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AD A146 268 NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL DAMS i/2,GREEN HILL POND DAM (..(U) CORPS OF ENGINEERS WALTHAM

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REPORT DOCUMENTATION PAGE BEFORE COMPLE~TING V014M1. REPORT NUMBER 12 GOVT ACCESSION NO. J RECIPIENT'S CATALOG NUMBER

MA 00149 ______________

4 TITLE (and S.b6i~ TYPE Of REPORT A PERIOD COVIERED

Green NHl Pond Dam INSPECTION REPORT

NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL 6 PERFORMIN ORG. REPORT NUMDER

P.AUT4S s 8. CONTRACT OR GRANT kUMUEPI(s)

U.S. ARMY CORPS OF ENGINEERSNEW ENGLAND DIVISION

S. PENFORMINC. GRGANIZATION NAME AND ADDRESS WC -PROGRAM ELEMENT. PROJECT. TASK(^MARA WORK UNMIT NUM9CRS

I I. CCWftTROLLING OfFPIC& NAME AND ADDRESS Ia. REPORT DATE

DEPT. OF THE ARMY, CORPS OF ENGINEERS July 1979NEW ENGLAND DIVISION, TJEDED 13. NUMDER OF PAGES

424 TRAPELO ROAD, WALThAM, MA. 02254 .65

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UNCLASSIFIEDIts. DECLASSFICATIONIDOWNGRADINu,

SCH4EDULE

16. 01IST RIDU TION ST ATE&MENkT (of &hi. Report)

APPROVAL FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED

IT. Of ST 019 UTIN ST A I Fo N T (at who astitact entered in &Joeeb 2*I dit C*' 11oo1 fom RAwT) -

18. SUPPLEMENTARY NOTES

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

19. KEY WORDS (Confinue en toersim side of noeey and 6~110~Y 6F' block PM1116r)

DAMS, INSPECTION, DAM SAFETY,

Blackstone River BasinWorcester, Mass.

20. A EST RACT (Continu.enor tevoroeaitdo 10 n.esesaand identity by block Member)-Green Hill Pond Dam Is an earthfillI embankment 200 feet long and 20 feet high witla stone masonry core wall 17 feet high. Generally the dam is in good conditionalthough the outlets to the spIllway and overflow diversion are in'poor conditionGreen Hill has been classified in the "high" hazard category. There is potentialhazard at the site. An inflow test flood of 280 cfs will overtop the main damby an average of 0.2 feet.

DD 1473 ILDITIoN OF I NOV SD IS OBS1OLETE

GREEN4 HILL POND DAM

MA 001)49

BLACKSTONE RIVER BASINWORCESTER, MASSACHUSETTS

PHASE I INSPECTION REPORT

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NATIONAL DAM INSPECTIONPROGRAM

ri~ i d o c i i r e "~ I ' " " i t s

d itribution unlimited

NATIONAL DAM INSPECTION

PROGRAM


BRIEF ASSESSMENT

Identification No.: MA00149

Name of Dam: Green Hill Pond

Town: Worcester

County and State: Worcester County, Massachusetts

Stream: Hermitage Brook - Tributary of the BlackstoneRiver

Date of Inspection: July 31, 1978

Green Hill Pond Dam, which was originally builtaround 1850, was reconstructed about 1881. The dam isan earthfill embankment 200 feet long and 20 feet highwith a stone masonry core wall 17 feet high. The spill-way is an ungated overflow weir with a vertical dischargeshaft which is located near the midpoint of the dam.The weir is 23.6 feet long with an elevation (El) of651.0 at the crest. The ungated outlet conduit fromthe spillway is 573 feet long. It consists of an18-inch diameter reinforced concrete pipe which con-nects to a 30-inch diameter reinforced concrete pipe.There is an overflow diversion structure located at thenortheast end of the pond. The outlet conduit for theoverflow is 30-inch diameter reinforced concrete pipe.The inlet to the diversion has an elevation of 650.9.Due to downstream pipe sizes and slopes, the overflowdiversion could be inoperative during peak storms.

Green Hill Pond Dam was neither designed nor con-structed according to current state-of-the-art procedures.There are areas of concern which must be corrected toassure the continued performance of this dam. This con-clusion is based upon the visual inspection at thesite, the limited engineering data, and limited evidenceof operational and maintenance procedures. Generally,

the dam is in good condition although the outlets to thespillway and overflow diversion are in poor condition.Green Hill has been classified in the "high" hazardcategory.

The following are visible signs of distress whichindicate a potential hazard at the site: blockage ofthe shaft of the spillway, blockage of the overflowdiversion, leakage through the walls of the spillway,misalignment of the stone block forming the western halfof the spillway, siltation of the outlet conduit at 121feet and 573 feet downstream of the dam, erosion andlack of riprap on the upstream face of the dam, erosiondue to surface runoff on the downstream face of the dam,accumulation of surface runoff in the playground area atthe toe of the dam, and erosion of the trash gate andthe concrete on the intake box of the diversion conduit.

Hydraulic analyses indicate that the spillway atthe dam can discharge a flow of 33 cfs at El 653 whichis the average elevation of the crest of the dam. Aninflow test flood of 280 cfs will overtop the main damby an average of 0.2 feet. These calculations are basedon an unobstructed flow through the spillway and do notconsider overflow through the diversion. In the eventof overtopping, complete failure of the dam is unlikelyto occur. However, erosion of the dam could occurresulting in a breach and partial failure of the dam.

It is recommended that the Owner accomplish thefollowing: remove debris from the shaft of the spillwayand from the overflow diversion, install a trash rack onthe spillway and repair the trash rack on the overflowdiversion, construct an overflow spillway, construct agated outlet, repair leakage and the misaligned slab atthe weir of the spillway, clean accumulated silt out ofthe outlet conduit, repair erosion on the upstream faceof the dam and protect the slope with riprap, constructa swale to prevent surface runoff from eroding thedownstream face of the dam and collecting in the area atthe toe of the dam, and repair the concrete on theintake of the diversion conduit. The Owner should alsoimplement a systematic program of inspection andmaintenance.

The debris in the spillway and in the overflowdiversion should be removed within 30 days. Theremaining recommendations and remedial measures out-lined above and in Section 7 should be implemented

by the Owner within a period of 2 years after receipt ofthis Phase I Inspection Report. An alternative to theserecommendations would be to drain the pond and breach orremove the dam.

Edward M. Greco, P.E.Project ManagerMetcalf & Eddy, Inc.

Connecticut RegistrationNo. 08365

Approved by:

STEPHEN

Vice President IOMetcalf & Eddy, Inc. N173

Massachusetts Registration st ON L

No. 19703

This Phase I Inspection Report on Green Hill Pond Damhas been reviewed by the undersigned Review Boardmembers. In our opinion, the reported findings, con-clusions, and recommendations are consistent with theRecommended Guidelines for Safety Inspection of Dams,and with good engineering Judgment and practice, and ishereby submitted for approval.

CHARLES G. TIERSCH, ChairmanChief, Foundation and MaterialsBranchEngineering Division

FRED J. Ravens, Jr., MemberChief, Design BranchEngineering Division

SAUL C. COOPER, MemberChief, Water Control BranchEngineering Division

APPROVAL RECOMMENDED:

JOE B. FRYARChief, Engineering Division

PREFACE

This report is prepared under guidance containedin Recommended Guidelines for Safety Inspection of Dams,for a Phase I Investigation. Copies of these guidelinesmay be obtained from the Office of Chief of Engineers,Washington, D.C. 20314. The purpose of a Phase IInvestigation is to identify expeditiously those damswhich may pose hazards to human life or property. Theassessment of the general condition of the dam is basedupon available data and visual inspections. Detailedinvestigation, and analyses involving topographicmapping, subsurface investigations, testing, anddetailed computational evaluations are beyond the scopeof a Phase I investigation; however, the investigationis intended to identify any need for such studies.

In review.ing this report, it should be realizedthat the reported condition of the dam is based on obser-vations of field conditions at the time of inspectionalong with data available to the inspection team. Incases where the reservoir was lowered or drained priorto inspection, such action, while improving thestability and safety of the dam, removes the normal loadon the structure and may obscure certain conditionswhich might otherwise be detectable if inspected underthe normal operating environment of the structure.

