HomeMy WebLinkAboutAlaska Dam Safety Program Phase I Inspection Report 1984SWITZER CREEK DAM NO. 1, AK00176
JUNEAU, ALASKA
JUN
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ALASKA DAM SAFETY PROGRAM
PHASE I INSPECTION REPORT
PREPARED FOR: STATE OF ALASKA DEPARTMENT OF NATURAL RESOURCES
DIVISION OF LAND AND WATER MANAGEMENT
BY CHAS. T. MAIN, INC.
SEPTEMBER 15, 1984
PROPERTY OF:
Alaska Power AuthoritY,
334 W, 5th Ave. ·
Anchorage, Alaska 99501'
SWITZER CREEK DAM NO. 1, AK00176
JUNEAU, ALASKA
RECEnveo
JAN 1 5 1985
&AsKA POWER AUTHORITY.
ALASKA DAM SAFETY PROGRAM
PHASE I INSPECTION REPORT
PREPARED FOR: STATE OF ALASKA DEPARTMENT OF NATURAL RESOURCES
DIVISION OF k~ND AND WATER MANAGEMENT
BY CHAS. T. MAIN, INC.
SEPTEMBER 15, 1984
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1893
CHAS. T. MAIN. INC.
101 EAST 9TH AVE. SUITE 4A, ANCHORAGE, ALASKA 99501 (907} 272·5433
September 21, 1984 3945-1-1000
SUBJECT: Alaska Department of Natural Resources
Dam Safety Inspection Program
Switzer Creek Dam No. 1-AK 00176
State of Alaska
Department of Natural Resources
Division of Land and \Jater lianagement
555 Cordova Street: Pouch 7-005
Anchorage, Alaska 99510
Attention: Mr. Kyle J. Cherry, P.E.
State Dam Safety Engineer
Gentlemen:
MAIN is pleased to submit herewith our final report on
our inspection of Switzer Creek Dam No. 1, AK 00176.
This inspection was conducted on 12 July 1984.
APD/RJT/1em
Very truly yours,
CHAS. T. MAIN, INC.
Registered Professional Engineers
Alton p. Davis, .Jr.
Project ~ianager
Richard J. Tucker
Project Engineer
PHASE I REPORT
ALASKA STATE DAJ1 SAFETY PROGRAM
SWITZER CREEK DAM NO. 1
EXECUTIVE SUMMARY
On 2 December 1977, President Carter initiated a National Dam Safety Program by
directing the Corps of Engineers to administer a program of inspection of all
dams classified as high hazard potential by reason of their location. The
National Dam Safety Program was completed in 1982. It was intended that each
state would thereafter accept responsibility for non-federal dams located within
their jurisdiction. In July 1966, Governor William Egan signed Alaska Statute
AS 46.15 "Water Use Act" under which the Alaska State Dam Safety Program has
been initiated.
Under AS 46.15, Switzer Creek Dam No. 1 was inspected on 12 July 1984 by Chas.
T. Main, Inc. under contract to State of Alaska Department of Natural Resources,
Division of Land and Water Management. Based on design drawings, it was
determined that the project spillway was designed for the 100 year flood event.
The dam could therefore be overtopped by approximately 2.7 feet in the event of
a Probable Maximum Flood. Recommendations for remedial action of deficiencies
are made such as clearing brush on the downstream embankment slope, restoring
or relocating the roadway drain culvert on the left abutment and conducting
studies to modify the dam to safely pass larger floods.
