AO-A109 966 METCALF AND EDDY OF NEW YORK INC NY F/6 ... · ao-a109 966 metcalf and eddy of new york inc ny f/6 13/13 national dam safety program. potters falls dam (inventory numbe--etc(u)

AO-A109 966 METCALF AND EDDY OF NEW YORK INC NY F/6 13/13NATIONAL DAM SAFETY PROGRAM. POTTERS FALLS DAM (INVENTORY NUMBE--ETC(U)SEP 81 S P FULTON DACW51-81- -0044

UNCLASSIFIED NL

I ,EEhhE=,lfillIImIIIIIBII,IIIIIIIIIIIIIBI EEEEEIIIIIIIII IIIIIIEEEEmEEEEEEEEEEEEE

IF

SECURITr CLASSAIaICATfO 7013H PACE (W40-. 0.1. -i,,

REPORT DOCUMENTATION #AGLf REAL) 1I43TRUUUONSb:__FOR CO.%,PLFTrtN 1-2M

I. EPOft NUMObbR 12. covr AccESSIoN 4Q] i I R4C4P1r6'S Cx-TALf0 :4tiM.

4. TITL (end 3blide)t WpE OF PrEPORT 6 i'l kiD -OVEREOPhase I .*pciriRpr Phase I .hn-pec : -,7 F ±portPotters Falls.Dar' '-JnlDmSf-y rsaOswe.. River Basin, 'Tompkins County Ny . RE .T"rj*Kk, ORC. P~R U CJPT)VEP

Inventory No. 378

7. ^5 rHof()no.38rajRtrtIjB

GEORGE P. FULTON DAW578 -- 4

.PEaRoooomW oncGAblzAirsoi. SAME AND AO ESS E **,.~ k5Metcalf hnd Eddy of New York, Inc, .

60 East"42nd Street'*New York,-New York 100017L EII C___

it*:HJoiUOoFFICE NAME AN'D ArlORiESS 0,47'r.

Dprma.of the Army ' _3____eme 1826. Federal. Plaza,-New York U-i .tiict, 2ofE i% u~isnflVAGE

New York, New-Yor- 10287 ________

14. NOWTORING AGShCY "AMR It AODRESQif diIIervaI frrgw Conti'llhfug Office) is. Sscuaj-y C:L^SS. (of L).I, r-pat

Department of the Army

*New York, ,NY 10287 -~Is&. DECLASSfFICX-TIOHOOW"GPAk*

IS. DISrR,3uTICc4 STArEmE?.r (of thf- R-pofl)

Approved for public release; Distribt(;:ian iil-

17. DISTA13UT1O.4 STAT~ F I l'-,'ftl h ---

19. KIEV WORDS (Ceftllma on uvwaa side u1 neseemAry and td~flfy by block Ana.et)

Dam SafetyPotrFlspnNational Dams Safety Program Oswego River BsmVisual Xftspecticn- T'~mpkins Cot- -._

Hydrlog, StuctralStability

This report provides information and analysis on hl& ph.-IsicaL c ad* toa of Ll%:-Se~m as of the report date. Information. aid analysis are based o~t y-.suaLIapectio. of the daim by the perfo,-W. g organization.

Vsual ins~pection of .4 dir i~ A ~ ne2, ~.performed revealed ti several deiince xist onLhi t rucs

I " 17) " "71 vI r. -, Li/

ECII41TV CLAIPICA 11-19 OF I HIS PAE"W bat

The worst of these deficiencies was the localized spalling and erosior, Ifthe gunite covering the dam. This was observed i. three areas on the do.-.stream !ace and toe. A more thorough examination uf thc gunite when thor.,there is no discharge over the spillway is needed to evaluate the extent andcause of this deterioration. If the gunite is not repaired, the interior cors-crete of the dau, will bec:ome exposed to erosion.

Using the Corps of Engineer's Guidelines for the initial review ofspillway adequacy, it has been determined that the structure would be ovcr-topped by all storms exceeding 31 percent of the Probable Maximum Flood (PMFDuring a one-half PMF storm, the abutments of the dam would be overtoppedby 3.4 feet. The dam is a concrete arch-gravity Aructure with bedrock atboth. abutments. While overtopping-is not likely to induce failure fromerosion, a stability analysis indicates that the factor of safety is belowthe reccl,,!,mended level during the one-halt PMF stori,, If the dam were tofail, it would increase the degree of flooding in downstream residertieiareas. t{h-*efore, thc spillway is assessed as seriously inadequate. -"

4'

SECU1II'Y (.LA 'I *I.,\ .t)14 (1I T~IM, PA(-t (WI,*1 Pa.. h'., J)

DISCLAIMER NOTICE

THIS DOCUMENT IS BEST QUALITYPRACTICABLE. THE COPY FURNISHEDTO DTIC CONTAINED A SIGNIFICANTNUMBER OF PAGES WHICH DO NOTREPRODUCE LEGIBLY.

i

OSWEGO RIVER BASIN

POTTER'S FALLS DAM

TOMPKINS COUNTY, NEW YORKI INVENTORY NO. NY 378

PHASE I INSPECTION REPORT~ I NATIONAL DAM SAFETY PROGRAM

.PPROVED FOR PUBLIC 'RELEAQCz;

01158 05NEW YORK DISTRICT CORPS OF ENGINEERS

1 AUGUST 1981

IIJ

..... ..... U " _ _,_ _ __,_ _ _ _

PREFACE

This report is prepared under guidance contained in the Recommended

Guidelines for Safety Inspection of Dams, for Phase I Investigations.Copies of these guidelines may be obtained from the Office of Chief ofEngineers, Washington, D.C. 20314. The purpose of a Phase I Investigationis to identify expeditiously those dams which may pose hazards to human lifeor property. The assessment of the general condition of the dam is basedupon available data and visual inspections. Detailed investigation, andanalyses involving topographic mapping, subsurface investigations, testing,and detailed computational evaluations are beyond the scope of a Phase IInvestigation; however, the investigation is intended to identify any needfor such studies.

In reviewing this report, it should be realized that the reported con-dition of the dam is based on observations of field conditions at the timeof inspection along with data available to the inspection team. In caseswhere the reservoir was lowered or drained prior to inspection, such action,while improving the stability and safety of the dam, removes the normal loadon the structure and may obscure certain conditions which might otherwise bedetectable if inspected under the normal operating environment of the struc-ture.

It is important to note that the condition of a dam depends on numerousand constantly changing internal and external conditions, and is evolution-ary in nature. It would be incorrect to assume that the present conditionof the dam will continue to represent the condition of the dam at some pointin the future. Only through frequent inspections can unsafe conditions bedetected and only through continued care and maintenance can these conditionsbe prevented or corrected.

Phase I inspections are not intended io provide detailed hydrologicand hydraulic analyses. In accordance with the established Guidelines, andSpillway Test flood is based on the estimated "Probable Maximum Flood" forthe region (greatest reasonably possible storm runoff), or fractions thereof.Because of the magnitude and rarity of such a storm event, a finding that aspillway will not pass the test flood should not be interpreted as neces-sarily posing a highly inadequate condition. The test flood provides ameasure of relative spillway capacity and serves as an aide in determiningthe need for more detailed hudrologic and hydraulic studies, considering thesize of the dam, its general condition and the downstream d mage potential.

AecasQto:n For

i I................N7

rT K

SPECTED

PHASE I INSPECTION REPORTNATIONAL DAM SAFETY PROGRAM

POTTER'S FALLS DAMI.D. No. 378# 75A-717

OSWEGO RIVER BASINTOMPKINS COUNTY, NEW YORK

TABLE OF CONTENTS

PAGE NO.

- .ASSESSMENT

- OVERVIEW PHOTOGRAPH

1 PROJECT INFORMATION 1

1.1 GENERAL 1

1.2 DESCRIPTION OF PROJECT 1

1.3 PERTINENT DATA 2

2 ENGINEERING DATA 4

2.1 GEOTECHNICAL 4

2.2 DESIGN RECORDS 4

2.3 CONSTRUCTION RECORDS 4

2.4 OPERATION RECORDS 4

2.5 EVALUATION OF DATA 4

3 VISUAL INSPECTION 6

3.1 FINDINGS 6

3.2 EVALUATION OF OBSERVATIONS 7

4 OPERATION AND MAINTENANCE PROCEDURES 8

4.1 PROCEDURES 8

4.2 MAINTENANCE OF DAM 8

4.3 WARNING SYSTEM IN EFFECT 8

4.4 EVALUATION 8

Elil

PAGE NO.

5 HYDRAULIC/HYDROLOGIC 9

j 5.1 DRAINAGE AREA CHARACTERISTICS 9

5.2 ANALYSIS CRITERIA 9

5.3 SPILLWAY CAPACITY 9

5.4 RESERVOIR CAPACITY 9

L5.5 FLOODS OF RECORD 9

5.6 OVERTOPPING POTENTIAL 10

5.7 EVALUATION 10

6 STRUCTURAL STABILITY 11

6.1 EVALUATION OF STRUCTURAL STABILITY 11

7 ASSESSMENT/RECOMMENDATIONS 13

7.1 ASSESSMENT 13

7.2 RECOMMENDED MEASURES 14

I APPENDIX

A. PHOTOGRAPHS

I B. VISUAL INSPECTION CHECKLIST

C. HYDROLOGIC/HYDRAULIC ENGINEERING DATA AND COMPUTATIONS

* D. STRUCTURAL STABILITY

E. REFERENCES

F. PREVIOUS INSPECTION REPORTS

I G. DRAWINGS

I,

II[, , A

I

PHASE I REPORTNATIONAL DAM SAFETY PROGRAM

Name of Dam: Potter's Falls Dam (I.D. No. NY 378)

I State Located: New York

I County: Tompkins

Watershed: Oswego River Basin

Stream: Sixmile Creek

Date of Inspection: July 8, 1981

A$SESSMENT

11 Visual inspection of this dam and engineering analyses which have beenperformed revealed that several deficiencies exist on this structure.