It is important to note that the condition of adam depends on numerous and constantly changing internaland external conditions, and is evolutionary in nature.It would be incorrect to assume that the present condi-tion of the dam will continue to represent the conditionof the dam at some point in the future. Only throughcontinued care and inspection can there by any chancethat unsafe conditions be detected.

Phase I inspections are not intended to providedetailed hydrology and hydraulic analyses. In ac-cordance with the established Guidelines, the SpillwayTest flood is based on the estimated "Probable MaximumFlood" for the region (greatest reasonably possiblestorm runoff), or fractions thereof. Because of themagnitude and rarity of such a storm event, a findingthat a spillway will not pass the test flood should notbe interpreted as necessarily posing a highly inade-quate condition. The test flood provides a measure ofrelative spillway capacity and serves as an aid indetermining the need for more detailed hydrologic andhydraulic studies, considering the size of the dam, itsgeneral conditions and the downstream damage potential.

!

TABLE OF CONTENTS

Page

BRIEF ASSESSMENT

PREFACE

OVERVIEW PHOTO

LOCATION MAP iii

REPORT iv

SECTION 1 - PROJECT INFORMATION 1

1.1 General 11.2 Description of Project 21.3 Pertinent Data 5

SECTION 2 - ENGINEERING DATA 10

2.1 General 102.2 Construction Records 112.3 Operation Records 222.4 Evaluation of Data 11

SECTION 3 - VISUAL INSPECTION 12

3.1 Findings 123.2 Evaluation 14

SECTION 4 - OPERATION PROCEDURES 15

4.1 Procedures 154.2 Maintenance of Dam 154.3 Maintenance of Operating

Facilities 154.4 Description of Any Warning

System in Effect 154.5 Evaluation 15

SECTION 5 - HYDRAULIC/HYDROLOGIC 16

5.1 Evaluation of Features 16

TABLE OF CONTENTS (Continued)

Page

SECTION 6 - STRUCTURAL STABILITY 18

6.1 Evaluation of StructuralStability 18

SECTION 7 - ASSESSMENT, RECOMMENDATIONS,AND REMEDIAL MEASURES 20

7.1 Dam Assessment 207.2 Recommendations 217.3 Remedial Measures 21

APPENDIXES

APPENDIX A - PERIODICAL INSPECTION CHECKLIST

APPENDIX B - PLAN OF DAM AND PREVIOUSINSPECTION REPORTS

APPENDIX C - PHOTOGRAPHS

APPENDIX D - HYDROLOGIC AND HYDRAULICCOMPUTATIONS

APPENDIX E - INVENTORY FORMS

ii

II

OVERVIEW

GREEN HILL PONDWORCESTER, MASSACHUSETTS

VIEW FROM EAST ABUTMENT

Location and Direction of PhotographsShown on Figure in Appendix B

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NATIONAL DAM INSPECTIONPROGRAM


GREEN HILL POND

SECTION 1

PROJECT INFORMATION

1.1 General

a. Authority. Public Law 92-367, August 8,1972, authorized the Secretary of the Army,through the Corps of Engineers, to initiate anational program of dam inspection throughoutthe United States. The New England Divisionof the Corps of Engineers has been assignedthe responsibility of supervising the inspec-tion of dams within the New England Region.Metcalf & Eddy, Inc. has been retained by theNew England Division to inspect and report onselected dams in the State of Massachusetts.Authorization and notice to proceed was issuedto Metcalf & Eddy, Inc. under a letter of May3, 1978, from Ralph T. Garver, Colonel, Corpsof Engineers. Contract No. DACW 33-78-C-0306has been assigned by the Corps of Engineersfor this work.

b. Purpose

(1) Perform technical inspection and evalua-tion of non-Federal dams to identifyconditions which threaten the publicsafety and thus permit correction in atimely manner by non-Federal interests.

(2) Encourage and assist the States to ini-tiate quickly effective dam safety pro-grams for non-Federal dams.

(3) To update, verify and complete theNational Inventory of Dams.

1

1.2 Description of Project

a. Location. The dam is located on the head-waters of Hermitage Brook, a tributary of theBlackstone River, in the City of Worcester,Worcester County, Massachusetts (see LocationMap).

b. Description of Dam and Appurtenances. GreenHill Pond dam is an earth fill dam about 200feet long with a maximum height of 20 feet(see Plan of Dam and Sections, Figures B-1and B-2). The embankment is founded on bed-rock and is constructed of a stone masonrycore wall 5 feet thick at the bottom, 2 feetthick at the top, and 17 feet high (see FigureB-4). The remainder of the embankment isearth fill. The crest of the dam is generallyabout 30 feet wide but increases to about 100feet wide at the west abutment. The elevation(El) of the crest varies from 652.5 to 654.0.A paved road, Green Hill Parkway, is locatedon the crest. The upstream slope is 7:1 andis a sandy beach. The downstream slope is5:1 and is covered with grass.

A vertical shaft spillway is located near themidpoint of the dam. It consists of a 23.6feet long (side to side) granite overflow weirand a 3.6 by 25.6 foot (inside dimensions)vertical stone shaft with 2.7 foot thick walls.The crest of the spillway is at El 651.0. Theshaft descends about 17.4 feet to an invert atEl 633.6 and connects with the outlet conduitwhich is perpendicular to the dam (see FigureB-3). A stone headwall which was part of theoriginal dam may still be located below theground surface downstream of the spillway (seeFigure B-4).

Water over the spillway discharges about 573feet downstream of the upstream face of thedam. Manholes are located 121 feet, 306 feet,and 424 feet along the outlet conduit fromthe spillway (see Figure B-2). At the upstreamend of the first manhole, the conduit is 18-inch diameter reinforced concrete pipe. Fromthe downstream end of the first manhole to the

2

outlet, the conduit is 30-inch diameter rein-forced concrete pipe. The size of the outletfrom the spillway to the 18-inch diameter pipeis unknown. Drawings (Figures B-3 and B-4)indicate that there is a 38-foot-long approachchannel on the bottom of the pond which leadsto a 1.3-foot-wide by 4.5-foot-high opening atthe base of the stone shaft of the spillway.This opening leads to a box conduit whichpasses beneath the shaft and the wall of theold dam and enters a 3.8-foot-wide by 7-foot-high stone horseshoe-shaped tunnel. Thetransition from this old conduit to the 18-inchdiameter reinforced concrete pipe is unknown.The invert of ,he 18-inch pipe is at El 636.6at the first manhole. The invert of the30-inch pipe is El 633.0 at the outlet.

An overflow diversion structure is located at thenortheast end of Green Hill Pond (See LocationMap). Flow from this diversion is to CoalMine Brook, about 0.4 miles to the northeast(see Figure B-5). The diversion conduit is a30-inch diameter concrete pipe which leads toa 48-inch diameter tunnel beneath Green Hill,discharging to various smaller pipes downstream.The inlet to the conduit is a concrete boxwith a 1.6-foot-high by 12-foot-long openingon the upstream face. The overflow weir to theconduit is at El 650.9.

c. Size Classification. Green Hill Pond Dam isclassified in the "small" category since ithas a maximum height of 20 feet and a maximumstorage capacity of 300 acre-feet.

d. Hazard Classification. Immediately down-stream of the dam is a public park and play-ground. Thickly developed commercial andresidential areas of Worcester are located inthe downstream valley about 0.3 miles from thedam. Memorial Hospital is also located 0.7miles downstream in the valley. In the eventof dam failure, more than a few lives could belost and extensive property damage could occur.

3

A 12-foot-high, abandoned dam located 1,300 feetbelow Green Hill Pond may impede some floodflows. However, the condition and stability ofthat dam is unknown. Accordingly, Green HillPond Dam has been classified in the "high"hazard category. A 1973 inspection report bythe Massachusetts Department of Public Worksindicates there is no risk to life andproperty.

e. Ownership. The dam is presently owned bythe Worcester Department of Public Works, 30 E.Worcester Street, Worcester, Massachusetts01604. Mr. F. Worth Landers, Commissioner(617-798-8151) granted permission to enter theproperty and inspect the dam.

f. Operator. There are no known operators ofthedam since there are no operational features.

g. Purpose of Dam. The dam was originally con-structed by the Green family at their estatefor recreational and aesthetic purposes. Inabout 1905, the estate was given to the Cityof Worcester. The pond was used for swimminguntil about 195,. After that time recordsindicate the water became polluted from thecesspool for the bathhouse and from livestockgrazed nearby. Since 1955, the pond has notbeen suitable for swimming. The adjoining landis utilized for a playground, picnic area,and a golf course.

h. Design and Construction History. The ori-ginal dam, shown on the 18B1 drawings as the"old dam" (see Figure B-3), was probablybuilt around 1850 and is presumably still inplace below the ground surface. Drawings indi-cate it consists of a 14.5 foot high, 10.5foot thick vertical stone wall with an outletconduit at the base which lead to a 3.8 footwide by 7 foot high (inside dimensions) stonehorseshoe-shaped tunnel (see Figures B-3 andB-4).