TABLE OF CONTENTS
EXECUTIVE SlJM:t-f.ARY
TABLE OF CONTENTS
GENERAL LOCATION MAP: Figure 1
PROJECT DATA
1. GENERAL 1
1.1 Authority 1
1.2 Purpose and Scope 1
1.3 Inspection Team 2
2. PROJECT DESCRIPTION 3
2.1 Location 3
2.2 .Size and Hazard Potential Classification 3
2.3 Purpose of Dam 4
2.4 Construction History 4
2.5 Geology and Soils 4
2.6 Basin Description 5
2.7 Description of Project 5
2.8 Operation and Maintenance 6
3. FIELD INSPECTION 7
3.1 General 7
3.2 Reservoir Area 7
3.3 Dam 7
3.4 Abutments 8
3.5 Outlet Works 8
3.6 Spillway 8
3.7 Downstream Channel 8
3.8 Instrumentation 8
4. HYDROLOGY 9
4.1 History of Flooding 9
4.2 Probable Maximum Flood 9
5. HYDRAULIC EVALUATION 10
5.1 Spillway Adequacy 10
5.2 Flood Routing 10
TABLE OF CONTENTS (Cont'd)
6. STRUCTURAL STABILITY
7. PRIOR REPORTS 12
8. CONCLUSIONS 13
9. RECOMMENDATIONS 14
APPENDIX A Inspection Photographs
APPENDIX B Project Plates
APPENDIX C Inspection Checklist
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PROJECT DATA
A. GENERAL
Name .•
Location •
Year Built •
Purpose
Inventory of Dams I.D. Number
Hazard Potential Classification
Size Classification
Owner
B. DAH
Type
Crest Length .
Crest Width . . . .
Crest Elevation
Height • • . • •
C. SPILLWAY
Type .•
Location •
Side Slopes
Crest Elevation
Bottom Width •
Length . . . .
Discharge Capacity @ Dam Crest •
.
Switzer Creek Dam No. 1
Juneau, Alaska
1972
Water Supply
AK 00176
High
Intermediate
Southeast Utilities
c/o Schneider Scott Mobile
Home Park
6590 Glacier Highway,
Juneau, Alaska 99801
Charles Schneider (907) 586-1635
Robert Scott (907) 586-2717
Concrete Faced Rock Fill
137 ft.
15 ft .
190 ft.
44 ft.
Broad Crested Weir & Chute
Centerline of Dam
Vertical
187 ft.
12 ft.
110 ft.
190 cfs
D. OUTLET WORKS
E.
Type •
Location •
Invert Elevation .
Size .
Length .
Discharge Capacity @Dam Crest
RESERVOIR
Normal Maximum Water Surface Elevation •
Water Surface Elevation @ Dam Crest
Maximum Storage Volume @ Dam Crest
Maximum Surface Area @ Dam Crest
Storage Volume @ Spillway Crest.
Surface Area @ Spillway Crest.
F. HYDROLOGIC DATA
Drainage Area
Average Annual Rainfall
Average Annual Discharge
Flood of Record
Project Design Flood .
Probable Maximum Flood • .
.
.
.
.
Low Level Outlet with Stem Gate
Through Dam
168 ft.
32 in. Diameter
145 ft.
17 5 cfs
187 ft.
190 ft.
11 AF
0.65
10 AF
0.60
Acres
Acres
0:41 sq. mi.
92 inches
2.4 cfs
None Recorded
2300 cfs
2300 cfs
1. GENERAL
ALASKA DAM SAFETY PROGRAM
PHASE I INSPECTION REPORT
OF
SWITZER CREEK DAM NO. 1
AK 00176
1.1 Authority: Inspection authority is Alaska Statute AS 46.15 "Water Use
Act" signed by Governor William Egan on 1 July 1966. Inspection procedures and
criteria for a Phase I Inspection are set forth in the "Recommended Guidelines
for Safety Inspection of Dams", Appendix D, Volume I, u.s. Army Corps of Engi-
neers report to the U.S. Congress on National Program of Inspection of Dams,
dated May 1975, and published under Title 33CFR Part 222.
1.2 Purpose and Scope: The purpose of the Alaska Dam Safety Program Phase I
Inspections is to assemble information and records on existing non-federal dams
located within the State of Alaska and to insure continued public confidence in
the integrity and safety of these important structures.
The scope of this report is to compile results of a visual inspection of Switzer
Creek Dam No. 1 and an examination of currently available information relating
to design, construction and performance history of the project. In addition,
the potential risk to upstream and downstream residents is evaluated and preli-
minary spillway adequacy and structural stability assessments are made. Finally,
adequacy of existing records and documents relating to the project are discussed
and recommendations for additional studies and/or remedial actions are made.
