PROGRAM FOR INSPECTION OF NON-FEDERAL DAMS ii … · The dam was originally built in 1911 to provide hydroelectric power for the Rockingham County Light and Power Company. The dam

RD-R156 552 NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL DAMS iiPACKERS FALLS DAM (NH..(U) CORPS OF ENGINEERS WALTHAMMR NEW ENGLAND DIV DEC 88

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NATIONAL BUREAU OF STANDARDSMICROCOPY RESOLUTION TEST CHART

PISCATAQUA RIVER BASINDURHAM, NEW HAMPSHIRE

• ::PACKERS FALLS DAM

N H 00441(NHWRB 71.04

* Lfl

PHASE I INSPECTION REPORT

NATIONAL DAM INSPECTION PROGRAM

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.- ~JUL. 1 1 1985 :::

DEPARTMENT OF THE ARMY

4 ? NEW ENGLAND DIVISION, CORPS OF ENGINEERS

WALTHAM, MASS. 02154

_~~~!-_,=,=MoN STAUM-Ma A"::::

DECEMBER 1980 " * S,.

4:,*.~ 8 5 6 19 0 8 1

DEPARTMENT OF THE ARMYNEW ENGLAND DIVISION. CORPS OF ENGINEERS

424 TRAPELO ROAD

WALTHAM. MASSACHUSETTS 02254

REPLY TO Ilv 0ATTENTION OF: i1.i 1 9

REDED '-.-

Honorable Hugh J. Gallen

Governor of the State of New Hampshire

State HouseConcord, New Hampshire 03301

Dear Governor Gallen:

Inclosed is a copy of the Packers Falls Dam (NH-00441) Phase IInspection Report, which was prepared under the National Program forInspection of Non-Federal Dams. This report is presented for your useand is based upon a visual inspection, a review of the past performanceand a brief hydrological study of the dam. A brief assessment is in-cluded at the beginning of the report. I have approved the report andsupport the findings and recommendations described in Section 7 and askthat you keep me informed of the actions taken to Implement them. Thisfollow-up action is a vitally important part of this program.

A copy of this report has been forwarded to the Water Resources Board,the cooperating agency for the State of New Hampshire. In addition, acopy of the report ,as also been furnished the owner, City of Durham,City Hall, Durham, New Hampshire 03824.

Copies of this report will be made available to the public, uponrequest, by this office under the Freedom of Information Act. In thecase of this report the release date will be thirty days from the dateof this letter.

I wish to take this opportunity to thank you and the Water ResourcesBoard for your cooperation in carrying out this program.

Sinceel

Incl C. E. EDGAR, IIIAs stated Colonel, Corps of Engineers

Division Engineer

0iiii

S%

liNCI ASSITTMSECURITY CLASSIFICATION OF THIS PAGE (Whon Dae hneoved)

REPOT DCUMNTATON AGEREAD INSTRUCTIONSREPOT DCUMNTATON AGEBEFORE COMPLETING FORM

1. REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER

4. TITLE (tid S.61ielI) S. TYPE OF REPORT & PERIOD COVERED

*Packers Falls Dam INSPECTION REPORT

NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL 2 EFRIGOG EOTNME

DAMS__ _ _ _ _ _ _ _ _ _ _ _ _ _

7. AUTNOR(n) 4. CONTRACT OR GRANT NUMBER(o)

U.S. ARMY CORPS OF ENGINEERSNEW ENGLAND DIVISION

9. PERFORMING ORGANIZATION NAME AND ADDRIESS 10. PROGRAM ELEMENT. PROJECT, TASKAREA A WORK UNIT NUMBERS

I I. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE

DEPT. OF THE ARMY, CORPS OF ENGINEERS December 1980NEW ENGLAND DIVISION, NEDED 13. NUMMER OFPAGES

*424 TRAPELO ROAD, WALTHAM, MA. 02254 614. MONITORING AGENCY NAME 6 ADDRESS(iI different IMM GOI1,d011 ffcc) 1S. SECURITY CLASS. (of this reorot)

UNCLASSIFIEDIs. DIECL ASSI PIC ATION/ DOWNGRADING

SCHEDULE

16. DISTRIBUTION STATEMENT (of div. RePort)

APPROVAL FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED

17. DISTRIBUTION STATEMENT (of Cho abstract eeed In Black 20. It 411119rae bass Repor)

* III. SUPPLEMENTARY NOTES

Cover program reads: Phase I Inspection Report, National Dam Inspection Program;however, the official title of the program is: National Program for Inspection ofNon-Federal Dams; use cover date for date of report.

* I9. KEY WORDS (Cmftenwe on mevereod 01OO S OM ne aer nd 0,de1011I 61' by * block mem r)

DAMS, -INSPECTION, D~AM SAFETY,

Piscataqua River BasinDurham, New HampshireLamprey River.

* 20. ABSTRACT (Cotilnwo ean rovorse side If noce..arv and tdmIi#l hr black ffimbetf)

TXe dam is a 17.8 ft. high concrete gravity structure with two low embankmnentsand an old mill race gate structure. THe dam is about 200 ft. long. -. It issmall in size with a significant hazard potential. the 100 year flood has beenadopted as the appropriate test flood. The dam is in fair condition at the pre-.- .* ent time. &here are various remedial measures which the owner should implement.

*DD I ,A0R7 14731 tDITION OF I eNov I5s OBSOLETE

DISCLAIMER NOTICE

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

.- ". . . . . . . . . . . . . . . .

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-. . . . .. . . . . . . . . . . . . . . . . . . .

SSAecession For:TTS GRA&I

LDTc TABUl ,announc ed

Justifloation

NATIONAL DAM INSPECTIONDistribution/

PHASE I INSPECTION REPORT Availability Codeso Avail and/or --Dist Special

Identification No.: NH 00441 A INHWRB No.: 71.04 2Name of Dam: Packers Falls DamTown: DurhamCounty and State: Strafford, New Hampshire ----- -IStream: Lamprey RiverDate of Inspection: November 6,1980 *-

BRIEF ASSESSMENT

The Packers Falls Dam-is located on the Lamprey River, approximately one mileupstream of the village of Packers Falls in Durham, New Hampshire. WiswellRoad crosses the Lamprey River approximately 500 feet upstream of the dam.

The datis a 17.8 foot.high concrete gravity structure with two low embankmentsand an old mill race gate structure. The concrete gravity section consists ofa run-of-the-river spillway, 110 feet long, and a concrete outlet structurewith two gates. The gates are each 5 fat. high by 6 feet wide. The dam isapproximately 200 fotjlong. .

The dam was originally built in 1911 to provide hydroelectric power for theRockingham County Light and Power Company. The dam presently impounds waterfor use as a water supply for the Town of Durham and the University of NewHampshire. It is owned by the Town of Durham.

The drainage area for the dam covers approximately 183 square miles of rolling, S

forested terrain with some minor development and pasture.

The Packers Falls Dam is SMALL in size and its hazard potential classificationis SIGNIFICANT since appreciable economic loss and possible loss of a few livescould result in the event of dam failure. The appropriate test flood for a damclassified SMALL in size with a significant hazard classification would be Sbetween the 100-year flood and one half of the Probable Maximum Flood. Sincethe risk downstream is on the low side of the significant classification, the100-year flood has been adopted as the appropriate test flood.

.............

S

The analysis in Appendix D shows a peak 100-year outflow of 7,055 cfs, with thewater surface at 62.2 feet NGVD, which is 1.7 feet above the top of the dam.The spillway is capable of passing 66 percent of the Test Flood outflow beforeovertopping.

The dam is in FAIR condition at the present time. It is recommended that theowner retain the services of a qualified registered professional engineer toperform detailed hydraulic and hydrologic investigation to further define theneed for and means to increase the project discharge capacity or its ability towithstand overtopping, and to evaluate the need and make recommendations for 0the redesign or replacement of the right corewall, and to evaluate the spalledconcrete, misaligned steel sluice gate, abandoned mill race, and the effect ofthe use of flashboards on the structural stabilitiy of the dam. The spillwaysection should be inspected under low flow conditions. The engineer shouldalso make recommendations for the removal of trees from the embankments.

Remedial measures to be undertaken by the owner include removing brush fromembankment slopes, implementing an annual maintenance and inspection programs,and developing a written warning system for downstream residents in the eventof an emergency.

These engineering studies and remedial measures should be implemented by the 0owner within one year of receipt of this Phase I Inspection Report.

1,'.%'.,.

INY

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S.- . No. 21,6

TV- Lp r.VI

I'l.oOAL 0 F, NO

William S. Zoino Nicholas A. Campagna, Jr. SNH Registratip.-1lo. 3226 California Registration No. 21006

" "-..-, _.

This Phase I Inspection Report on Packers Falls Dam (NH-00441)has been reviewed by the undersigned Review Board members. In ouropinion, the reported findings, conclusions, and recommendations areconsistent with the Recommended Guidelines for Safety Inspection of -Dams, and with good engineering judgement and practice, and is herebysubmitted for approval.

