NAD-ATI 910 D.APPOLONIA CONSULTING ENGINEERS INC PITTSBURGH PA F/ U3/13

NATIONAL DA INSPECTION PROGRAM. GRACETON DAM (NOI I0 NUMBER PA--ETC (U)JUN 80 DACW31-0-C-0022

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OHIO RIVER BASINUNNAMED TRIBUTARY OF TWO LICK CREEK, INDIANA COUNTY

PENNSYLVANIA

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NDI I.D, NO: PA-00279

DER I.D. NO: 32-25

PHASE I INSPECTION REPORT

NATIONAL DAM INSPECTION PROGRAM

D'APPOLONIA CONSULTING ENGINEERS

DACW31-80-C-0022

ELECTE

AUG 15HI

PRI PARM FOR FIDEPARTMENT OF THE ARMY

BALTIMORE DISTRICT, CORPS OF ENGINEERS

BALTIMORE, MARYLAND 21203

BY

®r DAPPOLONIA CONSULTING ENGINEERSfI0 DUFF ROAD

PITTSBURGH, PA. 15235

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PREFACE F

This report is prepared under guidance contained in the RecommendedGuidelines for Safety Inspection of Dams, for Phase I Investigations.

Copies of these guidelines may be obtained from the Department of

the Army, Office of Chief of Engineers, Washington, D.C. 20314.

The purpose of a Phase I investigation is to identify expeditiouslythose dams which may pose hazards to human life or property. Theassessment of the general condition of the dam is based upon visualobservations and review of available data. Detailed investigationsand analyses involving topographic mapping, subsurface investigations,material testing, and detailed computational evaluations are beyondthe scope of a Phase I investigation; however, the inspection isintended to identify any need for such studies which should be

performed by the owner.

In reviewing this report, it should be realized that the reportedcondition of the dam is based on observations of field conditions atthe time of inspection along with data available to the inspectionteam. In cases where the reservoir was lowered or drained prior toinspection, such action, while improving the stability of the dam,removes the normal load on the structure and may obscure certainconditions which might otherwise be detectable if inspected underthe normal operating environment of the structure.

It is important to note that the condition of the dam depends onnumerous and constantly changing internal and external factors whichare evolutionary in nature. It would be incorrect to assume thatthe present condition of the dam will continue to represent thecondition of the dam at some point in the future. Only throughfrequent inspections can unsafe conditions be detected and onlythrough continued care and maintenance can these conditions beprevented or corrected.

Phase I inspections are not intended to provide detailed hydrologicand hydraulic analyses. In accordance with the established Guidelines,the spillway design flood is based on the estimated "ProbableMaximum Flood" for the region (greatest reasonably possible stormrunoff), or fractions thereof. The spillway design flood provides ameasure of relative spillway capacity and serves as an aid indetermining the need for more detailed hydrologic and hydraulic

studies, considering the size of the dam, its general condition and

the downstream damage potential.

The assessment of the conditions and recommendations was made by

the consulting engineer in accordance with generally and currentlyaccepted engineering principles and practices.

i4

I

PHASE I REPORTNATIONAL DAM INSPECTION PROGRAM

NAME OF DAM: Graceton DamSTATE LOCATED: Pennsylvania

COUNTY LOCATED: IndianaSTREAM: An Unnamed Tributary of Two Lick CreekSIZE CLASSIFICATION: SmallHAZARD CLASSIFICATION: Significant

OWNER: Lower Indiana County Municipal AuthorityDATE OF INSPECTION: March 18, 1980 and March 19, 1980

ASSESSMENT: Based on the evaluation of the existing conditions,the condition of Graceton Dam is considered to be poor. A portionof the spillway discharge chute was collapsed, causing erosion onthe embankment side of the spillway discharge channel. An activelandslide on the abutment side of the spillway discharge channel isthreatening to block the channel. Swampy areas and ponded waterbelow the toe of the dam suggest the presence of underseepage

through the embankment. The dam is overgrown with brush and treesup to 1-1/2 feet in diameter, and it appears that it is not beingmaintained. A portion of the downstream slope at the middle of theembankment near the toe level was found to have been excavated. Theowner indicated that the excavation was done in an attempt to locatea blocked supply pipe through the embankment.

The flood discharge capacity of the dam was evaluated according tothe recommended procedure and was found to pass 10 percent of theprobable maximum flood (PMF) without overtopping the embankment.This capacity is less than the recommended spillway capacity rangeof 100-year flood to 50 percent PMF, the upper limit of which isconsidered to be applicable to the dam considering the height of thidam and downstream damage potential. Therefore, the flood dischargecapacity is classified to be inadequate.