The worst of these deficiencies was the localized spalling and erosion ofthe gunite covering the dam, This was observed in three areas on the down-stream face and toe. A more thorough examination of the gunite when there-there is no discharge over the spillway is needed to evaluate the extent andcause of this deterioration. If the gunite is not repaired, the interior con-crete of the dam will become exposed to erosion.

Using the Corps of Engineer's Guidelines for the initial review ofspillway adequacy, it has been determined that the structure would be over-topped by all storms exceeding 31 percent of the Probable Maximum Flood (PMF).During a one-half PMF storm, the abutments of the dam would be overtoppedby 3.4 feet. The dam is a concrete arch-gravity structure with bedrock atboth abutments. While overtopping is not likely to induce failure fromerosion, a stability analysis indicates that the factor of safety is belowthe recommended level during the one-half PMF storm. If the dam were tofail, it would increase the degree of flooding in downstream residentialareas. Therefore, the spillway is assessed as seriously inadequate.-

Within three months of the receipt of this report, the owner shouldcommence a more detailed stability analysis. Further hydraulic/hydrologicstudies are needed to accurately determine flood reservoir levels. Additionalinspection and evaluation of the deteriorated gunite is also required. Theowner should exercise the gate on the low-level outlet and maintain it ingood operating condition. Remedial measures deemed necessary as a resultof these studies should be completed within 18 months.

1

I Other deficiencies as outlined below should be corrected within 12 monthsof the date of notification of the Owner:

1 1. The operating condition of the sluice gate on the low-level outletshould be tested and repaired as necessary for dependable operation.

2. The deteriorated concrete on the abutments should be repaired, andthe brick facing replaced or repaired as necessary.

1 3. Vegetation growing on the abutment should be removed.

4. The concrete sill on the weir should be repaired to prevent furtherleakage beneath it.

5. Any open joints in the spillway should be repointed, particularly inthe area of heavy efflorescence.

6. An emergency action plan should be developed for the notificationand evacuation of downstream resident.

Edward M. Greco, P.E.Project ManagerMetcalf & Eddy of New York, Inc.Newabrk Registi No. 47463

Seorge/P, Fulton; P.E.

Vice PresidentMetlf & Eddy of ew York, Inc.N Yrk isra on No. 22390

Approved By:

New York strict Engineer

II

Date: t -/

r

I

* p..

OVERVIEW

Po'Fi 'S FALLS DAMNY ID) NO. 378

SO

I

PHASE I INSPECTION REPORTNATIONAL DAM SAFETY PROGRAM

POTTER'S FALLS DAMI.D. No. NY 378

# 75A-717OSWEGO RIVER BASIN

TOMPKINS COUNTY, NEW YORK

I SECTION 1: PROJECT INFORMATION

1.1 GENERAL

I a. AuthorityThe Phase I inspection reported herein was authorized by the Departmentof the Army, New York District, Corps of Engineers, fo fulfill the re-quirements of the National Dam Inspection Act, Public Law 92-367.

b. Purpose of InspectionIThis inspection was conducted to evaluate the existing conditions of thedam, to identify deficiencies and hazardous conditions, to determine ifthese deficiencies constitute hazards to life and property, and torecommend remedial measures where required.

1.2 DESCRIPTION OF PROJECT

Ja. Description of DamPotter's Falls Dam, locally known as the 60 Foot Dam, impounds the IthacaReservoir used as a water supply for the City of Ithaca. The dam is aconcrete gravity structure that is arch-shaped in plan view. A spillwayweir is centrally located on the top of the dam, and a low-level outletis located at the base. On the upstream side, there is a gatehouse con-taining mechanisms to operate valves on the water supply line and thelow-level outlet.

The dam is 220 feet long with a maximum height of 70.5 feet. It is con-j structed of cyclopean concrete covered with gunite and mesh. The top

width is 8.5 feet. The upstream face of the dam is vertical and thedownstream face is 0.7 to 1 (horizontal to vertical).

I The spillway is a 100-foot long, ungated ogee weir. Discharge flowsonto the downstream face of the dam and into a 100-foot wide bedrockgorge.

A 72-inch cast iron pipe passes through the base Of the dam and servesas the low-level outlet. The pipe is 45.5 feet long. Flow is controlledby a gate at the upstream end of the pipe. The gate is operated fromthe upper level of the gatehouse.

A 24-inch cast iron pipe passes through the right abutment of the damand serves as the water supply line. The pipe extends from a wet wellin the lower level of the gatehouse to the treatment plant 9,400 feet5 downstream. Flow is normally regulated at the treatment plant, however,

L1

I-,L , -- . ... .. 2. . . . . .... . . . . . . ... . "

I

there are also two gates on the pipe in the gatehouse. One is at theupstream end of the pipe and the other is on the opening into the wetwell. Both are operated from floor stands in the upper level of thegatehouse.

b. LocationThe dam is located on Sixmile Creek about 2.5 miles southeast of down-town Ithaca. An unpaved road that leads to the dam is located offRoute 79, 0.3 miles south of the junction with Route 174.

c. Size ClassificationThe dam is a maximum of 70.5 feet high and has a storage capacity of1,290 acre-feet. Therefore, the dam is in the intermediate size categoryas defined by the "Recommended Guidelines for Safety Inspection of Dams".

d. Hazard ClassificationThe dam is classified as "high" hazard due to the presence of densecommercial and residential development adjacent to the stream bed in theCity of Ithaca, about 2.5 miles downstream.

e. OwnershipThe dam is owned by the City of Ithaca and operated by personnel fromthe Department of Public Works - Water and Sewer Division. Mr. PhillipCox, City Engineer was contacted concerning the Phase I Inspection. Hisaddress is City Hall, 108 East Green Street, Ithaca, New York 14850.

f. Purpose of Dam

The dam is a water supply reservoir for the City of Ithaca.

g. Design and Construction HistoryThe dam was constructed in 1911. Drawings were prepared in 1910 andsigned by Donald F. McLeod, City Engineer. Specifications are not avail-able, and the name of the construction contractor is unknown. By 1925,siltation had decreased the storage capacity of the dam by 12 percent.The Silt Dam was therefore constructed 3,500 feet upstream to controlsiltation. In 1939, a covering of gunite and mesh was placed over theentire dam. There are no drawings or construction data available forthat work.

e. Normal Operating ProceduresI There are no regular operating procedures at the dam. The gate on thelow-level outlet has not been operated since 1959 when the reservoirwas drained to inspect for siltation. The gates on the water supplypipe are operated once or twice a year to dewater the wet well and cleanthe screens in the gatehouse.

1.3 PERTINENT DATA

a. Drainage Area (sq. mi.) 45.6

9 2

" 2 . .... ..... . . . . .i

I b. Discharge at Dam (cfs)Concrete Spillway-water surfaceat top of dam 10,450

72-inch Outlet-water surface atcrest of spillway 1,044

c. Elevation (Plan Datum)Top of Dam 715.5Spillway Crest 705.0Invert of 72-inch outlet pipe 647.0Invert of 24-inch water pipe 665.0

d. Reservoir (Surface Area) (acres)Top of Dam 47Spillway Crest 47

e. Storage Capacity (acre-feet)Top of Dam 1,290Spillway Crest 800

f. DamType: cyclopean concrete gravity dam, arch in plan, surface cover-

ing of gunite and meshLength (ft) 220Slopes (V:H) Upstream Vertical

Downstream 0.7:1Crest Width (ft) 8.5

g. SpillwayType: Concrete ogee overflow weirLength of Weir (ft) 100

h. Low Level OutletType: 72-inch cast iron pipe through dam, 45.5 feet long, gate

controlling flow at upstream end of pipe, operating mechanisminside gatehouse

k. Appurtenant Structures24-inch cast iron water supply pipe through dam at right abutment,9,400 feet long, two gates at upstream end (gatehouse), but flowis controlled at downstream end (treatment plant)

13

I

I,

SECTION 2: ENGINEERING DATA

2.1 GEOTECHNICAL DATA

a. GeologyPotter's Falls Dam is located in the Southern New York Section of theAppalachian Plateaus physiographic province. The bedrock in th4s areaconsists of shales, siltstones, and sandstones that have been Uplifedand gently folded into regional basin structures. The bedrock at thedam is a dark gray, thin bedded shale with prominent vertical jointsthat form the steep walls of the gorge below the dam. A review of the"Geologic Map of New York" indicated that there are no faults in thevicinity of the dam.

Surficial soils in the area are the result of glaciations during thePleistocene Epoch, the last of which was the Wisconsin glaciation.

b. Subsurface InvestigationsThere are no records of any subsurface investigation for Potter's FallsDam. Continuous bedrock outcrops are visible at the abutments andalong the base of the dam.

2.2 DESIGN RECORDS

Design plans were prepared in 1910 under the direction of the CityEngineer for the City of Ithaca. These were the only design recordsavailable.

2.3 CONSTRUCTION RECORDS

This dam was constructed in 1911. The name of the contractor is unknown,and there are no as-built drawings available. There was some correspon-dence available concerning the construction. Personnel from the NewYork State Conservation Commission inspected the structure about halfwaythrough construction. The principal comment made by the ConservationCommission was that the concrete was not of good quality, containing toomuch coarse aggregate (3/8 to 3/4 inch crushed shale) and not enoughsand. The sand fraction was increased as a result of this comment. Therewere no records of significant changes made in the design of the damduring construction.

2.4 OPERATION RECORDS

The only operation records available are hydrographs of the height ofthe reservoir above the crest of the spillway for the years 1939through 1944.

2.5 EVALUATION OF DATA

Information used for the preparation of this report was obtained fromthe Department of Environmental Conservation files and from the City of

4

AMA

Ithaca's Water and Sewer Division files. The information available

appeared to be reasonably accurate. The plan datum agrees with eleva-tion given on U.S. Geological Survey quadrangle maps.

III!