.S

ARAMAST MAHTESIAN, MEMBERGeotechnical Engineering BranchEngineering Division

CARNEY H. TERZIAN, MFMBERDesign BranchEngineering Division

PW. FINEGAN JR\ CHAIMAN*WatrJControl Branc C.. -* Engineering Division

,

APPROVAL RECOMMENDED:

JOE B. FRYAR

Chief, Engineering Division S

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

PREFACE

This report is prepared under guidance contained in the Recommended Guidelinesfor Safety Inspection of Dams, for Phase I Investigations. Copies of these -,

guidelines may be obtained from the Office of Chief of Engineers, Washington,D.C. 20314. The purpose of a Phase I Investigation is to identifyexpeditiously those dams which may pose hazards to human life or property. Theassessment of the general condition of the dam is based upon available dataand visual inspections. Detailed investigation, and analyses involvingtopographic mapping, subsurface investigations, testing, and detailedcomputational evaluations are beyond the scope of a Phase I investigation:however, the investigation is intended to identify any need for such studies.

In reviewing this report, it should be realized that the reported condition ofthe dam is based on observations of field conditions at the time of inspectionalong with data available to the inspection team. In cases where the reservoirwas lowered or drained prior to inspection, such action, while improving thestability and safety of the dam, removes the normal load on the structure andmay obscure certain conditions which might otherwise be detectable if inspectedunder the normal operating environment of the structure.

It is important to note that the condition of a dam depends on numerous andconstantly changing internal and external conditions, and is evolutionary innature. It would be incorrect to assume that the present condition of the damwill continue to represent the condition of the dam at some point in thefuture. Only through continued care and inspection can there be any chancethat unsafe conditions be detected.

Phase I inspections are not intended to provide detailed hydrologic andhydraulic analyses. In accordance with the established Guidelines, theSpillway Test flood is based on the estimated "Probable Maximum Flood" for theregion (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 necessarilyposing a highly inadequate condition. The test flood provides a measure ofrelative spillway capacity and serves as an aide in determining the need formore detailed hydrologic and hydraulic studies, considering the size of thedam, its general condition and the downstream damage potential.

The Phase I Investigation does not include an assessment of the need forfences, gates, no-trespassing signs, repairs to existing fences and railingsand other items which may be needed to minimize trespass and provide greatersecurity for the facility and safety to the public. An evaluation of theproject for compliance with OSHA rules and regulations is also excluded.

. .. • _-

TABLE OF CONTENTS

Section Page

Letter of Transmittal

Brief Assessment

Review Board Page

Preface i

Table of Contents ii

Overview Photo v

Location Map vi

REPORT

1. PROJECT INFORMATION

1.1 General I-I

a. Authority 1-Ib. Purpose of Inspection 1-1

1.2 Description of Project 1-1

a. Location 1-1b. Description of Dam and Appurtenances 1-2 "C. Size Classification 1-3d. Hazard Classification 1-3e. Ownership 1-

f. Operator 1-4g. Purpose of Dam 1-4h. Design and Construction History 1-4 5i. Normal Operational Procedure 1-4

1.3 Pertinent Data 1-4

2. ENGINEERING DATA 2-1

2.1 Design Data 2-1 .

2.2 Construction Data 2-1 . -. !

ii S

... ,.:

. . .. .

I _ I - . I . , _I . . . .

TABLE OF CONTENTS - (cont.)

Section Page

2.3-Operation Data 2-1

2.4 Evaluation of Data 2-1 0

3. VISUAL INSPECTION 3-1

3.1 Findings 3-1

a. General 3-1b. Dam 3-3c. Reservoir Area 3-2d. Downstream Channel 3-3

3.2 Evaluation 3-3

4. OPERATIONAL AND MAINTENANCE PROCEDURES 4-1

4.1 Operational Procedures 4-1

a. General 4-1b. Description of any Warning System in Effect 4-I

4.2 Maintenance Procedures 4-1

a. General 4-1b. Operating Facilities 4-1

4.3 Evaluation 4-1 5

5. EVALUATION OF HYDRAULIC/HYDROLOGIC FEATURES 5-1

5.1 General 5-1

5.2 Design Data 5.1 •

5.3 Experience Data 5-1

5.4 Test Flood Analysis 5-1

5.5 Dam Failure Analysis 5-2 0

iii S

. . . .. . . . -•i .-. -. . - -. .- -L :- - . . , , .: . : :

TABLE OF CONTENTS - (cont.)

Section Page

6. EVALUATION OF STRUCTURAL STABILITY 6-1

6.1 Visual Observation 6-1

6.2 Design and Construction Data 6-1

6.3 Post-Construction Changes 6-1 0

6.4 Seismic Stability 6-1

7. ASSESSMENT, RECOMMENDATIONS AND REMEDIAL MEASURES 7-1

7.1 Dam Assessment 7-1

a. Condition 7-1b. Adequacy of Information 7-Ic. Urgency 7-i

L 7.2 Recommendations 7-1 0

7.3 Remedial Measures 7-2

7.4 Alternatives 7-2

APPENDICES "

APPENDIX A INSPECTION CHECKLIST A-I

APPENDIX B ENGINEERING DATA B-i

APPENDIX C PHOTOGRAPHS C-i

APPENDIX D HYDROLOGIC AND HYDRAULIC COMPUTATIONS D-I

APPENDIX E INFORMATION AS CONTAINED IN THE NATIONAL E-i 0INVENTORY OF DAMS

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GOLOBERG' ZOINO$ ASSOCIATES,INC. U.S. ARMY ENGINEER DIV. NEW ENGLANDFROM USGS NEW MARKET- N.H. GEOTECHNICAL-GEO4YOROLOGICM. CONSULTANTS I CORPS OF ENGINEERSQOAO RANGLE MA .

NEWTON UPPER FALLS, MASSACHUSETTS WALTHAM. MASS CHUSI"ItT

NATIONAL PROGRAM OF INSPECTION OF NON-FED. DAMS

LOCATION PLAN0z

-j PACKER FALLS DAM . DURHAM NEW HAMPSHIREI SCALE AS SHOWN

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National Dam Inspection Program

Phase I Inspection Report

Packers Falls Dam S

Section I: Project Information

1.1 General

(a) Authority

Public Law 92-367, August 8, 1972, authorized the Secretary of theArmy, through the Corps of Engineers, to initiate a National Progam of DamInspection throughout the United States. The New England Division of theCorps of Engineers has been assigned the responsibility of supervising theinspection of dams within the New England Region. Goldberg-Zoino &Associates, Inc. (GZA) has been retained by the New England Division toinspect and report on selected dams in the State of New Hampshire.Authorization and notice to proceed were issued to GZA under a letter ofSeptember 23, 1980 from Colonel William E. Hodgson, Jr., Corps ofEngineers. Contract NO. DACW 33-80-C-0055 has been assigned by the Corps Sof Engineers for this work.

(b) Purpose

1) Perform technical inspection and evaluation of non-federal damsto identify conditions which threaten the public safety and thus Spermit correction in a timely manner by non-federal interests.

2) Encourage and prepare the states to initiate quickly effectivedam safety programs for non-federal dams.

3) Update, verify, and complete the National Inventory of Dams.

1.2 Description of Dam

(a) Location

The Packers Falls Dam is located on the Lamprey River approximatelyone mile upstream of the village of Packers Falls in Durham, NewHampshire. It can be reached from Wiswell Road which crosses the LampreyRiver just upstream of the dam.

The dam is shown on USGS Newmarket-NH quadrangle at approximatelycoordinates N4306.2, W7057.8 (see location map on Page vi). Page B-2 of 0Appendix B is a site plan for this dam.

4S

1-1 . -

0

(b) Description of Dam and Appurtenances

Packers Falls Dam is a 17.8-foot-high concrete gravity dam with twolow earth embankments and an old mill race gate structure. The concretegravity section contains a run-of-the-river spillway and a concrete outlet Sstructure with two gates. The overall length of the dam is approximately200 feet, of which 110 feet is spillway. The dam consists of the -following components:

1) Right Embankment (see Page B-4)0

At the right abutment is a 19-foot-long, 4-foot-high earthembankment with a 12-inch-thick unreinforced concrete corewall. Thecorewall extends about 1 foot above the earth fill on the upstreamside and about 3-1/2 feet above the earth fill on the downstreamside. Both up and downstream slopes are irregular and averageapproximately 1 vertical to 3 horizontal. 0

2) Right Spillway End Wall (see Pages B-2 and B-4)

The right concrete corewall abuts a concrete end wall which is2-1/2 feet wide by 13.5 feet long. This end wall is part of theconcrete gravity spillway. The top of the end wall is at Elevation 060.5 feet (NGVD). This elevation has been adopted as the top of thedam. There is rubble stone masonry training wall extendingdownstream from this end wall for approximately 20 feet.