The following recommendations should be implemented immediately oron a continuing basis.

1. The owner should immediately retain an .L

experienced professional engineer to prepare SA&and execute plans for the repair and restora- .8tion of the embankment, spillway structures, J0sedand outlet facilities or to develop a pro- ftot1ticedure for orderly abandonment of the dam.Repairs and restoration should include, butnot be limited to, the following work:

A vallWli _c.a,

Dnt e aMee&

a. Conduct additional detailed hydrologicand hydraulic studies to more accurately

ascertain the spillway capacity.

b. Take the necessary steps to preventblockage of the spillway dischargechannel by the active landslide locatedon the left abutment.

c. Provide an emergency drawdown facility.

d. Backfill the excavated portion of the

downstream slope of the embankment andthe low areas on the crest of the dam.

e. Provide adequate surface drainage to the

area below the toe of the dam.

f. Clear brush and trees on the embankment.

2. Around the clock surveillance should be

provided during unusually heavy runoff and aformal warning system should be developed toalert the downstream residents in the eventof emergencies.

3. The dam and appurtenant structures should beinspected regularly and a formal maintenancemanual should be developed for the future

maintenance of the dam.

r 0 >

f pCrj~ NA Lawrence D. Andersen, P.E.Lawrnce . ie \1 Vice President

- r. June 18, 1980

=--; Date

Approved by:

4 AME gWn. PECK

5iii ID)

GRACETON D)AMNDI I.D. PA-279

I DER 1.D. 32-25MARCH 18, 1980

Upstream Face

Downstream Face

iv

TABLE OF CONTENTS

PAGE

SECTION 1 - PROJECT INFORMATION 1

1.1 General 11.2 Description of Project 11.3 Pertinent Data 2

SECTION 2 - DESIGN DATA 5

2.1 Design 5

2.2 Construction 62.3 Operation 62.4 Other Investigations 62.5 Evaluation 6

SECTION 3 - VISUAL INSPECTION 7

3.1 Findings 7

3.2 Evaluation 8

SECTION 4 - OPERATIONAL FEATURES 9

4.1 Procedure 94.2 Maintenance of the Dam 94.3 Maintenance of Operating Facilities 94.4 Warning System 94.5 Evaluation 9

SECTION 5 - HYDRAULICS AND HYDROLOGY 10

5.1 Evaluation of Features 10

SECTION 6 - STRUCTURAL STABILITY 12

6.1 Evaluation of Structural Stability 12

SECTION 7 - ASSESSMENT AND RECOMIMENDATIONS/PROPOSEDREMEDIAL MEASURES 13

7.1 Dam Assessment 137.2 Recommendations/Remedial Measures 13

v

TABLE OF CONTENTS(Cont inued)

APPENDIX A - CHECKLIST, VISUAL INSPECTION, PHASE IAPPENDIX B - CHECKLIST, ENGINEERING DATA, DESIGN, CONSTRUCTION,

OPERATION, AND HYDROLOGIC AND HYDRAULIC, PHASE IAPPENDIX C - PHOTOGRAPHSAPPENDIX D - HYDROLOGY AND HYDRAULICS ANALYSESAPPENDIX E - PLATESAPPENDIX F - REGIONAL GEOLOGY

vi

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9 flPASE I R P RORM-NATIONAL DAM JVISPECTION PROGRAM.

.GRACETO AM - -. (79e ---,

DER I.?3 2-25) 4 '.

SECTION 1 C\PF TECT INFORMATIO -

1.1 General

a. Authority. The inspection was performed pursuant to theauthority granted by The National Dam Inspection Act, Public Law92-367, to the Secretary of the Army, through the Corps of Engineers,to conduct inspections of dams throughout the United States.

b. Purpose. The purpose of this inspection is to determine ifthe dam constitutes a hazard to human life or property.

1.2 Description of Project

a. Dam and Appurtenances. Graceton Dam consists of an earthembankment approximately 250 feet long with a maximum height ofapproximately 26 feet from the downstream toe. The crest width isapproximately 10 feet. A 10-foot-wide berm is located on thedownstream slope at about midheight of the embankment. The down-stream slope of the embankment is approximately 1.5H to IV abovethe berm and 2.5H to IV below that level.

The flood discharge facilities for the reservoir consist of aconcrete overflow structure located on the left abutment (lookingdownstream). The overflow section is approximate!- 15 feet wide and3 feet deep and discharges onto an approximately 30-foot-longconcrete chute.