-1-
1.3 Inspection Team: The inspection of Switzer Creek Dam No. 1 was conducted
on 12 July 1984. The inspection team was composed of the following personnel:
CHAS. T. MAIN, INC.
Alton P. Davis, Jr.
Richard J. Tucker
DEPARTMENT OF NATURAL RESOURCES
Kyle J. Cherry
Kenneth B. Hunt
Project Manager/Geotechnical
Project Engineer/Hydraulics
State Dam Safety Engineer
Assistant Dam Safety Engineer
Messrs. Virgil Hulse and John Woods of Schneider Scott Mobile Home Park and
Ms. Sara Hunt of DNR Southeast District Office accompanied the inspection team.
-2-
2. PROJECT DESCRIPTION
2.1 Location: Switzer Creek Dam No. 1 is located on an unnamed tributary
near Switzer Creek at 58° 21.8' North Latitude, 134° 31.4' West Longitude near
the Tongass National Forest. The nearest city is Juneau as shown on Figure 1.
The nearest settlement is the Schneider Scott Mobile Home Park approximately
one quarter mile southeast of the dam. The dam is owned by Southeast Utilities.
The dam is being operated by Southeast Utilities as a water supply for the
mobile home park. The National Dam Inventory for the State of Alaska identifies
this dam as AK 00176. Switzer Creek Dam No. 1 is one of two dams which impound
water for the mobile home park. Switzer Creek Dam No. 2 is located on another
small creek just east of No. 1
2.2 Size and Hazard Potential Classification
2.2.1 Size Classification: The height of Switzer Creek Dam No. 1 is 44 feet
and the reservoir has a maximum storage capacity of 11 acre-feet at the dam
crest. The size classification is determined by the dam height or the maximum
storage capacity, whichever gives the larger size category. An intermediate
size dam is from 40 to 100 feet in height or from 1000 to 50,000 acre-feet of
maximum storage capacity. A small size dam is from 24 to 40 feet in height and
less than 1000 acre-feet of maximum storage. Switzer Creek Dam No. 1 is there-
fore classified as Intermediate Size based on height of dam.
2.2.2 Hazard Potential Classification: Switzer Creek Dam No. 1 is classified
as High-Hazard Potential for damage and loss of life in the event of failure.
Specification of Hazard Potential for a dam does not infer anything with regard
to safety of the dam; it simply states the hazard if the dam should fail for
any reason. The downstream area is heavily forested and has a steep narrow
channel exiting into the Schneider Scott Mobile Home Park. Numerous mobile
homes and trailers line the channel through the Schneider Scott Mobile Home
Park and would be at risk if the dam should fail. The breach discharge would
then impact Glacier Highway. Due to the potential for loss of human life and
the potential for damage, Switzer Creek Dam No. 1 is classifed as High Hazard
Potential.
-3-
2.3 Purpose of Dam: Switzer Creek Dam No. 1 was constructed in 1972 to
provide water supply to the Schneider Scott Mobile Home Park.
2.4 Construction History: Switzer Creek Dam No. 1 was designed by R&M Consul-
tants, Inc. in 1971. R&M maintains a complete set of drawings and copies of
the construction specifications at their office in Juneau. The dam was keyed a
minimum of 10 feet into the dense glacial till abutments and is founded on bed-
rock in the creek channel. Construction of the dam was monitored by R&M. The
dam was constructed in 1972.
2.5 Geology and Soils
2.5.1 Regional Geology: The project area lies within a belt of deformed and
metamorphosed Paleozoic and Mesozoic sedimentary and volcanic rocks which flank
the coast range of southeast Alaska and extend into British Columbia. Following
a vague sequence of geological events including outpouring of lavas, metamor-
phism, uplift and faulting, the area was modified by glaciation and erosion.
The most recent glaciation is believed to have been in the late Pleistocene Time
and the ice receded from the area on the order of 6000 years ago. The ice is
estimated to have been perhaps 3500 feet thick and has considerably modified the
character of the rock and overburden soils.