About 1881, Martin Green designed changes tothe dam which presumably were built a shorttime later. These changes included construc-tion of the vertical shaft spillway, recon-struction of the embankment with a stone core

.4

wall, and extension of the outlet conduit up-stream, including a slide gate and an approachchannel. About 1905, the dam and part of theGreen family estate were given to the City ofWorcester.

An inspection report written in 1938 statedthat the slide gate to the outlet was brokenand inoperable and a fish screen was on thespillway weir. After the 1936 floods, theoverflow diversion was constructed by the Cityof Worcester. Also, some time between 1955and 1965, the area below the toe of the damwas filled in to make a playground, and theoutlet conduit was extended to its presentlocation.

i. Normal Operational Procedures. There are nonormal operating procedures at this dam. Thereis no apparent outlet control, and it appearsthat the approach to the outlet conduit isfilled with sand. However, a flow of 5 to10 gallons per minute is discharging from thedownstream end of the conduit.

The spillway for Green Hill Pond is ungatedand flows are unrestricted, although the verticalshaft is blocked with debris.

The overflow diversion is also uncontrolled,and the opening to the 30-inch conduit is filledwith debris.

1.3 Pertinent Data

a. Drainage Area. The approximately 136-acre(-.21 square mile) drainage area above the damconsists of a park and golf course. The landis sparsely developed, mostly grassed, and hasmoderate slopes. Discharge is to HermitageBrook, which flows to a 12 foot high abandoneddam located about 1,300 feet downstream ofGreen Hill Pond. Some flow appears to entera 2.6 foot high by 5.3 root wide box conduit atthe dam and could not be detected further down-stream. Residential areas are situated 150feet downstream of the abandoned dam, and thevalley continues approximately along HooperStreet into downtown Worcester.

5

b. Discharge at Dam Site. Water discharges fromthe pond through an 18-inch and a 30-inchdiameter, reinforced concrete outlet conduit.Drawings indicate that flow into the conduitis through the 25.6-foot by 3.6-foot verticalshaft of the spillway and from a 1.3 foot by4.5-foot slide gate opening at the bottom ofthe upstream wall of the shaft. Presently,debris is blocking the shaft, and sand hasaccumulated upstream of the gate opening.Both the spillway and the opening are uncon-trolled. The outlet conduit discharges 573feet downstream, at an invert elevation of633.0. The lower 452 feet of conduit has a0.2 to 1.3 percent slope.

The pond can also overflow through a 30-inchdiameter diversion conduit located at theopposite end of the pond from the dam. Theconduit has a 1.6-foot by 12-foot intakeopening with an overflow elevation of 650.9.The conduit has a slope of about 0.4 percent.

Hydraulic analyses indicated that the spillwaycan discharge an estimated 33 cfs at El 653which is an average elevation of the crest ofthe dam. An inflow test flood of 280 cfs(half of the probable maximum flood) willovertop the main dam by an average of 0.2feet. These calculations do not take intoconsideration the discharge into the overflowdiversion which is presently blocked withdebris. Due to downstream pipe sites and slopes,the overflow diversion could be inoperativeduring peak storms even after the debris iscleared.

The maximum flood at the dam site is unknown;but personnel at the Worcester Parks Depart-ment recall the dam being overtopped with flowover Green Hill Parkway.

c. Elevation (feet above Mean Sea Level (MSL)). Abenchmark at El 651.0 was established at thespillway crest. The elevation was estimatedfrom a U.S.G.S. topographical map.

6

(1) Top dam 652.5 to 654.0

(2) Test flood pool: 653.2

(3) Design surcharge (original design):unknown

(4) Full flood control pool: Not Applicable

(N/A)

(5) Recreation pool: 650.9 overflow diversion651.0 spillway crest

(6) Spillway crest (ungated): 651.0

(7) Upstream portal invert diversion tunnel:650.9

(8) Stream bed at centerline of dam: 633.9

(9) Maximum tailwater: None

d. Reservoir

(1) Length of maximum pool: 2,400 feet

(2) Length of recreation pool: 2,400 feet

(3) Length of flood control pool: N/A

e. Storage (acre feet)

(1) Test flood surcharge: 60 at El 653.9

(2) Top of dam: 300

(3) Flood control pool: N/A

(4) Recreation pool: 250 (Approximate)

(5) Spillway Crest: 250

7

f. Reservoir Surface (acres)

*(l) Top dam: 27

*(2) Maximum pool: 27

(3) Flood-control pool: N/A

(4) Recreation pool: 27

(5) Spillway crest: 27

g. Dam

(1) Type - earthfill

(2) Length - 200 feet

(3) Height - maximum 20 feet

(4) Top width: 30 to 100 feet

(5) Side slopes - upstream 7:1; downstream 5:1

(6) Zoning: Unknown

(7) Impervious core: Stone masonry core wall

(8) Cutoff: Unknown, bedrock foundation

(9) Grout curtain: Unknown

i. Spillway

(1) Type: overflow weir with vertical shaft

(2) Length of weir: 23.6 feet

(3) Crest elevation: 651 MSL (ass nedbenchmark)

(4) Gates: None

*Based on the assumption that the surface area willnot significantly increase with changes in reser-voir elevation from 651.0 to 653.0.

8

(5) Upstream Channel: None

(6) Downstream Channel: 25.6 feet by 3.6 feetvertical stone shaft to outlet conduit

j. Regulating Outlets. The regulating outlet atthe dam is an 18-inch and a 30-inch diameterreinforced concrete pipe which are ungated.

Discharge is presently flowing at 5 to 10gpm from the downstream end of the pipe. Thesource of this flow is unknown, but could befrom the shaft of the spillway and/or from theintake of the conduit. There is no apparentcontrol of this outlet.

The pond level is also regulated by a side inletbox spillway which discharges to a 30-inchdiameter diversion conduit located at thenortheast end of the pond. This inlet is notcontrolled. The pond level is below theoverflow level at the present time.

9

SECTION 2

ENGINEERING DATA

2.1 General. The only plans, specifications, orcomputations available from the Owner, State, orCounty offices relative to the design and con-struction of this dam are: two sheets of drawingsdated May 10, 1881 showing the original dam andproposed reconstruction (copies in Appendix B);and three undated drawings for the overflow diver-sion (copy of Sheet No. 1 in Appendix B). Theonly other data available for this evaluationwere visual observations made during inspection,review of a previous inspection report, andconversations with personnel at the WorcesterDepartment of Public Works (Owner of the dam), theWorcester Parks Department, and State and Countyagencies.

We acknowledge the assistance and cooperation ofpersonnel of the Massachusetts Department of PublicWorks: Messrs. Willis Regan and Raymond Rochford,and of the Massachusetts Department of Environ-mental Quality Engineering, Division of Waterways:Messrs. John J. Hannon and J<)seph Tagallo.

Also, we acknowledge the cooperation and assistanceof personnel from the Worcester County Engineer'sOffice: Messrs. John O'Toole, Joseph Brazauskas,and Mr. Wallace Lindquist - recently retired fromcounty service.

In addition, we thank Mr. F.W. Landers, Commissioner,Worcester Department of Public Works, who allowedus to inspect the dam. We also thank Messrs. RichardGrant and Edward Mara of the Worcester Departmentof Public Works, and Tom Taylor of the WorcesterParks Department, each of whom researched theirfiles for information on the dam.

10

2.2 Construction Records. There are no detailed con-struction records available.

2.3 Operation Records. No operation records areavailable, and there is no daily record kept of theelevation of the pool or rainfall at the dam site.

2.4 Evaluation

a. Availability. Due to the age of this dam,there is limited engineering data available.

b. Adequacy. The lack of in-depth engineeringdata did not allow for a definitive review.Therefore the adequacy of this dam could not beassessed from the standpoint of reviewingdesign and construction data, but is basedprimarily on visual inspection, past perfor-mance history and sound engineering judgment.

c. Validity. The limited engineering dataavailable is valid.