III

II

IL

III5

SECTION 3: VISUAL INSPECTION

3 3.1 FINDINGS

a. GeneralVisual inspection of Potter's Falls Dam was conducted on July 8, 1981.The weather was sunny with the temperature around 90 degrees. The waterlevel at the time of the inspection was slightly above the crest to thespillway.

b. DamInspection of the dam was hampered by the flow of discharge over thespillway and by the lack of access to the abutments on the downstreamside of the dam.

Spalling and erosion of the gunite and mesh covering the dam has occurredin the following areas on the downstream face:

1. left abutment - halfway down2. bottom of face - from outlet opening to left abutment3. downstream toe - right abutment

IA large bulge in the gunite is also visible on the downstream face oppo-site the level of the water pipe. There are hairline cracks with slightefflorescence in many areas on the dam. This deterioration could becaused by flowing water, freezing and thawing, seepage through the dam,improper construction techniques or materials, or a combination of thesefactors.

Minor seepage indicated by wet areas on the bedrock face was observed$at both abutments on the downstream face of the dam. At the left

abutment, the wet area is larger, extending from the top to about half-way down. There is no visible flow in the wet areas, and the bedrockis intact. It is likely that this seepage is occurring along nearlyhorizontal bedding planes in the bedrock.

1Brush and trees are growing on the upstream side of both abutments ofthe dam.

c. SpillwayThe spillway weir is in satisfactory condition. No voids or crackswere visible. The crest is clear of obstructions.

I d. Low-Level OutletThe low-level outlet was partly submerged and only visible at the down-stream end. This end of the pipe is clear of debris and silt. To in-spect the pipe further, it should be dewatered and ventilated.

e. Water Supply PipeThe water supply pipe is mostly embedded in concrete or in bedrock. Theconcrete around the pipe just downstream of the dam is moderatelyeroded. Where the pipe is visible farther downstream, it is in satis-

* factory condition.

6

iI

m f. GatehouseThe gatehouse is in fair structural condition. There are some thinvertical cracks in the walls and localized spalling of the concrete atthe water line. Inside, the floor stands for operating the gates on thelow-level outlet and the water supply pipe are intact.

Sg. Reservoir

There were no indications of slope instability in the reservoir area.

h. Downstream ChannelThe channel downstream of the dam is a bedrock gorge. There are nosignificant obstructions in the floor or sides of the channel.

I 3.2 EVALUATION OF OBSERVATIONS

Visual observations revealed several deficiencies on this structure.I The following items were noted:

1. Localized spalling and erosion of the gunite surface.2. Minor seepage at the dam abutments.3. Brush and trees growing next to the upstream face.4. Eroded concrete on the exterior of the gatehouse and around the

water supply pipe downstream of the dam.

II

IIIIIII

I7

ISECTION 4: OPERATIONAL PROCEDURES

4.1 PROCEDURES

This reservoir is used as a water supply by the City of Ithaca. Flowthrough the water supply pipe is controlled downstream at the watertreatment plant. The two gates on the water supply pipe at the dam arenormally kept open. Once or twice a year, these gates are closed to de-water the wet well and clean the screens on the water supply pipe. Thegate on the low-level outlet is normally kept closed. Its condition isunknown, since the last time it was operated was in 1959.

4.2 MAINTENANCE

Periodic visits 'e made to the dam to check on the condition of thefacilities. The visits are made by personnel from the Ithaca Water andSewer Division.

4.3 WARNING SYSTEM IN EFFECT

There is no apparent warning system for the notification and evacuationof downstream residents.

4.4 EVALUATION

The operation and maintenance procedures on this structure are notsatisfactory. Additional maintenance efforts are required to correctsome of the deficiencies noted in Section 3.2.

8I i - . .. .. .-.. --- I

I SECTION 5: HYDROLOGIC/HYDRAULIC

I 5.1 DRAINAGE AREA CHARACTERISTICS

The delineation of the watershed contributing to this dam is indicated

on the Vicinity Map (Appendix F). The irregularly shaped 45.6 squaremile (29,184 acre) watershed is comprised of relatively undevelopedland consisting of open fields and woodland. The village of Brooktondalelocated near the center of the watershed is the largest developed area.Slopes along the primary drainage paths are flat (1.5 percent). However,the adjacent hillsides have steep (9 percent) slopes. The hills thatform the watershed divide are 700 to 1,200 feet above the reservoirelevation. There are a few small ponds and wetlands in lowland areasof the watershed. The only upstream dam is Silt Dam which fills withdebris flowing toward the reservoir.

j 5.2 ANALYSIS CRITERIA

No hydrologic/hydraulic information was available regarding the originaldesign for this dam. Therefore, the analysis of the floodwater retardingIcapability of the dam was performed using the Corps of Engineers HEC-Icomputer program, Dam Safety version. This program uses the SnyderSynthetic Unit hydrograph and the "Modified Puls" flood routing procedure.

1 1The spillway design flood selected for analysis was the Probable MaximumFlood (PMF), in accordance with the Recommended Guidelines of the U.S.Army Corps of Engineers.

S5.3 SPILLWAY CAPACITY

A 100-foot long ogee-crested spillway is located at the center of thedam. Flow over the weir was analyzed using a discharge coefficient of3.97. The computed discharge capacity of the spillway is 10,450 cfswith the reservoir level at the top of the dam. The flood analysis per-

1 |formed for this dam indicates that the spillway does not have sufficientcapacity for discharging one-half the PMF. For this storm event, thepeak inflow is 18,850 and the peak outflow is 18,830 cfs. The full PMFJ peak inflow and peak outflow are 37,700 cfs and 37,680 cfs respectively.

5.4 RESERVOIR CAPACITY

1 |The normal water surface is at or near the spillway crest elevation of705.0 (plan datum). The impounded capacity at this elevation is 800acre-feet. Surcharge storage capacity to the top-of-dam (elev. 715.5)adds 490 acre-feet which is equivalent to a direct runoff depth of 0.2inches over the watershed. The total storage capacity is 1,290 acre-feet.

I 5.5 FLOODS OF RECORD

The maximum flood at the dam site is reported to have been in 1935, butthe reservoir level at that time is unknown. The highest level on record

9

I

1

occurred March 17, 1942 when the reservoir reached elevation 709.1.This elevation is 4.1 feet above the crest of the spillway and 6.4 feet3 1below the top of the dam.

5.6 OVERTOPPING POTENTIAL

3 Analyses using the PMF and one-half PMF storm events indicate that thespillway does not have sufficient discharge capacity. The computeddepths of overtopping for these two events are 9.6 feet and 3.4 feetrespectively. All storm events exceeding 31 percent of the PMF willresult in the dam being overtopped.

5.7 EVALUATION

The spillway is inadequate for the peak outflow from one-half the PMF.Due to the concrete construction of the dam and bedrock outcrops atboth abutments, overtopping is unlikely to result in failure due toerosion. However, as discussed in the following section, a prelimin-ary stability analysis indicates that the factor of safety is belowthe recommended value with the reservoir at the one-half PMF level.Dense residential and commercial development exists 2.5 miles down-stream in the City of Ithaca. If the dam were to fail, it wouldincrease the degree of flooding downstream from that which would existprior to failure. Based on the capacity of the spillway, the lowfactor of safety, and the increased flooding as a result of failure,the spillway is assessed as seriously inadequate.

I

1II

11

SECTION 6: STRUCTURAL STABILITY

6.1 EVALUATION OF STRUCTURAL STABILITY

a. Visual ObservationThe dam is a combined arch and gravity design, constructed of concretewhich was later covered with gunite and mesh- The reason for addingthe gunite is unknown.

close inspection of the downstream face of the dam was restricted by

discharge over the spillway and a lack of access to the abutments. Thedownstream toe near the middle of the dam was submerged and could not beI inspected. No major settlement was visible. The gunite covering thedam is locally spalled and bulging. Minor seepage was observed on thedownstream face at both abutments.

b. Data Review and Stability AnalysisNo design information corcering the stability of either the concretedam or spillway section;- was available. The design drawings providedcross sections used in the analyses. There are no as-built drawingsor other constructio: data available for the dam.

A stability analysis :,as performed for this report in accordance withthe "Recommended Guit'-ies for Safety Inspection of Dams". The analysiswas performed usigg a section at the center of the dam perpendicularto the spillway weir. It was assumed that the structure is constructedof cyclopean concrete, as shown on the construction drawing datedAugust, 1910. The foundation material is horizontally bedded shale. Nodrainage system to relieve uplift pressures is shown on the drawings.

Due to the arch design of the dam, an overturning analysis was notperformed for this structure. Therefore, only the safety factorsagainst sliding were computed. The results of the analysis are asfollows:

Sliding: Factors of SafetyCase: Spillway Sectiona) Reservoir level at spillway crest 0.76b) a) plus ice load of 5,000 lb./ft. 0.73c) Reservoir level at top of dam 0.49d) a) plus seismic coefficient of 0.10 0.57

c. Evaluation of Structural StabilityThe analyses indicate that the factors of safety for the spillwayare significantly below recommended levels. Due to the very lowfactors of safety for the spillway section, the non-overflow sec-tion of the dam was not analyzed.

Although the dam appears to be stable, the factors of safety arebelow acceptable values. If the dam were to fail during a storm orunder other loading conditions, a significant amount of flooding wouldoccur in downstream residential areas. Furthermore, failure would re-sult in the loss of a public water supply reservoir.

11

I. ~ , .- -.- . - .

I A more detailed analysis is required to accurately evaluate the struc-tural stability of the dam. Two features in its construction wouldprovide stability and have not been taken into account in this analysis.One feature is the cut-off wall shown on the drawings as extending intobedrock under the entire length of the dam and the keying of the baseof the dam into the bedrock. The second feature is the arched curva-ture of the dam which would resist lateral pressures from the reservoir.It is also known that the structure has withstood a reservoir level 4.1feet above the spillway crest (6.4 feet below the top of the dam) with-

I out failure.

