ma00062 lake warner dam hadley phase ii 2013-7-15

8/13/2019 MA00062 Lake Warner Dam Hadley Phase II 2013-7-15

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PHASE II INSPECTION / EVALUATION REPORTFor The

LAKE WARNER DAMMA Dam #: 2-8-117-3

NID #: MA00062

HADLEY, MASSACHUSETTS

Prepared For:LAKE WARNER, LLC.

Funded By:KESTREL LAND TRUST

PO BOX 1016AMHERST, MA 01004

Prepared By:

ROOT ENGINEERING

305 SUMMER STREET

SPRINGFIELD, VT 05156

JULY 2013


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Lake Warner Dam Root Engineering

MA Phase II Inspection / Evaluation i July 2013

EXECUTIVE SUMMARY

Lake Warner DamHadley

The Kestrel Land Trust representing Lake Warner, LLC (Owner) of Amherst, Massachusetts isresponding to a Certificate of Non-Compliance and Dam Safety Order for the Lake WarnerDam in Hadley, Massachusetts. The Certificate of Non-Compliance and Dam Safety Order wasissued by the Executive Office of Energy and Environmental Affairs (EOEEA) on December11, 2012. Root Engineering was retained by Kestrel Land Trust to evaluate the condition of theLake Warner Dam.

The Lake Warner Dam in North Hadley is a concrete structure with an overall length of 82 feetand a structural height of 15 feet. The normal hydraulic height is 13.4 feet. Construction on theexisting concrete dam began in 1918 and saw various undocumented changes through until1925. Improvements were made to the dam by the Town of Hadley in 1947 and by the Hahnand Klimoski families who owned the dam in 1965. This site has been occupied by variousdams since 1660. The dam is listed on the National Historic Register.

The dam retains Lake Warner which is a 70 acre water body on the Mill River containing avolume of 480 acre-feet by previous estimates. The Mill River watershed is 30 square miles.

The deficiencies observed with the structure and the appurtenant environs are: Woody vegetation growth on and adjacent to the structure; Uncontrolled leakage through the cracks in the concrete elements of the dam; Inoperable low level outlet gates; Failing concrete/masonry lateral training walls; Uncontrolled limited discharge through the former penstock.

Analyses have been performed to show that the spillway has adequate capacity for the requiredspillway design flood and the structure is stable. The measures required to bring this dam intocompliance with dam safety regulations include: Removal of all woody vegetation from the dam and within15 feet of the structure Reconstruction of the right concrete sluiceway area to include replacement of the sluice

gate and operator along with adjacent retaining wall fascia Removal of deteriorated stand-alone wall downstream of the right abutment Improve the upstream fascia of the spillway Add reinforced concrete fascia to downstream left spillway face near left abutment Reconstruct the upper (1947) element of the left training walls and add upstream

concrete facing.

Complete demolition and reconstruction of this dam is not warranted as the bulk of the structureis stable. The cost effective treatment for the existing deficiencies is repair or replacement ofthe deteriorated parts and preserving the substantial mass of the existing dam. The total projectcost for engineering, construction, permitting, and administrative burden is estimated to beabout $240,000.00 for large capital items combined with structural repairs. Annualmaintenance costs are estimated to be from $1,250 to $3,000.00 per year.


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MA Phase II Inspection / Evaluation ii July 2013

PREFACE

The assessment of the general condition of the dam reported herein was based upon availabledata and visual inspections. Detailed investigations and analyses involving topographicmapping, subsurface investigations, testing and detailed computational evaluations were beyondthe scope of this report unless reported otherwise.

In reviewing this report, it should be realized that the reported condition of the dam was basedon observations of field conditions at the time of inspection, along with data available to theinspection team.

It is critical to note that the condition of the dam depends on numerous and constantly changinginternal and external conditions, and is evolutionary in nature. It would be incorrect to assumethat the reported condition of the dam will continue to represent the condition of the dam atsome point in the future. Only through continued care and inspection can there be any chancethat unsafe conditions be detected.

_____________________________________

Morris J. RootMassachusetts License No.:33093License Type: CivilPrincipal

Root Engineering

PROFESSIONAL

ENGINEERS

SEAL


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MA Phase II Inspection / Evaluation iii July 2013

TABLE OF CONTENTS

EXECUTIVE SUMMARY ............................................................................................................. iPREFACE ....................................................................................................................................... ii1. DESCRIPTION OF PROJECT............................................................................................1

1.1 Introduction ..............................................................................................................11.2 Purpose of this Report ..............................................................................................11.3 Dam Data .................................................................................................................11.4 Description of Dam and Appurtenances ..................................................................21.5 Description of Lake And Watershed ........................................................................31.6 Engineering Data .....................................................................................................3

1.6.1 General Elevations (feet) .............................................................................31.6.2 Primary Spillway Data .................................................................................3

2.0 PREVIOUS INSPECTIONS & REPORTS .........................................................................42.1 Dam Safety Inspections ...........................................................................................42.2 Other Reports and Correspondence .........................................................................5

3.0 VISUAL SITE INSPECTION .............................................................................................63.1 General Findings ......................................................................................................6

3.1.1 Dam ..............................................................................................................6 3.1.2 Appurtenant Structures ................................................................................73.1.3 Downstream Area ........................................................................................7

3.2 Review of Operations and Maintenance ..................................................................83.2.1 Operations and Maintenance Procedures .....................................................83.2.2 Emergency Warning System........................................................................8

3.3 Topographic Survey .................................................................................................84.0 HYDROLOGIC & HYDRAULIC ANALYSIS ..................................................................9

4.1 Overview ..................................................................................................................94.2 Summary of Hydrologic/Hydraulic Analysis ..........................................................94.3 Dam Hazard Classification ......................................................................................9

5.0 STRUCTURAL STABILITY ASSESSMENT .................................................................105.1 General ...................................................................................................................105.2 Visual Observations ...............................................................................................105.3 Design and Construction Data ...............................................................................105.4 Seismic Evaluation/Stability ..................................................................................105.5 Stability Analysis ...................................................................................................10

6.0 ASSESSMENTS, REMEDIAL MEASURES, AND RECOMMENDATIONS ..............136.1 Assessment of Existing Conditions .......................................................................136.2 Routine Maintenance Activities .............................................................................136.3 Additional Studies and Analyses ...........................................................................146.4 Required Maintenance and Repairs .......................................................................146.5 Remediation Measures to Address Identified Deficiencies ...................................15


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MA Phase II Inspection / Evaluation iv July 2013

6.6 Alternative Remediation Measures ........................................................................166.7 Conceptual Opinion of Probable Costs ..................................................................176.8 Permitting Considerations ......................................................................................176.9 Recommendations for Implementation ..................................................................18

FIGURES

Figure 1 Lake Warner Dam Location MapFigure 2 Lake Warner Dam Watershed Map (adopted from the Mill River Flood Study

ReportFigure 3 Lake Warner Dam Conceptual Measures PlanFigures 4, 5, 6, 7, 8 Conceptual Remediation Measures Details

APPENDICES

Appendix A Inspection PhotographsAppendix B Inspection ChecklistAppendix C Proposed Remediation Measures with Costs

Appendix D Definitions


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MA Phase II Inspection / Evaluation 1 July 2013

1. DESCRIPTION OF PROJECT1.1 IntroductionA Certificate of Non-Compliance and Dam Safety Order for the Lake Warner Dam in Hadley,Massachusetts was issued by the Executive Office of Energy and Environmental Affairs(EOEEA) on December 11, 2012. The privilege to operate and maintain the Lake Warner dam isheld in part by the Lake Warner LLC, which is owned by the Valley Land Fund Inc., whose solemember is Kestrel Land Trust. Since the Dam Safety Order was issued, a title investigation hasrevealed that the Lake Warner, LLC, is not the sole entity with rights to the dam. Legal researchhas revealed that the prior owner (the Boisverts) may still own the land underneath the dam andthat the current abutter (James Sector) holds rights to operate and maintain the dam as well.