3) Spillway (see Pages B-2, B-4, and B-5)

The spillway is a concrete ogee structure founded on bedrock.The crest is 110 feet long with crest elevation 55.7 feet (NGVD). -There are three concrete buttresses, roughly at the quarter points ofthe spillway on the downstream side. They are about 1 foot wide by 6feet long and 1 foot deep.

4) Gate Structure (see Pages B-2, B-4 and B-5) *1

At the left end of the spillway is a concrete gate structure withtwo outlet gates. The wasteway openings are 5 feet high by 6 feetwide with invert elevations at 48.0 feet (NGVD). The gates are ofaluminum and steel with 2-inch-diameter stainless steel riser stems. SThe hoisting equipment are two crank-operated floor stands mounted onsteel wall brackets.

The gate structure is concrete with a more recent layer ofpneumatically applied mortar (gunite) over the entire surface. Thetop of this structure is about 3.5 feet wide by 20 feet long and ties Sdirectly into a concrete end wall at the left end.

1-2

* . . ... S . . . " '- .- - - , , ' : . . . . .

5) Left End Wall (See Pages B-2 and B-4)

The left concrete end wall is approximately 11 feet long by 2feet wide with the top at elevation 60.8 feet (NGVD). The sides of Sthe end wall have a recent coating of pneumatically applied mortar.Extending downstream from this end wall is a rubble masonry training -wall. The portion of this wall within 10 feet of the end wall hasalso been covered with pneumatically applied mortar. The training -wall extends several hundred feet downstream.

6) Left Embankment (see Pages B-2 and B-4)

To the left of the end wall is a 30-foot-long earth embankmentwith a 12-inch thick concrete corewall. This earth embankment isapproximately 4 feet high with crest elevation approximately 60.8feet (NGVD). The upstream and downstream slopes appear to be Sapproximately 1 vertical to 2 horizontal.

7) Mill Race Gate Structure (see Pages B-2, B-4, and B-5)

At the left end of the left embankment is a reinforced concretemill race gate with three gate openings. The mill race canal Supstream of this gate structure has been partially filled with earth.The hoisting mechanism and gate stems for the old wooden gates havebeen removed. The partially deteriorated old wooden gates are stillin place but are no longer operable. Extending downstream from thegate structure is an old mill race canal which is no longer used.The canal is approximately 10 feet wide with vertical stone masonrywalls on either side.

If flond stage reaches sufficient height, the partially filledmill race canal may be overtopped prior to overtopping of the dam.It is probable that failure of this fill section would wash out thetimber gate structure as well. .

(c) Size Classification

The dam has a maximum impoundment of 500 acre-feet and a height of17.8 feet. According to the Corps of Engineer's Recommended Guidelines,a small size dam is one with a maximum storage between 50 and 1000 acre- 0feet or a height between 25 and 40 feet. Therfore, this dam is classifiedOq small in size based on its storage.

(d) Hazard Potential Classification

The hazard potential classification for this dam is SIGNIFICANT Sbecause of the appreciable economic losses and ootential fnr Inss of a f-.1lives downstream in the event of dam failure. There are two houses located2,200 feet and 3,000 feet downstream which could be affected by the damfailure flood. The prefailure flow conditions would cause no flooding, butthe post-failure flow would cause 1-2 feet of flooding above the first floorlevel in the first home and 4-1 feet of floodinr above the first floor level Sin the second home.

1-3

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(e) Ownership

The dam is presently owned by the City of Durham, New Hampshire. Itis controlled by the Department of Public Works, Durham, New Hampshire,03824.

(f) Operator

The operation of the dam is controlled by the Department of PublicWorks. The Public Works Director, Mr. George Crombie can be reached bytelephone at (603) 868-5571

(g) Purpose of the Dam

The dam was originally constructed to provide hydroelectric power.At present, the sole purpose of the dam is to impound water to be used as S

water supply for the Town of Durham and the University of New Hampshire.

(h) Design and Construction History

The dam was originally constructed in 1911 to provide hydroelectricpower for the Rockingham County Light and Power Company. Some repair workat the gate structure was undertaken in 1966 although all of the workshown on the design drawings was not completed.

(i) Normal Operating Procedures

No formal operating procedures exist for this dam. The steel wastegates are normally closed. The abandoned timber sluice gates areinoperable.

1.3 Pertinent Data

(a) Drainage Area a

The drainage area for thi., dam covers 183 square miles. It is madeup primarily of rolling woodland and pasture.

(b) Discharge at Dam Site

1) Outlet Works

The outlet works for this dam consists of two steel gatedwasteways at the left abutment. These are each 5 feet wide by 5 feethigh with inverts at Elevation 48.0 feet (NGVD). The capacity ofthese gates with the reservoir at top of dam elevation (60.5 feet SNGVD) is 1,644 cfs.

2) Maximum Known Flood

Based on the flows recorded at a gauging station downstream ofthe dam, the maximum known flood occurred in March, 1936, with a flowat the dam of approximately 5,590 cfs. A flood of 5,000 cfs occurredin March 1977.

1-4

3) Ungated SpilIway Capacity at Top of Dam

The capacity of the spillway with the reservoir at the top of thedam elevation (60.5 feet NGVD) is 4,650 cfs. a

4) Ungated Spillway Capacity at Test Flood

The discharge capacity above the spillway at the test floodelevation (62.2 feet NGVD) is 6,600 cfs.

5) Gated Spillway Capacity at Normal Pool

There are no gated spillways.

6) Gated Spillway Capacity at Test Flood

There are no gated spillways

7) Total Spillway Capacity at Test Flood

The capacity of the spillway at Test Flood elevation (62.2 feetNGVD) is 6,600 cfs.

8) Total Project Discharge at Top of Dam

The total project discharge at top of dam elevation (60.5 feetNGVD) is 4,650 cfs.

9) Total Project Discharge at Test Flood Elevation

The total project discharge at Test Flood elevation (62.2 feet

NGVD) is 7,055 cfs.

(c) Elevation (feet NGVD)

1) Streambed at toe of dam: Approximately 42.7

2) Bottom of cutoff: Unknown

3) Maximum tailwater: Unknown S

4) Normal Pool: Approximately 55.7

5) Full flood control pool: Not applicable

6) Spillway crest: Approximately 55.7

7) Design surcharge: Unknown

8) Top of dam: 60.5

9) Test flood surcharge: 62.2 S

1-5S

(d) Reservoir (length in feet)

Thib is a run of the river dam with a reservoir length ofapproximately 7,000 feet.

(e) Storage (acre-feet)

1) Normal Pool: 360

2) Flood Control Pool: Not applicable

3) Spillway Crest Pool: 360

4) Top of Dam Pool: 500

5) Test Flood Pool: 560

(f) Reservoir Surface (acres)

This is a run-of-the-river dam with a reservoir surface area of 30acres.

(g) Dam 0

1) Type: Gravity, overflow, concrete

2) Length: Approximately 200 feet

3) Height: Approximately 18 feet

4) Top width: Approximately 4 feet, variable

5) Side slopes: Left Embankment: 1 vertical to 2 horizontalRight Embankment: I vertical to 3 horizontal

6) Zoning: Not applicable.

7) Impervious Core: Not applicable

8) Cutoff: Unknown

9) Grout curtain: Unknown

(h) Diversion and Regulating Tunnel

Not applicable

(i) Spillway

1) Type: Concrete, broad crested weir

2) Length of weir: 110 feet

3) Crest elevation: 55.7 feet (NGVD)

1-6

S

4) Gates: Spillway not equipped with gates

5) Upstream channel: Lamprey River

6) Downstream channel: Lamprey River

(j) Regulating Outlets

The regulating outlets at this dam consist of two 5 foot by 6 footwasteways equipped with vertical stem steel slide gates. The invertelevation of these wasteways is 48.0 feet (NGVD). The water supply outletis located more than one half mile upstream. It is normally closed,having been used only twice in the last ten years according to the owner.

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1-7 •.

Section 2: Engineering Data

2.1 Design Data

None of the original design drawings or calculations are available forthis dam. Lacking are data concerning the length and depth of any cutoff andthe foundation conditions, and the cross section of the spillway. Availabledata include preliminary design drawings for the 1966 repairs. These weredrawn by Camp, Dresser & McKee Consulting Engineers of Boston, Massachusettsand dated March, 1966. Also available are the specifications for this work, Sdated April, 1967. Some early inspection reports are available and have beenincluded in Appendix B of this report.

2.2 Construction Records

No construction records are available for this dam.

2.3 Operational Records

No operational records are available for this dam.

?.4 Evaluation of Data S

a) Availability

There is no detailed design or construction data available forevaluation.

(b) Adequacy

The lack of in-depth engineering data does not permit a definitivereview. Therefore, the adequacy of the dam cannot be assessed from thestandpoint of reviewing design and construction data. This assessment ofthe dam is based primarily on the visual inspection, past performance, andsound engineering judgment.