There is a lack of data concerning the concrete in the dam, the as-builtconstruction of the cut-off wall, the physical properties of the bedrock,

I and seepage (uplift) conditions under the dam. Also, the conditionof the downstream toe could not be evaluated during the visual inspec-tion. Field investigations are required to obtain more informationabout the structure. This information should then be incorporated intoa more detailed stability analysis. Based on this analysis, a designmay be required to correct deficiencies in the stability of the dam.

d. Seismic StabilityThis dam is located in Seismic Zone 1. However, a seismic stabilityanalysis was performed in accordance with Corps of Engineer's Guidelines.The analysis is based on an assumed seismic coefficient of 0.10 andth2 reservoir level at the crest of the spillway. For the spillwaysection, the safety factor against sliding is 0.57. This low factor ofsafety further indicates that additional stability studies are needed.

I

iil

I

1 12

II '

II

SECTION 7: ASSESSMENT/RECOMMENDATIONS

7.1 ASSESSMENT

a. SafetyThe Phase I inspection of Potter's Falls Dam revealed that the gunitesurface is eroded in three areas on the downstream face and toe. Alarge bulge was also visible in the gunite on the downstream face aswell as hairline cracks in other areas on the dam. Further deteriorationwill occur if the gunite is not repaired.

Outflows from all storms exceeding 31 percent of the Probable MaximumFlood will overtop the dam. During the one-half PMF, the abutments ofthe dam would be overtopped by 3.4 feet. The dam is a concrete struc-ture that ties into bedrock at both abutments. However, a preliminarystability analysis of the spillway indicates that the factor of safetyis less than 1.0 when the reservoir is at the one-half PMF level. Afailure of the dam would increase the degree of flooding in downstreamresidential areas. Therefore, the spillway is assessed as seriouslyinadequate.

b. Adequacy of InformationThe information which was available for the preparation of this reportwas limited. Drawings prepared during design of the dam were used forthe stability analyses. No as-built drawings or detailed constructiondata is available.

c. Need for Additional InvestigationInvestigation of the materials and as-built construction of the dam isrequired to conduct a detailed stability analysis. The investigationshould develop accurate data on the construction of the cut-off wall,the nature and strength of concrete in the dam, the condition and strengthof bedrock under the dam, and the uplift pressures acting on the baseof the dam.

Additional hydraulic/hydrologic studies are required to more accuratelydetermine reservoir levels that would occur during the full PMF. Theselevels are needed to evaluate the stability of the dam under maximumhead conditions.

Additional investigation is required to determine the cause and extentof deterioration of the gunite covering the dam. This should includean inspection of the gunite when there is no flow over the spillway.

Evaluate the possibility that seepage is causing the gunite to spall.If this is the case, repairs such as sealing the upstream face or pro-viding internal drainage may be necessary.

I

13

II

d. UrgencyThe required investigations should be commenced within three months ofthe date of notification of the Owner. Within the same time, the gateon the low-level outlet should be exercised and maintained in goodoperating condition in the future.

Remedial measures deemed necessary as a result of the investigationsand repairs required to correct other deficiencies which exist should beJ completed within 18 months of the date of final approval of this report.

7.2 REC OMENDED MEASURES

a. After the structural stability analysis has been completed, performnecessary remedial work.

b. After the condition of the gunite has been evaluated, conduct neces-sary repairs.

c. Visually monitor wet areas at both abutments of the dam. If flowingwater or spalling bedrock is evident, conduct an investigation andcorrect the seepage.

d. Repair the deteriorated concrete on the exterior of the gatehouseand around the water supply pipe downstream of the dam.

e. Clear brush and trees along the upstream face of both abutments ofthe dam.

f. Develop an emergency action plan for the notification and evacuationof downstream residents.

1IIIIIIII

IIIIIIIII

APPENDIX A

PHOTOGRAPHS

II1IIUII*

~.. I'

IUIII

1 PSTR~ 4M ~ IF ~ OF DAM

II1I

TOP OF DAM. RIGhT ABUTMENT

III

I.'

III:

I

Ii'

ICREST OF SPILLWAY AND LEFT ABUTMENT

"1. • _

I'I ,. . .

.,I

I

~GUNITE N DOWNSTREAM FACE BETWEEN OUTLET AND

1 4

-- - ~ -I _________NNE= -

GAEOS N IH BTIN

4k

DONTRA ATOE A RIGHTTET(OEULEN

DOWNSTREAM FACE AND EROSION OF GUNITE AT TOE)

UC

ii

EROIDED CONCRETE UNDER WATER.NMAIN IN WALL OFDOWNSTREAM C"ANNEL

II

XPSE!) SECTION OF WATER MAIN IN WAL.L OF3 DOWNiSTREAM CHANNEL

-- T~I

IUIUI

IIri

II

APPENDIX B 1

VISUAL INSPECTION CHECKLIST

II

I III

'II

93-15-3(9/80) Po.-er ai r#5 A

3A NY- 378) BVISUAL INSPECTION CHECKLIST

i) Basic Data

a. General

Name of Dam PoHer'S .a#// Dar /60- Poo" Da'M

Fed. I.D. # NY 378 DEC Dam No. 75A-7/7

River Basin- OSWeqO

Location: Town 2+a7Co. County 7-om .kins

Stream Name -Six mile Cree 1

Tributary of Oswego River

Latitude (N) 420 25.0' Longitude (W) 76 *2 7

Type of Dam #clopmean on erge ah-jrav;j d&,n Coveied w 4; un i/e

Hazard Category ___ _

Date(s) of Inspection Jul 8 195

Weather Conditions Sunnx + hot

Reservoir Level at Time of Inspection 705.1

b. Inspection Personnel _eq;nl_ ._ __rr _,_,_ Carol _ee

c. Persons Contacted (Including Address & Phone No.)

Mr. Ph,, X Co, E,,;neer

Cr' 1 NA11)I / Gr een 5,rfef

X4C&, -Aletj Y 0,/c 14850(607)' .2 -/7,1(o,

d. History:

Date Constructed ,ql1 Date(s) Reconstructed 1q3?-SUnie added

a Designer QnknoWn)

Constructed By o Wrn

Owner IC iL of r4,e,. - Df,. of P,,/ab 14)o,-s. Se,,W# 1 el1ak Dv.

93-15-3(9/80) NOIrSIStn

2) Embankment

a. Characteristics

(1) Embankment Material eycloee" CefCrth doVerd WIA gn

(2) Cutoff Type Reg A&ofL ;#7&,£ ,a

(3) Impervious Core eona'4e

(4) Internal Drainage System neOe 5oow n drawL;2g

(5) Miscellaneous____________________________

b. Crest

(1) Vertical Alignment rCr,

(2) Horizontal Alignment eurved I F-dsjretn(rJi

(3) Surface Cracks Ai;r/;ne 4,Lnrsvrsp rCtks In g&P'rnk (p,4er

ivsa iv,.- doeon"s ra

(4) Miscellaneous____________________________

c. Upstream Slope

(1) Slope (Estimate) (V:H) Ver~cal

(2) Undesirable. Growth or Debris, Animal Burrows brush and a few

47,15 Q'oaJ -I /on upst~ream 4 ee a -a obi ~amenl~s

(3) Sloughing, Subsidence or Depressions 12one

93-15-3(9 /8o) PoHer'5 rals bwo7AY- 378

(4) Slope Protection Covered wi44 yuni/e

(5) Surface Cracks or Movement at Toe Some h'trflE enacks- one /o

hori3of( Crack. -rm _qdekVUse -& rIA*I "4&#ren

d. Downstream Slope

(1) Slope (Estimate - V:H) bol,-eedl /:/.44 (O,7pereen4)

(2) Undesirable Growth or Debris, Animal Burrows minor weed

IrOW4A 0- rigA* abuJ-men+f

(3) Sloughing, Subsidence or Depressions eroded gunie : 0)mldway o/own

510op aS lef# al u/-nen/, a) bdeween oule+ and le,' aha ene2

3)down,rea.en 4 ve a-f rl,*, abactme,,. Alo larae & ,;, fut,'[on dolonsireJm -aee near wai-'e- supply pipe.-

(4) Surface Cracks or Movement at Toe

noi vis,'6le due to isa;//ly disca,',e and -b;wace,-

(5) Seepage auri areas on bedr-ocL ail hOdh a,.mm _nen . Ifli

nm vis;ble flow

(6) External Drainage System (Ditches, Trenches; Blanket) no.l*

(7) Condition Around Outlet Structure grogd ed kun /e(

Of vuLLHd zeF 4a

(8) Seepage Beyond Toe no YlS;b- 5bme4ed.

e. Abutments - Embankment Contact

d=ft 41es &t/ ,drock a-4L 6vM &Affvlqe1 5-

Condihon 's a14s Azdiy exeo#f iCr minor Sejoage sho'da&ve

£ I.il

-- Pefieris Falls 174pv93-15-3(9/80) N"-S 78

(1) Erosion at Contact eoded gonI/e ai le4 alSmenf, M, d

on downs#reg ,n 3ope

(2) Seepage Along Contact minor Sees ae (wei are s) Sa 6oMtabphnenls - ,trc t5 m ¢ ,

3) Drainage System

a. Description of System nene

b. Condition of System

c. Discharge from Drainage System

4) Instrumentation (Momumentation/Surveys, Observation Wells, Weirs,Piezometers, Etc.) ()tOe.

1..5

P0#kr~s Pa//s &miv3 93-15-3(9/80) NY-378

3 5) Reservoir

a. Slopes 5egt ,1joo'de ,Iloes- VTaIo, w bhedroyk..

b. Sedimentation eond;'ons n04 VISi;e ble ! si- l a s een a..

o 0 blm , 4- Sii Dam b;Ml us4 ear., y inlerr=ot S','er

c. Unusual Conditions Which Affect Dam

I 6) Area Downstream of Dam

a. Downstream Hazard (No. of Homes, Highways, etc.) 2.5 r",les l/dowsn~own

SX44aeA. - /i#/e a/Ienaa/,on of f/cod efxo4 A 7 gor e downs 4 red," oi d-n.

b. Seepage, Unusual Growth none In eMzA e/

c. Evidence of Movement Beyond Toe of Dam none v1341/

I d. Condition of Downstream Channel 54f" bedrod. wals. 5oMe loose

blocks of rock i, -floor

7) Spillway(s) (Including Discharge Conveyance Channel)

SoeQ.ee weir near Jog of dam- d;scAare flows ono downsream

-ireae- and nAo bedroec ehane/

a. General .ond;'on C tS sa.b eOIOp " disc], ,e .