11

L.!

SECTION 3

VISUAL INSPECTION

3.1 Findings

a. General. The Phase I Inspection of the dam atGreen Hill Pond was performed on July 31, 1978.A copy of the inspection check list is includedin Appendix A. Previous inspections of thisdam have been made by others since 1938. Apartial listing of these inspections is inAppendix B. An inspection was made in 1973 bypersonnel from the Massachusetts Department ofPublic Works. A copy of their report isincluded in Appendix B.

b. Dam. Green Hill dam is an earth fill embank-ment with a stone masonry core wall. The damis generally in good condition. Nc seepage wasnoted at the dam. The slopes of the dam areflat and clear of trees. The crest is mostly apaved roadway. Two signs of distress wereobserved at the site. First, erosion hasoccurred on the upstream face of the dam nearthe west abutment. Sand has been washed awayaround the concrete slabs in the picnic areas.The slabs are cracked and settled. There areno signs of riprap protection on the upstreamface of the dam. Secondly, surface runoff fromGreen Hill Parkway, which collects near themidpoint of the dam, has eroded a gully in thedownstream face. This runoff combines withrunoff from the hillside east of the dam andforms large puddles of water in the playgroundarea downstream of the toe of the dam.

c. Appurtenant Structures. The spillway is avertical stone shaft with a granite overflowweir. The structure is in poor condition.Water is flowing under the granite weir andinto the shaft. The piece of granite on thewest half of the weir is misaligned. The shaftis filled with soil and debris to within 2 feetof the crest of the weir. This obstructionrestricts all flows over the spillway. Thereis a fence located upstream of the crest of thespillway.

12

The outlet conduit extends 573 feet from theupstream face of the shaft of the spillway tothe outlet. The upstream approach area appearsto be completely filled with sand. The condi-tion of 121 feet of the conduit under the damis unknown. Sediment has accumulated to adepth of 0.5 feet at the bottom of the firstmanhole located 121 feet downstream. Theconduit appears to be blocked Ietween the firstand second manholes. The outlet end of theconduit contains a build-up of sediment 0.9feet thick at the invert of the pipe.

The overflow diversion structure is located atthe northeast end of the pond and has aconcrete box intake with a trash rack. Theconduit is completely blocked with leaves,trash, and other debris. This material passedthrough the 6-inch openings of the trash rackand through an opening on the top of the intakebox. The trash rack is severely corroded.Erosion of the concrete has also taken place onthe upstream face of the intake box.

d. Reservoir Area. The area around Green HillPond is a park and golf course. There are afew buildings, such as a club house and main-tenance buildings, but no residences. It isunlikely that significant development willoccur in the future. The area is grassed andwooded and has moderate slopes of 10 to 20percent.

e. Downstream Channel. Discharge from the outletflows about 700 feet downstream in a naturalstream bed which slopes at about 2 percent. Atthat point, water enters a 5.3-foot-wide by2.6-foot-high concrete box conduit which ispart of a 12 foot high abandoned dam. Theoutlet to the conduit was not visible. Flowmay continue downstream in the natural streambed. The valley continues at a slope of 3percent into residential and commercial areasof downtown Worcester.

13

3.2 Evaluation. Although the dam appears to be in goodcondition, the two outlets of the dam are blockedand the outlet conduit from the spillway ispartially filled with silt. It is evident thatthese structures are not adequately maintained.Recommended measures to improve these conditionsare stated in Section 7.3.

14

SECTION 4

OPERATIONAL PROCEDURES

4.1 Procedures. There are no operational procedures atthis dam.

4.2 Maintenance of Dam. An of.ce of the Wo. :esterParks Department is located near the dam. However,the outlets for the darn are not adequately main-tained. Some maintenance to the dam has occurredsince the spring, such as repai- of erosion fromsurface runoff on the downstream face of the damand around the stone wall of the spillway. How-ever, the spillway, the outlet conduit, and thediversion conduit are all blocked with debris. The1973 inspection report prepared by the Massa-chusetts Department of Public Works (see copy inAppendix B) recommended that debris be cleared fromthe spillway.

4.3 Maintenance of Operational Facilities. Only thedownstream end of the outlet conduit was visibleduring inspection. The end of the pipe is filledin with silt to a depth of 0.9 feet. The condi-tion of the intake was not visible, since it isapparently plugged. The overflow diversion isplugged with leaves, wood, and trash.

4.4 Description of Any Warning Systems in Effect.There are no warning systems in effect at this dam.

4.5 Evaluation. There are no operational or warningsystems in effect at Green Hill Dam, and the main-tenance is inadequate. This is extremely un-desireable, considering the dam is in the "high"hazard category. A program of operation and main-tenance for this dam should be implemented asrecommended in Section 7.3.

15

SECTION 5

HYDRAULIC/HYDROLOGIC

5.1 Evaluation of Features

a. Design Data. The probable maximum flood (PMF)rate was determined to be 2,650 cfs per squaremile. This calculation is based on an averagedrainage area slope of 11 percent, thepond-plus-swamp area to drainage area ratio of23.8 percent, and the U.S. Army Corps ofEngineers' Flow Rates (dated December 1977).Applying one-half the PMF to the 0.21 squaremiles of drainage area results in a calculatedpeak flow of 280 cfs as the inflow test flood.By adjusting the inflow test flood for sur-charge storage, the maximum discharge at thespillway was established as 92 cfs with awater surface at El 653.2.

An overflow diversion structure at the north-east end of Green Hill Pond was not included inthese calculations. The structure consists ofa 30-inch diameter pipe having an overflow atEl 650.9. Outflow from Green Hill Pond wouldbe through this structure before dischargingover the spillway. However, because the pipewas obstructed with debris, it is inoperative.Furthermore, due to downstream pipe sizes andslopes, the overflow diversion could be inopera-tive during peak storms, even after the debrisis cleared. All calculations are thereforebased on the overflow diversion beinginoperable.

Flow over the crest of the dam is predicted tobe 58 cfs while flow over the main spill-way would be 34 cfs. The discharge over thespillway is controlled by the 18-inch outletpipe downstream of the spillway. The maximumhead on the dam would be 0.7 feet with a dis-charge of 1.5 cfs per foot of width. The depthof water over the dam at critical flow wouldbe at 0.4 feet with a velocity of 3.6 fps.

b. Experience Data. Hydraulic records are notavailable for this dam. Personnel at the Green

16

Hill office of the Worcester Parks Departmentrecall that in 1955 the dam was overtopped andthat flow was over Green Hill Parkway.

c. Visual Observations. Normal discharge fromGreen Hill Pond is over the main spillway andthrough an overflow diversion structure at thenortheast end of Green Hill Pond. The flowover the spillway before overtopping is con-trolled by an 18-inch pipe. The overflowdiversion structure upstream was partiallyfilled with leaves, silt, and debris and dis-charge was totally restricted. The trash rackwas severely corroded.

d. Overtopping Potential. Overtopping of the damis expected under the inflow test flood of 280cfs. Discussion with Personnel from theWorcester Parks Department indicated that thedam was overtopped during the 1955 flood. Inthe event of overtopping, complete failure ofthe dam is unlikely to occur. However, erosionof the dam could occur resulting in a breach orpartial failure of the dam.

A flood wave due to dam failure would have aheight of 4.0 feet at a velocity of 14 fps.

17

SECTION 6

STRUCTURAL STABILITY

6.1 Evaluation of Structural Stability

a. Visual Observations. The evaluation of thestructural stability of Green Hill Pond Dam isbased on the visual inspection conducted onJuly 31, 1978. As discussed in Section 3,Visual Inspection, the embankment of the dam isgenerally in good condition, although the shaftof the spillway, the outlet conduit, and thediversion conduit are blocked.

Based on these observations the embankment ofthe dam is not a potential hazard, however,blockage of the spillway and the overflowdiversion is a serious hazard.

b. Design and Construction Data. There are twodrawings dated 1881 available from the Countyon the design and construction of this dam (seeFigures B-3 and B-4). There are also threedrawings available from the City on the designand construction of the diversion conduit(Sheet No. 1 is included as Figure B-5). Thereare no other plans, specifications orcomputations available on the design,construction, or repair of this dam from theOwner, County, or State officers. Furthermore,information does not appear to exist on thetype, shear strength, and permeability of thesoil and/or rock materials of the embankment.