(c) Validity

The observations of the inspection team generally confirm theinformation contained in the records of the New Hampshire Water Resources 0Board. However, the preliminary design drawings for the repair work showsome work items which apparantly were not accomplished. In particular,the placement of backfill around the abandoned gate structure indicated onSheet No. 2 of the preliminary drawings has not been accomplished (seepage B-4 and C-7 of this report). Indicated repairs to the right abutmenthave not been accomplished. Caution must be taken in reliance on any data 0

contained on these drawings and specifications without a thoroughexamination.

p2-1

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I

Section 3: Visual Inspection

3.1 Findings

(a) General

The Packers Falls Dam is in FAIR condition at the present time.

(b) Dam

(1) Right End Wall (see Photos 3, 4, and 5)

The concrete right end wall, which was treated withpneumatically applied mortar, has been subjected to spalling ov'-approximately 75 percent of its exposed surface area. The remainingportion of this wall has been subjected to random cracking. The Sspalling and cracking can be attributed to poor quality control ofmortar application and subsequent deterioration. This deteriorationresulted in moisture intrusion and subsequent freeze-and-thaw cyclescaused further deterioration. The interface of the end wall and thespillway has eroded in excess of 12 inches which can be attributed tocavitation and subsequent ice damage.

The downstream extension of this wall, which consists of dryrubble stone masonry, is in fair condition with no evidence ofsettlement, bulging, or distress. However, there are large voids inthis wall.

The concrete core wall which extends into the right embankmenthas been subjected to partial failure. The center section of thiswall has sheared from the adjacent sections and is leaning in thedownstream direction. It has displaced up to 6 inches.

(2) Spillway (see Photos 1 and overview)

The spillway was inspected under high flow conditions. It is aconcrete structure founded on bedrock which was repaired with anapplication of pneumatic mortar. There are two continous horizontalconstruction joints in the mortar application which have beensubjected to spalling. These horizontal joints are located

approximately I foot and 10 feet below the crest of the spillway. Aconsiderable amount of pneumatic mortar has been eroded from thedownstream face of the spillway. The deterioration can be attributedto ice damage.

Pipe sockets for flashboard stanchions are located along the S

entire length of the spillway crest, but flashboards are not used.

(3) Waste Gate Structure (Steel Gates) (see Photos 6 and 7)

This is a concrete structure which was repaired with anapplication of pneumatic mortor. This structure has been subjectedto a high degree of spalling on its upstream face and the

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intermediate buttress on the downstream side. There is considerablerandom cracking and efflorescence over the entire surface of thepneumatically applied mortar. This condition also applies to theroofs and walls of the outlet tunnels. A high concentration ofstalactites were observed hanging from the outlet tunnel roofs. Theoverall spalling and cracking condition can be attributed to moistureintrusion subjected to alternate freeze-and-thaw cycles.

Observations of the bench stands revealed that the left stand ismisaligned and tilting downstream. The misaligment has causedbinding in the gate which precludes complete seating. Seepage is eapproximately 1 cfs of clear flow. Observations of the gates fromthe downstream tunnels revealed that they are in good condition, butappear to be inoperable. The gate operating wheels are storedoff-site in order to prevent unauthorized use.

(4) Left End Wall (see Photo 8)

The left end wall is a concrete structure which was repairedwith an application of pneumatic mortar. With the exception of minorsurface cracking, this wall is in good condition with no evidence ofsurface spalls or efflorescence.

(5) Left Embankment Core Wall (see Photo 9)

This concrete structure is in good condition with the exceptionof minor surface cracks. There is no evidence of surface spalls oreffl orescence.

(6) Mill Race Gate Structure (Timber gates) (see Photos 10 and 11)

This reinforced concrete structure has been subjected to aconsiderable degree of surface spalling on both the upstream anddownstream faces. Reinforcing steel is exposed and rusted.Observations revealed that this structure houses three timber sluice .0

gates. The timber stems of these gates have been cut offapproximately 8 feet below the concrete platform. All operatingmechanisms have been removed. The forebay entrance has beenpartially filled with earth. Standing water was observed downstreamof this structure which may be seepage although no visible flow wasnoted.

The downstream canal walls consist of dry stone masonry. Thesewalls are in good condition.

(c) Reservoir Area (see overview photo)

The reservoir is the Lamprey River channel. The shores of thechannel are generally shallow sloping woodland. They appear to be stableand in good condition.

3-2

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The Wiswell Road crosses the reservoir approximately 150 to 200 feetupstream of the dam. The bridge consists of two simply supported spans ofapproximately 30 feet each. The spans are Steel I Beam construction andare supported on granular fill.

(d) Downstream Channel (see Photo 2)

The downstream channel is the Lamprey River channel. In general, itis stable, and in good condition.

3.2 Evaluation

The dam and its appurtenant structures are generally in fair condition.The problem areas noted during visual inspection are listed as follows:

(a) Spalled concrete and deterioration of pneumatic mortar at right end S

wall and gate structure.

(b) Misalignment of left sluicegate and its operating mechanism.

(c) Failure of right core wall.

(d) The spillway should be inspected under low flow conditions.

(e) Trees and brush growing on embankments.

(f) Possible use of flashboards and their effect on structural stability.

(g) Possible failure of mill race canal prior to dam overtopping.

3-3

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Section 4: Operational and Maintenance Procedures

4.1 Operational Procedures

(a) General

No written operational procedures exist for this dam. The outflow isnormally uncontrolled. The water supply outlet is approximately one halfmile upstream of the dam. From this pumping station, the water is carriedthrough pipes to a small reservoir on the Oyster River. It is intended Sto serve as an emergency (drought) water supply, however, accordinq to atown official, this water supply has not been used for at least five years.The operability of the pumps was last checked two or three years ago.

(b) Description of any Warninq System in Effect

There is no downstream warning system in effect at this dam.

4.2 Maintenance Procedures

(a) General

No formal maintenance program exists for this dam, and maintenance isperformed infrequently.

(b) Operating Facilities

No formal maintenance program exists, and maintenance is performedinfrequently.

4.3 Evaluation

Emphasis on routine maintenance will assist the owner in assurinq thelong-term safety of the dam and operating facilities. A formal, written,downstream emergency warning system should be developed for this dam.

4

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Section 5: Evaluation of Hydraulic/Hydrologic Features

5.1 General

The principal spillway for Packers Falls dam is 110 feet wide with aheight of about 12 feet above the streambed. The dam also has two 5-foot highby 6-foot wide sluice gates. The impounding capacity at normal pool is 360acre-feet, with a maximum impounding capacity of 500 acre-feet.

In the left overbank area are the remains of an old bypass structure which eis blocked with fill and no longer used. The overbank on either side isheavily wooded. The stream slopes very gradually for approximately 3,200 feetdownstream of the dam to the location of a stream gauging site discussed inSection 5.3. Just downstream of the gauge, the river gradient increasessharply. About 200 feet downstream of the gauge is a 36 foot wide by 18 foothigh concrete arch bridge in relatively good condition. During the flood of S1977, which produced a flow of about 5,000 cfs, the arch was about half full.

After the Packers Falls Bridge, the river again takes on a flat gradient,and the river banks become wider. The hydrologic storage increases as theLamprey River approaches the sea and the low-lying area becomes marshy. Theriver eventually reaches Newmarket, about 3 miles downstream of the dam. S

5.2 Design Data

Data sources for Packers Falls Dam included preliminary plans of the damsite before general maintenance improvements were made in 1966. Also availableis the New Hampshire Water Resources Board's January 29, 1980 "Inventory ofDams in the United States" and a 1939 sketch. Copies of this material can befound in Appendix B of this report.

5.3 Experience Data

Located about 3,000 feet downstream of the dam is a U.S. Geological Survey S

stream gauging site. The difference in drainage area between the two sites isminimal and for the purposes of this report will be neglected. Stream gaugerecords at the Lamprey River site are excellent with a period of record fromJuly 1934 to the current year. The greatest discharge recorded at the site is5,590 cfs, which occurred in March of 1936. Another high discharge (5,000 cfs)was recorded in 1977 and flood notes were taken by the stream gauge operator Sfor the surrounding area. Packers Falls Dam was not overtopped during thishigh runoff, but according to the operator, the dam did appear to be in dangerof overtopping.

5.4 Test Flood Analysis

Guidelines for establishing a recommended Test Flood based on the size andhazard classification of a dam are specified in the "Recommended Guidelines" ofthe Corps of Engineers. The impoundment of 500 acre-feet and the height ofless than 40 feet classify this dam as a SMALL structure.

The appropriate hazard classification for this dam is SIGNIFICANT because S

of the potential for loss of a few lives at two houses and related economic

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losses. As shown in Table 3 of the "Recommended Guidelines," the appropriateTest Flood for a dam classified as SMALL in size with a SIGNIFICANT hazardpotential would be between the 100 year flood and half the Probable MaximumFlood (PMF). Since the risk downstream in the event of failure is on the lowside of SIGNIFICANT, the appropriate Test Flood is the 100-year event.