La eroion of gunde on doywns ,rwa 4ee and ,40e of dAv

b. Condition of Service Spillway aoOd- no vij;ble cracis or vods-

I 2r, J ,s elear of debrs and ObSi-rePonS

II,

* Pofter! 5 Falls &m , 193-15-3(9/80) AVP- 378

3c. Condition of Auxiliary Spillway none

d. Condition of Discharge Conveyance Channel '00/e beerock.

on 5&ides a, ,,n Lffo,m- some loose rock- eaP& 12e" IP;ke isp dr"9~ food flos

I 8) Reservoir Drain/Outlet

Type: Pipe vo Conduit Other

1 Material: Concrete Metal V"#$sA ron Other

Size: ,72-.m, dZ-. Length 45"'. 5'ee "

I Invert Elevations: Entrance 04 7. 0 Exit 647.0

Physical Condition (Describe): Unobservable _ _

Material:J IJoints: Alignment

Structural Integrity:

Hydraulic Capability:

3 ~Means of Control: Gate V Valve _____Uncontrolled ____

Operation: Operable , Inoperable , Other jinc .95

Present Condition (Describe): 5ubmer3ad a-i *he ps reaiv

end of 41he owule

II

PoHer95 fells &M 793-15-3(9/80) N -3 ?8

9) Structural

a. Concrete Surfaces IOnerge ofdA..n eyvered &w;l4'unilf ishiA I

eroded in el/oces (See ewe- 3)-a/s concr-e on gydahouse 1s

eroded a wakr line - e dne'e i's Ooded around .w-er

,oge downsh&grn of dAM

b. Structural Cracking h,;r/ine tracks "0 , tn/i, v; ,,/e ,on,

and U sIywm Aee of alm-a/so arooud beg1e on

downseahr a c-

c. Movement - Horizontal & Vertical Alignment (Settlement) none ai5s;d1e

d. junctions with Abutments or Embankments 3 enerAz& ja 7:'sfao,

b+ elose invsp e,'r,,ol I oRs;4le d 4v lock of aeeess

e. Drains - Foundation, Joint, Face no dr&ijade ss/lern Vj 54ie

f. Water Passages, Conduits, Sluices ojgdej no' inspeeAed- ki,5;6/e

-jeeb~ors of Lagsiwol 5e .04

g. Seepage or Leakage inor wei- ar an bedryzk a bo/i-

P041ier'5 FOI/ AMI 3-15-3(9/80) NI- 378

h. Joints - Construction, etc. none i b e

!

i. Foundation A/A- roc.

j. Abutments A!A - bedrek.

k. Control Gates 5ubJmroed - i, g 'nsec}edL

1. Approach & Outlet Channels A/I- na/oral eCAnnels

m. Energy Dissipators (Plunge Pool, etc.) tyne

n. Intake Structures nOne

o. Stability

p. Miscellaneous

1 '

, -

P#e, e 5 Falls ba93-15-3( 9/eo) N - 31

10) Appurtenant Structures (Power House, Lock, Gatehouse, Other)

a. Description and Condition

G¢e/hou.se- f do-rSio, -made of pocred concre-e.

Japerj5ruac rg ' eonerele //oes- Concre/ on

elieri'wr is ervded e" .a-er line - mor ver4-,a,,

11) Operation Procedures (Lake Level Regulation):

Re•ev. , r /i5' re......e.d dowIlsYear, &V. IIIer I4Ial.n....

APPENDIX C

HYDROLOGIC/HYDRAULIC ENGINEERINGDATA AND COMPUTATIONS

i.

Po44er's Falls Dam3 NV 378

I CHECK LIST FOR DAMSHYDROLOGIC AND HYDRAULIC

ENGINEERING DATA

3 AREA-CAPACITY DATA:

Elevation Surface Area Storage Capacity1 (ft.) (acres) (acre-ft.)

1) Top of Dom 715.5 47 12q0

I 2) Design High Water(Max. Design Pool) unknown_

3) Auxiliary SpillwayCrest NI/A

4) Pool Level withFlashboards N/AI

5) Service SpillwayCrest 705_ 0 47 _ 00

DISCHARGES

Volume(cfs)

1) Average Daily unKnown

2) Spillway @ Maximum High Water 10. 50

3) Spillway @ Design High Water N/A

4) Spillway @ Auxiliary Spillway Crest Elevation Al/A

5) Low Level Outlet (7z"Op;pe, ws E1.705) 1044

6) Total (of all facilities) @ Maximum High Water 114 94

7) Maximum Known Flood (reservoir El 709. 1) .240

8 8) At Time of Inspection (rServolr Al 705. 1) 10

IIl -[ 93-15-4(9/80)

I I'- --- - .. ... . . . .-

Poffer's Fails DarnNY 378 2

CREST: ELEVATION: 715.5

Type: broad- cresiedi Concreie wiM ,n;e Sorface

Width: .5 fee I Length: 2.20 fel

Spillover 5erviCC sAg;llw&X

Location C.nkr o1 detrer

SPILLWAY:

SERVICE AUXILIARY

705.0 Elevation

Una4ed ojee uxwr Type

100 Width

Type of Control

_ _ _ _ _Uncontrolled

Control led:

Type

(Flashboards; gate)

Number

Size/Length

Invert Material

Anticipated Lengthof operating service

Al/A Chute Length

Verheal u$( rJ PSi r V) Height Between Spillway Crest

-Patee o4 cfar & Approach Channel Invert(Weir Flow)

93-15-4(9/80)jq

L , .. .. . . , ,, ,.,. , ... . . ,,.....,.. . . .. ., . ii_.. . = :. -.. , ._ . .

o-Aferps Fralls bw

NV 378 3HYDROMETEROLOG ICAL GAGES:

Type : tnOn

Location:

Records:

Date -

Max. Reading -

FLOOD WATER CONTROL SYSTEM:

Warning System: rlorf

Method of Controlled Releases (mechanisms):

'72-iflci low-level ctSRef- go S &4!S/faM en iv (61.(64749

9 4

I

Ik I

PoOeAr~s Falls Dbv,A.l?- 378

RAN AGE AREA: 45.4 5 .u. (aI,4 acres)

DRAINAGE BASIN RUNOFF CHARACTERISTICS:

Land Use - Type: re/adv/j urt vdo.e w/ojo. le(s; woS, aO /-.

Terrain -Relief: dratir js- iwt lWsA; i;lI,'des - sleaE Slopes

Surface - Soil: ,Iaid -i over ,shel o &droek.

Runoff Potential (existing or planned extensive alterations to existing(surface or subsurface conditions)

runog will flow d , ,Ajn ,m 40 S*rm;le Creek . Reserwvr

Potential Sedimentation problem areas (natural or man-made; present or future)

5a~r~n~z4 1 o a rob1,ein th Wf pgsJ- 9;14 ibLrv bu /

;a1925 46 eonke sdmolw

Potential Backwater problem areas for levels at maximum storage capacityincluding surcharge storage:

backuyuer Wll ,Anndee SiA- lbeen &fLoa

aoa-u_ 0.4m i;. luDStrgAY,,,.,, of ZT.a_ feservo;r

Dikes - Floodwalls (overflow S non-overflow ) - Low reaches along the

Reservoir perimeter:

Location: IoM

Elevation:

Reservoir:

Length @ Maximum Pool 0 o.4 (Miles)

Length of Shoreline (@ Spillway Crest) - l., (miles)

IS93-15-14(9/80)

Project big\ OzFA , I- I (~ Acct. No. M Ja -.--. Dte e 2 -A

ISubject F1TF't"& EAtI~r NN Comnptd. By Page oDat

DetilCk'd. By Date

0

I z

S r

ILc

, F-

-jiL O 4

uso(

W0~ L

ILI-I

Project Lr cu~L '- I f..s Acct. No. Page 0,

* Subject IhL Comptd. By Date -

Detail Ckd. By Date

4"

z

I~ (16

QA 42ON

GU

Subject ~~~~~Comptd. By -NC 3 ae 1 7Wail~k 3S ACk'd By Date _ _ _ _

6 CLZ

0

0

Wsa-sufr'rc eA 4v1 4 Ce-\\ \A\Jegrk GeJ

Z. +

>:

C (i4 .0z'A0

u~2

ev6+ 1O4c

'KZ

Project N V C t"N~ it p is Acct. No. Page 4- oSubject "d~T~R~ i Comptd. By NQLNk-Date A -Q

Detail Ck'd. By Date

4. 3\z" o s vvosA narrt Ck reCAy cimc)n% am 4- A4,.

'I

0

E Gz

ii i .I

w

'2- e) G Z4- (>03C

.. .. .k..2 G.. 24 1 ,

h.i

hi,

Project N .F- P44 I Kkne l - Acct. No.ZL..-. Page - of

Subject "d I--, F' A& Comptd. By Date - -

Detail 7 _____S tilf Ck'd. By Date

0

0

-o0z

I L AI

u CA

*0 I I

C A "00

00

.4 o

o. a 4c 0 1. oa An 0 C~09 S. a . *: A

W.. W u 4I

hi- fA t-~Cm l~ b

an 1-0-n

vq 40 in V- 10 0~f 00 0C4 cf i

u I re I I r. 0 M -

C,

t m 0 0. a

in . I. 1 .

0. .4U0. 04ad~

CC to

me a a .j*c me b~

VA A 1".

a A

09 I~

Ii,a.

94 Ac 0

m wa0 g

*a I

II 094 e a

19 I a

o= .4 00a' i 14

-- 00 N

64 C% N*.F 0 F in m C40

m 0 FA 0 -

w La L)0w010 .1 Pta DF U. .J

Uc a MI, In a.1Ac 64. 1a. iiw 4-1 14 c o 4 k D , 0

me 00 60 0 i mfUU b" 4. rn 0 0.