Green Hill Pond Dam was originally built about1850 and was reconstructed about 1881.Drawings indicate the embankment contains a17-foot- high, tapered stone masonry core wall,5 feet thick at the base and 2 feet thick atthe top (see Figure B-4). The remainder of theembankment is earth fill. The dam is shown onthe drawings to be founded on bedrock.

18

c. Operating Records. There is no evidence ofinstrumentation of any type in Green Hill PondDam, and there is nothing to indicate that anyinstrumentation was ever installed in this dam.The performance of this dam under prior loadingcan only be inferred by physical evidence atthe site.

d. Post-Construction Changes. There are no as-built drawings available for Green Hill PondDam. The drawings dated 1881 show some of theoriginal 1850 dam. The outlet of the conduitwas extended from a point 75.5 feet downstreamto a point 573 feet downstream. The locationand type of transition from the old outletconduit under the dam to the 18-inch outletpipe is unknown.

An overflow diversion structure was alsoconstructed at the northeast end of the pond.This was probably built sometime after the 1936storms.

e. Seismic Stability. The dam is located inSeismic Zc e No. 2 and in accordance with PhaseI "Recommended Guidelines" does not warrantseismic analyses.

19

SECTION 7

ASSESSMENT, RECOMMENDATIONS,AND REMEDIAL MEASURES

7.1 Dam Assessment

a. Condition. Green Hill Pond Dam was neitherdesigned nor constructed according to currentstate-of-the-art procedures. Based upon thevisual inspection of the site, the limitedengineering data and a lack of operational ormaintenance information, there are areas ofconcern which must be corrected to ausure thecontinued performance of this dam. Generally,the dam is considered to be in good conditionalthough the outlets to the spillway andoverflow diversion structure are in poor condi-tion. Several signs of distress were observedat the site: blockage of the shaft of thespillway and the diversion conduit; leakagethrough the walls of the spillway; misalignmentof the stone block forming the western half ofthe spillway weir; silt depczlted in the outletconduit at the upstream manhole and at thedownstream end; erosion and lack of riprap onthe upstream face of the dam; erosion due tosurface runoff on the downstream face of thedam; poor drainage of the playground area atthe toe of the dam; and corrosion of the trashrack and spalling of the concrete intake on thediversion conduit.

Hydraulic analyses indicate that the spillwaycan discharge a flow of 33 cfs at El 653which is an average elevation of the crest ofthe dam. An inflow test flood at 280 cfs (halfof the probable maximum flood) will overtop thedam by an average of 0.2 feet. This calculationis based on an unobstructed flow into the spill-way, which is presently blocked, and does notconsider discharge through the overflow diversionwhich is blocked and may be inoperative duringpeak flows. Previous experience indicates thedam was overtopped in the 1955 floods.

20

b. Adequacy. The lack of in-depth engineeringdata did not allow for a definitive review.Therefore the adequacy of this dam could not beassessed from the standpoint of reviewingdesign and construction data, but is basedprimarily on visual inspection, past perfor-mance history and sound engineering Judgment.

c. Urgency. The recommendations and remedialmeasures outlined below should be implementedby the Owner within 2 years after receipt ofthis Phase I Inspection Report. However,clearing of the debris from the spillway andfrom the overflow diversion facilities shouldbe done within 30 days.

d. Need for Additional information. Additionalinvestigations to further assess the adequacyof the dam are outlined below in Section 7.2.Recommendations.

7.2 Recommendations. In view of the concerns over thecontinued performance of the dam and spillway, itis recommended that the Owner employ a qualifiedconsultant to:

a. conduct a more detailed field investigation ofthe spillway outlet and the overflow system.

b. conduct a more detailed hydrologic and hydrau-lic investigation of the spillway and overflowdiversion.

The recommendations on repairs and maintenanceprocedures are outlined below under Section 7.3,Remedial Measures.

7.3 Remedial Measures

a. Alternatives. An alternative to implementingthe recommendations listed above and the main-tenance procedures itemized below would be todrain the pond and breach or remove the dam.

b. Operating and Maintenance Procedures. The damand appurtenant structures are not adequatelymaintained. It is recommended that the Owneraccomplish the following:

21

(l) remove all debris from the shaft of thespillway and the overflow diversionfacilities

(2) install a trash rack on the spillway andrepair the trash rack on the overflowdiversion

(3) construct a gated outlet

(4) repair the weir of the spillway wherewater is flowing beneath the granite slabsand realign the western weir stone.

(5) clean accumulated silt out of the man-holes and outlet conduits

(6) repair erosion on the upstream face of thedam and protect the slope with riprap

(7) construct a swale along Green Hill Parkwaysuch that surface runoff does not erodethe downstream face of the dam and collectin the area of the toe of the dam

(8) construct a swale such that surface runofffrom the downstream side slopes does notcollect and form wet areas below the toeof the dam

(9) repair the concrete on the intake of thediversion conduit

(10) implement a systematic program ofmaintenance inspections. As a minimum,the inspection program should consist of amonthly inspection of the dam and appur-tenances, supplemented by additionalinspections during and after severestorms. The spillway and the overflowdiversion should be examined at that time.All repairs and maintenance should beundertaken in accordance with allapplicable State regulations

(11) periodic technical inspections of this damshould be continued on a bi-annualfrequency

22

4g

(12) institute a definite plan for surveillanceand a warning system during periods ofunusually heavy rains and/or runoff.

423

APPENDIX A

PERIODIC INSPECTION CHECKLIST

PERIODIC INSPECTION

PARTY ORGANIZATION

PROJECT Cgree /411, Poone DATE 7/31196

TIME 8.'oA,4M- /.' OMp/

WEATHERparijr e /oyz I - ,75"o

W.S. ELEV. 50.3 U.S. (33.qDN.S.

P a:vrned &j'hmart ekova/,'on 65/.0PARTY: on op / Ap' 1way toe;r - from U56S

1. /l,'/ke ,a,~5 n 6. Yopoqrph,c u Jra, e

2. 6rd ~,e o 7. r p-

3. Le dra,tan 8. v,, erna-

4. blc1. Weber 9. ha i'd Cole5. Cawl Jveet o.

PROJECT FEATURE INSPECTED BY REMARKS

3. oLd/ le nranltan , ,arson

4. dfver~lOn i!cnd " ,a rs on - lde-b,-

5.

6.

7.

8.

9.

10.

1 page Ad-o QLZ

PERIODIC INSPECTION CHECK LIST

PROJECT Oren #1i on' DATE //I'MPROJECT FEATURE a e2nhank'nyt NAME /f7;/fe /arson

DISCIPLINE ageoerhn, al/ NAME Ed rio

AREA EVALUATED CONDITIONS

DAM EMBANKMENT e'?eJ-maVed aspha i" r'adj qrai5 -/boati on

q4, face,' 9ra.56 on b -faceCrest Elevation raie' from 5.5 k i54.0

Current Pool Elevation 65,,03

Maximum Impoundment to Date

Surface Cracks a//iv/or erac/k,,Y on paereer)rt o

Pavement Condition por

Movement or Settlement of Crest none V'15 41e,

Lateral Movement none v/f5/,bk

Vertical Alignment re/aIwely Ja7

Horizontal Alignment doncate - ard pond

Condition at Abutment and at riqh* abufmen)-bes In/vl rara/ /;//sdeConcrete Structures l/I ahal'i- ,edro'k O/tro'as

Indications of Movement ofStructural Items on Slopes none 1 /

Trespassing on Slopes people n park

Sloughing or Erosion of Slopes no :iouiqh/'nor Abutments 6eral -1 / gar11 o /2 1 of / aWO_,

Rock Slope Protection - Riprap no r orap, a lea&" f s1olve on/ -h1 .5de..sFailures of-p;11awy, ,orle/, recedl,; -4,e k avve.