Kestrel Land Trust (KLT) voluntarily offered to contract with Root Engineering to do this PhaseII Report to move the dam evaluation efforts forward in a timely manner on behalf of LakeWarner, LLC. Root Engineering, in turn, retained the services of DuBois and King to assist inthe preparation of this report. The inspection and report was performed in accordance with MGLChapter 253, Sections 44-50 of the Massachusetts General Laws as amended by Chapter 330 of

the 2002 Acts.

1.2 Purpose of this ReportThe purpose of this evaluation is to evaluate suitable alternative remediation to address the safetyissues at the Lake Warner Dam. The applicable stakeholders will have structural options toaddress safety issues at Lake Warner Dam to assist in determining its future.

This investigation consisted of four parts: 1) review of available reports and data submitted toand collected by the owner; 2) Complete a follow-up visual inspection and perform atopographic survey of the dam; 3) Conduct hydrologic/hydraulic and structural stability

evaluation of the dam; and 4) Prepare and submit a Phase II Inspection / Evaluation Reportwhich presents the results of the evaluation and analyzes conceptual alternative remediationmeasures.

1.3 Dam DataDam Name: Lake Warner DamAKA Name: N/A

National ID Number: MA00062State ID Number: 2-8-117-3

Town Hadley

Dam Owner/Caretaker: Right Abutment and SpillwayLake Warner, LLCPO Box 1016Amherst, MA 01004Contact: Benjamin Wright


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Left Training Wall, Abutment andPenstockJames Sector1 Mt. Warner RoadNorth Hadley, MA 01035

Hazard Potential: Significant (previously determined)Size Classification: Intermediate (>15feet)

Drainage Area 30 square milesReservoir Area 70 acres

Reservoir Volume (normal pool) 480 acre-feetCoordinate Location (lat/long): 42.38555, -72.58194

Street Address / Nearest Intersection: Rte. 47 (River Dr.) / Mt. Warner Rd.Purpose of the Dam: Current: Recreation/Conservation

Historic: Mech. Hydropower / Grist MillConstruction Date: Beginning 1918

*Length: 82*Structural Height: 15.1

*Hydraulic Height: 13.4Type of Dam: Cyclopean Concrete / Cast Concrete

Low-Level Outlet: 30 inch x 30 inch timber sluice gate w/hand operated Rodney Hunt lift operator

*Determined as part of this evaluation, superseding previously reported values.

1.4 Description of Dam and AppurtenancesThe current Lake Warner Dam was constructed circa 1918 to provide mechanical hydropowerfor a grist mills. The 82 foot long, 15 foot high cyclopean concrete dam has been in servicesince that time. The dam is a run-of-river structure with the 55.7 foot spillway spanning the

outlet of Lake Warner into the Mill River. There have been other mill dams at this site since themiddle of the seventeenth century.

The lake level may be controlled by a 30 inch by 30 inch low level outlet. The sluice way islocated at the right of the spillway and is controlled by a Rodney Hunt gate and operator. Aformer penstock (blocked) is located at the upstream left of the spillway. In addition, there is alow level drain, mud sluice located at the center of the spillway.

The dam has received two rehabilitation efforts in the span of its service life, 1947 and 1965.There is little information on the 1947 rehabilitation. In addition to raising the left training wall

to its current elevation, it is assumed that the concrete cap and operator, possibly the low leveloutlet gate, was constructed in 1947. In 1965 rehabilitation to the right side training wall wasconstructed along with the right abutment wall. Limited information including engineeringsketches and construction photographs for the 1965 work is available.


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1.5 Description of Lake And WatershedLake Warner is located on the Mill River approximately 2,400 feet upstream of the confluencewith the Connecticut River on North Hadley, Massachusetts (shown in Figure 2). Theimpoundment surface area is approximately 68 acres at normal pool and extends upstream fromthe dam nearly 7,000 feet at an average width of 500 feet. The total contributing watershed tothe lake is approximately 30 square miles in area, consisting of mild to moderate slopedagricultural and developed lands.

1.6 Engineering Data1.6.1 General Elevations (feet)

A. Top of Dam / top of Right concrete training wall ..................... 130.0*B. Top of Dam / top of Left concrete training wall ....................... 131.0*C. Normal Pool .............................................................................. 128+/-*D. Spillway Crest ........................................................................... 128.3*E. Upstream Water surface at time of inspection .......................... 128.5F. Downstream Water surface at time of inspection ..................... 115.0

G. Low-Level Outlet / Sluice Gate ................................................ 119+/-H. Waste Gate ............................................................................... 115+/-I. Streambed at Toe of the Dam: .................................................. 114.9*


1.6.2 Primary Spillway DataType: .................................................. Run-of-River / Broad Crested WeirControls .............................................................................................. N/A*Length of Weir .............................................................................. 55.7 ft*Crest El. ......................................................................................... 129.3Downstream channel: ................................................................... Bedrock*Hydraulic Capacity at Top of Dam: ............................................. 410 cfs


Location and Watershed maps are presented in Figures 1 and 2.


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2.0 PREVIOUS INSPECTIONS & REPORTSIn the course of the evaluation of the Lake Warner Dam the following reports, correspondence,and historic data were obtained. This information was examined in order to lend insight into thecondition of the dam and potential rehabilitation concepts.

2.1 Dam Safety InspectionsThe following engineering inspection reports were reviewed as part of this current evaluation ofthe Lake Warner Dam.

1. Letter of Inspection, author unknown, August 22, 19242. Letter of Inspection, North Hadley Pond, Howe Dam, author unknown. 19463. 1960 Inspection Report of Dams Located in Hadley, MA, author unknown, July 30, 19604. 1962 Inspection Report of Dams Located in Hadley, MA, Tighe & Bond Consulting

Engineers, October 10, 19625. 1963 Inspection Report of Dams Located in Hadley, MA, Tighe & Bond Consulting

Engineers, August 23, 1963

6. Letter of Inspection, Lake Warner Dam, Tighe & Bond Consulting Engineers, November 8,1963

7. Correspondence, Hampshire County Commissioners, July 21, 1964; and August 4, 19648. 1964 Inspection Report of Dams Located in Hadley, MA, Tighe & Bond Consulting

Engineers, July 24, 19649. Correspondence, Hampshire County Commissioners / Tighe & Bond / Hadley Board of

Selectmen July 27, 1964; August 4, 1964, November 4, 196410.Correspondence, Tighe & Bond Consulting Engineers / Board of County Commissioners

Hampshire County, March 22, 196511.1965 Inspection Report of Dams Located in Hadley, MA, Tighe & Bond Consulting