0 4 1" m0 00 .440 .9o 00 aN ; 6 m . 6-14e

'4..4 uA 1- &4 9. p-.19 m 4% .614 0 1; a u

C, 021 66 64' 1* .4 -e 0 m d w 0@ b

430 0 a 4 ,4a o4 U w 0ll .P. INc 0-a 041 N w mu1

9d 40 . 'm e C, 6 0 gn - m - 6 .A . II C4 -m4 190 m ic t = m 1 a

lb . 6.4 n 0. .- , r a M0r IA dl 1 die 0 B'-1'4a"ag0.- P% ~ =n 0 1 d. Q. rnG 0k

a 9 Ma Im m a, 0 6-'w-s ar .002.30 a .g IC 6 1 Va "4 af

.4~ "i m 00 IU 6 40 1- 1" 1 C

N.1d ag 0. a. - * [email protected] Um ka BLO6 . .. m ~

4@m~~a 4 64 a6e - 00 6C 4 m6- 6 64 * 4 0- - 10 6-

4~~~~~~d 0n Nr 060 C 4N 10

MO~~ 6-mf- 04n 40 W0 (ft4 *.

UU~~~~0 04 4-00@a 4 46 4 4

0 In64 *l a 40 In-l m3 un/a N@.

In arn60 K 0 0 . UC 0 sm tU6.0M

IM *4 M m 0 4 0 04* a

Soo em N d .0d b- Mn 4I

:4 ma./ 614 0d~ a. N0O. 0:~ .4.4. Ol .44 0 120 M

do so Q4@f 0~ ~ a a r ra

I". On a.ON.. 1 . - a.

0- Ake I. u U 0a 4

da. " .e n UOas do c -

; I I-

at a

I10

I eq-I

1 N I

I g:

i. in!

mtl

I10

I ,I * *.

I00 I 1NMOO

of I, No"19

m r... .

0. 0000000000000000000000000000ea 00o000c00000o0o 00000 W

U 000000999 9999" *9- *t 9*w0O00 c 0o00 4

10 0 00 0 *-@@I: "SMMW.Ogg9q; .9.9-O00000000o0@ I

a a 0

Q~~9 C499- Mb-9O9-9 in-..99, *0 N NDO N 0 NM o N N N 0 m z ~ - :

2: 10 = . i 9 . .. C! I C! 9 1! 19 1 !11.1 iiiC 7 i i91 l 9 l 9 17WIS 0 - - - - -- - -- - - - - -- ~~ .r . ---as-- -- -

McU

'aCo o 0

0.u

6

C; : ; 0000000000000to000000 00F000In00N @0 I000 0 nnono 0000 o8000000 o Coco cc 0000000ooa cac Coco -

u. 00000000000000000000000000000 000000 00000000000

l* *.. . 9 ~ ~ ~ .. . .d~~~9 . * 9 * 9

gang 4a0 00 0 0 0 006 9-Ma~P.C-We.m0.W~nt01 W.S" -. e-IW.Smo.

At A

* @oeoa ooeoooooo@@b@@Oo e@oo0 e00 oo00 co000oo@Ooo0

NJ-------------.-999999999999999 11---------999999999

I I

40

41 h

I

beI

* . in.f. N . a 'a in a

C4 N r pa. 9.

0tf C4 0 nm C4~~I- C 4 4fI-rC3

IH ~~~ - -dC

%0 0ef V*iM V0 % 0 4Q M***4

C, C in m C

.4 ati 4 40 4M

r~~ *ac * * W i .. f ..12, 1: 4r-.44M. 4 *Ma w log 0 64 a 0 0n0

0~~t aiM M r 1- 00 Im~l-NI ('440 on6t-

64 r- e 4 0e 6"4 A la 4A

ft'06An 0 1.i A60 , n- e~l* ~~~~~ ~ e 10oo, Ii 64 t4 l.

or- a. C4m - o,4.1 410 s

0zl 06m - 1 to a f" on 0 PO~eqno on f C1M pina i-P1MOa('4 Yl11i M o66 V. in O i-

- NN * ** . . * * . * * * * .* . * . .ona..- ~ o ns -beln*

one~~%Mn .- on. f" au * atM I e* .* ~ rmat-Ofa 0it M luMa in

-e. I" **** OU Id M *b *9 W w aft .. *4.Li i-4'4 e = OMPM..M,

no 04 4W 9 f"

W r - a - IN % toAt 44 far t 0 edO t-

M4o, r

I

I o

b

oen. a

o n.

i eniN f

rPe

* **N '

eli"

', I I

o ''u-

* l~ 111 i l: 111

. i

mfr-o %* Mo

U0 U. ftIOt

on Dat 0tq v 1 -mo * 5A 4 ""h

mg:, 40%t* m in

0 o .4 cc

W. lo w- 9.4.~~~0 .1Se .0- * S** I** fS

dc *A U. 614t 1 t o. 1A Iin 08 Mr6 'Alf A F. 0- fteI

10,.U It a10 14to in a4 11

I0 4 9M I 14 r, u0 0fAU ,* I I

00 140 aV 94 M .40A a1 A 0 m i

:,64 4 0. =. in40i

f" C44 t- in * oJ 0 *w

14 1*I .0 ft01 TAMO 1ei1 0 .6 a

O V**- I- C 4m t N on14 U

a- C, ,0 'lowE14fU.1 14 a 0049 00 - 140

* fm-* t ta. 2~fot~ a. U .. c0. . U~a0U.aA 0 1

r. atar CDm4. a

mm e om w 0 4 u a4 ' f aw- to a- M6 in 01A44

00 E'iaw U. af '-Oia 0 w ta ma

0 ft ft.*Uc10 1 ft 0; z - a

U.MA WineO. a ftWI: U* U.* U a #A 04 0 0io4 aw4.O U ch on A a o- 0

Ofta * on in a y one-a. i 6 a d P

WW4a q In M L43 fM 0 z- 'A *I'

94 it I%0 14 6* Wi-U m NUa a* UO U.U 4* ** @ * 01 ft-f t- IS O

a. I* - in a I-C * 4*

on 10- 0. fr 161 G0l 16 aIi ~~~~~401 404Ua c i

5.0161~9 U a o M* ~~~ a M 4-*

* U.14** @4@E01 O'~in iO U~-I4U.~~~~~1 0f..11.01 0 B

I iI

assaIH i i .**I I

L ,I I

I

!

I*,- *

ef

t,- i-, U*

I I

oC , * 4

0 'I " I *

a I

a ,

I,S8

I I..

I I a a

9'2

It I

II 0'Of afo"4, es ., 99 9. . 0 0 0

o ~ ~ ~ ~ ~ ~ ~ ~ t a 0 aOO @.. aq~~-a~ a in a

on *USN w * 9 aN to9 a m - onOn i

* U- C 99. .....1e6 .6 r:C 9 -m c m o

ft N ~ t. Af%6,t *o 90 09aA4

"aI nmq

o01 a a *PC1-"ma a9 4"" ~ n .

4%D 4.a999 0 0 0

O" 10 am +n.ntU An 0% f" Ii

N g a fn 0A Cw -0 to C-4 a m - ma a 00400e.e e-

.4"m In T 0 0 -0 0 .000.~ w. . -0 IDI v %1

r- An f%

u a 0 0 0 a

a p 9 a N Nw UOON 4. 4. 4 0 N4 0 0

In 6n Go 1. n 0 ' 0 . a U 0 00 rrW 6-0. 16 9 .. 9 . * * * * *

SnWOOMM01% 0 1- N Pn .0 0 0 mm"R cz-~o

f" f9 9 9 In int-SSM~~~CV 0 0 Is %D %a999 9 r-999 * r.n- -~nn

P.4n 9: 9 N m1U-fl S p S e m iS .0 C 0 054~n.U. S-~-.49 M 9SCpnf

IV in Z- In'9 C!PS9 * M N 9 tE S Q S n a n9.5fO mo r om foo - 'a=~n.4er-,-

m 4" -0: 4

9999 1.0e 0 q 9 6... . .. mnNC.S

0 im N aaai

I., C; 14;Sn. N 40 0*. .... *.. .. nfwC=r

* Is I 04ON A 0r

A~. 1S 0 0 0arm 4 N 0 nN ni o o4 ~ ~ j l

in E' B B

VISin g q 4 14U

Sni-S 94 1 bl

9.99. 0 0 0

* 'I

I j.1

* I r

* I *

* I II * *

* f

tflK=0

aS

p.B

U- I'4.4

.4 I* I

* *

p.

H ~a I

ji. a I5 IKI'

- I ~ -

-. i N oaNn f 0I N

W f c W o, i

We * IsI

I 000 1-

, . . . 9 *e.,0ee0, .. . oC.oo No to o

o @ @ * 0 eeo00. M9 *oe oeeeo*~@ eec.

0 N N a 0 : t -6n r.9 a o r atNoo 00 + 0 * .9°;c; 1; 4

* e e . .V

I- 9.. 9. I . . . .. . .

=sl-*e~4 4N 41 1 'a4

E0a 0 0

N ... n . ...

meoeeo o, oooe .417o

be -Ar i.n n in ekc In Nn iih

I o a 0 u :MoV e ua . . . . .Dr-04t-M M 94 94

.. I a0,0

• C e

0 i o a toaIad

fte~-ce a m Nr-m.-.'.492 e e c .

10 94 N U U U

"= PI :19 t 44 n Mo

on In 6n m*ine. ff.. *.cC .C a on IA*Wn0eq on 00

Lo UU P -e-.~rc

a. ee4 ee .. 'S e ... * ge

IH 11. 94 N. 94 okI nq 0a P - c-**oon*ia~ ~ n U9

e~~0 f:.4.04 a in 4"l -ot 0M9

- a m 0

atw "b

Ines10 0 j

inon .

