded. The flood waters would back up approximately 1200 feet into North

Fork (at Wildwood) and probably would back 1000 feet up the South Fork into

Vivian Park. New landslides would be initiated due to bank undercutting and

channel scour by the flood and old landslides would be rejuvenated.

-19-

It would take approximately 10 minutes (after dam failure) for the

flood-wave to reach Wildwood, the first vehicle escape route out of the

canyon. In about 15 more minutes the flood-wave would be at the canyon mouth

and approximately 90 minutes after the dam failure flood waters would reach

Utah Lake. The average velocity of the flood waters from Deer Creek Dam to

Utah Lake would be approximately 15 mph.

Facts that should be considered while planning emergency responses should

include the following:

A) People in the Provo River Canyon should not try to drive out of the

canyon, but instead should head for high ground. A warning system

should be installed in the canyon, one that is not dependent on

normal communication channels (telephone or CB). People in the

canyon will have less than 1/2 hour to save themselves.

B) Refugee areas would likely be on the northwest and southeast sides of

Provo River, the bench at Orem and the BYU campus plateau. North­

south highways will be severed. The evacuation paths should be

east-west. Even after flood waters have subsided normal

transportation routes will be clogged with sediment and debris.

C) Evacuation time below the canyon mouth would range from one-half to

one hour.

D) All lifelines (phone, sewer, water, power, gas) may be severed or

contaminated. The sewer treatment plants (Timpanogos, Orem, & Provo

City) may become inoperative. Administrative operations may have to

be moved from Provo.

-20-

CITED REFERENCES

Baker, Arthur A., 1964a, Geology of the Aspen Grove Quadrangle, Utah: United states Geological Survey Geologic Quadrangle Map GQ-239.

------1964b, Geology of the Orem Quadrangle, Utah: United states Geological Survey Geologic Quadrangle Map GQ-241.

------1972, Geologic map of the Bridal Veil Falls Quadrangle, Utah: United states Geological Survey Geologic Quadrangle Map GQ-998.

Bureau of Reclamation, 1982, Guidelines for defining inundated areas downstream from Bureau of Reclamation dams; Bureau of Reclamation unpublished report.

Butler, E., J.K. Reid, V.K. Berwick, 1966, Magnitude and frequency of floods in the United States: Part 10, the Great Basin: United States Geological Survey Water Supply Paper 1684, 256 pp.

Corps of Engineers, 1971, Flood plain information Provo River and Rock Canyon Creek, Provo and Orem, Utah: Department of the Army, Sacramento District, 34 pp.

---~--1972, Flood plain information Provo River and Slate Creek, Provo, Utah: Department of the Army, Sacramento District, 34 pp.

Linsley, Ray K., Jr., Max A. Kohler, Joseph L.H. Paulhus, 1975, Hydrology for engineers: McGraw-Hill Publishers.

Shroba, Ralph R., Paul W. Schmidt, Eleanor J. Crosby, and Wallace R. Hansen, 1979, Geologic and geomorphic effects in the Big Thompson Canyon area, Larimer County: United States Geological Survey Professional Paper 1115, pp 87-152.

APPENDIX

Table A-I consists of the top-widths, elevations, slope, and discharge used for the calculations of Flood-wave crest parameters for cross-sections #2 through #15. Diagrammatic representations of cross-sections #2 through #15 follow below the table.

-22-

Table A-I. Cross-Section Data - Continued

TOP ELEVA-WIDTH TION (FT) (FT)

* 35 5178 75 5190

CROSS-SECTION 119 100 5192 FLOOD-WAVE CREST RIVER MILE = 6.26 120 5198 ELEVATION = 5261 feet SLOPE=0.0019 ft/ft 270 5200 PEAK DEPTH = 83 feet PEAK DISCHARGE,Qx= 732,107cfs 298 5208 ARRIVAL TIME = 20 minD

670 5250 AVE. VELOCITY = 15 mph 800 5270

CROSS-SECTION 1110 * 38 5096 FLOOD-WAVE CREST RIVER MILE = 7.25 55 5104 ELEVATION = 5153 feet SLOPE=0.0157 ft/ft 120 5108 PEAK DEPTH = 57 feet PEAK DISCHARGE,Qx= 715,607cfs 210 5114 ARRIVAL TIME = 22 minD