2.5.2 Site Geology: Switzer Creek Dam No. 1 is on an unnamed stream near
Switzer Creek on the side of Thunder Mountain. The channel is characterized
by very heavy vegetation ranging in size from bushes to very large trees.
Examination of the bedrock visible at the site shows slight surface weathering
and moderately spaced jointing. Test pits conducted during the design show
relatively shallow bedrock but no details on rock quality. Typical of the
local geology, the visible rock appears to be schist with numerous quartz seams.
Bedding planes are rather widely spaced. The somewhat massive nature of the
rock is substantiated by visible rock in the spillway discharge channel. The
rock is fine grained and hard with no adversely orientated joints or obvious
weak seams. Overburden till is fine grained with gravel and dense.
-4-
2.6 Basin Description: The drainage basin is one of many watersheds which
drain excess precipitation and snow melt from Thunder Mountain and Heintzleman
Ridge near Juneau, Alaska. The headwater area begins on steep precipitous
slopes whose peaks reach about 2,500 feet above the reservoir on Thunder Mountain.
Lower elevations of the watershed are covered with dense stands of conifer trees
underlain by a thick blanket of low growing vegetation and a surface mantle of
spongy peat. As elevation increases, vegetation decreases. At about 2,000
feet, vegetation is near non-existent with the soil mantle removed to near bed-
rock by past glaciation. Prevailing maritime storms drench the area with heavy
precipitation during the summer and covers the higher elevation zones with deep
snow in the winter. As the temperature moderates in the spring, snowmelt occurs
leaving the area nearly snowfree by the end of July.
Climatic records for Juneau show a mean annual temperature of 42.8°F with
extremes of +84°F and -2l°F. Average annual precipitation is 92 inches of
rainfall equivalent. Rainfall at over one inch per hour over a several hour
period have been experienced. Under the general classification after Koppen,
the climate in the Juneau area is classified Cfb or Humid Mesothermal. At
higher elevations and on the easterly slopes of the Coastal range, the vegetation
turns alpine reflecting the orographic effect of that range up to elevation 2000
which approximately delineates the tree line. Numerous glaciers and a large
ice field are located just north and east of Juneau.
2.7 Description of Project:
gravel fill dam, Photo No. 1.
Switzer Creek Dam No. 1 is a concrete faced
The dam is approximately 137 feet long including
a 12 feet wide concrete lined chute spillway located at the center of the dam.
The dam is approximately 44 feet high at its highest point. The crest width is
15 feet at elevation 190 and the face slab is 8 inches thick keyed into the
foundation.
An access bridge is provided to a 32 inch diameter outlet pipe upstream of the
dam, Photo No.'s 2, 4 and 5. This slide gate is used to drain the reservoir
for periodic maintenance of the water system intake, Appendix B, Plates II, III
and IV. A six inch water main passes under the dam. The drawings in Appendix
B are original design drawings provided by R&M Consultants, Inc. at the time of
-5-
the inspection. Minor as-built changes were made during construction to meet
site conditions. Among these changes were relocation of the access road on the
left abutment, Photo No. 1. Modifications of the access bridge design, Photo
No. 2, and relocation of the pipe drain outfall to the right ot the spillway
chute, Photo No. 4. A major change is that the spillway crest is only 3 feet
below the top of the dam versus the four feet shown on the drawings.
2.8 Operation and Maintenance: Mr. Virgil Hulse, resident manager of the
Schneider Scott Mobile Home Park, maintains and operates the reservoir and dam.
-6-
3. FIELD INSPECTION
3.1 General: The field inspection of Switzer Creek Dam No. 1 was conducted
on 12 July 1984 by Messrs. A. P. Davis, Jr. and R. J. Tucker of Chas. T. Main,
Inc. accompanied by Messrs. K. J, Cherry and K. B. Hunt and Ms. s. Hunt of
Alaska Department of Natural Resources. Messrs. v. Hulse and J. Woods of the
Schneider Scott Mobile Home Park also accompanied the inspection team. The
Inspection Checklist is included as Appendix "C".