Engineers, August 10, 1965

12.1968 Inspection Report of Dams Located in Hadley, MA, Tighe & Bond ConsultingEngineers, December 2, 1968

13.1970 Inspection Report of Dams Located in Hadley, MA, Tighe & Bond ConsultingEngineers, July 13, 1970

14.Inspection Report Dam Reservoirs, Massachusetts Department of Public Works, August 3,1973

15.Inspection Report Dam Reservoirs, Massachusetts Department of Public Works, January11, 1976

16.Notice of Inspection, Massachusetts Executive Office of Environmental Affairs Departmentof Environmental Management, November 14, 1985 [MA DEM Office of Dam Safety]

17.Notice of Inspection, MA DEM Office of Dam Safety, January 25, 1994

18.1995 Inspection/Evaluation Report, Tighe & Bond Consulting Engineers, May 11, 199519.2007 Phase I Inspection/Evaluation Report, Huntley Associates, P.C., April 25, 200720.2012 Phase I Inspection/Evaluation Report, Huntley Associates, P.C., May 3, 201221.2013 Phase I Follow Up Inspection, Root Engineering, February 28, 2013


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2.2 Other Reports and CorrespondenceThe following engineering inspection reports were reviewed as part of this current evaluation ofthe Lake Warner Dam.

1. National Register of Historic Places Registration Form, November 29, 19932. Mount Warner Road Over Mill River Bridge, Construction Plans, March 3, 20013. Mill River Flood Study Report, University of Massachusetts at Amherst, January 21, 20034. Correspondence, Department of the Army Regulatory Division to Lake Warner, LLC, March

26 2013


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3.0 VISUAL SITE INSPECTIONRoot Engineering conducted an inspection of the dam on May 10, 2013, led by Morris J. Root,PE. At the time of the inspection, the temperature was approximately 75 F with clear skies and aslight breeze. The Warner Lake pool level was at elevation 128.5. The base flow was freelydischarging over the spillway. Underwater portions of the dam were not inspected. Theturbidity of the water interferes with diving inspection. A drawdown of Lake Warner for theinspection would have required permits both under Chapter 131, Wetlands Protection Act; andChapter 91, Water level management of a Great Pond. The general horizontal and verticalalignment of the structures is good which is indicative of overall stability. Photograph #14 takenin 2005 (A11 this report) shows the downstream face of the spillway to be in good conditionwith the exception of a long standing deficiency near the left abutment. Photographs todocument the current conditions are presented in Appendix A; a formal inspection checklist isincluded in Appendix B.

3.1 General FindingsIn general, Lake Warner Dam was found to be inPoorcondition. There were no changes from

Phase I Follow-up Inspection conducted by Root Engineering on February 25, 2013. Thedeficiencies observed during the visual inspection include:

Woody vegetation growth on and adjacent to the structure;

Uncontrolled leakage through the crack in the concrete elements of the dam;

Inoperable low level outlet gates;

Failing concrete/masonry lateral training walls; and,

Uncontrolled limited discharge through the former penstock.

A designation of Poor is in keeping with the reporting standards established by the MA DCROffice of Dam Safety. In the case of the Lake Warner Dam, the presence of excessive vegetationimpeding the inspection and possibly affecting the concrete walls along with the deterioratedconcrete make Poor an obligatory finding.

3.1.1 DamRight Lateral Training Walls/ Right Spillway Contact

o There is seepage (>1gpm) flowing from margin of contact between the 1965

concrete abutment / training wall and the original dam construction,immediately right of the low level outlet.o There are voids located at the base of the sluiceway from which significant

leaking is discharging, >1gpm.o The concrete cap between the 1965 wall and the original dam is cracked in

several locations.o The original dam along the right training wall is eroded and deteriorating.

Voids are forming under the 1947 sluice gate operator platform.


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o The low level outlet deflector wall is in a state of progressive failure.

Left Lateral Training Walls

o There is seepage (>1gpm) flowing from the margin of contact between the 1947concrete training wall and the original dam construction along the left trainingwall extending from the downstream limit to penstock headwall.

o The training wall is cracked in several locations and is becoming delaminatedfrom the spillway at the downstream face.

Upstream Face

o The upstream face of the dam was not inspected due to the level of the water inthe lake during the inspection.

Crest

o The crest is in fair condition. The line and grade of the crest, including flow lines,did not reveal significant undulations or voids.

Downstream Face

o The downstream face of the dam was not inspected due to discharging flow overthe spillway. The left lateral end of the spillway shows minor seepage along themargin between the original concrete and the 1947 training wall, extending fromthe crest downward to the base. This face can be seen in photo #14 from 2005inspection.

3.1.2 Appurtenant StructuresLow Level Outlet

o Significant discharge is flowing from the sluice way due to the gate having rottedtimbers. The operator is not operational.

Penstock/Headrace

o James Sector, owner at the left abutment, has placed a closure wall made fromplywood over the upstream end of the penstock. Some discharge is still flowingthrough the penstock as seen from the downstream outlet end.

o A drain system is in place to control leakage that flows through the penstockheadwall.

3.1.3 Downstream AreaThe reservoir is located in a rural area with minimal development in the area immediately

downstream of the dam. The outlet channel is within 30 foot high bedrock stream banks. Thereis one roadway crossing (MA RT 47) approximately 900 feet downstream of the dam. The MillRiver then flows into the Connecticut River. The entirety of the Mill River downstream of theLake Warner Dam is within the 100 year floodplain of the Connecticut River.


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3.2 Review of Operations and Maintenance3.2.1 Operations and Maintenance ProceduresA current Operations and Maintenance Plan is not in place for the Lake Warner Dam. The lowlevel outlet operator is inoperable, so the water level cannot be lowered by using the sluice gate.

3.2.2 Emergency Warning SystemThere is no remote sensing alarm system at the dam and no formalized procedures for alertingthe residents in the vicinity of the lake should a problem arise. There is no formal EmergencyAction Plan (EAP) for the Lake Warner Dam.

3.3 Topographic SurveyA topographic survey of the dam and surrounding lands was conducted on April 30, 2013. Thesurvey included limited bathymetry in the area between the dam and the Mount Warner RoadBridge. A base map was prepared by Root Engineering and is presented on Figure 3.


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4.0 HYDROLOGIC & HYDRAULIC ANALYSIS4.1 OverviewA comprehensive flood study and hydraulic modeling was conducted on the Mill River in 2003.This report, the Mill River Flood Study Report, University of Massachusetts at Amherst, January21, 2003, was extensively reviewed and interpreted for use in this evaluation. The studymethodology of the Mill River Flood Study Report is consistent with the HydrologicInvestigation requirements presented in 302 CMR 10.14(5).

4.2 Summary of Hydrologic/Hydraulic AnalysisThe drainage area to the Lake Warner Dam is approximately 30 square miles. For this drainagearea the estimate of peak rainfall runoff was determined both through the use of the standardNRCS TR-20 methodology and multiple regression techniques from the USGS Water SupplyPaper 2214. The results from the USGS approach were used in the hydraulic modeling. Thejustification for this approach was the presence of multiple stream gages located in the regionthat could be used to calibrate the hydraulic modeling for the Mill River.

Hydraulic modeling of the Mill River was conducted using the USACE HEC-RAS modelingsoftware. The riverine model extended from Amherst downstream to the Lake Warner Dam. Themodel included the Lake Warner dam. Backwater effects from the Connecticut River wereconsidered; however, it was found that there was a free discharge condition from the dam. Thedam crest elevation is about128.3, while the 100-year elevation of the Connecticut River is128.0.