Using the Log-Pearson Type III analysis of the stream gauge recordsdownstream, the 100 year flood (.01 annual exceedance probability) is 7,055cfs. This is 6.5 feet above the main spillway crest and 1.7 feet above theleft abutment. The spillway capacity of 4,650 cfs with the water surface atthe dam crest is 67 percent of the peak test flood outflow of 7,055 cfs.

5.5 Dam Failure Analysis

The peak outflow at Packers Falls Dam that would result from dam failureis estimated using the procedure suggested in the "Rule of Thumb Guidelines forEstimating Downstream Dam Failure Hydrographs." Failure is assumed to occurwith the pool level at the top of the left abutment, 4.8 feet above thespillway crest. This is 17.8 feet above the natural streambed level. Justprior to failure, the normal outflow through the spillway would be 4,650 cfs.Assuming a 55 foot gap is opened in the dam, the peak failure outflow throughthis gap and over the remainder of the spillway would be 9,890 cfs.

Four houses are located in the reach extending from the dam to the PackersFalls bridge about 3,200 feet downstream. The first house is greater than 20feet above the streambed and is about 800 feet downstream of the dam on theleft bank. Two more houses, 15 and 20 feet above the streambed, are locatedabout 2,200 feet downstream of the dam. The last house, on the left Kaik, isabout 12 feet above the streambed at the stream gauging site discussed inSection 5.3.

Within this reach only two houses will be affected by flooding. The houselocated 2,200 feet downstream and 15 feet above the channel bottom, is abovethe prefailure flow stage of 11.8 feet. The failure flow of 9,890 cfs createsa stage of 16.6 feet and will probably cause damage to this house.

The second house to be affected by flooding is located at the gauging site3,000 feet downstream of the dam. The prefailure stage of 11.8 feet may causesome minor damage, but the 16.6 foot stage created by the failure flood willcertainly damage the structure and the possibility of loss of life exists.

The failure flow then enters the Packers Falls section of the LampreyRiver, at the end of which is Packer Falls bridge. The rating table for thisbridge indicates that the failure flow will only create a stage of about 8.5feet, so the bridge will probably not be overtopped. The structure is inrelatively good condition, so no damage is expected here.

Downstream of the bridge, no serious damage is expected from the failureflow. Housing in the area is well above the failure flow stages, and the wide

and swampy overbanks provide ample storage for attenuation.

Because of this potential for loss of a few lives at two houses andrelated economic losses, the hazard classification for Packers Falls Dam isSIGNIFICANT.

5-2

Section 6: Structural Stability

6.1 Evaluation of Structural Stability 0

(a) Visual Observations

The Packers Falls dam is in FAIR condition at the present time.Considerable spalling of concrete was noted in the right end wall, thespillway, the gate structure, and the abandoned mill race gate structure. SThe right corewall has failed The left sluice gate operating mechanism isout of alignment.

(b) Design and Construction Records

No plans or calculations of value to a stability assessment areavailable for this dam.

6.2 Design and Construction Data

No records of structural stability analyses are available for this dam.

6.3 Post Construction Changes

The dam was constructed in 1911. The dam was repaired in 1967 includingthe installation of two new metal sluice gates and bench stands.

6.4 Seismic Stability U

The dam is located in seismic zone No. 2, and, in accordance with therecommended Phase I guidelines, does not warrant seismic analysis.

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Section 7: Assessment, Recommendations and Remedial Measures

7.1 Dam Assessment

(a) Condition

The Packers Falls Dam is in FAIR condition at the present time.

(b) Adequacy of Information

The lack of in-depth engineering data does not permit a definitivereview. Therefore, the adequacy of the dam cannot be assessed from thestandpoint of reviewing design and construction data. This assessment isbased primarily on the visual inspection, past performance, and soundengineering judgement.

(c) Urgency

The Engineering studies and improvement described herein should beimplemented by the owner within one year of receipt of this Phase 1Inspection Report.

7.2 Recommendations

It is recommended that the services of a qualified registered professionalengineer be retained to

(a) Conduct a detailed hydraulic and hydrologic study to further definethe need for and means to increase the project discharge capacity and theability of the dan to withstand overtopping

(b) Evaluate the need and make recommendations for the redesign orreplacement of the right corewall.

(c) Inspect the spillway under low flow conditions and evaluate theeffect on the structural stability if flashboards were used.

(d) Develop a method to remove all trees from the embankments, includingthe roots, and backfill the resulting voids with suitable compactedmaterial. S

(e) Evaluate the misaligned steel sluice gates and make recommendationsfor repair.

(f) Evaluate the condition of the abandoned mill race and makerecommendations for appropriate treatment. S

The owner should implement the findings of the above engineering studies.

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7.3 Remedial MeasuresIt is recommended that the following remedial measures be undertaken by

the owner:

(a) Remove all brush from the embankments.

(b) Implement a program of annual technical inspections of the dam andits appurtenances including operation of all functional outlet works.

(c) Develop a plan for surveillance of the dam during flood periods and aformal written downstream emergency warning system for warning downstreamresidents and officials.

(d) Implement and intensify a program of diligent and periodicmaintenance. 0

7.4 Alternatives

There are no meaningful alternatives to the above recommendations.

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APPENDIX A

VISUAL INSPECTION CHECKLIST

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Inspection Team Organization

DATE: November 4, 1980

PROJECT: NH00441Packers Falls DamDurham, New HampshireNHWRB 71.04

WEATHER: Clear, warm

INSPECTION TEAM:

Nicholas A. Campagna Goldberg-Zoino & Assoc. Team CaptainWilliam S. Zoino GZA SoilsJeffrey M. Hardin GZA SoilsAndrew Christo Andrew Christo Engineers StructuresPaul Razgha ACE Structures S

Carl Razgha ACE StructuresBrian Chevalier Resource Analysis, Inc. HydrologyRichard Laramie RAI Hydrology

NHWRB Representative Present - Richard Debold S

NOTE: Brian Chevalier and Richard Laramie of Resource Analysis Inc., - .

performed the hydrologic inspection of this dam on October 24, 1980Paul Razgha and Carl Razgha of Andrew Christo Engineers, performed "the structural inspection of this dam on November 13, 1980.

* S

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PACKERS FALLS DAM November 4, 1980

Durham, New Hampshire NH00441

CHECKLIST FOR VISUAL INSPECTION

AREA EVALUATED BY CONDITIONS AND REMARKS

DAM EMBANKMENT

Crest Elevation 60.5 feet (NGVD)

Current Pool Elevation Approximately 56.0 feet(NGVD)

Maximum Impoundment to Date Unknown 0

Surface Cracks None noted

Pavement Conditions Not applicable

Movement or Settlement of Crest None noted

Lateral Movement None noted

Vertical Alignment Good

Horizontal Alignment Good

Condition at Abutment and atConcrete Structures Good

Indications of Movement ofStructural Items on Slopes Corewall in right embank-

ment has been subjectedto partial failure

Trespassing on Slopes None noted

Vegetation on Slopes Much brush and smalltrees growing on bothleft and right embank-ments

Sloughing or Erosion of Slopesor Abutments None noted

Rock Slope Protection - RiprapFailures None

Unusual Movement or Cracking at noe Sor near Toes None noted

A-3 S




AREA EVALUATED BY CONDITIONS AND REMARKS 0

Unusual Embankment or DownstreamSeepage None noted with exception

of abandoned sluicewaydiscussed at that item

Piping or Boils None noted

Foundation Drainage Features None

Toe Drains None

Instrumentation System JA None

LEFT EMBANKMENT CORE WALL

Condition of Concrete Good, some minor surfacecracks

Rusting or Staining None noted

Spalling None noted 0

Visible Reinforcing None noted

Seepage None noted

Efflorescence None noted 0

RIGHT EMBANKMENT CORE WALL

Condition of Concrete Partially failed, centralsection leaning down-stream, approximately 6inch displacement

Rusting or Staining None noted

Spalling None noted


Seepage None noted

Efflorescence None noted

* A-4 0





OUTLET WORKS - SPILLWAY WEIR,APPROACH AND DISCHARGE CHANNELS

a. Approach Channel P

General Condition Gord

Loose Rock OverhangingChannel None

Trees Overhanging Channel Some overhanging trees up

to 12 inch diameter. Notsignificant

Floor of Approach Channel JA Submerged

b. Right End Wall

Condition of Concrete Poor

Erosion Up to 12 inches oferosion at interface withspillway

Spalling 75% of subsurface areaspalled

Cracking Non-spalled surfacessubjected to high degreeof random cracking

Rusting or Staining ofConcrete None noted



Seepage None noted

c. Spillway Weir

Condition of Concrete Fair

Erosion - Spalling /+- Pneumatic mortar ondownstream face heavilyeroded

A-5 5





Cracking Two continuous horizontalconstruction jointsspalled




Seepage None noted

d. Left End Wall

Condition of Concrete Good

Erosion None noted

Spalling None noted

Cracking Minor


Visible Reinforcing None noted 5


Seepage 4qc None noted

e. Discharge Channel

General Condition JM 4 Good

Loose Rock OverhangingChannel None

Trees Overhanging Channel Minor

Floor of Channel Submerged

Other Obstructions Am P Some minor debris

A-6 5





OUTLET WORKS - OUTLET STRUCTURE

a. Gate Structure

Condition of Concrete Ac- Poor

Erosion None noted

Spalling Extensive on upstreamface and downstreamintermediate buttress

Cracking Extensive cracking overfinished surface ofpneumatically applied S

mortar



Efflorescence Extensive over non-spalled concretesurfaces. High degreesof stalactite concen-tration on roof of outlettunnel s

Seepage None noted

Sluice Gates 4c- Left bench stand tilteddownstream, gate not Sseated. Continuous flowaround gate. Right gateseated and in goodcondition

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Durham, New Hampshire NH00441 0



b. Mill Race Gate Structure

Condition of Concrete A Poor

Erosion None noted

Spalling Heavy on upstream anddownstream faces

Cracking Considerable random 0

cracking

Rusting or Staining ofConcrete At exposed reinforcing

steel

Efflorescence At random cracking

Visible Reinforcing Extensive on upstreamand downstream faces

Efflorescence Considerable on upstream 0and downstream faces.