According to the previous inspection reports, the outlet facilitiesconsist of two cast-iron pipes 4 and 6 inches in diameter. Thelocation of the pipes and the manner in which flow through thesepipes is controlled is unknown. In the design drawings, flow

* through these pipes is shown to be controlled by valves located in avalve chamber on the downstream side of the dam. However, thisvalve chamber could not be located at the site during this inspec-tion. As it presently exists, the dam has no functional emergencydrawdown facilities.

b. Location. Graceton Dam is located on an unnamed tributary•1 of Two Lick Creek approximately one mile east of Coral in Center

O1

Township, Indiana County, Pennsylvania. Plate I shows the locationof the dam.

c. Size Classification. Small (based on 26-foot height and21 acre-feet maximum storage capacity).

d. Hazard Classification. The dam is classified to be in thesignificant hazard category. Below the dam for approximately 1000feet, the stream flows through a narrow uninhabited valley. Then,the valley widens and the stream flows under U.S. Route 119 approxi-mately one mile downstream from the dam. Residential areas of thetown of Coral are located in the vicinity of the Route 119 underpass.It is estimated that failure of the dam may cause loss of a fewlives and property damage in the residential areas of the town ofCoral. It is estimated that flooding in the vicinity of Coral islikely to be shallow.

e. Ownership. Lower Indiana County Municipal Authority(address: Ms. Evelyn J. DeMarines, P.O. Box 444, Black Lick,Pennsylania 15716).

f. Purpose of Dam. The dam was built for industrial watersupply. Presently, the dam is reportedly serving a single customer,

a farm approximately 1000 feet downstream from the dam.

g. Design and Construction History. The dam was designed byC. W. Knight and Sons, engineers from Rome, New York, and built bythe original owner, The Potter Coal and Coke Company, prior to 1917.In 1921, the dam was enlarged by the placement of additional fill onthe downstream face of the dam.

h. Normal Operating Procedure. The reservoir is normallymaintained at the crest level of the uncontrolled spillway. Whenthe lake is at or above the spillway crest level, inflow is dis-charged through the uncontrolled spillway.

1.3 Pertinent Data. Elevations referred to in this and subsequentsections of the report were calculated based on field measurementsassuming the spillway crest level (normal pool level) to be atElevation 1129.2 (USGS Datum), which is indicated to be the normalpool elevation of the reservoir according to the design files andwhich generally agrees with the current USGS topographic maps.Elevations shown in Plate 2 are relative to an arbitrary sites datumwhich is not in conformance with the current USGS datum.

a. Drainage Area 0.65 square mile

b. Discharge at Dam Site (cfs)

Maximum known flood at dam site Unknown

2

IOutlet conduit at maximum pool Not applicable

(i)

Gated spillway capacity at maximum pool Not applicableUngated spillway capacity at maximum pool 149Total spillway capacity at maximum pool 149

c. Elevation (USGS Datum) (feet)

Top of Dam 1131.4(measured lowspot);

1132 (designelevation)

Maximum pool 1131.4Normal pool 1129.2

Upstream invert outlet works UnknownDownstream invert outlet works UnknownMaxim,-- tai 1water Unknown

Toe of Dam 1105+

d. Reservoir Length (feet)

Normal pool level 450Maximum pool level 500+

e. Storage (acre-feet)

Normal pool level 12Maximum pool level 21+

f. Reservoir Surface (acres)

Normal pool level 1.8Maximum pool level 3.7+

g. Dam

4 Type EarthLength 250 feetHeight 26 feetTop width 10 feetSide slopes Downstream:

1.5H:IV(above berm),2.5H:IV(below berm);Upstream:

2H: IV

Zoning Unknown

(")The dam has no functional outlet facilities.

3

Impervious core UnknownCutoff UnknownGrout Curtain None

h. Regulating Outlet(l)

Type 6-inch cast-iron pipe

Length UnknownClosure UnknownAccess InaccessibleRegulating facilities None

i. Spillway

Type Rectangularopen channel

Length 15 feet, 2.8feet deep

Crest elevation 1129.2Upstream channel LakeDownstream channel Earth channel

4

SECTION 2DESIGN DATA

2.1 Design

a. Data Available. The available data consist of filesprovided by the Commonwealth of Pennsylvania, Department of Environ-mental Resources (PennDER), which contain design drawings, limitedcorrespondence, and several past inspection reports.

(1) Hydrology and Hydraulics. The available informationincludes the design capacity-of the spillway.