The analysis is confined to the 100 year flood event. This is consistent with 302 CMR 10.14 (6),under which the Spillway Design Flood of a significant hazard, intermediate size dam is the 100year frequency.

The discharge at the Lake Warner dam was estimated to be 3,964 cubic feet per second at awater surface elevation of El. 132.6. This water level is approximately 4.3 feet over the spillwaycrest; 1.6 feet over the left training wall, and 2.6 feet over the right abutment wall.

4.3 Dam Hazard ClassificationLake Warner Dam is currently classified as a Significant Hazard dam by the Office of DamSafety. There is no structural development in the downstream hazard area of the Lake WarnerDam as the channel is within the Connecticut River floodplain. The current hazard classificationis based on the presumption that the abutments of the downstream MA Route 47 bridge may be

damaged in the event of a dam failure. If the Office of Dam Safety were presented an analysisdemonstrating that the likelihood of damage is limited, the Hazard Classification could bereduced to Low. The reclassification procedure is allowed per 302 CMR 10.06 HazardReconsideration. The requisite application form and outline of required analysis is given on theMassachusetts DCR, Office of Dam Safety website.


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Given minimal engineering data available, including soil properties, bedrock and concretestrengths, presumptive values were assumed. These presumptive values are listed below:

Backfill Soil: Med.-Dense Sand; d = 110 pcf; = 34 deg

Saturated Silt: Very loosely deposited; s = 100 pcf; = 28 deg

Modern (1965) Concrete: fc = 3000 psf; = 145 pcf

Cyclopean Concrete: fc = 2000 psf; = 145 pcf

Bedrock/Concrete Coefficient of Friction: = 0.70

Load Cases

The load cases examined include Case I Usual Loading and Case II - Unusual Loading. Case Iinvolves the water surface in the lake at normal elevation of 128.3. Observations during theinspection indicated that there is minimal tail water present on the dam during this load case. ForCase II the unusual loading is taken during the occurrence of the spillway design flood, 100 yearreoccurrence interval. The water surface elevation during this event is elevation 132.26.According to the FEMA flood insurance study for North Hadley, the 100 year flood elevation forthe Connecticut River is elevation 128.0. This is 13 feet above the toe of the dam. For

conservatism in the analysis the passive pressure from this flooding is neglected during thecomputations. In both load cases the stability factors are estimated with and without upliftpressures taken into account. This is due to unknown foundation conditions when the structurewas constructed.

Location 1The spillway is assumed to be constructed of cyclopean concrete with a concrete membrane ofunknown thickness on the downstream face. For the purposes of this analysis the entire spillwaysection is assumed to be of monolithic construction founded on sandstone bedrock. Themonolith is assumed to be of cyclopean construction. The section extends from the spillwaycrest to the foundation as observed on the downstream face. Silt on the upstream face was

assumed to be 3 feet deep, based on bathymetry taken during the topographic survey.

The results from the analysis of this location indicate that FOS for Case I is 1.8 and 1.2 forsliding and overturning, respectively. When uplift is neglected, the FOS is 3.0 and 4.7. UnderCase II loading the FOS are 1.1 and 0.9, and 2.0 and 2.5 without uplift. It should be noted thatCase II has not included the backwater effect from the tail water either localized to the site orfrom the Connecticut River. The backwater would substantially improve the FOS to the pointwhere the FOS for Case II would be higher than that of Case I. Complete inundation of this damhas been known to occur due to the backwater from the Connecticut River, see photo #A 14 inappendix A.

Location 2Engineering sketches and construction photographs were obtained for the right abutment wall,constructed in 1965. These drawings depict a modern cantilevered retaining wall design; fullheight wall with vertical downstream and battered upstream faces sits upon a concrete footinganchored to bedrock with dowels. The right contact between the wall and bedrock stream bankis also anchored with dowels. The engineering sketch indicates that these dowels are 1 inch indiameter, but spacing along the vertical contact, embedment depth and bonding agent was notnoted. Therefore, initially the dowels were neglected. As a result, the gravity analysis approach


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indicates that the stability of the wall is reliant upon the dowels. Given the unknowns about theconstruction, stability factors cannot definitely estimated. The stability of this area must bedetermined by professional observation. During the field inspection there were no signs ofinstability, distress or deterioration of the wall. From the field inspection and photographicevidence that the wall has experienced normal and extreme loading, the conclusion is that theright abutment is structurally stable.

Based on the results of this analysis the overall global stability of the dam does not meet thecurrent regulations. However by inspection and supporting justification of photographicevidence, the dam has been subjected to 100 year flood levels (Case II loading) and the dam hasremained undisturbed and undamaged. It is can be concluded that the dam in its currentcondition is considered structurally stable under the two load cases considered.

Note: The condition rating of poor, in the case of this dam, does not indicate that the structure is

structurally unstable. The structural analysis performed in this evaluation following the MA

ODS guideline indicates structural soundness. Deficiencies noted in in Section 3 of this report,

in their totality, result in an overall condition rating.


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either repair or replacement; routine operation is necessary to prevent deterioration of theoperating mechanism and to ensure its operability.

2. Mowing of grassed areas and regular trimming of trees and woody vegetation. Allwoody vegetation should be cut and prevented from growing within 15 feet of thestructure. Tree roots can dislodge and exacerbate cracking of concrete and stoneelements. Grass and weeds should be trimmed to allow easy observation of theabutments and adjacent areas to the dam. Both tree trimming/removal and grass mowingshould be conducted on a semi-annual basis, typically during middle and at the end of thegrowing season.

*Note: Since Lake Warner LLC does not own the areas to be mowed and trimmed, coordination

between all applicable stakeholders and property owners is required.

6.3 Additional Studies and AnalysesThe Phase II Inspection and Evaluation process is a comprehensive effort to identify thenecessary repair and potential remediation measures to address the identified deficiencies; no

further studies are recommended at this time. The recommended repairs and remediationmeasures presented herein are considered to present a robust plan for conservation of thestructure. Further assessment when the dam is dewatered may determine that there are costeffective limits to the remediation; i.e., a reduction in the scope of the remediation is possible. Ifthis is the case, the full scope of the remediation measures may be modified to match thenecessity of repairs/remediation measures. This will occur when there is an opportunity todewater the dam and further explore the areas obscured by the impounded and flowing water.

In addition to the Phase II investigation for dam repairs, the KLT has initiated an investigationfor the removal of the Lake Warner Dam. The study regarding dam removal is beingcoordinated by the Massachusetts Division of Ecological Restoration (MA DER). The

objectives are to identify costs for dam removal and evaluate the effects of its loss to provide acontrast and comparison to rehabilitation of the dam.

6.4 Required Maintenance and RepairsThe following maintenance and repairs should be conducted as soon as reasonably practical,either separately or in conjunction with more extensive Remedial Measures identified below.Note that work requiring the altering of the water surface level in the lake, work within the lakeor disturbing the ground or removing trees in or from protected buffer zones adjacent tojurisdictional area is subject to regulatory oversight and permit authorization may be required.

1. Clear all trees and stumps within 15 feet of the dam. As mentioned above, treeroots and woody vegetation can exacerbate the deterioration of concrete and stoneelements on the dam. Any holes resulting from the removal of the trees and rootsshould be filled and seeded to promote a grassed surface.