263 5130 AVE. VELOCITY = 36 mph 440 5160

CROSS-SECTION 1111 * 66 4968 FLOOD-WAVE CREST RIVER MILE = 8.68 495 4972 ELEVATION = 4993 feet SLOPE=0.0017 ft/ft 660 4974 PEAK DEPTH = 25 feet PEAK DISCHARGE,Qx= 692,428cfs 746 4990 ARRIVAL TIME = 24.5 minD

790 4993 AVE. VELOCITY = 29 mph

* 33 4826 FLOOD-WAVE CREST CROSS-SECTION #12 50 4828 ELEVATION = 4864 feet RIVER MILE = 10.75 255 4834 PEAK DEPTH = 38 feet SLOPE=0.0013 ft/ft 385 4836 ARRIVAL TIME = 28.5 min# PEAK DISCHARGE,Qx= 660,199cfs 453 4850 AVE. VELOCITY = 31 mph

502 4870

CROSS-SECTION #13 * 40 4796 FLOOD-WAVE CREST RIVER MILE = 11.23 80 4805 ELEVATION = 4828 feet SLOPE=0.0118 ft/ft 310 4810 PEAK DEPTH = 32 feet PEAK DISCHARGE,Qx= 652,942cfs 523 4814 ARRIVAL TIME = 30 minll

1265 4816 AVE. VELOCITY = 20 mph 1340 4825 1378 4850

CROSS-SECTION #14 * 75 4751 FLOOD-WAVE CREST RIVER MILE = 12.11 650 4760 ELEVATION = 4774 feet SLOPE=0.0097 ft/ft 1620 4764 PEAK DEPTH = 23 feet PEAK DISCHARGE,Qx= 639,845cfs 3200 4800 ARRIVAL TIME = 33.5 min#

AVE.VELOCITY = 16 mph

CROSS-SECTION #15 * 80 4575 FLOOD-WAVE CREST RIVER MILE = 15.63 95 4590 ELEVATION = 4600 feet SLOPE=0.0095 ft/ft 1270 4594 PEAK DEPTH = 25 feet PEAK DISCHARGE,Qx= 590,031cfs 6430 -4596 ARRIVAL TIME = 54.5 min#

6464 4600 AVE. VELOCITY = 10 mph 6624 4625

-23-

Table A-I. Cross-Section Data

TOP ELEVA-WIDTH TION (FT) (FT)

* 55 5272 103 5284

CROSS-SECTION #2 340 5286 FLOOD-WAVE CREST RIVER MILE = 0.16 475 5300 ELEVATION =-5347 feet SLOPE=0.0024 ftlft 600 5310 PEAK DEPTH = 75 feet PEAK DISCHARGE,Qx= 842,509cfs 670 5330 ARRIVAL TIME = 0.5 minD

715 5340 AVE.VELOCITY = 15 mph 1900 5360

* 67 5261 75 5262

CROSS-SECTION 113 307 5264 FLOOD-WAVE CREST RIVER MILE = 0.74 480 5266 ELEVATION = 5309 feet SLOPE=0.0036 ftlft 530 5270 PEAK DEPTH = 48 feet PEAK DISCHARGE,Qx= 831,332cfs 580 5274 ARRIVAL TIME = 2.5 minD

656 5294 AVE.VELOCITY = 19 mph 774 5310

* 33 5250 CROSS-SECTION #4 150 5264 FLOOD-WAVE CREST RIVER MILE = 1.34 335 5288 ELEVATION = 5331 feet SLOPE=0.0035 ftlft 420 5314 PEAK DEPTH = 81 feet PEAK DISCHARGE,Qx= 819,926cfs 550 5316 ARRIVAL TIME = 4 mini

613 5340 AVE. VELOCITY = 21 mph

CROSS-SECTION lIS * 70 5212 FLOOD-WAVE CREST RIVER MILE = 3.84 160 5218 ELEVATION = 5293 feet SLOPE=O.0029 ftlft 238 5226 PEAK DEPTH = 81 feet PEAK DISCHARGE,Qx= 774,060cfs 293 5250 ARRIVAL TIME = 11min#