Sluice Gates Gates buried, stems andoperating mechanismsremoved. Forebayentrance filled with 0earth

Seepage Minor

A-8

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APPENDIX B

ENGINEERING DATA'p.a S

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THE STATE OF NEW BESHIRE

County of Strafford ss. March 28. 66

STAMMT OF INTENT TO CONSTRUCT OR 6

RECONSTRUCT A DAM AT Durham. N H.

TO THE WATER RESOURCES BOARD: APR 1 9 1966

In compliance with the provisions of RSA 482:3. NEW HArMPSHIRE,',, r ' ifS01jRr':s B , ,A?

V':-Ci The Boawrd of Selectmnen: Durha-m New 14ampshirt-

(Eere state arze of person or persons, partnership, association, corporation,

etc.)

hereby state our intent to the Water Resources Board toto rake repairs to, a dam x or (cross out portion not applicable) across:

The Lamprey River(Eere state name of stream or body of water)

At a point near Wiswell Road, Durham, New Hampshire, approximately 2.6 miles" (Here give location, by distance from mouth of stream, county or

north and west of the Strafford-Rockingham county linemunicipal boundary)

in the town (s) of Durham, New Hampshire

in accordance with PRELIV aRY PLANS, and SPECIFICATIONS FILED WITH THIS STATE=IAND MADZ A PART HEREOF.we)

We, understand that more detailed plans and specifications may be requested

by zhe B-ard in conformance with PSA 482:4 and that, if such plans are requested,construction will not commence until such plans have been filed with and approvedby the Board.

B-6

The purpose of the proposed construction is to restore the

(Here briefly state use toexisting dam and sluice gates. The impounded water is to be used as an

3 which stored water is to be put)-

additional water suply for the Town of Durhaim and the

University of New Hampshire

The construction will consist of restoring the existing concrete(Here give brief description of 0

surfaces with pneumatically applied mortar, installing new sluice gates andwork contemplated including height of dam)

the filling of the existing canal.

All land to be flowed is not owned by applicant.

• See note below Board of Selectmen

/I A-f .A.. 41

Address Town Hall

* Durham, New Hampshire

Note: This statement together with plans, specifications and information anddata filed in connection herewith will remain on file in the office ofthe Water Resources Board. This statement is to be filed in duplicate.

Note: No change in elevation of the existing dam is proposed. 6

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April 26, 1966

ff Mr. William E. Macley, Jr.Camp,, Dresser & McKee18 Treimont StreetBoston, Massachusetts 02108

Dear Mr. Mackey:

One copy of the plans you submitted on the kers FallsDam has been forwarded to the New Hampshire Fish d CameDepartment.

They have indicated that th like a c waterpipe included in the dam so that idle flow is as d tomaintain fish life at all times

Also, they mentioned possibi y of a fish ladder.I suggest that you contact them ec to work out thesepoints. The individual to contac Allen 1.I. Lewis, Fishand Came Engineer, N. . d CA partment, 34 BridgeStreet, Concord, N aMpshir 301.

The Wate 1 fesources Boar ill temporarily withholdapproval pending he outcome of t Fish and Came requests.

If you ha any questlo aplease contact us.

Very truly yours,

Wayne E. Kibby0 Civil Engineer

wek: c

B -9

Mr. Smith, Pub.Serv.Co. of N.H. phoned at 2:00 - Sept. 15, 1960

Newmarket Company sold the Packer's Falls to the Lamprey River ImprovementCompany who in turn sold it to the New Hampshire Gas and Electric Company,now the New Hampshire Electric Company. Sold it on December 28, 1945,recorded in Book 1043, Page 17.

On October 10, 1955 New Hampshire Electric Company conveyed to the MacaLlenCompany in Newmarket various pieces of land and also conveyed as follows:Such rights and interests in that portion of the Lamprey River extendingnortherly from said dam in Newmarket to Packer's Falls, so-called,in Durham, together with such other rights and privileges in thePiscassic River, Sheppard's Brook, Oyster River, Doe's Moat in theTowns of Durham and Newmarket, including rights of flowage, drainage,dyking privileges and such other rights as were originally acquiredby the New Hampshire Gas and Electric Company, now New HampshireElectric Company, by deed of the Lamprey River Improvement Company

L dated December 28. 1945. Such rights and interests as herein conveyedare limited strictly to the areas herein specified and do not includeany similar rights and interests in the Towns of Barrington and Leeor in the Town of Nottingham.

Deed read from is recorded but Mr. Smith just had a copy of it so doesnot know the book number or page. Could be looked up in the RockinghamCounty Registry of Deeds.

Mr. Smith believes it includes Packer's Falls as it says: to Packer'sFalls. They sold some land that they owned around Packer's falls.Mr. Smith tried to contact Manager of the New Hampshire ElectricCompany. Mr. Smith said that to the best of his knowledge thePacker's Falls had been conveyed.

* B-10

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September 15, 1960

Hr. Roland S. BurlingameCamp, Dresser and McKee18 Tremont StreetBoston 8, Massachusetts

Dear Roland:

I am enclosing copies of a map and a plan whichwe have in our files on the Packer's Falls project on theLampley River. Francis has also examined the Public Utilitiesdocket and pulled out some co-ments which I am enclosing.

I think the dam that is referred to as "presentpc.ad" in this docket information is not existing at thistime.

If there is any interest on your part, I thinkthere is more information that could be worked up on thisproject from other sources.

Very truly yours,

Leonard R. FrostWater Resources Engineer

lrf:cencls. S

[B - .S

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20 HAMPSHIRE WATER CONTROL CO24ISSIOIT

REPORT ON DAM INSPECTION

Tow OWN ___________ DAM NO o ST-A 71 S4

In accordance with Section 20 of Chapter 133, laws of 1937, tho above dam wau* inspected by me on 2[j& L 1s ,..1 by- ______________

NOTES ON PHYSICAL CONDITIONAbutments ,

SToillwmy

Gates J',e-i#- ~~-/~ ~4.

CRAITGES SIINC"E LAST IN7SPECT ION t d' .jaL qA

* V'1JVP. Il'-ECTIONS _________________________

This dam (is) menace because < t / ..I. k .4 ...

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Copy to Ownor Date

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(Additiona ITotcs Over)

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WATER RESOURCES

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0 NEW HAMPSHIRE WATER CONTROL COMMISSIONDATA ON DAMS IN NEW HAMPSHIRE

LOCATION STATE NO . f......,04......

Town ......... Djjrham ............................ : County ............. tAM &..... ..........Stream ..... .................... . .............................................................Basin-Primary ........ 00z ......... Secondary ........ Lajp~ey.. R.................Local Name...o. keru.&.a1...... . ...........................................................-......Coordinates-Lat ..... 430 "..5.i-...7400 ........ Long . ... .. f9.800..........................

GENERAL DATA 7/ ' ~-Drainage area: Controlled .3.3Sq. Mi.: Uncontrolled ........... Sq. Mi.: Total..18,1... Sq. Mi.

Overall length of dam ... ..... ft.: Date of Construction .... i ............................................Height: Stream bed to highest elev ... ... ft.: Max. Structure .... 3............................. ft.

Cost-Dam...........................%JJ Reservoir..................................................DESCRIPTION Gravity Concrete Ledge Foundation

Waste GatesType................................................................................................................

Number ........ .... Size .... 6............ ft. high x ..............7.....................ft. wideElevation Invert ...........II.............:Total Area ... m42P .. 84................ Sq. ft.

*Hoist ........................................... ...................................................................Waste rates Conduit

Number ........................ Materials..............................................................

*Size................... ft.: Length................... ft.: Area ............................................ sq. ft.Embankment

Type ............................................ ..................................................................Height-Max ...................................... ft.: Min...................................................... ft.