2. Remove and replace or repair chain link fence at right abutment. During theinspection, the chain-link fence located on the right abutment was found to be


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significantly damaged and needing repair. The fence should be repaired and reset inits original location to prevent an inadvertent fall hazard.

3. Rehabilitate the low level outlet slide gate. The slide gate has not been operated forseveral years and leaks significantly. Given the age and original construction of thegate full removal and replacement is warranted. Rehabilitation of the existing gateoperating mechanism and replacing the timber components may be possible;however, the cost effectiveness of this approach is highly dependent on the laboravailable and the undisclosed condition of submerged components of the gate itself.

*Note: Since Lake Warner LLC does not own the areas to be mowed and trimmed, coordination

between all applicable stakeholders and property owners is required.

6.5 Remediation Measures to Address Identified DeficienciesThe objective of this evaluation is to inspect, evaluate, and develop suitable recommendationsfor remediation measures that are beyond the scope of minor repairs to individual dam elements.The remedial measures presented herein will address the deficiencies at the Lake Warner Dam in

their totality. From this, the applicable stakeholders can weigh the cost of a singular remediationeffort against potential removal, which is addressed in an independent study.

The following remediation measures address the identified deficiencies and meet current damsafety regulations. Refer to Figure 3 for a diagrammatic sketch of the dam and its components.

Right Sluice Area:

The right abutment was rehabilitated in 1965 with a new end wall and training wall castagainst the original cyclopean concrete training wall and a portion of the 1947 concrete.This new concrete does not extend to the sluiceway and there is significant leakage along

the margin between the new (1965), the older concrete (1947) and the original damconstruction.

This remediation measure involves removing the majority of the 1947 concrete andreplacing it with a closure wall connected to the 1965 wall. This includes removal andreplacement of the slide gate and operator, casting a new concrete platform and upstreamcutoff wall. The cutoff wall will also extend laterally to the right training wall and extendupstream 15 feet.

This replaces the concrete between the spillway and the 1965 wall. The leakage andseepage will be cutoff and prevented from flowing through the abutment area and provide

a new operational sluice gate.

Spillway:

The spillway appeared to be in satisfactory condition as observed from the downstreamside. To preserve this condition, a reinforced concrete membrane cast on the upstreamface is proposed as it may be required if it is discovered to be composed of cyclopeanconcrete. This will reduce the deteriorating effects caused by seepage flowing through


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the cyclopean concrete and bond the mass of large stones in a more cohesive manner.Subject to inspection when this area is dewatered during construction, cost effectivemeasures such as lower cost water proofing application may be justified.

The waste gate in the center of the spillway is no longer functioning and with a new lowlevel outlet installed at the right sluiceway, the waste gate will no longer be essential.This remediation measure includes filling the void with concrete and fastening a steelplate on the upstream face.

Left Training Wall

The left training wall, extending from the spillway crest upstream to the penstockheadrace was constructed in 1947. After 66 years of ice and hydraulic forces acting onthe training wall, the concrete has deteriorated and significant seepage flows through theinterface between the concrete and the original dam. The recommended repair involvesremoving the 1947 concrete and replacing it in kind. The new concrete will be connectedto the original dam with reinforced steel anchors grouted in place and a bonding agent.The face of the new concrete training wall would extend down the upstream face of the

original dam to the foundation. This will serve the same purpose as the concretemembrane on the spillway by preventing seepage into and reinforcing the originalcyclopean concrete.

This repair is proposed for the upstream (wet) side of the dam and does not impact oraffect the foundation of the Sector house.

Left Penstock Closure

As part of the new concrete membrane and replacement of the left training wall theconcrete will be continued to close and cover the penstock. The reinforced concrete

cutoff wall will extend from the crest to the foundation across the headrace wall.

The leaking penstock would be closed and the existing cutoff wall reinforced.

Given modern design and construction techniques, this repair can have an expected design life of50 years. Beyond that time period additional remediation measures may be necessary.

Plan, cross section and profile views for the remediation measures are provided in Figures 3through 8. Cost summaries are provided in Section 6.7 below.

6.6 Alternative Remediation MeasuresAs mentioned above, the KLT has voluntarily initiated the reconnaissance phase with the MADER to explore potential dam removal. MA DER will provide a report similar to this oneestimating the costs and considering the effects of removing the Lake Warner Dam. The resultsof that investigation may be compared to this report to determine the preferred course of action.


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Typically, dam repair projects which strive to maintain the existing structural footprint and keeptemporary and permanent resource impacts to a minimum set aside a larger permitting forum.The threshold for expanded authority rests at 5,000 square feet of resource impacts and 100 cubicyards of dredging. Due to the age of the dam, it is presumed that it may be a structure exemptfrom the Chapter 91 program. A request for jurisdictional determination is required under theChapter 91 regulation.

Repairing the dam to substantially its existing footprint would qualify for the Corps of EngineersGeneral Permit (GP), Category #1 which is non-reporting. For the GP to be valid, the followingconditions must be satisfied:

A final Order of Conditions from the local Conservation Commission, Chapter 131

A Chapter 91 license or permit, if required. In the case of this dam, a Chapter 91 licenseor permit may not be required per 310 CMR 9.05(3) (f), as this is the continuation of astructure built prior to 1939 and has not had any unauthorized repairs since 1984. Inaddition, the structure will maintain the water level of the Great Pond at its existing level.

A Water Quality Certificate, if necessary. For the project as proposed, an applicationfrom the Division of Water Pollution Control would not be required as the square footimpact would be less than 5,000 square feet (314 CMR 9.03 (1)) and the amount ofdredged material would be less than 100 cubic yards (314 CMR 9.03(3)).

Notification to and approval from the Massachusetts Historic Commission for structureson or eligible for the National Historic Register.

The recommended repairs keep substantially to the existing geometry and the overall impacts arewithin the quantitative thresholds. The applicable stakeholders should commence the permitapplication phase with a review meeting with the team assembled monthly by MA DEP inSpringfield. Representatives from USACOE, MA DEP and NHESP program would be presentto give guidance for proceeding with the permit applications. The Massachusetts HistoricCommission has requested a Project Notification Form to initiate their review when a specificproject approach has been chosen.

6.9 Recommendations for ImplementationThe recommended repairs represent a cost-effective plan for meeting the long term needs of thestructure. Complete demolition and rebuilding the dam is not necessary as the bulk of the dam isstructurally stable with small sections suffering concrete deterioration. Removal andreplacement of the spillway element alone would double the project cost raising the total to over$450,000.00


24/55


25/55

LAKE WARNER DAM


26/55

LAKE W

NORTH

PH

INVES

SHEET

Copyright 2

PROFE

NO

CONST

PREL

P

28 NORANDO

TEL: (8FAX: (8www.du

SHEE

PROJ. ENG.

ENGINEERMANAGEMEN

WILSPRI

BED

DRAWNBY

CHECKEDBY

SRP

SRP

SHE

ZDC

SIT

F


27/55

ENGINEERING PLANNING

LAKE WARNER DAM

NORTH HADLEY, MA

PHASE II INVESTIGATION 92201

JUNE 2013

PROJ. ENG.