(2) Embankment. The available information consists of adesign drawing and description of the embankment included in thepast inspection reports.

(3) Appurtenant Structures. The available informationconsists of description of the appurtenant structures included inthe previous inspection reports.

b. Design Features

(1) Embankment. As illustrated in Plate 2, the dam appearsto be a homogeneous embankment. A Commonwealth report dated June 2,1919, indicates that the dam was designed by C. W. Knight and Sons,engineers from Rome, New York prior to 1917. The same reportindicates the embankment material consisted of clay mixed with sandand gravel excavated from the reservoir area. No other informationwas found relative to the design of the dam.

(2) Appurtenant Structures. The appurtenant structuresconsist of an open channel spillway located on the left abutment andan outlet works. The spillway consists of a rectangular overflowsection approximately 15 feet wide and about 3 feet deep, discharg-ing into a 30-foot-long concrete chute. The concrete chute in turndischarges into an earth channel. According to the 1919 Commonwealthreport, the outlet facilities consist of two cast-iron pipes, 4 and6 inches in diameter. No other information was found relative tothe details of the outlet facilities.

c. Design Data

(1) Hydrology and Hydraulics. No design data are available.

(2) Embankment. Other than a design drawing, no engineeringdata are available on the design of the embankment.

5

(3) Appurtenant Structures. No design data are available onthe appurtenant structures.

2.2 Construction. Available records indicate the dam was con-structed prior to 1917 by the original owner, The Potter Coal and

Coke Company. The exact date of construction is unknown. In 1921,the downstream slope of the dam was flattened by the construc-tion of a berm and a toe buttress to remedy a slope failure andseepage problem which existed prior to 1921.

2.3 Operation. There are no formal operating records maintainedfor the dam.

2.4 Other Investigations. None reported.

2.5 Evaluation

a. Availability. The available information was provided byPennDER.

b. Adequacy

(1) Hydrology and Hydraulics. No design information isavailable to assess the adequacy of the spillway.

(2) Embankment. No information is available to assess thestructural adequacy of the embankment.

(3) Appurtenant Structures. No information is available toassess the structural adequacy of the appurtenant structures.

6

SECTION 3VISUAL INSPECTION

3.1 Findings

a. General. The on-site inspection of Graceton Dam consistedof:

1. Visual inspection of the embankment, abutments,and embankment toe.

2. Visual examination of the spillway structures.

3. Evaluation of downstream area hazard potential.

The specific observations are illustrated in Plate 3.

b. Embankment. The general inspection of the embankmentconsisted of searching for indications of structural distress, suchas cracks, subsidence, bulging, wet areas, seeps and boils, andobserving general maintenance conditions, vegetative cover, erosion,and other surficial features.

In general, the condition of the embankment is considered to bepoor. The embankment is overgrown with trees up to 1-1/2 feet indiameter. Swampy areas and ponded water below the toe of the damsuggest the presence of underseepage through the embankment.However, no isolated seepage points were identified. An excavatedarea was found on the downstream slope of the dam located at aboutthe center of the dam at a level halfway between the berm and thetoe level. The owner indicated that the excavation was done in anattempt to locate a blocked supply line through the embankment.The upstream slope of the dam was found to have no erosion protec-tion, such as riprap.

4' The crest of the dam was surveyed relative to the spillway crestelevation and it was found to be on the order of 0.5 to 0.8 footbelow the top of the spillway wall, which appears to be the designcrest level for the embankment. The dam crest profile is illus-trated in Plate 4. The downstream slope was surveyed and the slopeswere found to be reasonably within the design slopes which are 1.5Hto IV above the berm and 2.5H to IV below the berm level.

c. Appurtenant Structures. The spillway structures wereexamined for deterioration and other signs of distress and obstruc-tions that would limit flow. The spillway structures were found tobe in poor condition. A portion of the spillway chute was found tohave collapsed, causing erosion along the toe of the dike which is

7

separating the spillway discharge channel from the embankment. Anactive landslide was observed on the left abutment side of thespillway discharge channel, threatening to block the spillwaydischarge channel. Two railroad rail sections were found installedin the spillway crest extending from the crest level to the top ofthe spillway wall. Apparently, these rails were installed with the

intention of placing flashboards across the spillway. The presenceof these steel sections in the overflow section is considered topose a potential for the blockage of the spillway with debris in theevent of a major flood.