Unusual Movement or Cracking ator near Toes /lone Vilb/e

Unusual Embankment or Downstream

Seepage

Piping or Boils /l/ne v//5/C

Foundation Drainage Features A/On i,6eToe Drains *one 41';/I

Instrumentation System A/onepage ,-o fil_


PROJECT 6 reea 9/I/ Pnd DATE 7/3,170

PROJECT FEATURE - 5p//way NAME a/e Br -"aa

DISCIPLINE yerkehnvcai NAME /1, Ke ta,,on

AREA EVALUATED CONDITION

OUTLET WORKS - SPILLWAY WEIR,APPROACH AND DISCHARGE CHANNELS

a. Approach Channel A4,e

General Condition ,/A (no/ app/,'gh/e)

Loose Rock OverhangingChannel A(//A

Trees Overhanging Channel g/,A

Floor of Approach Channel A//A4

b. Weir and Training Walls nlhe 5a1&b overf di r- frarn,

General Condition-ef_ _ _ _ _ _ _ _ poor

Rust or Staining noneSpalling ltvSf pfee c/ qra.,;Ie i we,, hasSpalling_ __ h;frt'd c/ of o/,cz.Any Visible Reinforcing I}oge

Any Seepage or Efflorescence yerge7¢r/4y di.6c5hary 3ha/- /rom

Drain Holes nonefl, rfa red_~

c. Discharge Channel ver-hal drop 6ha/l- Sve aoa//General Condition very poor- f//led wi6 50, #- -Irash

General~~/ Codiio /Am1,~ 211 ,/ Cre.51-

Loose Rock Overhanging /OpOe 5/,b on weirChannel

Trees Overhanging Channel rOne

Floor of Channel /701 V,51sb/e

Other Obstructions 1oe

page aof_1__


PROJECT Ogen ' PonS DATE /31/?e

PROJECT FEATURE dV' €VerO, do,,dik,/- NAME Inl;/fe 1-a r,5 on

DISCIPLINE yecieehn;ea/ NAME Dick .e,6e r-

AREA EVALUATED CONDITIONDIVERSON CAtOVOL r

OUTLET WORKS - .P...Y W,',".APPROACH AND DISCHARGE CHANNELS

eo -ro e box ('e d - wd W e ,p e n /n l

General Condition f-7 debru Imlnee box, 7o e ,

Loose Rock Overhanging k-', I/ed e ,/ botChannel t90ne

Trees Overhanging Channel /,5

Floor of Approach Channel irah deb/ ,s

b. ~Q' &riigWalls renkr d w~nt.-ek pq' e - 2.S'dtameler

General Condition e-F b/c-/b wiM /eave5 Irash, apd'eamerete ~/

Rust or Staining none. v/:51'/l

Spalling none 11'5 41e,

Any Visible Reinforcing /iore vl/'b/e

Any Seepage or Efflorescence nerlz il5,'b/e

Drain Holes ,, ,,p app/_.a/e,

c. Discharge Channel no near ,5i e

General Condition noi inspeci-ed

Loose Rock OverhangingChannel toi 1'lspeded

Trees Overhanging Channel 001 ifspeckac

Floor of Channel nol 'nspeef#ed

Other Obstructions no inspeofeet

page . _o f_4


PROJECT 6 ree #//I Pond DATE _ / __j__

PROJECT FEATURE Oujllf~ e - NAME 4yle S,-na ?a

DISCIPLINE lee/eeh na/ NAME Ifik /,so,


OUTLET WORKS - INTAKE CHANNEL ANDINTAKE 'STRUCTURE

a. Approach Channel ubnwv¢ed- nol v'5 iV d/e

Slope Conditions nol v1b1/e

Bottom Conditions noi- V}*51.be

Rock Slides or Falls no" vi-i ble

Log Boom none

Debris appe 15v e l di //d 1 5a/n-

Condition of Concrete Lining o/7,e

Drains or Weep Holes noneop e,4,'.aI bock, of o/ao~rev Inowall

b. Intake Structure aj/ 1)u-2lja& Shaom- --

IflasonryCondition of fl!t n k/''bl/e,

Stop Logs and Slots no v/5/',/e.

p ageAo f-L


PROJECT Orfen ,/I Pond DATE '7/3/178

PROJECT FEATURE Oul//e/ eorku' NAME lq/e 8/7nay

DISCIPLINE qeo/pehnwa/ NAME /2,'Ae /k. ao,.


OUTLET WORKS - TRANSITION ANDCONDUIT 1,41da t 2. 5 Vi/a rt'ifr're eel rf 4 pp

General Condition of Concrete ppe v,6,1/e (! raloao/es

Rust or Staining on Concrete none v,5d/1e

Spalling )one v/1,ble

Erosion or Cavitation t90 V/5/6 le

Cracking nonel i/ /'/

Alignment of Monoliths nf P/':5/',/e

Alignment of Joints nok vls, I/e

Numbering of Monoliths r7o# V/5'4/e

page- 4o f_2_


PROJECT dPo DATE 1/ ,mPROJECT FEATURE oVllel Cpl ,'t/ NAME 1Lye 8ranaO14

DISCIPLINE ageoeAncaf NAME In'e Laro,


OUTLET WORKS - OUTLET STRUCTURE

AND OUTLET CHANNEL

General Condition of Concrete _0_ _ _ _

Rust or Staining ,,one-wa/er e/ear

Spalling 0/1 1IO

Erosion or Cavitation none vlSi I/e

Visible Reinforcing hone

Any Seepage or Efflorescence l5,charyl/b & 6--/'5pr7

Condition at Joints nof su ,6l/e

Drain Holes /IO1- 0,4he,

Channel overarown& &amp- gras. t weeds

Loose Rock or Trees Over-hanging Channel none

Condition of DischargeChannel L/ re WI/6 9r4,ss

page 2f-l_

APPENDIX B

PLANS OF DAM AND PREVIOUSINSPECTION REPORTS

Page

Figure B-I Plan of Dam B-I

Figure B-2 Sections B-2

Figures B-3 and B-4Drawings of Dam, dated May 10, 1881 in pocket

Figure B-5 Drawing of Overflow

Diversion, undated in pocket

Previous Inspections (Partial Listing) B-6

Inspection by Mass. Department ofPublic Works, dated February 5, 1973 B-7

ws $I C U. 4

30-0

bSSJ. - -

X463-S "&-S .-4 SU (-3.0

M.N.* *----- 4 -&.14631

U/ 5______ ConC.._A ____

;y s 1 1 OAC b;L

Z)

ELE~dCowell3,

x ILVI~

zO~s

1624

B-m1"-R 0/ -11W,

2. ZDeca.s / ae on, ,eld suvlvy

~'e- ~phata ?r#A3. )9%o7-o Aa.*V

rm or em V50 Fr.Sar ocml l

Lao,'raVa. A'osr.Y. See &a $ seczwj.

FIUEPAV PIAI

GPFFN 14ILL

1 .5- 3I G0

WS ELEV- 650 .1-

_ 6~~ft53.' '52-

SECT10ON 2-2

GWoI 9.~ o~w

GEErN 33 PW

B~3~ZDI3O PAGE LMCNIF3, EC 1 h '1 ~ ~

1.0 /00.0 --

TMH.2 ~ 2MH*3 ourter1Ivv. &,33.oLNV. IN .w . IN .o .4 £1 .33-9

30", /1 4 a 30, RCAXMRS

Sco~t in Fee r

F/o uRe iE -2O

PFI~rXL11 PAGR BLJWL-Mo? Y1ue

FIGUREI 2

'WAS~TE WA ST E' j WASTE WASTE

FIGURE1

rn

CATOP OF ROAD'

WASTE1>

F:IGURE 3

OF ROAD

31

/-

FIGURE 4

Y- WSTE------WASTE -___WA STE____

'VIEW FROM NORTHFACE OF CEMENT Nf\L.

FIGURE 5

'VIEW FROM SOUTH

TOP OF

SOLID ROC

ROAD

ii-'WASTE WASTE j D WASTE WASTE

~1~

EV

-- ~iLF-

SOLID -~

.1. ~ - I-

A

""o

7 zTOP OF ROAD

-4

I RC

. I

- I SOLID ROOK

DAM AT GREEN HILL

SCALE 4FT- I INCH

MARTIN GREEN C.E.

P OF ROAD

0HIL 4F

C._SOLID .

HILL

-H

C.E.