'I 0 T-

InIt 1

In 0 0-

in in

to to

I , in ok

Iv 7

on to 0 in ar.T

iD I-

ni A 0 0 in, ,

10 e

.4 e

05b e P4 4 . N. ON, *....ts

a9 M .n .S

61 . W. q. . f

a C . .* . . .. . .. .

o to v 9- t oa 04 Of

of ~ ' f F4 At . I W. %- 1OCS bC9St N b 9a0 0 Z.f M I C t- en

V. an AM N" Wen %a ond. cti~ r4"c- e~ w ne t in 0 ianmnV.W

in ~ .. 9i

W- W ft &1 Iao.ee Ad a A" it

n gtos .in" 0 0 %D in a%,o99 99 0.* . . . t- w f-~oeno

* 1in en 04 Nn W, C p .: .%i .nI r

*~~W 00 0 Id9 9 9 9 9 9 9 99 9 . m - O nft94nsntV, *rotcet 9

lb 0 ee-eeni snnae1n i9e0--tIn.at-- 'vek i~t 9-

I- Ic '-9. .aneQetn4-t

.0 99

I I - - - I

4

I

(AmUa=a0

1.4I..

4

U,SS

VA-

I'~

14.1I~3biibI...

*4

I * - -. *-~

0 4' J.

Iom - o I~-o~o~

I~ ii*0 N *MC@ or-rn mON00 i -

rC'in ~N a-tCa-eOa~ Igl-41 - r-t

r- 0 00 #A n~ MC4aa w*nUl:uNN . ;a1

0*~~s 0 * N N

In~m~n~

* ~ ~ ~ - C;i C; *: . . . . . . . . lr0rone flfl * hi C CUN.rea0ae r'N - flrrwi1" MN .. ac *1 N "I P0 0 0 CW - -~~4 4 F A *r *c . M ar N C408n.C. *Q0r .M At- *n

.. NMI-- C1ta* V on iinM'cI-r on CCW in fin n 0 Nt Ni~ Ot

aet 0 0, z ;r

C4 a 0 r- 0mr -r 14 NNoe Lp * .: *.zl; M%*.1..own *rn* r'eern-qD. am aC aNI- ra. NC-.t-C0 ....%...... 1.

I a - m 0 q V Na" 0-a~t *~ f0 tofI-bo N f" CCCttt

0;iff* 00 0C

At :C f" mn 0tC4t-N. NW. 1 14 M 0 IN Naa, a hi DnMW0-fC D UI V ~ %Vj MP :C4:1 ; ;1 :1

0 1. 0N p-lC; -4 hn *6 . C. C * %D C*C**C*C 4 O S M

P% atmdo e in 3. Dat- in t

OOU C4 %a* N nr006 0 0~ U N.

*W OinI a q= Na a NNt am Mn Z,; 4. - AN-n

U*NC 0tN f%~c Ct0t bl In 0 mnU- N Alhi. U)Wt-o vv0 0t 0 V. P.CCC tt

td aM ad lt- w6:. In u C ,*U a

L4 or r* *C 0C C 00 C 0C CC N* N 0 Ma MN U M n -inO i ~ e f N* C C C CC

OnNONrIe- MOM.t-as~ "NANO-MN~f 0-

0,bl M NI-I rI' i NS Mt- 01-CIA.AbnA-"N *I C- *C UCUmint

II isj I *

I ii

ji I I.I I,

I I

CaanC

Camfla

0a@1ft

C

U-N

= I

D * IU I

* I .* Io-Iq

[. I * *

-- *---- .- ~.- -. - -. . -~ * ~ - ~ .--- * -:

L? u

o4

IdfW dI- f V f

W00

go aAW~d " be fn -04 02 01 In on a~

A.IO 4 0 0

inJ atl -4in imawM a is

In 04 a in - j w

.am m

0 . W 0 P- -bl CAA 0 02 i

In 4 0e a ~ * e

bi 0-Wa - -

o~i r~ n- In1pq u a 00 a P a

ec4 a~U Sd let4

04

i in -

.4.04

U LI4 . .

a .1 .VI~ doA' d~

I0 I 10 ~

C.o 000i

ml.1. a-hh 000Q

5.464

In

coo

0.1n o 1 0 1" I b

Mfdi 64 0 in4CM

16 ~~ m~~

90.41m

:=:4 mom.

M0

44

a ICA, -O . .

iI

t

APPENDIX D

STRUCTURAL STAB IL ITY

L-I [

-

Project AA -~ Byct No. Page oft__ _

Subject 100 j ' Ckmd. By_ _ _ _ _ Date _ _ _ _

E/ 705 *9-1~i

U 1Mae xp/Ia f echon

0

0

0

0

z

0

z6

6/64 1

reA

91 ? 3 -S

Project I~ s -A 9V baz*,s Acct. No. 75f4 page ot____

Subject 00P H&erS grLU. Dalm Comptd. By ~ LDate

DealCkd. By Date

I. &rma/ eond,hfo,,sAzjaer 5uriee x/~ cre$stS 5V11t

le2 e Wite ero:5- 0*3p: la V

lee 2 fee ' Ytich

C

2 4, WormSd Conld bos w, sv*b r ic.

a0

I

SPL.IWAY 5E,0CrOAI

STABILITY ANALYSIS PROGPJtL - WORK SHEET 0 0. -.

INPUT ENTRY ANALYSIS COMJITION1 2 3 4

Unit Weight of Dam (K/ft 3 ) 0 . 0./- . 4

]aof Seg.ent Io. I (ft 2) 5 531 531 S

Distance from Center of gravity 2 45.5 4.5 45.5 4..of Segment No. 1 to DownstreamToe (it)

Area of Segment No. 2 (ft 2 ) 3 1210 1 0 /210 1.210

Distance from Center of Gravity 4 .27.3 27.3 ;27.3of Segment No. 2 to DownstreamToe (ft)

Area of Segment No. 3 (ft2 ) S .. ..

Distance from Center of Gravity . 6 .. . .of Segment No. 3 to DownstreamToe (ft)

Bse Width of Om (Total) (ft) .7 5 0 50 5-0

lgt of Dam (ft) S 5q 51 5? 5?

Ice Loading (KIL ft.) 9 - 5 -

Cefficient'of Sliding 10 0.55 0.55 0.55 0.5

.git Weight of So1 (lift3 ) --

(. (deduct 18) 11

Active So11 Coefficient - Ka 12"

. Passive Soil Coefficient - Np 13

* Height of 'Water over 14 - 5Top of Da or SpIllway (ft) /0.5

IHight of Soil for Active Pressure (ft) 16

I4ei.ght of Soil for Passive Pressure (ft) 16. - . -

Neight of Water in Tailrace Channel (ft) 17 ... ..

.leight of Water (K/ft3 ) 18 ,or.3 .o6 .o S 4 oz &.

" -hrea of Segment No. 4 (ft2) 19 - - -

Distance from Center of Gravity ofSepment o. 4 to Downstream Toe (ft) 20

Height of Ice Load or Active Water (ft) 46. 5,9' 57' .5 5? /'"(does not include 14)

"" SlefMi€ Coefficient (s) • - -- O

RESULTS 'OF ANALYSTS

Factor of Safety vs. Overturn.-Distance Frog Toe to Resultant

," • Factor of. Safety' vs. Sliding 0-6 073 04 0571_

Protect . . cct. No .9 P, -.. 5

I Subject /~JCv /rComptd By Date

Detail Ck'd. By Date

Z ?r

I A-l -

- . * 9Z - .4- r ---

aI-• " _ / Z ,

I,0 '!,d -,, O*Pr;i~ I iiijji"iIiIjIfa: I

l. -, t-I

+ .... . -. - -'" --- -

1'iI- C i -,,, -. - -;,.

-, i - -.'

- - ! . I

P v,.,, ,, Acct. No . Pap 5 oSubject Ald/W VComptd. By Date

"t i 4 ,At/ C 'd. By D ate

L 01.

" I

Y3. 7A

"U'

I[. I I-II* III

% --. . . .,-..-

APPENDIX E

* REFERENCES

.L ... --

I

LIST OF REFERENCES

IGENERAL

Harris, Dorothy, History of Ithaca's Water & Sewer Systems, ReprintedAugust 1956.

University of the State of New York, Geologic Map of New York, Map andChart Series No. 5, 1962.

University of the State of New York, Geology of New York, EducationLeaflet 20, Reprinted 1972.

HYDRAULICS

Chow, Ven Te, 1959, Open Channel Hydraulics, McGraw Hill.

King, H.W. and E.F. Brater, 1963,Handbook of Hydraulics, 5th Edition,McGraw-Hill

U.S. Army Corps of Engineers:

HEC-I Flood Hydrograph Package - Dam Safety Version, September 1978.

Engineering Manual 1110-2-1405; Flood-Hydrograph Analyses and Computations,August 1959.

U.S. Department of Agriculture, Soil Conservation Service:

National Engineering Handbook; Section 4 - Hydrology, August 1972.

U.S. Department of Commerce; Weather Bureau:

Hydrometeorologicdl Report No. 33: Seasonal Variation of the ProbableMaximum Precipitation East of the 105th Meridian for Areas from 10 to 1,000Square Miles and Durations of 6,12,24, and 48 Hours, April 1956.

U.S. Department of the Interior:

.. BUREC, 1977, Design of Small Dams, 2nd Ed. (rev. reprint).

USGS, 1980, Water Resources Data For New York, Western New York, USGSWater Data Report NY-80-3.