503 5300 AVE. VELOCITY = 21 mph

CROSS-SECTION 116 * 43 5204 FLOOD-WAVE CREST RIVER MILE = 4.20 188 5208 ELEVATION = 5258 feet SLOPE=0.0046 ft/ft 340 5211 PEAK DEPTH = 54 feet PEAK DISCHARGE,Qx= 767,670cfs 485 5240 ARRIVAL TIME = 12.5 mini

604 5280 AVE.VELOCITY = 23 mph

CROSS-SECTION 117 * 35 5198 FLOOD-WAVE CREST RIVER MILE = 4.45 190 5209 ELEVATION = 5274 feet SLOPE=O.0045 ftlft 268 5230 PEAK DEPTH = 76 feet PEAK DISCHARGE,Qx= 763,264cfs 340 5260 ARRIVAL TIME = 13 minD

419 5280 AVE. VELOCITY = 25 mph

CROSS-SECTION #8 * 65 5190 FLOOD-WAVE CREST RIVER MILE = 5.05 ~O 5192 ELEVATION = 5231 feet SLOPE=0.0029 ftlft 570 5196 PEAK DEPTH = 41 feet PEAK DISCHARGE,Qx= 752,792cfs 913 5210 ARRIVAL TIME = 15 minD

1019 5250 AVE. VELOCITY = 16 mph

(Note: * = streambed width and elevation, # = approximate travel time from dam)

E L E 1,,)

A ..,.. I

I o ~'l

F E' e t

5:350

('~u.:., t e r' n ar ) ...

DEER CREEK DAM FAILURE INUNDATION AREA

~ 1 y I ~

! ~~

~: FLOOD l .... IAI..)E CF.:EST ______ ~ --'?-(5347-ft-El;~~ti;~~-----~

\ 75 ft Drep) , j

\ I ! ~:::'~::/:~~;~;'~; ~,~n , ~r, ~ 1 )

~ I ~/ \ I / ~I~

\ II

(sandstone & cherty 1 i rne':.tone)

527~3 - ~

5250 I .::;. 5 o

, 5 '? i

o

QuaternarY Alluvium (sand a~d oravel) , -

I

::::~

g

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION # 2: River Mi le=0.16

- 1 H' t 1 ~ca €os: orlzon.a = 1 : ~:281, l.)e r' tic a 1 = 1: 41 (1 ; t,)e r' tic .:.. 1

-'-

::'1

E ! J....

E t) A T I [I j' .. J

F e e t

531.:;. DEER CREEK DAM FAILURE INUNDATION AREA

!

i ,--~~~~~-~~:~-~~~~~-:~~~:-:!-~~~~~!~~~~-~~-:!-~~~~~------------------J

5:30:3 - \ I !

'\ I / I . 5:300 - ! /

52E:4 -

526(1

I I " ! -.~ I f \ ! / \ I I \ I I \ I f \ I : \ I J

\ ! J

G!u .~. t e r' n .~.r·)t" All u v i UrT! ( ·:·a.n d ,£" I~r' .~I.) E' 1 )

! .-. ~~I

1 ~3

I 1 c-'-' c-._I

7 7

I ~

I -// I ~.

I !

L ~.j

PRI~ll.)O R I l)E~:

(t, .. lic:lth~ feet)

7 7

! I 1 .--::'

"'-c- .-, '-' .:., c-._1 2

.-, .:t 1 ~1

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION # 3: River Ml le=0.74

--

~

F E' E' t

5340 \ DEER CREEr< DAt'l FA I lURE I t···JUNDAT I ON AF~EA jf

\ I f 5:=1:3 ~J • 5 - \ - -: ~ ~ ~ ~ - t::!~': § - ~ ~ §~:: - ~ ~ ~ ~.:. - i!.: -§ ~ ::1:: ~! ~ ~ ~.: -§.:. -i!.: - ~:::: ~ ~ -- -- -- -- --- --/

W i .• -( . f

f 5:321 - \ 1 I

8 J 5] 11 .5

527:3.5 -

5254.5 -

5245

\ I~ \ I \ I \ I

\ / \ f \ I \ j

\ I .1. \ /~

f It ···-:o··\ It" 1+"'-'" ,:c. U I., : ) a. IJ "I..:" )