DRAWN BY

CHECKED BY

SCALE

D&K PROJECT #

DATE

SRP

SRP

ZDC

AS SHOWN

FIGURE

24


28/55


MANAGEMENT DEVELOPMENT

LAKE WARNER DAM

NORTH HADLEY, MA


JUNE 2013

PROJ. ENG.

DRAWN BY

CHECKED BY

SCALE

D&K PROJECT #

DATE

SRP

SRP

ZDC

AS SHOWN

FIGURE

SECTION B35


29/55



LAKE WARNER DAM

NORTH HADLEY, MA


JUNE 2013

PROJ. ENG.

DRAWN BY

CHECKED BY

SCALE

D&K PROJECT #

DATE

SRP

SRP

ZDC

AS SHOWN

FIGURE

SECTION C46


30/55



LAKE WARNER DAM

NORTH HADLEY, MA


JUNE 2013

PROJ. ENG.

DRAWN BY

CHECKED BY

SCALE

D&K PROJECT #

DATE

SRP

SRP

ZDC

AS SHOWN

FIGURE

SECTION D57


31/55



LAKE WARNER DAM

NORTH HADLEY, MA


JUNE 2013

PROJ. ENG.

DRAWN BY

CHECKED BY

SCALE

D&K PROJECT #

DATE

SRP

SRP

ZDC

AS SHOWN

FIGURE

SECTION E68


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NAME OF DAM: STATE ID #:

REGISTERED:

CHANGE IN HAZARD CLASSIFICATION REQUESTED?: No

CITY/TOWN: COUNTY:

DAM LOCATION: ALTERNATE DAM NAME: N/A

(street address if known)

USGS QUAD.: LAT.: LONG.:

DRAINAGE BASIN: RIVER:

TYPE OF DAM: OVERALL LENGTH (FT):

YEAR BUILT:

STRUCTURAL HEIGHT (FT): EL. NORMAL POOL (FT):

HYDRAULIC HEIGHT (FT): EL. MAXIMUM POOL (FT):

FOR INTERNAL MADCR USE ONLY

FOLLOW-UP INSPECTION REQUIRED: CONDITIONAL LETTER:

131.0

PURPOSE OF DAM: Public Water Source Storage ~ Abandoned

15.1

1875 MAXIMUM POOL STORAGE (ACRE-FT): 590

128.3

13.4

Connecticut Mill River

NORMAL POOL STORAGE (ACRE-FT): 480

IMPOUNDMENT NAME(S): Lake Warner

GENERAL DAM INFORMATION

Masonry/Concrete/Stone 82

Significant

Hadley Hampshire

1 Mt. Warner Road

Williamsburg 42.23.08 72.34.55

DAM SAFETY INSPECTION CHECKLIST

Lake Warner Dam 2-8-117-3

MA00062NID ID #:

STATE SIZE CLASSIFICATION: Intermediate

DAM LOCATION INFORMATION

STATE HAZARD CLASSIFICATION:

YES

YES YES

Lake Warner Dam

Hadley Date of Inspection: May 10, 2013


40/55


INSPECTION DATE: NID ID #:

DATE OF INSPECTION: DATE OF PREVIOUS INSPECTION:

ARMY CORPS PHASE I: If YES, date

CONSULTANT: PREVIOUS DCR PHASE I: If YES, date May 2012

OVERALL PHYSICAL

CONDITION OF DAM: DATE OF LAST REHABILITATION:

SPILLWAY CAPACITY:

EL. POOL DURING INSP.: EL. TAILWATER DURING INSP.:

Click on box to select E-code Click on box to select E-code

E1) 3

E2) 3

E3) 2

E4) $200,000

E5) NO

E6) NO

E7) LOW-LEVEL OUTLET CAPACITY

NAME OF INSPECTING ENGINEER: SIGNATURE:

TEMPERATURE/WEATHER: 75 deg.F, Clear, Breezy

Root Engineering


INSPECTION SUMMARY

MA00062

May 10, 2013 2/25/2013 (Phse I Follow up)

115

PERSONS PRESENT AT INSPECTION

128.5

BENCHMARK/DATUM: NAVD 88

POOR 1965

90-100% of the SDF

NAME TITLE/POSITION REPRESENTING

Morris J. Root, P.E. Snr. Engineer, Insp. Leader Root Engineering

Shawn R. Patenaude Dam Engineer DuBois & King, Inc.

EVALUATION INFORMATION

TYPE OF DESIGN 2 E8) LOW-LEVEL OUTLET CONDITION

EMERGENCY ACTION PLAN 2 E10) OVERALL PHYSICAL CONDITION

LEVEL OF MAINTENANCE 3 E9) SPILLWAY DESIGN FLOOD CAPACITY

ROADWAY OVER CREST

CONCRETE CONDITION 2

EMBANKMENT SEEPAGE N/A E11) ESTIMATED REPAIR COST

May 10, 2013

3

BRIDGE NEAR DAM

EMBANKMENT CONDITION N/A

YES

YES

Lake Warner Dam



41/55



OWNER: CARETAKER:

EMERGENCY PH. # EMERGENCY PH. #

FAX

EMAIL

OWNER TYPE

SPILLWAY LENGTH (FT) SPILLWAY CAPACITY (CFS)

AUXILIARY SPILLWAY TYPE AUX. SPILLWAY CAPACITY (CFS)

NUMBER OF OUTLETS OUTLET(S) CAPACITY (CFS)

TYPE OF OUTLETS TOTAL DISCHARGE CAPACITY (CFS)

DRAINAGE AREA (SQ MI) SPILLWAY DESIGN FLOOD (PERIOD/CFS)

HAS DAM BEEN BREACHED OR OVERTOPPED IF YES, PROVIDE DATE(S)

FISH LADDER (LIST TYPE IF PRESENT)

DOES CREST SUPPORT PUBLIC ROAD? IF YES, ROAD NAME:

PUBLIC BRIDGE WITHIN 50' OF DAM? IF YES, ROAD/BRIDGE NAME:

MHD BRIDGE NO. (IF APPLICABLE)


ORGANIZATION ORGANIZATION Kestrel Land Trust

MA00062

Lake Warner, LLC

May 10, 2013

STREET PO Box 1016 STREET PO Box 1016

NAME/TITLE Benjamin Wright NAME/TITLE Benjamin Wright

PHONE 413-549-1097 PHONE 413-549-1097

TOWN, STATE, ZIP Amherst, MA 01004 TOWN, STATE, ZIP Amherst, MA 01004

FAX

EMAIL [email protected]

none

N/A

1

Timber Slide Gate ~30"x30"

30

unknown

500

100 / 3964

PRIMARY SPILLWAY TYPE Uncontrolled Broad Crest - Run of River

Private Association or other non-profit

not recorded

500

N/A

55

Lake Warner Dam



42/55



AREA

INSPECTED

X

X

X

D/S WALLS min: 6" max: 3' avg: 1.5'

X

X

X

ADDITIONAL COMMENTS:

Leakage at left possibly due to penstock leakage

6. ABUTMENT CONTACT

7. EROSION/SINKHOLES BEHIND WALL

8. ANIMAL BURROWS

9. UNUSUAL MOVEMENT

10. WET AREAS AT TOE OF WALL

Lake Warner Dam

May 10, 2013

2-8-117-3

MA00062

4. HEIGHT: TOP OF WALL TO MUDLINE

5. SEEPAGE OR LEAKAGE

DOWNSTREAM MASONRY WALLS

CONDITION OBSERVATIONS

Cyclopean concrete w/ some modern concrete capping

ok for line and grade

Poor at margins between 1947 construction and original; Good 1965 right abutment wall