3.2 Reservoir Area: At the time of the inspection, the reservoir was at
elevation 187.1 or 1 inch over the spillway crest. There was a shoreline slide
on the right upstream shore. This appears to be unchanged from photos taken in
August 1979. A view typical of the upstream basin can be seen in Photo No. 2.
The topographic map, Appendix B, Plate I, shows that peaks reaching 2,500 feet
above the reservoir occur within 1.3 miles of the dam.
3.3 Dam
3.3.1 Crest: Switzer Creek Dam No. 1 is a concrete faced gravel fill structure
typical of many current designs. Due to the use of native sand-gravel fill
materials, the dam has flatter slopes than many similar designs. There was no
evidence of settlement, dips or sags in the crest. There was no evidence of
distress along the spillway crest walls at the dam spillway.
3.3.2 Upstream Face: The concrete face slab above waterline was in good condi-
tion. The construction joints around the spillway appeared tight and there was
no evidence of cracking or deterioration of the face slab.
3.3.3 Downstream Face: The downstream face was heavily covered with brush and
small trees which partially obscured the slope from inspection, Photo No. 3.
There was no seepage at the abutment contacts and there was no evidence of sags
or slides on the downstream face. Bedrock was observed in the downstream
channel toe area only at the spillway chute (Photo No. 5).
-7-
3.4 Abutments: Both abutments appear to be dense glacial till. There was no
evidence of erosion or seepage on the downstream abutment contacts. A small
slide area was observed on the right upstream shoreline near the abutment, how-
ever, this appeared unchanged from photos taken in 1979.
3.5 Outlet Works: The access bridge to the outlet stem gate operator is shown
on Photo Nos. 1, 2 and 4. The bridge deck is in need of repair.
3.6 Spillway: Approximately one inch of water was flowing over the spillway
at the time of the inspection (Photo No.'s 3 and 4). The concrete retaining
walls and chute slab appeared in good condition with no misalignments or off-
sets. Spillway discharge impacts on bedrock in the downstream channel (Photo
No. 5) which is hard schist.
3.7 Downstream Channel: The downstream channel was inspected to evaluate
potential hazard to life and property in the hypothetical event of dam failure.
Photo No.'s 7 and 8 show the areas that would be impacted. Photo No. 7 is
looking up the creek channel from a point near the center of the mobile home
park shown in Photo No. 8.
3.8 Instrumentation: There are no records of instrumentation or monitoring
programs at the dam.
4. HYDROLOGY
4.1 History of Flooding: No specific details of past flooding were available.
No general information was found regarding local floods on the creek or in the
area which may have overtopped the dam or caused local damage.
4.2 Probable Maximum Flood: HMR No. 54 "Probable Maximum Precipitation and
Snowmelt Criteria for Southeast Alaska" was used for the PMP/PMF analysis of
Switzer Creek Dam No. 1. The Depth-Area-Duration values as ratios at the 24
hour -10 square mile PMP value were used to determine a regression curve of
total PMP vs. Duration for the 0.41 square mile drainage basin. The incremental
PMP values for 15 minute intervals were calculated and arrayed. A 0.1 inch/hour
loss rate was applied up to the time of maximum incremental rainfall to obtain
rainfall excess values. These rainfall excess values were then applied to the
derived unit hydrograph to obtain the PMF. This gave a PMF peak of 2000 cfs
(when superimposed on a 500 cfs peak snowmelt estimate) and a Creager "C" equal
to 100. Because of the small size of the basin and the lack of data with which
to confirm the unit hydrograph, the Creager "C" was increased to 115 for conser-
vatism to yield the adopted PMF of 2300 cfs. The PMP was estimated at 23 inches
in 24 hours with a peak of 5.25 inches per hour.
-9-
5. HYDRAULIC EVALUATION
5.1 Spillway Adequacy: The project spillway is an uncontrolled crest spill-
way. The spillway crest is a broad crested weir discharging to a concrete
chute on the downstream face of the dam, Photo No. 3. The spillway crest
length is 12 feet with a 12 foot width and 3 foot height to crest of dam. The
spillway is capable of passing 190 cfs at zero freeboard. Based on estimates
of Probable Maximum Flood (PMF) of 2300 cfs, the spillway can safely pass 8.6
percent of the PMF. In the event of a PMF, the dam would be overtopped by
approximately 2.7 feet.