Pe rm i .~rl.'/ Penns;,.'l IJan i .:-.n

\ / Penn'::.}"1 I .... ·:«on i .~n.·"" \

R // t"l i·::,·:. i ·::,S· i I) P i ·~,n A

~;~;;;;g;;~:A:~~~\y ~ ~ g / MANNING CANYON SHALE " A D/" \D /

\ / , / Quaternary, I / Quaternary

All u v i UTTr 'x I J(/ I I I ~1

PRO'·.)!] F.: P.)ER

Al1u 1.} j UTTr

(I..· . .lidth~ teet)

I 1 ~ '-'

( '::··~,n d g~

DIAGRA~~ATIC REPRESENTATION OF CROSS-SECTION # 4: River Mi le=l .34

Scales: Horizontal= 1:1057~ Vertical= 1:195 ;Vertical Exaggeration=5x

E L E ! I ",,,'

A T I n t::-J

F e e t

"'"'\ DEER CPEEN DAt"1 FA I L(J F.: E I NUNDAT ION AREA j'" 5:3€H3 \ I

52-;:$1 -

527:3

52.54 -

C"-.C'C' -._'.:, . ..)._'

5246 -

522:3 -

521 ~3

\ FLOOD WAVE CREST (5293 ft. ELEGATON, 81 ft. Deep) /

\ ------------------------------...;.-,,-----.;..--------------------------j

\

1 I I I

\ I / \ I I \ I I

\ I I \ I I \ I / \ I /

\ 1 /

\ I I \ ~

\ I / i\ ·1 / 1 IT IJ \ ! J,;. .:. "\ I r , ! I u

\ : I .:. PEon n s y 1 I.) a. n ian \ I IF' e n n .:. >' 1 I.) .:c. n j .? '-1

OQUI F~RH

F I] Rt"lA T I ON

(·:.andstone & 1 i mestone)

! 2 ~1

i

\ ! J \ I /OQUIRRH

\ H I I FORt"'1AT I ot···J

\ Y I ~ / ~ 1 I [)

~i I § / i A / I Dx

Quaternary I Quaternary

Al l1J'.} i um

I 1 C'

--' 1

! 1 ~1

i

! 5 a

I

I '€I

PF.:Ot)O RIt)ER

(1.-".1 i dth. fee t)

I 5 f1

A! 1 u I.} i urn

I I

1 ~3 1

t ; 1 t:: ._1

1

-,.-(1 ; l.

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION # 5: River Hi 1e=3.84

Scales: Horizontal= 1:1732~ Vertical= 1:185 :Vertical Exaggeration=9x

2: --,

E l E ! .. )

A T I n r:::-J

e e t

5280 DEER CREEK DAM FAIL~RE INUNDATION AREA ,

~\ ! ! I !

\ I / \ I f \ I I \ I I \ I ! \ I i , FLOOD WAVE CREST (5258 ft. El~vation. 54 ft. Deep) t \------------------------------~------~-----------~----------1

\ I I , I I \ f

\ I /

5272

5264 -

525.:· -

524:3 -

\ ! ~ \ I /

\ ! I T \ I

524(1 -

t \ / ~ \ /

\ ! \ ~ f /

5224 -

~· .... ?1~_~ - \ 1 R I - Pennsylvanian 8 d /Pennsylvan i a0

OG!U I F.~F.~H ~ B .---1 OC!U I PPH

52(1 :::! - F o Rt"'lAT ! or···J ~ ! ~------- F 0 Fl'1AT ! OJ···j

52(10 L, .:. o .j 4

I

~ 1

I 1 .::. '-' 1

OIJ.:..terna.r·y~ ! ~ Alluvium~Quaternary (sand & Qravel) ! Alluvium'