NO

ACTION

MO

NITOR

REPAIR

Leakage along margins between construciton joints, original to 1949 and 1965

None Observed

Good both ends

None Observed

None Observed

1. WALL TYPE

2. WALL ALIGNMENT

3. WALL CONDITION

Lake Warner Dam



43/55



AREA

INSPECTED

X

X

X

U/S WALLS min: max: avg:

X

X

X

X


1. WALL TYPE

2. WALL ALIGNMENT

3. WALL CONDITION


Brick and concrete ~ Gate House Structure

Satisfactory ~ No evidence of movement or misalignment

Satisfactory ~ Minor evidence of seepage through the former screen "windows"

NO

ACTION

MO

NITOR

REPAIR

Lake Warner Dam

May 10, 2013

2-8-117-3

MA00062

N/A

N/A

N/A

4. HEIGHT: TOP OF WALL TO MUDLINE

5. ABUTMENT CONTACT

6. EROSION/SINKHOLES BEHIND WALL

7. ANIMAL BURROWS

8. UNUSUAL MOVEMENT None Observed

UPSTREAM MASONRY WALLS

Lake Warner Dam



44/55



AREA

INSPECTED

X

X

X

D/S X

AREA X

X

X

X


0

MO

NITOR

REPAIR

Mill River to Connecticut, approx ~2500 feet downstream

Riverine, vegetated streambanks

Leakage through the base of the structure, somewhat obscurred by spillway flow

N/A

N/A

NO

ACTION

MA00062

Difficult access to right involves climbing down streambank, direct from left

Lake Warner Dam

May 10, 2013

2-8-117-3


None

Obscurred by spillway flow

N/A

5. DRAINAGE SYSTEM

6. INSTRUMENTATION

7. VEGETATION

8. ACCESSIBILITY

1. ABUTMENT LEAKAGE

2. FOUNDATION SEEPAGE

3. SLIDE, SLOUGH, SCARP

4. WEIRS

DOWNSTREAM AREA

10. DATE OF LAST EAP UPDATE

9. DOWNSTREAM HAZARD DESCRIPTION

Lake Warner Dam



45/55



AREA

INSPECTED

MISC.

WHAT:

DATE:

DATE:

DATE:

DATE:

DATE:

PURPOSE:


Developed, agricultural land

mild to moderate slopes

None

None5. SECURITY DEVICES

6. VANDALISM OR TRESPASS

9. AVAILABILITY OF EAP/LAST UPDATE

Unknown

10. AVAILABILITY OF O&M MANUAL

1. RESERVOIR DEPTH (AVG)

4. ACCESS ROADS

Lake Warner Dam

May 10, 2013

2-8-117-3

MA00062

8. AVAILABILITY OF DESIGN CALCS

2. RESERVOIR SHORELINE

3. RESERVOIR SLOPES

MISCELLANEOUS


12. CONFINED SPACE ENTRY REQUIRED

7. AVAILABILITY OF PLANS

February 25, 201311. CARETAKER/OWNER AVAILABLE

Lake Warner Dam



46/55



AREA

INSPECTED

X

X

X

SPILLWAY X

X

X

X

X

X

X


NO

ACTION

MO

NITOR

REPAIR

None Observed

Uncontrolled run of riverSPILLWAY TYPE

Clear, Lake Warner

Clear, Mill River

broad crested weir

Fair, see Masonry Dam Crest

Left is in poor condition; Right is in poor condition

N/A


May 10, 2013 MA00062


WEIR TYPE

SPILLWAY CONDITION

TRAINING WALLS

SPILLWAY CONTROLS AND CONDITION

UNUSUAL MOVEMENT

APPROACH AREA

DISCHARGE AREA

DEBRIS None Observed

128.5, 3 inches over crestWATER LEVEL AT TIME OF INSPECTION

PRIMARY SPILLWAY

Lake Warner Dam



47/55



AREA

INSPECTED

X

X

X

OUTLET X

WORKS

X

X

X

X

X

X

X


None Observed

SEEPAGE/LEAKAGE

This section of the dam is in poor condition, particularly the deflector wall

Minimal

(1) wall of the gate house structure.

None

NO

ACTION

MO

NITOR

REPAIR

Upstream face of dam

Yes, through the gate

None Observed

2-8-117-3

MA00062


Rodney Hunt Timber Slide Gate

Slide gate with rising stem operator, minimally operational

N/A

Clear, unobstructed Mill River

30"X30" box void from gate to d/s face

TYPE

INTAKE STRUCTURE

TRASHRACK

PRIMARY CLOSURE

Lake Warner Dam

May 10, 2013

DOWNSTREAM AREA

SECONDARY CLOSURE

CONDUIT

OUTLET STRUCTURE/HEADWALL

EROSION ALONG TOE OF DAM

OUTLET WORKS

MISCELLANEOUS

DEBRIS/BLOCKAGE

UNUSUAL MOVEMENT

Lake Warner Dam



48/55



AREA

INSPECTED

X

X

X

GENERAL X

X

X

X

X


CONCRETE/MASONRY DAMS

AVAILABILITY OF DESIGN CALCS

PIEZOMETERS

OBSERVATION WELLS

INCLINOMETERS

SEEPAGE GALLERY

UNUSUAL MOVEMENT

Lake Warner Dam

May 10, 2013

2-8-117-3

MA00062

TYPE

AVAILABILITY OF PLANS


Cyclopena Concrete with concrete caps

N/A

N/A

N/A

N/A

None Observed

None

NO

ACTION

MO

NITOR

REPAIR

None

Lake Warner Dam



49/55



AREA

INSPECTED

X

X

X

CREST X

X

X


D/S Fair

NO

ACTION

MO

NITOR

REPAIR

Fair with minor spalling and cracking

2-8-117-3

MA00062


Cyclopean Concrete capped with modern concrete

None Observed

Good

Good

TYPE

SURFACE CONDITIONS

CONDITIONS OF JOINTS

UNUSUAL MOVEMENT

Lake Warner Dam

May 10, 2013

HORIZONTAL ALIGNMENT

VERTICAL ALIGNMENT

CONCRETE/MASONRY DAMS (CREST)

Lake Warner Dam



50/55



AREA

INSPECTED

X

X

X

D/S X

FACE X X

X


CONCRETE/MASONRY DAMS (DOWNSTREAM FACE)


UNUSUAL MOVEMENT

ABUTMENT CONTACT

LEAKAGE

Lake Warner Dam

May 10, 2013

2-8-117-3

MA00062

TYPE

SURFACE CONDITIONS


Concrete

None Observed

Good Right abutment wall to bedrock streambank, Left - see above

Leakage observed at left and right between construction joints

Joint at left contact is deteriorating

NO

ACTION

MO

NITOR

REPAIR

Poor at left training wall / spillway contact

Lake Warner Dam



51/55



AREA

INSPECTED

X

X

X

U/S X

FACE X


Under water at time of inspection Not inspected

NO

ACTION

MO

NITOR

REPAIR


2-8-117-3

MA00062


Cyclopena concrete, capped with modern concrete

None Observed


TYPE

SURFACE CONDITIONS


UNUSUAL MOVEMENT

Lake Warner Dam

May 10, 2013

ABUTMENT CONTACTS

CONCRETE/MASONRY DAMS (UPSTREAM FACE)