No portions of the outlet works were visible for inspection.

d. Reservoir Area. A map review and visual observationsindicate that the watershed is predominantly covered by woodlands;however, portions have been strip mined. No signs of landslideactivity in the vicinity of the reservoir were found. A review ofthe regional geology is included in Appendix F.

e. Downstream Channel. Below the dam, the stream flowsthrough an uninhabited valley for approximately one mile where itflows under U.S. Route 119 near the town of Coral. A furtherdescription of the downstream conditions is included in Section1.2d.

3.2 Evaluation. The overall condition of the dam is considered tobe poor. The embankment, spillway structures, and outlet facilitiesare in need of repair and restoration or orderly abandonment.

8

SECTION 4OPERATIONAL FEATURES

4.1 Procedure. There are no formal operating procedures for thedam. A it presently exists, the reservoir is normally maintainedat the crest level of the uncontrolled spillway.

4.2 Maintenance of the Dam. The visual observations indicate thatthe dam has essentially been abandoned. Maintenance is nonexistent.

4.3 Maintenance of Operating Facilities. The dam has no visibleoperating facilities. According to the owner, a portion of thedownstream slope of the dam has been recently excavated to locateand clean a blocked supply line through the embankment.

4.4 Warning System. No formal warning system exists for the dam.Telephone communication facilities are available via a farm locatedabout 1000 feet from the dam.

4.5 Evaluation. The visual observations indicate that the dam isessentially abandoned and is no longer maintained.

9

SECTION 5HYDRAULICS AND HYDROLOGY

5.1 Evaluation of Features

a. Design Data. Graceton Dam has a watershed of 0.65 squaremile and impounds a reservoir with a surface area of 1.8 acres at

normal pool level. The flood discharge facilities consist of anopen channel spillway located near the left abutment. The spillwayis approximately 15 feet wide and 2.8 feet deep. The capacity of

the spillway, based on the available 2.2 feet of freeboard relativeto the low spot on the crest of the dam, was determined to be 149cfs, as indicated in the computer output in Appendix D.

b. Experience Data. As previously stated, Graceton Damis classified as a small dam in the significant hazard category.Under the recommended criteria for evaluating emergency spillwaydischarge capacity, such impoundments are required to pass from the100-year flood to one-half PMF. In view of the downstream hazardpotential, the upper limit of the recommended range is considered tobe applicable to this dam.

The PMF inflow hydrograph for the reservoir was determined utilizingthe Dam Safety Version of the HEC-1 computer program developed bythe Hydrologic Engineering Center of the U.S. Army, Corps of Engi-neers. The data used for the computer analysis are presented inAppendix D. The one-half PMF inflow hydrograph was found to have apeak flow of 717 cfs. The 100-year flood, calculated according tothe recommended procedure, was found to have a peak flow of 773 cfs,which is in excess of the one-half PMF peak flow. It appears thatdue to the small watershed, the procedure used for calculating thePMF yields a low estimate for the peak discharge, causing thecomputed 100-year flood to be in excess of 50 percent of the com-puted PMF. Computer input and summary of computer output for thePMF analysis and the 100-year flood calculations are included in

Appendix D.

c. Visual Observations. Although the presence of railsections in the spillway overflow section was considered to pose apotential for blockage of the spillway by debris which would reduce

the spillway discharge capacity, no reduction in the capacity wasconsidered for the purpose of evaluating the adequacy of the spill-way. Similarly, a potential for reduction in the capacity of thespillway exists in the event the spillway discharge channel isblocked by the progressing landslide on the left abutment. As itpresently exists, the landslide is not affecting the capacity of the

spillway.

10

d. Overtopping Potential. Various percentages of the PHFinflow hydrograph were routed through the reservoir, and it wasfound that the spillway can pass 10 percent of the P1F withoutovertopping the embankment. It was found that during the passage of50 percent PMF, the dam would be overtopped for a duration of 9.5hours with a maximum depth of 0.7 foot over the low spot on thecrest of the dam.

e. Spillway Adequacy. The spillway was found to pass 10percent of the PNF, which is less than the required spillway capacityof 50 percent PIF. Therefore, the spillway capacity is classifiedto be inadequate.

11

SECTION 6STRUCTURAL STABILITY

6.1 Evaluation of Structural Stability

a. Visual Observations

(1) Embankment. As discussed in Section 3, although theoverall condition of the embankment was considered to be poor, noneof the observations were found to be serious relative to the overallstability of the dam at this time.