- ! I 1 2 ~~1

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION # 6: River Mi 1e=4.2

E L E

52:3(1 \ DEER CREEI< DAt-1 FAI LllRE INUNDATIor···! AF.:EA /

\ -~~~~~-~~:~-~~~~~-~~~~~-~!:-~~~~~!~~~!-~~-~!:-~!~~~------------- / 5271. 5 - \ . I /

\ I / \ I j

\ I r

\ / 5263 -

5254.5

I..,..' 524,~,- \ / A T I [I \ I t···!5237.5 Pennsyl- \ /~1!'!~~,1~:1-F eo €' t

I.} .~n i an ',' ·:;!.l! , .::;I.! I

OQUIRRH \ , OQUIRRH

FORMATION, \ / FORMATION~

8r' i da 1 ;,.1 €' \ I c' ! ,j .~. L me's r"1 mbe

t).:?.1 e

5220.5 -

5212 -

52~]3. 5

51 '7'5 I 2 1 \3

Limestone \ I Member \ J

\ IT \

R ,I '~1 H A \ ~:~ [/ ~i

F: I

9/ f-I D

QI.J a teo r' n .~r·}' ./ G!IJ.~ter·n.~.r>··

Alluvium

.:: ·:·an d 8-c: 9r·a1.} e 1 )

I I I 1 1 ,-,

c· t!1 ,-,

..::. 4 :3 ~:.

./ ..... ----I~-W"

I I 4 0 :3 PROl)O

R It . ...'EF.: (k1idth, feet)

I 4 '':1 ,_,

All u') i um

! I :3 1 4 "') ....

6

1 I~r ,;:. ;-~

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION # 7: River Mile=4.45

Scales: Horizontal= 1:724 Vertical= 1 :175 ;Vertical Exaggeration=4x

~ . i ~]

E L E I . .)

A ,.. I

I 1] t···J

F e e t

5250\ DEER CREEl< DAt'l FAIlURE INUNDATION AREA

5243 -\ I

\ i J

\ 1 j l FLOOD WAVE CREST (5231 ft. Elevation, 41 ft. Deep) ) l------------------------------------------------------------------J l I I

522 t? - l I j l I j l J l I j \ I 1 1 !I ~ \ ~

\ I 1

5222

5215 -~ I j

\ ~ I I k A I j ,I I /

520:3 - ~E I R / ,R 1 A / ,r' H I I /

'-'0 I.N I L / "-.U 'y' I R / 52£11 -

Pennsyl van i ~T § I ~ -"'"~nno;Yl -.}.3."; 3.n :t.n ~ '7' I _______ 51'-;4 - OG!UIR~:H FOR~·'1ATIOt'··J ~ I ~_______ OOUIFFH FC:Pt"'1ATICl"'~

I c:-'-' 1 o

Bridal Vale Limestone Member \ 1 ' Bridal Vale Limestone t"1emt,e r'

I 4 a :3

I Quaternary Alluvium (sand & gravel)

I I

I OJ o

I I i 1 0 1 a PRO~)O 0

4 2 RII.,)ER 2 (l,J.,1 i dth ~ fee t)

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION # 8: Rjver Mi le=5.05

Scales: Horizontal= 1:1754~ Vertical= 1:840 ;Vertical ExaQQera~!on=2x

T f , ; I ," i

5 1 o

E

E I.)

A T I o t···J

F eo eo t

5270 DEER CREEK DAM FAILiRE INUNDATION AREA /

\--~~~~~-~~':::~-~~~~~-~~~~:-:!.:-~~~~~!~~~!-~~-:!.:-~~~~:------------j 5250 -

5240 -

5230 -

522~1 -

521 ~j -

5200 -

5190 -

5180 -

5170 I 4 0 0

\ I / \ i l

\, I J \ I /

\ I / \ I /

\ ! / \ ! /

\ I / \ I /

\ I'R / 1)IJ·a t e r' n ·ar· y \ I~ I ~ /

, Y I ~ I \ ~ I g J Pennsylvanian

~ 1 .... ~ ClI]U I RRH FOFl'1AT I or···J

\ I r E:r' i d.:..l !·.).~.l e Lime -:;. t on e i"lembe:'

G 1 ·9.C i .9.1 Ou tlAl.:..sh

( ·:.an d 8-:: gr' .9. V e 1 )

~ I ) 1 I r \ I J If-J

Quaternary Alluvium ( ·:··9.n d ,~~ ';I r' .9. I.) e 1 )

I ! ! .-. .-. 1 . .:, £.. .j ... 4 ·5 ~3 ~~1 (1

I I I :3 (1 :3 ~3 F'ROl.)O ~3

R I t·..JEF: (1..· . .Iidth, feet)