FIGURE 5

vicw rROM SOUTH

TOP OF IROAD

Lb

SOLID ROCK 510RC

-- - WORCESTER COUNTY COMMISSIWORCESTER COUNTY ENGINEERING DEPA

PLAN OF

GREEN HILL DAM

WORCESTER MASS

AS FILED AND APPROVED B3Y

COUNTY COMMISSIONMARCH MEETING DOCKET

SCALES AS NOTEDTRACED BY PPPDA

JRACING CHECKED BYt

~APPROVED MAY 10, 1881 BY

D aOCK~ SOLID ROCK

WORCESTER COUNTY COMMISSIONERSWORCESTER COUNTY ENGINEERING DEPARTMENT

PLAN OF

GREEN HILL DAM

WORCESTER MASS

AS FI LED AND APPROVED BY THE

COUNTY COMMISSIONERSMARCH MEETING DOCKETro ?1 8

SCALES AS NOTEDTRACED BY PPP

DAM NO fJ_23TRACING CHECKED BY

APPROVED MAY 10 188I BY

iN NO. - el- 3 FIGURE B-3

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

Dnr rJQo-& I-)

mczm~oPAGE BIM-NO? nULM

FIGURI

_ 71!--:

__ 4L-Z7 .4-r - - . .E . .. . . .. .-_. ....-_ ... ... . ...... T .. .. ---

..._ - .Z - : - l -... T .. --- r - --.... ---...... . . 1----

F F - 1-_- --F-.,_ _ - '--- 1 .. ... ....-- -.. *.-k**_UI ....T ]._. ! I .7 1 I 7 --. --- *

.f± 7_-- -7~ i -. -T-W , __.. ....... ....... ____

LONGITUDINAL SECIA NI

CROSS SECTION O

FIGURE 7

FIGURE 6

J 3

[--_T,..T.--

- _____"

-_

/ (

.. W- . J SECTIO. O CULIV.EI... . 4_ -_ T

-4___. 7_ _ '7 71171 -. 1 7 _I._I T ; . L ' . :

... .I ..... I . .. _ . T T .. . . T . ." I J_ ... _ _...

. ..

DINAL SECTION OF CULVERT

ANDSECTION OF DAM AND ROADS

FIGURE 6

r --

DINAL I~i SEC I NO UVRAND1SECTON O DAMAND OA/

3

:E D

4._

-. OLx I

j_ - (

%C.OVERING STONE , ,t7 "--

0 F'-L j

* :.LJ W-

z

L..i

SHEE T 2 OF 2 SHEETS

FIG~URE 8

> NORTHERLY OR UP STREAM

30'

03

SHEETS

11

/i

-. LEVEL 0

ROAD

OLD TURF_IS

I (0m

III

I INORT

"I

SOLID 3' _ ROCK

LEVEL WITH FLOOR OF

.,_#

I

!':tLEyc_ OF Ov _EL OW .

OLD TURfI I

I I

I .1

NORTHERLY

fI

I I

ROCK,-"

rH FLOOR OF GATE-

DAM AT GREEN HILL

SCALE 4FT = I INCH

MARTIN GREEN C.E.

FIGURE 9

-WESTERLY'

__ __ __ __20 2'6"~ -- 3 .'---.-- 6 ~ -

* ----- 2-23' --

PROFILlE OF ROCK FOUND&

EEN HILL

SI INCH

REEN C. E.

C?

9

• I.EAS$TE RLY

" 0' I.

.. 4 7"

K FOUND,- OF CEMENT WALL

DAM NO. - 61- 23

-. I

I--

I . •

N I, ,

L FIGURE B-'q

~~~~~~~PAWE BLUM-MO? MAW

.. ,67 4

I I

44*I 4

41.,

4t 7 2-~-At

p Poa

. -,,. w * *~- *~

<I -

-~ ~ ~- fb~

A ~ ~K4 ~.7

S.-#t ~*s '4.

~ A.

~

Cs 1~

I . I~ *

.. ~

.4'PS5 4 5 le

+5

a ~ j

PLAN 8 -PROR!~

GREEN HILL. PONDJDIVERS lON4 OF OVERFLOW'i

CITY OF WORCESTER MAI-STA. 0+00 TO- STA. ?9

HORIZONTAL SCALE 40 FEET TO AVERTICAL SCALE 8 FEET TO A

01

PLAN OF INTAKSCALE Y-TO A FOO

.ii 7£A $Mo EET&-

*g

a PROFU-

_N HI,L. PON04 Ot' OVERFLOW 7'WORCESTER. MASS.

TO STA. Z+*TCALE 40 FEET'TO AN INCH

ALE 8 FEET TO AN INCH

NL

PLAN OF INTAKESCALE 40TO A FOOT

.- I

IV..>IL o -.

i2,+.4J, . ; I

'L" - :, .. '•i ,,

::Y . ., V i,'",

S'+.

;gi., .;i. 4 , '."

II

A. .0

4 % V':L -'+ LV " -" I.,"

4-I.

1$

- a

ALTEI~NATE A~ BLOCkS

-~. ~- - - - t- - - - - .~-. - ~ ~V~)4W~SU~~VAGE

- - - - - - - -- - -

- - - - - - -

'4

3 4t

PON Ea~o3

6/so

'.

* I

~~~i'/Z2~,r i 0

M) 14

+ 8756 7 +50.5

4'-0"

POF.6 O3 . ._ , *.1 , .-- o

SECTIONSCALE 14" TO A FOOT

,7 ii

/ 50

~ B-5

CROSS SECTION

48 EMN BLOCK SEWER

SCALE . TO A FOOT '-

50.5 ,,

-- - " FIGUk B-5S ,)

111

FA V

x 2

o ow

1;j' 4: AN .

A 4a Ifv2z;I -53i

I.-- A A-

B-6 MRBM m AG BLAaU --~

DESCrIPTIot OF DAMIDISTRICT ,

Subn5tted by 02LAYaAAV Dam No. 2 3'B -2

Date . - 2 City/To:n /4o#.C!.7 .

Name of Dam C,&EeA 4/ ,

1. Locations Tope Sheet No. 24 p

Provide -'- x 11" in clear copy of topo map with location ofDam clearly Indicated.

2. Year builts - Year/s of subsequent repairs

3. Purpose of Dams %ater SuppLy Recreational k/

Irrigation Other

4. Drainage Areas __ __________ sq. ml. acres

5. Normal Ponding Areas . Z:.7---acres; ave. depth

Impoundr.nt .gls.1 - _ acre ft.

6. No. and type of dwellings located adjacent to pone or reservoir

_ W006_____ J.e* summer homes, etc.

7, Dimensions of Dams Length O Max. Height _.

Slope.. Upstream Face - _K TrjC,4._

Downstream Face J,-/

V'ldth acroas top 5* 0 1

Be ClassifIcation of Dam by Materials

Earth t Conc. m.asonry Stone flasonry _ _

Timber Roclfi]l _Other

9. As Description of present land usage dor'nstreama of dams

rural; S- S urban,

3. Is there a storage area or flood plain dotinstream of dam whichcould accomedato the iPoundinent in the event of a completedam failure? yes no _.. . ._________

B-7

A

DAMA H10. 3- &.

10% Risk to life and property in event of complete failure.

Rol of people A'eA' .

Not of horaes ,4toN °

Nos of Dusinesses ,/N'0,4

No* of industries * '01Vf . Type

No. of utilities ,&.Vc E * Type .

Railroads ,/O

Other dams A'OyW e

Other -

110 Attach Skotch of dam to this form showing section and planon 8." x 11" sheet.

12. How to I oca +sd I 'oAW eet 6oA7" $r7, e,10 SKY/ Y 6* 4 4/?/V6

sr. ,y ov "H- s o.4v o,#,v v/, aL.& oiv / H r .Ar

"" E ,4,r,, o,v/ ,

I "B-8

INSPECTION hEFORT - DAIS A!D IESL,\'OjRS

1 Locations City/Town WO $g IrS .n. I o. 3-/9-348n A.

Name of Dam - .Q.1EEN hill- PO/VO I nspected by 1

Date of Inspection .- 6-- 7Z

2. Owner/st pert Assessors ,_ _ Prey. Inspection k/

Reg. of Deeds Pers. Contact

~* c~y~ ,S?2 84F.AoorfS S7'Mane 3t. a No. City/Town !state Tel. Wo.

Name St. & ilo. City/Town State Tel, o.

Name 3t. & No. city/Town State Tel. '.o#

3a Caretaker (if any) eeg. superintendent, plant manager, appointedby absentee owner, appointed by multi owners.

Names St, & No.s

City/Towns State% Tol.T!o, s

4. No. of Pictures taken N0 hJC

5* Degree of Hazards (if dam should fail completely)'

1. Minor .. 2. Moderate

3. Severe 4. Disastrous

* This rating may change as land use changes (future development)

60 Outlet Controls Automatic ___Manual _

#SA'r Operative yes; No.