(2) Appurtenant Structures. The spillway structures werefound to be in poor condition and partially collapsed. Ongoingerosion below the toe of the spillway chute is considered to bethreatening the overall stability of the spillway structures. Noportions of the outlet facilities were visible to assess theirstructural condition.

b. Design and Construction Data

(1) Embankment. The available information does not includeany data to aid in the assessment of the structural stability of thedam. However, as previously noted, the deficiencies observed in theembankment were not considered to be serious relative to the overallstability of the dam at this time. Therefore, based on visualobservations, the static stability of the dam is considered to beadequate.

(2) Appurtenant Structures. No information is available toassess the structural adequacy of the appurtenant structures.

c. Operating Records. The structural stability of the dam is

not considered to be affected by the operational features of

the dam.

d. Post-Construction Changes. In 1921, additional fill wasplaced on the downstream side of the dam, forming a 10-foot-wideberm at midheight of the embankment with a 2.5H to IV slope belowthe berm level. This work was undertaken to remedy a slope failureand seepage problem that existed at the time.

e. Seismic Stability. The dam is located in Seismic Zone 1,and based on visual observations, the static stability of thedam appears to be adequate. Therefore, based on the recommendedcriteria for the evaluation of seismic stability of dams, the

structure is presumed to present no hazard as a result of earthquakes.

12

SECTION 7ASSESSMENT AND RECOMMENDATIONS/REMEDIAL MEASURES

7.1 Dam Assessment

a. Assessment. The visual observations indicate thatGraceton Dam is in poor condition. The dam appears to have beenabandoned and is no longer being maintained. The dam crest isirregular up to 0.8 foot below the design elevation. A portion ofthe downstream slope has been excavated. The spillway structuresare in poor condition and have partially collapsed. An activelandslide observed on the left abutment is threatening to block thespillway discharge channel. The reservoir has no functionalemergency drawdown facilities.

In view of the above conditions, it is recommended that the overallcondition of the dam be evaluated by a professional engineer toprepare plans to repair and restore the embankment, spillway struc-tures, and outlet facilities or to develop a procedure for orderlyabandonment. A spillway capacity of 10 percent of the PMF was foundto be less than the recommended spillway capacity of 50 percent ofthe PMF. Therefore, the spillway is classified as inadequate.

b. Adequacy of Information. Available information, in conjunc-tion with visual observations and the previous experience of theinspectors, is considered to be sufficient to make the followingrecommendations.

c. Urgency. The following recommendations should be implementedimediately or on a continuing basis.

d. Necessity for Additional Data. In view of the conditionsdescribed above, the owner should retain a professional engineer toprepare and implement plans for restoration of the dam and toconduct additional hydrologic and hydraulic analyses to provideadequate spillway capacity or develop a procedure for orderlyabandonment of the dam.

7.2 Recommendations/Remedial Measures. It is recommended that thefollowing recommendations be implemented immediately or on acontinuing basis:

1. The owner should immediately retain anexperienced professional engineer to prepareand execute plans for the repair and restora-tion of the embankment, spillway structures,and outlet facilities or to develop aprocedure for orderly abandonment of the

13

dam. Repairs and restoration should include,

but not be limited to, the following work:

a. Conduct additional detailed hydrologicand hydraulic studies to more accuratelyascertain the spillway capacity.

b. Take the necessary steps to preventblockage of the spillway discharge

channel by the active landslide locatedon the left abutment.

c. Provide an emergency drawdown facility.

d. Backfill the excavated portion of thedownstream slope of the embankment andthe low areas on the crest of the dam.

e. Provide adequate surface drainage to thearea below the toe of the dam.

f. Clear brush and trees on the embankment.

2. Around the clock surveillance should be

provided during unusually heavy runoff and aformal warning system should be developed to

alert the downstream residents in the eventof emergencies.

3. The dam and appurtenant structures should beinspected regularly and a formal maintenancemanual should be developed for futuremaintenance of the dam.

14

APPENDIX A

CHECKLISTVISUAL INSPECTION

PHASE I

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APPENDIX B

CHECKLISTENGINEERING DATA

DESIGN, CONSTRUCTION, OPERATIONAND HYDROLOGIC AND HYDRAULIC

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CHECKLISTENGINEERING DATA

HYDROLOGIC AND HYDRAULIC

DRAINAGE AREA CHARACTERISTICS: 0.65 square mile

ELEVATION, TOP OF NORMAL POOL AND STORAGE CAPACITY: 1129 (12 acre-feet)

ELEVATION, TOP OF FLOOD CONTROL POOL AND STORAGE CAPACITY: 1131 (21 acre-feet)

ELEVATION, MAXIMUM DESIGN POOL: 1132

ELEVATION, TOP OF DAM: 1132 (as designed); 1131.4 (measured low spot)