I 1

! .-, ..:. 4 ~3

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION R i I·)er· t"1 i 1 e=·~·. 26

Scales: Horizontal= 1:1375, Vertical= 1:205 ;Vertical Exaggeration=7x

E L E ! ! .,,,'

A T I (I N

F

51 6~~1

515:3

51:3'7' -

5125 -

511:::! -

5111 -

5104 -

5(197

I 2

~

Quater·rtar::..-

131 ae i ,~ 1 Ou tl".Ja sh

All IJ I,' i urn

( ':.artd &: qr' a I.) e 1 )

! 1 7

I 1 ~':' '-' 2

I 4 4

All I,J 1.) j urn

! 4 4

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION #10: River Mile=7.25

Scales: Horizontal= 1 :756 ~ Vertical= 1:144 ;Vertical Exaggeratlon=5x

4999 - DEER CREEK DAM FAILURE INUNDATION AREA I I

K FLOOD WAVE CREST (4993 ft. Elevation. 25 ft. Deep) ~ ,-------------------------------------~---------------------------- / , I ~

\ R I / \ T I /

\ L I H i

\

R I !,. ... I J o I 'y' ! A f ~ I:~ ,, _______ -:4

G!IJ.:..tern,:..r'}, ~ I '~ ~Pef"!n.,,·/t·,·1i·=,·=,. Landsl ide MANNING CANYON SHALE

c­'-'

( san d .~~ I~ r .:to 1,,1 e 1 ) IJ. u ~. t ern .:to r' Y I X All IJ I,} i IJ IT! - I

I -::. { 6

I'J '1 17 1~3 ~ 5 9 PROVO '8 RIVER

(1,.. . .1 i I::!th ~ fee t)

1 7 '-;-

! 1 5 ~=~

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION #11: River Hi le=8.68

Scales: Horizontal= 1:1362, Vertical= 1:174 ;Vertical Exaggeration=8x

=':;=

E L E I,.)

A T I [I N

F

Eo t

DEER CREEK DAM FAILURE INUNDATION AREA

J FLOOD "'lAVE CREST (4864 f to El eJ" t ion. 38 f to Deep) ! \ ------------------------------------------------------------------ J

4855 -

485~3 -

4840 -

4:335 -

4 ,-,·-.= ,~c..._!

I 2 c-,_I

1

\ I I .1

\ I f \ I / \ I j \ I 1 , I r \ f \ I J

\ I / I

! R I

\ 7 I I~ / \ ~ I ,,{ / ~ 2 ! :~: j ____.....D ! ';' ~

______ I """~

t'l i "S.'::. i :,·S· i pp i ·:..n ~ I ~ t"l i ':,':. i ':,':, i ;:I\:' i ,~.r:

" I /" (3~:EAT BLUE GREAT BLUE L I t'lE:3TOr···JE

L, ~ i

I 1 = ,_I

1

""'-... 1,,/ L I f"l E ~=;T Of",J E

Qua t e r' n ar- )'

\)f--l-i--7([ I

I Alluvium (sand &

I I

1~1 F'RO~)O RIt)ER

(1,"'.1 i dth, fee t::.

! r::: '-' (1

9r' ,:r,I.}e 1 )

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION #12: River Mile:10.75

Scales: Horizontal= 1:863 , Vertical= 1:103 ;Vertical Exa9geration=8x

5

A T I o N

F e eo t

DEER CREEK DAM FAILURE INUNDATION AREA

I

1 I I

485~3 1 I \ i

4 - - C' _ll I .I~",; .,! " :=::3,_1 I

~ FLOOD WAVE CREST (4828 ft. Elevation, 33 ft. Deep) Y t ~---------------------------------f------------~-----------~-----~-J

\ I '7' / )Ii !,... x

4:320

LaKe Sed[~ents ~ GREAT BLUE G!uater'n':',r':." ~. I ~ t"1i':·si':.:.i;:'D!·;.!!