*Top-Width ..............................:Elev..................................................... ft.*Slopes--Upstream .............. on ...........:Downstream .................... on...................

Length-Right of Sp"way ................. Left of Spillway..........................................Spiliwa~y

*M aterials of Construction ..... 9 oqre .... .............................................

Length-Total ....................................... ft.: Net ............. 65 ................................ ft.*Height of permanent section-max. 1.3 ........... ft.: Min................................................. ft.

Flashboards--Type........................................................... : Height....................... ft.*Elevation-Permanent Crest ........................:Top of Flashboard ........................

Flood Capacity .... 41Q..................... cfs.:....................................... cfs/sq. mi.

Abutments

Materials: ...................................... ..................................................................Freeboard: Max.......... 9!......................... ft.: Min.................................................... ft.

Headworks to Power Devel.-(See "Data on Power Development")

OWNER ..1amnpzey .. R&vex..Imp..C.o ........ . ................... Newmarket...M ..................Use- Power- Conservation

REMARKS

Tabulation By...... ............................... Date ...... .........l 3 B ........R-14

PUBLIC SERVICE COMMISSION OF NEW HAMPSHIRE-DAM RECORD 1-4535

TOWN Durham TOWN 4 STATE

RIVER Lamprey RiverSTREAM

DRAINAGE 183.2 PONDAREA AREA

DAM Gravity FOUNDATION LedgeTYPE NATURE OF

MATERIALS OF ConcreteCONSTRUCTION

PURPOSE POWER- CONSERVATION-DOMESTIC-RECREATION-TRANSPORTION-PUBLIC UTILITY

OF DAM

HEIGHTS TOP OPF ~-- TOPOF DAM TODAM TO BED OF STREAM S PILLWAY CRESTS

SPILLWAYS. LENGTHS Approx. LENGTH A

DEPTHS BELOW TOP OF DAM- OF OAM

FLASHBOARDS None STYPE. HEIGHT ABOVE CREST

OPERATING HEAD l3 |

TOP OF FLASHSOARDS

CREST TO N. T. W. TO N. T. W.

WHEELS. NUMBER

KINDS & H. P.

GENERATORS. NUMBER

KINDS & K. W. .H. P. 90 P. C. TIME H.P. 75 P. C. TIME

100 P. C. EFF. 100 P. C. EFF.

REFERENCES. CASES.

PLANS. INSPECTIONS.

REMARKS

O,0T7_- Lamprey River Imp. Co.

C)YI:ITI NI- Fair

",'F!;CE- Yes. Vill be subject to oeriodc inrpection.

To the Public Service Comnission:

The fore-ong memor _ndum on th- ave dr is CI.tJitt c r z i _ctin..... 2., 13.15, crnd bill for s, z is enclosed.

Samuel J. LordSept. 1F, 1235 Hyd. Enz.

*• Copy to 07.ner

B-15

NE7W HAMPSHTRE 'V'A:ER RESO:RCES BOARD

InrEllTORY OF DAM; AND VTACE? POVIER ' ELOP,'T J:S

BASIf 61 r/9 No. -

R I VER / ,- IILESQ FROT4 MOU:'i D .A .SQ .1-II 3 Z 1I:-___ ____;1___1__ CiNE R i Y/A vZ (e-, , llgtl , 4 ;4r

LJOCAL NA1.E OF DAM /,/l

BU I L_______ DESCRIF.lIJj '-/o,

PO0ND AREA -AZ?~ -A'7 DRA' TrC -- FT. ____FIrD CPAIYCRF.HEIGH T_-20P TO BED OF SR~lF. /Lx._____MS___T I EEALL LENGT'H OF DAN-Fl.&P HEIT,_ A:OVE CRS_-:___

PEA~~DTETT ?E E U.. . . LC7AL G_%,E________TIL'!.T AT ELE. T S3.... LO'CAL CA'E_________

SPILL'...-! LE11NGTS-T FR~EaR,-'i t 4FTL.4S.- EOA- RDS -TYPE, HIEIG13H7_R3I___________________

V~rASB T-ES-NC. WIDT MA " OPLjTj F Zl~ LEc;: CRES T S

REleA RKS (,d2 /'- - ._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

PC'7l'B DE'VELOPTEIT7RA- ED HE AD C.F..

* JNIT._S i:o. -HP FEE 7 FULL GA:-_E KVJAE

USE

R AE 1rR i

B-16

7206

NEW HAMPSHIRE WATER CONTROL COMMISSION S

DATA ON WATER POWER DEVELOPMENTS IN NEW HAMPSHIRE

LOCATION AT DAM NO ....... 7a,o4 ..........Tow n ..... D ii am ................................................... : County ...... ... .t Z r , ...................................Stream ................. . . .............................................................................................................

Basin-Prim ary ........ .Q Q-= .................................................. : Secondary R ..mp.y RLocal N am e ....................................................................................................................................................

GENERAL DATAH ead-M ax ..... l a .......... ft.: M inl . ......... ft.: A ve ....................................... 2 ............................. ft.

D ate of Construction .............................................. : Use of Pow er .... P.o uer .4 .. Cause r.n J.t , .......Pondage ...................................................... ac. ft.: Storage .......................................................... ac. ft .

DESCRIPTIONRacks

Size of Rack Opening ...................................................................................................................................Size of Bar ........................................................ : M aterial ...................................................

A rea: Gross ............................................ Sq. Ft.: N et ...................................................... .... .sq. ft.

Head GatesType ..............................................................................................................................................................N um ber ........................ : Size ........................ ft. high x .............................................................. ft. w ide

Elevation of Invert .............................................. : Total Area ......................................... ..... sq. ft.

H oist ..............................................................................................................................................................Penstock

N um ber ................................................ : M aterial ...................................................................................... .

Size .......................................................... Length ......................................................................................Turbines

N um ber ......... .......... : M akers .................................................................................Rating H P. per unit ............................................ : Total Capacity ................................................. H P.

M ax. Dem ent C.F.S., per unit .................................................... : Total .............................................. cfs.

Drive

Type .............................................................................................................................................................

GeneratorN um ber .................................................................... ......................................................................................M ake ..............................................................................................................................................................Rating KW ., per unit ............................................ ; Total Capacity ................................................ K . W .

Exciter

N um ber ........................................ M a e ... . .......................................... ............................................. . .

Rating-per unit ........................................ : Total Capacity ............................................................ K . W .

OUTPUT-KWHRS-19 ........ ............................................................ : 19 ........ ......................................................

19 ........ ............................................................ : 19 ........ .....................................................

19 ........ ............................................................ : 19 ........ ......................................................19 ........ ........................................................... : 19 ........ ......................................................19 ........ ............................................................ 19 ........ ....................................................

O W NER .. ....... .................................. ...... .. ..... I ...............................

Tabulation By-..A .. 1.....R..L ..T ............................... Date ......... Nov.e. ....21.9.38 1 .........................B-17

Docket D-550 N.H. Public Service Comm. July 22, -1919Rockingham County Light and Power Company

Lamprey River - Durham, N. R.

Present Pond Level 56' - Area 82.0 Acres

Proposed Pond Level 74.51 Area 561.95 (479.95 additional)

18.5' rise

Dam originally built in 1911

6,000,000 KW#*Z annual capacity a

Estimate maximum flow has been 3,000 cfa.

Install 2 wheels with capacity of 550 cfs each.Install 2 Tainter Gates with combined capacity of 7,000 to 8,000 cfs.Can take care of 5,000 cfs. above average flow of river. S

Will gain additional 15' head by canal.

Started getting ater rights in August 1916

Drainage Area 190 square miles. S

Use 1100 cfs - 40 to 50 days. (possibly as little as 10 days) / year

10 hrs on both wheels lowers pond 6" (no inflow)

R-1R

S

S

S

S

S

APPENDIX C

PHOTOGRAPHS

S

S

S

S

S

S

0, A

-7-

IrS

1. Principal Spillway -Note Buttresses on Downstream Face.

jjj

2. Downstream Channel from Right Abutment

C-3

3. CoeWl tRgh btet Nt

Horionta DiplacmentandCracing

C-4

I j l,I. S

4. Right End Wall - Note Erosion at Water Level and SevereSpalling of Concrete.

a .

5. Detail of Erosion and Deterioration of Pight End Wall.

C-5

!0

6. Waste Gate Structure Near Left Abutment - Note SeepageThrough Gates.

7. Detail of Gate Structure -Note Spalling of Gunite ,i.i.'

C.oating. . • -.

C-6 -

"S "

mow

8. Lft Ed Wll Nte MnorE flrescnce

8. LetEnall Ebnometecto inor EfHrseae.

Brush rowth

C-7

10. Abandoned Sluiceway at Left Abutment - Note Gates at FarEnd and Slight Seepage Flow.

AS

-t,- .