SPILLWAY:

a. Elevation 1129.2

b. Type Concrete overflow section

c. Width 15 feet (perpendicular to flow)

d. Length Not applicable

e. Location Spillover Adjacent to spillway

f. Number and Type of Gates None

OUTLET WORKS:

a. Type 6-inch cast-iron blow-off pipe

b. Location Unknown

c. Entrance Inverts Unknown

d. Exit Inverts Unknown

e. Emergency Drawdown Facilities Not functional at this time

HYDROMETEOROLOGICAL GAGES:

a. Type None

b. Location None

c. Records None

MAXIMUM NONDAMAGING DISCHARGE: 150± cfs (existing spillway capacity)

Page B5 of 5

APPENDIX C

PHOTOGRAPHS

LIST OF PHOTOGRAPHSGRACETON DAM

NDI I.D. PA-279DER I.D. 32-25MARCH 18, 1980

PHOTOGRAPH NO. DESCRIPTION

1 Crest (looking west).

2 Spillway.

3 Spillway discharge channel (lookingupstream). Note tilting trees(landslide).

4 Downstream face (looking upstream).A recent excavation on the downstreamface.

:t4

Photograph No.

Ci-. 's (I ook ing wes;t).

ide

ro '4

L AA

Photograph No. 3

ischarg- channei (looking upstream)

.. ote tilting trees (landslide).

iPho t graph No.4

iin ~c (l onkint q),trumn). A recent' dlt ((own.strcuam fac.

APPENDIX D

HYDROLOGY AND HYDRAULICS ANALYSES

HYDROLOGY AND HYDDRAULIC ANALYSISDATA BASE

NAME OF DAM: Graceton Dam kWD1 I.D. PA-279)

PROIABLZ AXIMU4IM PRECIPITATION (pWq) - 21.8 INCUS/24 NWOURS1

STATION 2 2

Station Description LakDm

Drainage Area (square 0i.es)6

Cumulative Drainage Area(square miles) 0.6 0.6

Adlustment of PHF 4yr (ZONE 7)Drainage Area (1)

6 Hours 102

12 Hours 120

24 Hours 110

48 Hours 140

72 Hours -

Snyder HydrographParameters

Zone(3

) 241 C/ t (4) -

(a (i les)( 5 1

)

L a (wiles)( 5)

tp " Ct(L*lca)

(hours) f, -

Spillway Data

Crest Length (it) - 14.8

Freeboard (It) - 2.8

Discharge Coefficient - 3.1(6)

Exponent - 1.5

i IHydrom teoro cal Report3 (Figure I), U.S. Army, Corps of Engineers, 19 h.(2)Hydrometeorolo Ical Re ort 13 (Figure 2). U.S. Army. Corps of Engineers. 1956.

(3)Hydrological zone defined by Corps of ingineers, Baltimore District, for determining Snvder'sCoeff h irty (Cp and C .

('Snyder' Coefficients.

S(5)L - Length of longest water course from outlet to basin divide.( Lca - Length of water course from outlet to point opposite the centroid of drainage area.

Assumed based on field observations.

STORAGE VS. ELEVATION

ELEVATION AN. FlEET AREA () A VOUME (2) STORAGE(ACRES) (1 (ACRE£-FEET) I (ACRE-FEET)

1129.263 )

1081 3.8 0

1140.0 ... 3.7 43.8

(llplantmetered frol USCS maps.

(2AVolume - A I (A, + A2 + ,Al'2).

(3)Normal po1 elevation.

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.1 APPENDIX E

K2 ALLEGHENY RIVEKZ-1 lJO n dian County V A NEA'

0'

MONO AHELA RIVER PHILADELPHIA

'Sw KEY PLANCIO

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0.5FT. ABOVE SPILLWAY CREST FIELD INSPECTION NOTESFIELD INSPECTION DATE: MAR. 18,1980

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APPENDIX F

REGIONAL GEOLOGY

APPENDIX F

REGIONAL GEOLOGYGRACETON DAM

Graceton Dam is located in the eastern area of the AppalachianPlateau Province which is characterized by broad, nearly levelridges and deep steep valleys. Strata east of the dam have beenmildly folded to form the Chestnut Ridge Anticline which trends to

the northeast. Strata dip away from the axis toward the northwestand southeast at about three to four degrees.

The dam lies near the contact of the Allegheny and Conemaugh groups,both of Pennsylvanian Age. The Allegheny is about 295 feet thickand is composed of massive sandstones and several beds of limestoneand fire clay. It contains many coal beds, four of which are

economically minable. The Conemaugh Group is about 650 feet thickand consists of shales of various colors interbedded with coarse

sandstones, thin limestones, and several coal beds.