( ':,.~ n d ,~~ I~ r' .:',',} e 1 ) -.............. II L I j"1 E :=;T cr"-1 E 4:::a35 - -"

I C'

'-' 5 1

G~IJ,3.ter'n,~,r)" " I j Allu',} i UITI (sand & ~ gravel)

I I I ! 1 f.'1 1 :3 PRell) 0 :~: ':;'I ~: II,')EF: ''I

O},.Ii(:lth~ feet)

I I

4 1 ::~

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION #13: River Hi le=11 .22

Scales: Horizontal= 1:2373, Vertical= 1:309 ;Vertical Exaggeration=8x

E L E I .. )

A T I o N

F t? e t

DEER CREEK DAM FAILURE INUNDATION AREA 4820 I U

I N 'IC. I I ~

47~35

r~ I I..) ~~

~ § FLOOD Il.JA~)E CRE~3T A ~ ~ ----A--------------------------------I.)----~ ~ D (4774 f t El el.}.;:t. t1i on ,23 f t Dee!:,) E ...,.~

*-4750 -

Quaternary LaKe Quaternarv Sediments (sand & gravel) Sediments

4715 ! 1 .-, .:. .-. 1~

~3

Qu a. t e r' n ar' ~..,... I

Alluvium (sand & I

L, L I .:;. ~'1 :3 2 PR!~!I.)O 4 ~1 R I I·.)EF.~ H

(1, .• ,1 i dth, fee t)

! I

·5 4 o

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION #14: River Hi 1e=12.11

S C 24. 1 e s·: H CI r' iz c. n t ·a 1 = 1: 5 5 ~3 1, L.) e r' tic a 1 = 1: 7 1:3 ; I .. ) e r' tic a. 1 E ::< .:.. f~ 9 e r' ·a t i ':1 i: = ~=: ::{

1= [ E I.,) A T I [I 4~,1 '7' • 5 t·,~

Ft. 4550

DEER CREEK DAM FAILURE INUNDATION AREA

F·ROI..)O CITY

I !H I I.}.J ! 'y' I !:3

1 i --' t···j I

I.,)

I '7'. A FLOOD WAVE CREST (4600 ft. ElevatioM. 25 ft. Deep) V . ~ ___________________________________ '7'_~ ____________________ E _________ i

G~IJ .:r. t e r- n .:t. r' y G~ IJ .;t. t e r' n .;t. r' :'7" ----, ! -=...1 -------::?;v .. 1;""11 :-:"Ij ':"":'1.)~i -:-IJ:-:::rr:-, ------;l=;-~! l:-:-j -:-,~."T.t-:e-::::-::' f::-! -~:-:. r=--'- -:,.-LaKe Sediments (sand & gravel) LaKe Sedime~t~ 1 I ! I I 1 i j 12 I ~2 ':r 1 1 .:::- 0 1~1 1 1 .... 'J '-' ~, '7J .-:~

'-' i. ... ' PF.~OI..)O ,5 ,-, . .:, t7' !:::

1 C' E! ''') 2 R I ~.,.JER .j 2 I:' -=; '-' L. L. '-' 2 0 7 5 ( 1 ..•.. 1 i dth ~ fl?e t ) 5 J'~' ~)

DIAGRAMMATIC REPRESENTATION OF CROSS-SECTION #15: River Mi 1e=15.63

Scales: Horizontal=1:.11404, Vertical= 1:1426;Ver-tfcal ExaQQerat~on=8x

--= ..:' i :. ..;..

I o 1 Mile

Base from U.S. Geological Survey topographic quadrangles Aspen Grove and Bridal Veil Falls.

PLATE 1. INUNDATED AREA RESULTING FROM A

POSTULATED WORST-CASE SCENARIO DEER CREEK DAM

FAILURE, PROVO RIVER, UTAH

EXPLANATION

~ approximate limit of flooding

2 cross-section number

~

::c:

~ . ~

, ........

>4

~

o 1 Mile ~I--------------~I ..

. I

Baae from U.S. Geological Survey topograph ic quadrangles Crem and Provo.

PLATE 1: (continued) INUNDATED AREA RESUL TII\iG FROM A POSTULATED WORST-CASE SCENARIO DEER CREEK DAM FAILURE, PROVO RIVER, UTAH

EXPLANATION

.............. approximate limit of flooding

2 cr08l M section number