Lake Warner Dam



52/55

Item Item Description Quantity Unit Unit Total

# Cost1 Mobilization/EPSC (15% of subtotal) 1 LS $15,000 $15,000

2 Temporary Right Of Way Access 1 LS $5,000 $5,000

3 Control of Water 1 LS $50,000 $50,000

4 Excavation/Disposal of Silt 40 CY $15 $600

5 Partial Demolition of Existing Structure/Saw Cutting 1 LS $5,000 $5,000

6 Reinforced Structural Concrete ~ Spillway, T-walls, Apron 56 CY $1,000 $56,000

7 Sluice Gate [Cast Iron slide gate w/ operator, 24"x24"] 1 LS $12,000 $12,000

8 Loam (Seed, Fertilizer & Mulch built into unit price) 10 CY $50 $500

9

10

Note: Sub-Total $144,100

15% Contingency $21,615.00

25% Contingency $36,025.00Total Estimated Const. Cost (low) $165,715

Total Estimated Const. Cost (high) $180,125

Estimate Preparation Date: 6/27/2013

Spreadsheet Print Date: 6/27/2013

Prepared by: SRP

In providing opinions of probable construction cost, the Client understands that

D&K has no control over the cost or availability of labor, equipment or materials, or

over market conditions or the Contractor's method of pricing, and that our Opinion

of Probable Construction Costs are made on the basis of our professional judgment

and experience. D&K makes no warranty, express or implied, that the bids or

negotiated costs of the Work will not vary from the Opinion of Probable

Construction Cost provided herein.

Checked by:

Lake Warner Dam

Hadley, MA

Remediation Measures

Probable Cost


53/55

Lawrence Reservoir Dam Date of Inspection:May 25, 2011Lawrence

COMMON DAM SAFETY DEFINITIONS

For a comprehensive list of dam engineering terminology and definitions refer to 302 CMR10.00 DamSafety, or other reference published by FERC, Dept. of the Interior Bureau of Reclamation, or FEMA.

Please note should discrepancies between definitions exist, those definitions included within 302 CMR10.00 govern for dams located within the Commonwealth of Massachusetts.

Orientation

Upstream Shall mean the side of the dam that borders the impoundment.

Downstream Shall mean the high side of the dam, the side opposite the upstream side.

Right Shall mean the area to the right when looking in the downstream direction.

Left Shall mean the area to the left when looking in the downstream direction.

Dam Components

Dam Shall mean any artificial barrier, including appurtenant works, which impounds or diverts water.

Embankment Shall mean the fill material, usually earth or rock, placed with sloping sides, such that it forms a

permanent barrier that impounds water.

Crest Shall mean the top of the dam, usually provides a road or path across the dam.

Abutment Shall mean that part of a valley side against which a dam is constructed. An artificial abutment issometimes constructed as a concrete gravity section, to take the thrust of an arch dam where there is no suitable

natural abutment.

Appurtenant Works Shall mean structures, either in dams or separate there from, including but not be limited to,spillways; reservoirs and their rims; low-level outlet works; and water conduits including tunnels, pipelines, or

penstocks, either through the dams or their abutments.

Spillway Shall mean a structure over or through which water flows are discharged. If the flow is controlled by

gates or boards, it is a controlled spillway; if the fixed elevation of the spillway crest controls the level of the

impoundment, it is an uncontrolled spillway.

Size Classification(as listed in Commonwealth of Massachusetts, 302 CMR 10.00 Dam Safety)

Large structure with a height greater than 40 feet or a storage capacity greater than 1,000 acre-feet.

Intermediate structure with a height between 15 and 40 feet or a storage capacity of 50 to 1,000 acre-feet.

Small structure with a height between 6 and 15 feet and a storage capacity of 15 to 50 acre-feet.

Non-Jurisdictional structure less than 6 feet in height or having a storage capacity of less than 15 acre-feet.


54/55

Hazard Classification(as listed in Commonwealth of Massachusetts, 302 CMR 10.00Dam Safety)

High Hazard (Class I) Shall mean dams located where failure will likely cause loss of life and serious damage to

home(s), industrial or commercial facilities, important public utilities, main highway(s) or railroad(s).

Significant Hazard (Class II) Shall mean dams located where failure may cause loss of life and damage tohome(s), industrial or commercial facilities, secondary highway(s) or railroad(s), or cause the interruption of the use

or service of relatively important facilities.

Low Hazard (Class III) Dams located where failure may cause minimal property damage to others. Loss of life is

not expected.

General

EAP Emergency Action Plan Shall mean a predetermined (and properly documented) plan of action to be takento reduce the potential for property damage and/or loss of life in an area affected by an impending dam failure.

O&M Manual Operations and Maintenance Manual; Document identifying routine maintenance and operational

procedures under normal and storm conditions.

Normal Pool Shall mean the elevation of the impoundment during normal operating conditions.

Acre-foot Shall mean a unit of volumetric measure that would cover one acre to a depth of one foot. It is equal to

43,560 cubic feet. One million U.S. gallons = 3.068 acre feet.

Height of Dam (Structural Height) Shall mean the vertical distance from the lowest portion of the natural ground,

including any stream channel, along the downstream toe of the dam to the lowest point on the crest of the dam.

Hydraulic Height means the height to which water rises behind a dam and the difference between the lowest point

in the original streambed at the axis of the dam and the maximum controllable water surface.

Maximum Water Storage Elevation means the maximum elevation of water surface which can be contained by thedam without overtopping the embankment section.

Spillway Design Flood (SDF) Shall mean the flood used in the design of a dam and its appurtenant works

particularly for sizing the spillway and outlet works, and for determining maximum temporary storage and height of

dam requirements.

Maximum Storage Capacity The volume of water contained in the impoundment at maximum water storage

elevation.

Normal Storage Capacity The volume of water contained in the impoundment at normal water storage elevation.

Condition Rating

Unsafe Major structural*, operational, and maintenance deficiencies exist under normal operating conditions.

Poor Significant structural*, operation and maintenance deficiencies are clearly recognized for normal loading

conditions.

Fair Significant operational and maintenance deficiencies, no structural deficiencies. Potential deficiencies existunder unusual loading conditions that may realistically occur. Can be used when uncertainties exist as to critical

parameters.


55/55

Satisfactory Minor operational and maintenance deficiencies. Infrequent hydrologic events would probably result

in deficiencies.

Good No existing or potential deficiencies recognized. Safe performance is expected under all loading including

SDF.

* Structural deficiencies include but are not limited to the following:

Excessive uncontrolled seepage (e.g., upwelling of water, evidence of fines movement, flowing water,

erosion, etc.)

Missing riprap with resulting erosion of slope

Sinkholes, particularly behind retaining walls and above outlet pipes, possibly indicating loss of soildue to piping, rather than animal burrows

Excessive vegetation and tree growth, particularly if it obscures features of the dam and the dam

cannot be fully inspected

Deterioration of concrete structures (e.g., exposed rebar, tilted walls, large cracks with or without

seepage, excessive spalling, etc.)

Inoperable outlets (gates and valves that have not been operated for many years or are broken)

ma00062 lake warner dam hadley phase ii 2013-7-15

Documents