The Upper Freeport Coal has been strip mined extensively in thevicinity of the dam and to the east along the flanks of ChestnutRidge.

I IN

~Cummings Dom

~~ampe Run Dom

La>

L -e

..,~Elroy Face Da

\Graceton Dam.- Edwards Dom '

CUMMINGS, SAMPLE RUN,ELROY FACE GRACETON

SCALEAND EDWARbS DAMS

0S l0ifmiles GEOLOGY MAPREFERENCE

GEOLOGIC MAP OF PENNSYLVANIA PREPAREDBY COMMONWEALTH OF PENNA, ,PT.Of INTERNAL I Ir 22 01 OAFFAIRS, DATED 1960, SCALE I ur 4 MILES

LEGEND

I[ ] Conemasugh Formation Marcellus FormationF - J C_ lee e l btf red ad r.a :Ie;s ..lle jk.h f;. . r..h........e. hlepe ltA

malt enasler. he , ne tm d~etn. gnarl ehi l etiutl 1k eedytP ee l ~lee tpe.amnnI v-&a -,e ii hi.. Am. L-e..a#

ou . he enondtga Formation ..e

6--ifr$h& ,. b,;dd, ti darkb l u e i e m a t - - 6d 4 4 " P e n l

d e t , n

IKlur ,2herl -a- L.-mta, and %ee.

Pottsville ,;roup|,,,, e , .eve Iee r1 en l neerina

Wills Creek FormationAllegheny (Ireat thin bdded, eAc.0 thal.

luth l,'.n -0- ad .ndt.ne .oneo..Te mt',,e. t.,,. h,, '.. ,ont.,n red thal, and eltan. en the

e. . l, .t ,,..! . t.. , -t

.. ret".

Bloomshurg Formation

Rd, then and tchk bedded shael and Welt. sMa.- wh hc Ul . aad~ot-anthen iaeeere lenime atone. m greet tai.l

r>Cinton nroup plarte.

'A,~lk!lp . 'ect r ,,t t , tee terd nu e.ntn. keepntenieea e

m,,flu,,,b, (,e.nneel,..tent, teeth eeeeitl

,, , McKenie Formation

t, i1 Oris, '.. ,/t--,,ll It,,l'.,ll l ,,r r ay Irlthil fe ddelf~re t h eek bed-

4 ! - ec, I ? 4 . -q tS~,edld .rytth eler. thn bdlar len er.

S l t ecUce" l,*t ce-I'etel. I tec ,, h el ,.,r , u peer~n. e itt e le at teondetc.l and fDekro Te , h iee,, -tee .~lrI ,'*lle eetteecte? tren i tt i. ~tlfoat. Crell l

Aray, highly Inneid the .ddd

Mu-e p.rt Ah-nt -n Mtrr-bl-rp g..~d.

Precin- t i tc etr tect :,,,2., Keyser Formation[ ,,I. ,, - - , .e,,,, " . ,, ,o h, ,0 [ork prav, h~ohlvlf lfru thek W .d

q,,t /.,. : h •.... ~t. lnrtr, ill. 'ee rM l eentn . intemeec entrat~ci~dd teee~le~ nI- l "nent Itne ha en

te te-e -h t f-.t east..an D k*ttt'tt'el, ,r ,, A tote Im* . e/',',par l~lM~pII ndt( $dD rhconi) (rmap Tonoow y Formationfl, rtAl h ltttt, th. be dd d,

t*/,*te~~~~~t- IN-,-,,,* .%'h,, &,dol' a',l: ,t,

.... .. ........ ..... . ... ....... t..r e r e e

Catskill FormationCh:,fll r.-d h,o br . 1- ahll d .. nd.of,, .S n .d-lt orow and vr- -llh .1-1,

()riikany eiermeltien s.,e, tecgtw nnmre I.- lk Moautnn.M -4tietlr Shtheela. and Delawnar. R er

1.. fet ,. p eel .. . ... , . t

"1 I1(,l'l t l '. [tr u ctt

iltet I' ile * *. . tee ~lte ,'h~le tel, l

GEOLOGY MAP LEGENDREFERENCE:

GEOLOGIC MAP OF PENNSYLVANIA PREPAREDBY COMMONWEALTH OF PENNA. DEPT. OF INTERNAL e Db If'I bD fltNW AAFFAIRSDATED 160, SCALE 11b4 MILES arta a Or Ar N "