I1. Abandoned Sluiceway Upstream of Gates - Note IncompleteBackfill

6 SL

" "-*° "- -4-" -- " " " ." -' l d

" ,: m,

S

S

S

S

S

APPENDIX D

HYDROLOGIC AND HYDRAULIC COMPUTATIONSS

S

S

S

.4 S

S

L ... ~ . ...............................

RESOURCE ANALYSIS

a Camp D'esse' & Mcgee .!m

Dam Failure Analysis

See schematic sketch of dam on next page.

Outflow at Failure = Outflow through breach and

Normal Outflow at Failure elevation of pool

Assume that the dam fails with the pool level at the top of the right

abutment, which is :

4.8 feet above the main spillway and

12.5 feet above the bottom of the orifice gates, 5

-Normal Outflow at Failure

Orifice gates: Assumed to be open at failure

1. Low Flow - use weir equation

c= 3.1 L= 12

Q2 (3. 1) (12) (H) 1 .5

2. High Flow - use orifice equation and assume Cd approaches

.611 for this structure

Q2 = Cd(a % )

Cd = .611 a = 60 ft h HEAD-2.5'

Q2 = (.611)(60)(V'(2)(32.2)(H - 2.5)

D-2

RESOURCE ANALYSIS 0

a Camp Dresser & McKee firm

0

SCHE1ATIC DIAGRAM OF PACKERS FALLS DAM

E . 557 -7 "

0

Not to Scale

S

D-3

IL -

.o

RESOURCE ANALYSISa Camp Dresser & McKee firm

Main Spillway: ,

where: r

c = 3.1

L = 110'1.5

Q, = (3.1)(110) (H -7.7)

Abutment Flow and Overbank Flow:

Q3 = (3.0)(27) (H - 12.8) 1 5

Q4 = (2.8) (H - 12.8) (3) (.5 * (H - 12.8))1.5

Q5 = (2.8)(6) (H - 12.5) (.5 (H - 12.5)) 1.5

The BASIC program shown on the next page computes the rating curve

with the previous equations. A rating table for this structure is

shown on the following page.

From the rating table, a failure elevation of 4.8 feet above

the spillway crest (12.5 feet above orifice) would have 4650 cfs

flowing over the structure. 0

Normal Outflow at Failure 4650 cfs

Breach Outflow

3Qpl =(8/27) (Wb)(V) go

Wb Width of breach 5

0.4 x (Width of dam at height)

D-4

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ID-

RESOURCE ANALYSIS 0a Camp Dresse, & McKee frm

Breach Outflow (cont.)

use Wb = (.4) 137 = 54.8,

Yo = pool elevation at failure

= 13 + 4.8 = 17.8'

Qpi= (8/27) (54.8) W32.2) (17.8)1.5

Q. =6920 cfs

Total Outflow at Failure

Since the breach is assumed to occur at the main spillway

section, 40% of the normal spillway outflow is included in the breach

outflow calculation so,

Failure Flow = .6 (Normal Outflow) + Breach Outflow

= .6 (4650) + 6q20 = 9710 cfs

Stage Storage Curve

The storage capacity of Packers Fall Dams at the spillway crest

is 360 acre-ft. The storage capacity at the top of the left abutment,

or 4.8 feet above the spillway crest is 500 acre-ft.

If h = height above spillway crest, then

Surcharge Storage =500-360 -29.2 acre (h)

Total Storage = 360 + 29.2 (h) S

D-8

RESOURCE ANALYSISa Cam Dresse & McKee frm

For the drainage area of 183 square miles (117,120 acres):

117, 120 (11") _ 70 f.::~1" of runoff = '(12"1/ft) 9760 acre-ft.

1S

1 acre-ft. = = 0.00102" of runoff.9760

Surcharge storage to the top of the left abutment:

4.8 (29.2) = 140 acre-ft = 0.14" of runoff

The stage-surcharge storage curve is shown on the next page.

D

S

e D-9

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S ..... .. ... .. .. :: - : ... .. . . ....' . . . . . '

0.n

D _

j1 i i i Ii .. .. . .


Downstream Flooding

The next four pages show the rating table for a U.S.G.S. stream

gauging site on the Lamprey River. This site is located about 3000'

downstream of Packers Falls Dam. Following the rating table is shown

the rating curve which is extended beyond the largest stage shown in

the rating table.

From the rating curve a prefailure flow of 4650 (cfs) would create

a stage of 11.8 feet. A failure flow of 9890 cfs would raise the stage

to 16.6 feet above the streambed.

The attenuated affects in the reach between the dam and the Packers -

Falls Bridge are considered negligible due to the confining nature of

the channel and the lack of storage in the steep overbanks.

D-1

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_ _ _ _ _ __ra_ _ -_ _ _ _ N


Downstream Flooding (cont.)

About 200' downstream of the stream gauging site is a concrete

arch bridge crossing which is sketched in the picture below. The

stream gradient increases sharply in this reach, and water flows

rapidly over a rock streambed. The storm of 1977 (5,200 cfs) caused

the arch opening to fill about half way, so based on this high water

mark and the surrounding conditions, a 25 foot wide by 10 foot high

box was used to approximate the bridge opening. The rating table

for this section is shown on the next page.

__ I

* S

Box Opening 25' x 10'

slope = .1

Channel n = 0.3

D-17

•~~~~~~~~~~wii "om di ft•. . ". _. •.. "'

N -- NMN DN OcD - C Nr- I- - -0 I M r* D-C S OCV0rWC D( rK

I&1 r-- C C- CD0 q OD0 V - NN K Of N D C

I M - f 1) C-ONC- C DL L DO

ix I N N )r- VC W DN N N r-M

4 I -- NNN~ AC~c r-21

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I --- - - - - -

D0

I-- I 3qi)C )mL)C OGLOQL nGL oG1

11 0

ID-18

RESOURCE /

a Camp Dresser &

From the bridge rating table a prefailure flow of 4650 cfs would

create a stage of 5.0 feet. A failure outflow of 9890 cfs would create

a stage of 8.5 feet.

Of the four houses located in the reach between the dam and

Packers Falls Bridge, two are in danger of being flooded. About 2200

feet downstrear of the dam, one house is 15 feet above the streambed.

If flood stages for the gauging site can be assumed to apply here, a

prefailure flow would have a stage of 11.8 feet, but it would rise

to 16.6 feet after failure. This would probably cause damage and

there is a possibility of loss of life.

The other house affected by flooding is at the gauging site,

3000' downstream of the dam. It is located 12 feet above the stream-

bed and before failure some minor damage may occur, but at failure,

damage is likely and a potential for loss of life exists.

Another 200' downstream of the gauging site the steep gradient

of the falls and the arch bridge opening tend to create high velocities

but low stage heights. It is expected that the bridge, recently built

and in good condition, would be able to survive the failure flow wave.

The Failure Flow Wave is not expected to create any serious dam-

age downstream. The housing in the reach downstream of Packer- Falls

Bridge is sparse and all buildings are located well above the streambed.

The wave will substantially attenuate as the river approaches the sea

and the overbanks widen out and become swampy.

0-19

RESOURCE ANALYSIS 0

a Camp Dresse & McKee firm

Test Flood Analysis

Size Classification: SMALL (height< 25 ft., storage 1000 ac-ft.)

Hazard Classification: SIGNIFICANT based on the possibility ofloss of life and probable damage to in- S

habitable structures.

According to the "Recommended Guidelines" the hazard classification

and dam size call for a test flood between the 100 year flood and of a

the Probable Maximum Flood (PMF). Since the hazard classification is

on the low side of significant, we will use the 100 year flood.

Peak Uncontrolled Flow

Available from the U.S. Geological Survey are the results of a

peak flow frequency analysis summary for the stream gauging site on

the Lamprey River. Shown on the next page is the data summary, show-

ing the WRC estimate of the 100 year flood (.01 annual exceedance

probability) using a Log Pearson Type III analysis. On the page

following the summary is a computer plot of WRD estimates and obser-

ved peaks.

Although the gauge is located downstream of the dam, the differ-

ences in drainage areas are negligible, and the same flow rate can be

assumed to apply at both sites. From the data summary:

100 year Peak Uncontrolled Flow = 7055 cfs

D-20

... S". ..-. . .. . ." . . . . . . . . . . - " - - ' -" ... - " " " - : h - - -

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RESOURCE ANALYSIS 0a Camp Dresser & McKee frm

A peak inflow of 7055 cfs would create a stage of about 6.5 0

feet above the spillway crest, which is 1.7 feet above the left

abutment. The peak test flood outflow is:

70550 (100%) = 150%

TgT6

of the spillway capacity with the water surface at the dam crest.

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DOWNTREA HAZRDMA

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NAIOA 24 GA FISETONO O-E.DM

APPENDIX E

INFORMATION AS CONTAINED IN

THE NATIONAL INVENTORY OF DAMS

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Documents

PROGRAM FOR INSPECTION OF NON-FEDERAL DAMS ii … · The dam was originally built in 1911 to provide hydroelectric power for the Rockingham County Light and Power Company. The dam