I=

V

NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION17.1 47/76) DAM INSPECTION REPORT

(By Visual Inspection) Clr of /rT*4c4

Date

Dam Number River Basin Town County Hazard Class* & Inspector

Type of Construction Use

* f Earth w/concrete spillway Water Supply

5 Earth w/drop inlet pipe E Power

- Earth v/stone or riprap spillway S Recreation-

Concrete E Fish and Wildlife

O Stone 5 Farm Pond

-5 Timber 5 No Apparent Use-Abandoned

Estimated Impoundment Size Estimated Height of Dam above Streambed

0. 1-5 acres E Under 10 feet

E 5-10 acres L] 10-25 feet

Over 10 acresc/51*6IZI Over 25 feet (qIFr-

Condition of Spillway

Service satisfactory 5 Auxiliary satisfactory

5 In need of repair or maintenance In need of repair or maintenance

Explain: 4 t A" S. e Vo $rye -aC/e

t6,jddp-&e,S got a~u J AIFlows 1. s-ee le Arie "e a & jj 'n. or

Condition of Non-Overflow Section

SSatisfactory

In need of repair or maintenance Explaii:

Condition of Mechanical Equipment

0 Satisfactory

5 In need of repair or maintenance Explain:

Evaluacion (From Vii.ua ITnspection)

ii0 5 No defects observed beyond normal maintenance

j - Repairs required beyond norml raintenance

*ExplAin H1azard Class, if Necessary *11Z ',e ~_____p.l o/ ..- . -- - - 4 *- $ " -

J. J.a,.- " k " "- " - II II ll II_ _ll_..._ "_ _ _...._,_ _ _ _,. .-,,.r.__ _ _ _, _ _ _ _ __-_ _ _ _ _ _ __, ___,, ..... .. '.'" - - -"-'- .*, .. . .,_ _ • 1

i ,,1,,.W ,WWW Putters Falls Dai.*

If Fill out a form ns complete ais pomsile for each dam in your district and scml to S:,awConservation Commission, Albany, N. Y.

i. Name and address of owners...Go ..... .............................

2. D ate of constructioninpA..I ua . ....................................................................................................... N

3. Uses of impounded water.....Clty ..... .t.er...Yatr, ............................... .

4. Character of foundation bed ......... ...........................................................................................

5. M aterial of waste spill..... C. n r .............................................................................................

6. Length of waste and depth below dan......a...I. .ft ..... pt.h -.. ............ d....... ---.................

7. Total length of dam including waste....I:ornt. ...............................................................................

8. M aterial of dam .............. ,a r .:te...arld..9tpel -...................................... ............................9. Discharges, size and location...1rin..p.p .... t...b. Q.Q..rL..J f9.r3.-... ..... in,.r.

.Tw'o Yrilms to City Filt.r plant.Below sketch section of waste and section of dam, with greatest heights and top thickness

and bottom thickness. On opposite side sketch general plan of dan and give distance froma bridge or from a tributary stream.

-. • .A ,,r .

\.

' 1 , ~~......... ..... ... ........ .. .. . ........ ............................. :., .. ...............J7831ta.rp, addreJ anti ,late.)

P ., / ./ /

I"

October 31,,1911.

In ro Potters Falls DamS #722 Oswego-Sonoca W:atershed."

Donald F. gcLeod, Esq.,

City Engineer,

Ithaca, E..Y.

Dear 3ir:-

I visited the above darn on October 26th and it appeared

to be of good proportions and run well into the rock at the

sido. I regretted, ho.ovor, to Gec it built up at an annle

of obout 45 derrees for the entire longth instoad of keeping

the top of work horizontal. T'io sand was not a good qualityp,

one-half being coi:posed of Z/8 to 5/4 inch stones and the

other half of poorly washed screenings. I suGGest that this

be washed better and a test be made to be sure that the voids

are filled; if not additional sand should be added.

I further suggest to bond each-day's work to the preced-

Ing days by longitudinal and vertical grooves formed by 6 x 6

Jolat smoothed and battered built into the concrete.

We should like to receive,for the files of this office,

! plans, sections and elevations of this dam and of all- other dams

owned or controlled by the City.

Very truly yours,

Inspector of Dars and Docks.

. ! ' - . .'. ~ .. . . . . . . . . . . . .[

. .. . -* --

.

717

Os.;oo - It.aca

Potter3 Flls dam sAtunted on .-ix -lle Creek.

Usod for water supply purposes for tho City of Ithaca.

Built of reinforced concrete 9 foot top width, 46 feet botton

width, 64 feat high, l97 feet long.

Irsocted October 20, 1911.

Concrete work ahout finished.

CorM'.ont:- The concrete work was built up at about an an;Jlo

of 4. dogrees for the entire length of the dam instead of

buildir same up in horizontal layers. Sand was not a good

quality 1/2 being composed of 3/3 to 3/4 inch stones anC +'-,

other half of poorly washed screenings; the portions of con-

crcto being 2 of cement, 4 of sand and 7 of broken stone about

2 1/2 inch size.

As at present mixed the sand would be better -.ished. 'There

necessary to fill the voids a large proportion of sand should

be added. Also there should be bettor bonding between t-o

different day's work longitudinally - horizontally and verti-"-

cally by grooves.

I..-.

APPENDIX G

DRAWINGS-

66 0 5MILE

f KDryde

WSht A-Igpo

/ aTAr 0 A

CORNELLUNIVERSI ITHACA EAST QUADRANGLE

SECOND EDITION 1978

pill

77

936 se9

LawnCeFnetory

--

4" ohm,Del, f)o

43

&

awl

%

t .0

We

Sal

a a*

ITHA COLL

p s01 TER'F LS

-.We DAMat

oZ71

,;ol

"so cl

&

'6

S ILT ADAM

x

\A

00

b205 o

7cem

SCALE 1:24000

0 Ig!m 2= mW 4m SIM Gm mW Irm

TOPOGRAPHIC MAP

POTTER'S FALLS DAMID No. NY 378

( A AO

Oed- PO"A

7(. A. OFO.

4 t

' ' fir

i .P

40--

'7A-**, ~6~

--J

ltacW Wo~ S' -'

IlWHE COCCW

4 fy

* Got&

.. .... ...

4r a 'j

-T --- T ~ .

j. 2~/. -.* 4., #9 *4 1 'V.

4 0I- 9'

1 9 . -999

tv040

Crest of Rwe /a rOO~' V bL fronit of cP

Vetted S/00epa show buW/obeyoprod Cut Orf VcoI/.

opeppig Ore

Wesl Wina Wall, 7/S5

'71 ___

4~4W

tj I -X

44

\ Nx

oll FOTT- R's FALLS 0.4M* (thCooaNy Wo/br Supf1

________SC~IOtq. A -A

s CoC/w . lin. M loft

*e if -- 's

__ _ __ _ __ _ __ _ __ _ __ _ __ _ __ _ __ _ __ _ __ _ _ __ _ __ _ __ _ ___A_ _ __ _ __ _ __ _ __ _ __ _ __ _ __ _ _

Cast sideB-

N X9

AV""

C-CWs/5

ffe -

- 7C.

IV0

Sect72 G/o Pac off i.r

FOTrEFR 3S F-ALLS D7A/<-/thocaoANy Water -SUcPP/4

s~C7r/ON.qsSB-B." ,,C-C

Ci~s co /e.- /rn.-so ft~oii~p~LJ &v4~C~ty Enyne

A /910

0- '7

4-4

WOW

F,2

U/ off

CYC/Opea,-7

-/Oc

AD-A119 9b6 METCALF AND EDDY OF NEW YORK INC NYF/ 13 3NATIONAL DAM SAFETY PRDGRA M. POTTERS FALLS DAM (INVENTORY NUMBE--ETC(U)

SEP Al G P FULTDN DACW51-Al C 0044UNCLASSIFIED NL

2,

-3 2

HIIIt 125 IiIII III.4

MIR EOP SR~ I I ICN 111,1 CHART

9

*A~I ~ / -

,~- WV-.. 49

t 4:9 .

9 ~ S.1.~ .9, * ~ .E- - .. 9:99, ** ~

9 I ~ I

.9. 2 . . SecAI ~ I I

~ ~', ~

AIX-g.

j~4evu*Br.A~nPock p'p

~.*)* *.

4.,. -

-- -

-'4

A

~ / "

'V *v;iI ;~* ~g4 4 Pt.

~UL

A ~ .~v9:~.-.9 4 9-.

J'~ 1.-~.VI4.* .. "~ 9 '.9

- LI..'

-~ -~ /~~~/%9. 648.'4 / ~ XA~

-. ~ - ... V*4.~!

-4 .

V .. *~, ~* - *l.-. ~ 9

-S

A5 % 9 --

1.

a * j 9-. -

.9

4'

- *,~ ~.4r.d,

*., -

-. e

pOng

SecA/o,,,, but~, -

011

VSe 706! 7-7 I7 9

j' W. z Abund Bar,

fil t'Ln

RocA ~ .9' .\7f Rock.

witl oofoFmpninng

* ~POrTeR'S FAILSD~tZ2C A/l o,- SE IOI,S 'o /tNN

s /1 /I/Oo,d/ Z/ft A/,/iO

Cit'y cr-

7-7

'4L_ __ _

.to -74

- '4

It

44%

'4f

el4

* . . J

JLL

% %

* S S* 4 . ~ * 1' ..

.%Not,~.

Wk

* #oil

A .

~ I.I

~.1

t.t

:..., .

* .I . .

.4.

* . -

* I- ! -. -

'9 *"I .

3

- * .~ 713, *1

.1-s

.. ~r4.~&'~V~ . . -'

.3. . -~

- ,. .. -

.4.

- -. 3

. I . % .iv'~aa .1.

.3,.',; *. 'I

A, .' *..1...L 3. .1 *

t~ ,.. .. A.

- I,' ~1

4 I 9 IrI~~ 1 j . /

- I

9.) . 3. -V '-t 4 0)16.* I ~* -- '~.. -.,-4d* -. . p

* ~./r ~. ..

- *~ . -. .4,

* ;'. * - -, I &***~A~i~ *~

- .~* 9 -, -~- '3 1~ .9

~ 124 ) ~ ~

'9 *****1

h ~ * ID..;, 49 - -. ~*~i~' -. *,~-2';

9 3I.

--

* ~~ J% j&46 6- 0 A p

e- Olttw~

e~

-ml~~~dcv* IV -cl e -v~)6

**~.. 0"w it !oiL r %5%)C;/

S '..''c

SID..

144

I

f

I