5.2 Flood Routing: Due to the relatively small size of the reservoir, it is
expected that Switzer Creek Dam No. 1 would have little attenuation affect on
major floods. Due to the downstream hazard potential, Switzer Creek Dam No. 1
was evaluated for full PMF.
-10-
6. STRUCTURAL STABILITY
A review of the construction drawings prepared by R&M Consultants, Inc. indi-
cates the dam is conservatively designed in terms of current worldwide practice
for concrete faced rockfill dams. The 2.0H:lV side slopes are conservative for
the sandy gravel material used. The concrete face slab appears properly tied
into bedrock and abutments to form a watertight membrane.
Based on the state of the art for concrete faced rockfill dams, Switzer Creek
Dam No. 1 is adequately stable for all reasonable loading conditions. The
project is located in Seismic Zone 4 of ER 1110-2-1806 dated 16 May 1983, which
recommends a 0.20 g earthquake coefficient. For dry sandy gravel at these
slopes, this presents no stability or settlement problems.
The dam would be overtopped during a PMF event by approximately 2.7 feet. The
sandy gravel shell material would likely erode under such overtopping and sta-
bility of the dam cannot be assured for extreme flood conditions. Reinforcement
of the downstream slope especially at the abutments, provision of additional
spillway capacity and/or emergency warning plans should be studied to insure
safety of downstream residents in the event of a major flood condition.
-11-
7. PRIOR REPORTS
Copies of three design drawings were obtained from R&M Consultants, Inc. These
drawings are included as Plates II, III and IV in Appendix "B". R&M Consultants,
Inc. retains the original drawings and specifications at their Junean office.
A set of four photographs from August 1979 were on file with DNR's Dam Safety
Engineer.
-12-
8. CONCLUSIONS
From this inspection of Switzer Creek Dam No. 1, MAIN presents the following
conclusions:
1. A High Hazard Potential classification is appropriate for this dam
due to the potential for loss of human life in the Schneider Scott Mobile Home
Park downstream of the dam. The reservoir size classification is Intermediate
based on height of dam.
2. The dam and its appurtenances appear in generally good condition and
no emergency remedial work is indicated.
3. Analysis of spillway adequacy indicates the dam can safely pass less
the 9 percent of the Probable Maximum Flood. Overtopping of the dam during
major floods could cause loss of the dam.
4. Additional studies should be conducted to evaluate how the dam would
react under overtopping by a PMF event.
5. The dam appears properly designed and constructed and should be stable
for all reasonable loading conditions with the possible exception of overtopping
during a major flood.
6. Brush and trees on the downstream slope should be removed and con-
trolled to permit regular inspection by owner staff.
-13-
9. RECOMMENDATIONS
1. Brush and trees on the dwonstream embankment slope should be removed
and controlled to permit inspection by owner staff.
2. Additional studies should be conducted to evaluate how the dam would
react to overtopping by a PMF event.
3. The sluice gate should be exercised annually.
4. A procedure should be developed to warn downstream residents in the
event of a developing emergency.
-14-
APPENDIX A
INSPECTION PHOTOGRAPHS: 12 JULY 1984
~o. 2
No.
Switzer Creek No. l
Showing l'pstrenm Face
of nam and Sp il I wav
Switzer Creek No. 1
Reservoir Looking l'pstream
. .
~(). 3
Sp illwav Chute
No. 4
Bridge to Low Level Outlet Stemgate
No. 5
Jnw Level Outlet Pip~
and Toe nf Spillwav
!'/(). 6
Broken l~oadwav llra in P ipl'
Outfall al l'ikt• :\hutmt•!!l
Contact
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Pn\"n...:t r••.uu !! i \'l'r
Chann,•l l'hr,>u>!_h
~!,,hi !,• llnmc· l'.t r k
Photograph
Switzer Creek Dam No. 1 on Left
Switzer Creek Dam No. 2 on Right
Date: 2 June 1982
' Flight: 513
APPENDIX B
PROJECT PLATES
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11
SWITZER CREEK DAM NO. I
GENERAL S1TE MAP
ALASKA DEPT. OF NATURAL RESOURCES ~ 101v. OF LAND AND WATER MANAGEMENT
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ATIVE MAP OF 4
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APPENDIX C
INSPECTION CHECKLIST
. .