Comments

7. Upstrear ace of Dam: Conditions

1. Good V/ _ ,l.nr Repairs

3. MnJor repairs 4. Urgent :opairs -

j • arCommen t si

IB-9

II.

I.-2- DAI.; _O, ________-

B. Downstream Face of Dams

Conditions 1. Good 2. Minor Repairs

3. Lajor Repairs 4. Urgent Repairs

Commentss

9 Emergency Spillway&t'#~g

Conditions 1. Good _ _ __2. Minor Repairs

3. Iajor Pepairs 4. Urgent nepairs

Commentso

10. Water Level at time of inspection: 2-.5 ft. above belowe

top of dam /principal spillway

other

11. Summary of Deficiencies Noted:

Growth (Trees'and 3rush) on Embankment ,,','

Animal Burrows and Washouts .4eV5

Damage to slopes or top of dam go'o5YO

Cracked or Damaged iasonry _ _-o_'IV_ _

Evidence of Seepage -

Evidence of Piping ,,o,""

Erosion _Y __ __

"" Leaks "_____

Trash and/or- debis-Impeding-flvw . (/iV SI0LWY.L......

Clogged or blocked spillway . -- .

Other

I.

1 -3- DI..flo. 3,/D- .o-.3

12. Rlemarks & ecomendationst (Fully Explain)J ~vj O~V~4LC 0wwApT.*..v oj, roqls D4OVV4~

64.r czoop. .rS I r, ge.,,NoEvo rvqr rove' Ss/ali,4kir

3. Overall Conditions

1. Safe

2. Minor repairs needed

3. Conditionally safe - major re.pairs nocde d

4. Unsafe

5. resei' ,oir itpoundncrnt no lon:cr exists (explain)

flocomnend removal from inspection .ist

IBr

I..I i

%4L~± -\In

(B 1

I

APPENDIX C

PHOTOGRAPHS

I-

.1

IIIIII

NO. 1 VIEW OF SPILLWAY

I*1INO. 2 VIEW OF DEBRIS IN SPILLWAYI c-I

aanmS~

9

a

£

I

g

'~'~ ~ ~- ~

NO. 3 VIEW OF DOWNSTREAM DAM SLOPE

INO. 4 VIEW OF OUTLET CONDUIT

I

-j

APPENDIX D

HYDROLOGIC AND HYDRAULICCOMPUTATIONS

I:II

3 Project Arct. N., fS 4- Page of

Subject WAovcev1se.A Marr. Are-*- Comptd. By LE B Date -7/ biDetail -GRA/"'HfLtL*RoAJD D4AA Ckd. By Date LJZ

P* a k(ro -r~ r4e -odJ(0t'a-P

Qra a,&i *4e~ z A,8 p

771 -4r(

ToA (re4&~ e&~4(

Sl~od 2S'?. TTI -i4 &g~o~ Slb~rwTy

5 OC 7

FUI ~ -"L . .0 4,7t

_Rtoye. F(ooJ~ L(c~)O2A e .

-J

o 2O-fhneA r4(M o ~ (

too~~s tooA Floo Ilo tP-e(11

IM((OuJ~~~ S~ =~od QA 12.o(I-.

5 eAI kIkfO e+"SU I d4 - 4,*J . 04 D .P O " iF9

Project Nagf RtUeI.oLw *C Nmh -F% 0 D& 'Kt ACt o E O# Page -oSubject - Y. e se 'Mu.r 4 re a Comptd By Date

Netal G'R17fA. 9I/4e POdO L)AAA Ck-d. By Date IiL.~

C-=)L. e "O2, V4-Ql&A 4i. Fd

0 o ld ccIC

AA

C0", C st.. old ceza.-)

A- 'Pp~ Fh,.do Rkt&iodk -rmP

z3 ____0_/__?________ '7 , 'Q

Z Up : 174 /~ 6'

LAJ v zv Q?

14 g.E. 5-L /4, J.. - , / ,5 IB le, .

Qp 3/,Iw 3.f 2-(. 54255s 3 34

jU 4, -- T.' /9 (t4 s' 6/

4- 19 44 t S7

Pro ject _____R_ Lt_______fel'____-_cc N Page of ____

Subject Wo .rie. e o,;A rAre& Comptd By ZorDate-7zZ4

Detail IYceRL= I4(LL PO)pf)A4{ Ckd Byk Date______

C - C 4 x Flow

low Cee 142. Useb~ as 40, Iwele0iv d4- - Cre r4 (& rEl7 Cvea is 4'

QC 141 i #9'e 9# 2=v)' S I -u dip4 1-'/ w O

'lea 1 1 23 eo 5'4Is

wb, U' V6% ' b t ,'0 Pe 6 r o 14' t.oZwC

>:A 6Uol-erlFod-Da ekOilw 9 h(i ~mk/&'l

MLalorL~pA ow'C-S 6-1,7,-6 52,r, c.-7' ) ma ,S

) ' rITA /eV, 3 .rof ps

No Phw7AeA Ciwg'd

-Max, cscA, 6e aje 4Ow 9vLeA c~'~jv- : 334r- I.

AeeApo4ej,#i - oul(e+ Occov5; lv 4Lv I ov4 -co s4 -e tA o

B.,e (o4 -vov, a- £-U 4 VOii C TL I 1A S ci

D- 3

P4

Projct L~ cctii

3N

D- 4

old

• \r u

'4- ... o,- 11,

. .Protect N t I .... S Acct.No. . Page. o

Subject 4Jarett4etA J'ef 4rr- Comptd By Date f/22/7p

Detail :6EM //ILL Po O Ckd By Date

bJo~r?. C-Ar OurErr

/ ',

pr Cot of(C.pp

I a

4 ,r:

ij~wN

1%0

I ___ - -J -A---C

4/

44

hin

( ,. : v oCt~i .,, ,, ,7 It ,'41 to Will,) D', t,.,L- 5

.-,

Project Nn(. ~iuv U ofA ,o. 51 '~ Cj &TAcCt No. --1iq C Page G .

Subject JoceTL" mar FAr'- k Comptd ByDae c

Detail i4L cs Ck d. By Date

h'i'-r -l r-V..

a &

A-8 30" 648.32. 1 &V .oq- Z.S1 s

8. C 48 6 k7 f I) 4 67-f 00o'f(7 473,0 (fto

C-b t If 6 4r, 7 163-0 -024 1, 3 6,7 -70.7

~ ~3 7(0i,0 0.2&'31. 18,3 (0~&

-L. - 2' -'7 3, 3 -2391 O-OST-l IrO 68"O'.2-

Tke AJor Aeat4 0u4 (e4- COmm~ecd 4t..t. povd 4- &. r4vai. dra(c4eI ki- ~r4(, r.',.c q( Co-(Jime c ~ruv. .L

rw' ~4a.4 /W Rov woutgA aftvw& 4kt pomd 4v cr? duS 4&do&tbKq eelleue 43't im,* Me 43~ A 0.1

oo4, r4 a&.uul 5tse., 1TA 4Va e. w'e raiiao P, SU4A4A

44, oo po~t m .#SO&- 'T." 1P4 6t d Cwte I~

D- 6

7 AD-AIL46 26 NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL

DAMS

GREEN NIL POND DAM (. .(U) CORPS OF ENGINEERS WALTHAMMA NEW ENGLAND DIV AUG 7RUNCLASSIFIED F/G 13/13 NLIll, :: ,7

36

I111IL2 -4 111.

MICROCOPY RESOLUTION TEST CHARTNATIONAL BUREAU OF STANDARDS-1963-A

Project E- Acct No. Page f 7Subject warces4ev Ar v At Pa - Comptd By L* Date -

Detail WE .HILL POND PAM CkdBy Date

4e Subje &-l Po et/vI ( ,F re .Zo'k

pp, O .8 2 q4 8,)4 c4.S

Vot- S4ied 6.&I6o- Ce s

(-i) V,. r(i)o)(( Ao zn 7 td

00 2V.) 31.1 3

hihi

z

Z"0 2,83 /4.) Z 2I

J 3,I

/ 9 q7o ,I/"S-- 4v)eA,;* o 4

V t v) r r- 6 5 a6 - V , 1 0 Vs O e -I tR I Q ,

4$. /' SA-ic/cure: P?004 Wauoe cL Mo4 -K. oif 4vv~

D- 7

APPENDIX E

INVENTORY FORMS

i *mmmmm~mmbm green hill pond dam corps of non … · ad a146 268 national program for inspection...

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