• I
APPENDIX E
VISUAL INSPECTION CHECKLIST
!1.A .. 'i:E OF DA..'i:: .SwtfC.(...Y-Crt<-k.. No. i OWNER: 5 <> J J. h (. "' s .J.. u t J/JJ,e.:.
STATE: AlA.) k ""-
COUNTY: C ti-t P.. ... .,.( f3c· YC'-' 1"' l! 1-J"""" '"' t.l
I 2.)1/8 'f DATE INSPECTED: ,J' tJ / y
WEATHER: A~ I~
INVENTORY NO. : If)( 00 I ·=I-&.
HAZARD CATEGORY: l·htj S,
TYPE OF DAM: e~n c..H.h F,~J e•·rft. /d(
TEMPERATURE: s-s-0 ,
POOL ELEVATION: -166' I
TAILWATER ELEVATION: N~·.,~
Directions: Mark au "X" iu the YES or NO colum1.
If an item does not apply, write "NA" in the REMARKS colum1.
ITEM YES NO REMARKS
1. CREST.
a. ~lY visual settlements?
b. Nisaligument?
c. Cracking?
2. UPSTREAM SLOPE.
a. Adequate grass cover?
b. ~1y erosion?
c. Are trees grow11ing on slope?
d. Lom;itudinal cracks?
e. Transverse cracks?
f. Adequate riprap protection?
g. ~1y stone deterioration?
h. Visual depressious or bulges?
i. Visual settlements?
3. DOWNSTREAM SLOPE.
a. Adequate grass cover?
b. ~1y erosion?
c. Are trees growing on slope?
d. Longitudinal cracks?
e. Transverse cracks?
f. Visual depressions or bulges?
g. Visual settlements?
h. Is the toe drain dry? 'V!im;,
i. Are the relief wells flowing? N/11-
j. Are boils present at the toe? ~illiffiJ l--~k~.~I~s~s~e~e~p~a~g-e~~p:r~e~se~t~lt~?~~~~~----~----4~~i~*;-----------------------------
4. ABUTHENT CONTACTS.
a. Any erosion?
b. Visual differential movement?
c. Any cracks noted?
d. Is seepage present?
5. INTAKE STRUCTURE.
a. Do concrete surfaces show:
( 1) Spalliug?
(2) Cracking?
(3) Erosion?
( 4) Scaling?
(5) Exposed reinforcement?
(6) Other?
' I
' I
ITE?1 YES NO REMARKS
----------------------------~---~,-----------------------~ b. Do the joints show:
(1 Displacement or offset?
(2 Loss of joint material?
(3 Leaka~<e?
c. Metal appurtenances?
( 1 (;o_rrosion present?
(2 Breakage present?
(3 Anchor system secure?
a. Is the conduit concrete? IAJ//1 A
b. Do concrete surfaces show:
1 Spalling?
2 Cracking?
3 Erosion?
. 4 Scaling?
(5) Exposed reinforcement?
(6) Other?
c. Do the joints show:
(1) Displ..,,...,.m"'!nt or offset?
(2J Loss of joint material?
3 J Leakage? V
d. Ls the conduit metal? X.
< 1 J Corrosion present? !mmm
2 Protective coatings adequate? Wmmm
3 Is the co11duit misaligned? tmmm
7. STII .. LING BASIN.
a. Do concrete surfaces show:
( 1} Spalling?
2) Cracking?
(3) Erosion?
( 5) Other?
6) ,..,. ....... .,~d reinforcement?
b. Do the joints show:
(l Displacement or offset?
(2 Loss of joint material?
(3 Leakage?
c. Do the energy dissipaters show:
1 Signs of deterioration?
Z Are they covered _with debris?
3 Other?
d. ls the Channel:
l Eroding or backcutting?
2 Sloughing?
3 Obstructed?
e. Is released water:
1) Undercutting the outlet?
(2 Eroding the embankment?
8. SPILLWAY.
a. Does spillway concrete show:
l Spalling?
2 Cracking?
_;; Erosion?
\
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< s) Other 1 gm~m:
(6) Exposed reinforcement?
b. Do the joints show:
(1) Displacement or offset?
(2) Loss of joint material?
(3) Leakage?
c. Do the energy dissipators show:
(1) Signs of deterioration?
(2) Are they covered with debris?
(3) Other?
d. Is the spillway earth cut?
(l) Are slopes eroding? NA
(2) Are slopes slous;hiu."(?
(3) Other?
e. Is the channel:
(1) Eroding or backcutting?
(2) Obstructed?
f. Has released water:
( 1) Eroded the embatlkment?
(2) Undercut the outlet?
(3) Other?
g. Is weir in good condition?
h. Is control at the weir?
9. GATES • .. a. Are the flood ~ates:
(1) Broken or bent? iN/A m~mm
(2) Corroded or rusted? mmm
(3) Periodically maintained? m ~~m I
(5) Date lst operated. Y
b. Is there a low !eve 1 gate? )(
c. Is the low-level gate operational? !H~~m~
10. RESERVOIR CONTROL.
a. Recent upstream development?
b. Slides in reservoir area?
c. Change in reservoir operation?
d. Large impoundment upstream?
11. INSTRUMENTATION.
a. List type(s) of instrumentation.
b. In good condition? i~i' NIA
c. Read periodically? IH I
d. Is data available? iH
Other Comments:
1o -b J111"l<'Y" .sr .• !t.
. .
APPENDIX E
P9 B POD HJt B [32)
STATISTICS I I_ u .. u.J.
MISCDATA
MISC. DATA
tC untinucd)
MISC. DATA
(Cur.tinued)
REMARKS
ENG FORM
1 DEC 77
(49D
4474A
• •
PART II -INVENTORY OF DAMS IN THE UNITED STATES
(PURSUANT TO PUBLIC LAW 92-367)
PJB
SPILLWAY
[46 n
See reverse side for instnJction.s,
G34 D
VOLUME OF DAM
(CY)
!JSD (36~
POWER CAPACITY
(47)
1311 psg (391
OWHER EHGIMEERING BY
[SO) GstD
(531 11540
INSPECTION BY
i40D
FORM APPROVEO
OMB NO. 49-M421
..
110
IDEHTITY
HUMBER
REOUIREM~~~~.:g;:~~i SYMBOL I 1-,-I . I -,-I . I
H4tU [42 D (43 D U44D [450
I48D
COHSTRUCTION BY
(S2U
nss I
AUTHORITY FOR iNSPECTION
• .. . ..
I ~I ~
... IDENTITY w PART I -INVENTORY OF DAMS IN THE UNITED STATES FORM APPROVED .... ... NUMIIER
OMB NO. 49-R0421 t-
(PURSUANT TO PUBLIC LAW 92--J67) "' I J2 31•151~>17 REQUIREMENTS CONTROL SYMBOL ~lx oiCJI 1 l rjL 1 See reverse side lor instructions. OAEN-CWE·-17
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nnn 0 t4 D
POPULAR NAME
ID~(~(~~~~~~!!OHI 1 • 1 1 • r 1 1 1 1 1 t 1 r t 1 t. r r 1 1 .I 1 1 1 t 1 1 r 1 1 1 1 1 I 1 1 1 t r 1 1 1 1 1 t 1 1 L_l_l ~• 1 .I _r .I 1. r _r__r. r.. L.L_t 1 1 L l __ l _I t··J
n•sn U6H Ht7 n n 1s H 19 D Q20D
RIVER OR STREAM POPULATION
LOCATION
2.1c:.!(A H2
STATISTICS
ft28 D
REMARKS B 9
J_/
ENG 1 ~~~17 4474