3 Dam safety inspection reports 1995-2022.pdf

DAM SAFETY INSPECTION REPORT

BOSTON POND DAM

DAM ID NO. 00077

BOSTON CREEK BASIN

HOUGHTON COUNTY

SE 1/4, Section 7, T55N, R33W

OWNER/OPERATOR: Michigan Department of Natural Resources District 1, Fisheries Division

HAZARD POTENTIAL CLASSIFICATION: Low

INSPECTED BY: James T. Pawloski, P.E.

Michigan Registration No. 34034

INSPECTION DATE: October 12,1994

REPORT DATE: July 7,1995

PREPARED BY: *-T- f)+-Ck- (Jdmes T. Pawloski. P.E.

Dam Safety Unit Land and Water Management Division

Michigan Department of Natural Resources P. 0. Box 128

Roscommon, Michigan 48653 517/275-5151

INTRODUCTION

The purpose of this inspection report is to evaluate the structural condition and hydraulic capacity of this dam as required by Part 315 Dam Safety, Natural Resources and Environmental Protection Act, 1994 PA 451, as amended;

MCL 315.21 to 315.29. The report is limited to a visual investigation and review of any previous inspection reports, plans, and data which are available. This report should not be considered an in-depth engineering investigation.

The Boston Pond Dam was inspected by the Dam Safety Unit, Land and Water

Management Division, pursuant to the requirements of Director's Letter No. 65.

All reference to "right" and "left" in this report are based on the observer facing downstream.

CONCLUSIONS AND RECOMMENDATIONS

There were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway capacity under existing conditions.

The following recommended actions should be completed as soon as practical:

1) Remove significant accumulation of sticks, rocks, and other debris from riser and outlet pipe.

2) Fill eroded area adjacent to inlet structure with granular fill.

PROJECT INFORMATION

The Boston Pond Dam consists of a 2500 foot long earth fill embankment with a structural height of 12 feet. The dam creates a head of 9 feet and an impoundment with a surface area of approximately 140 acres.

The dam was reportedly constructed in 1968 for recreational purposes. Copies of original design drawings are on file with the Dam Safety Unit.

The spillway consists of a reinforced concrete drop inlet with a single row of 5 foot long stoplogs. The inlet is connected to a 60-inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet and downstream slope of 2.5 horizontal to 1 vertical. Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

Previous inspection reports were prepared in 1978, 1979, 1988, and 1991. No significant deficiencies were noted. An annual 2.5 foot drawdown has been implemented in early November every year since 1985 to reduce the potential for flooding upstream roads during spring runoff.

SITE INVESTIGATION

The following discussion of the physical condition of the dam and appurtenances is based on observations and photographs obtained on the date of the inspection.

0 0

1,11

The Boston Pond Dam is in fair condition. The concrete of the spillway inlet structure is in good condition. There is a crack in the headwall from the crown of the outlet pipe to the top of the wall. This crack has been observed during several previous inspections and does not present any problems at the present time. The stoplogs appear to be in good condition. The 5-foot diameter corrugated metal pipe (CMP) outlet pipe still has a good bituminous coating on the inside surface. There is some minor seepage at the first pipe joint downstream from the inlet structure that should continue to be monitored in subsequent inspections. The upstream water surface was 2.5 feet below the top of the concrete overflow section. There are significant amounts of sticks, rocks, and other debris in the inlet structure and outlet pipe. This should be removed as soon as practical.

The embankment is in fair condition. There is some minor erosion adjacent to the right side of the headwall of the inlet structure. This is not threatening the dam stability and is not a cause for concern since the water level is being held well below design levels. However, it should be filled with a granular fill as soon as practical.

No other deficiencies were noted during the inspection.

STRUCTURAL STABILITY

Based on the conditions observed dun-ng the field inspection, the dam appears to be stable. No further structural stability analysis is warranted at this time.

SPILLWAY CAPACITY

The contributing drainage area of the Boston Creek at the dam is 2.6 square miles. The design discharge for this dam is the 0.5% chance flood discharge of 340 cubic feet per second (cfs). The existing spillway capacity is estimated to be 230 cfs, with no freeboard.

The design flood event was routed through the impoundment, considering storage in the impoundment and the existing spillway capacity. Based on this analysis, the design flood outflow was estimated to be 80 cfs, with a corresponding rise in the impoundment of approximately 1 foot, leaving 2 feet of freeboard.

Therefore, the dam has adequate spillway capacity.

OPERATION AND MAINTENANCE

Operation of the dam is the responsibility of District 1, Fisheries Division. A written Operation and Maintenance (O&M) Plan is on file with the Dam Safety Unit.

EMERGENCY ACTION PLAN

No Emergency Action Plan (EAP) exists for this dam. Since the dam has a low hazard potential rating, an EAP is not required.

APPENDICES

Appendix A - Photographs Appendix B - Location Map

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

G

APPENDIX A-PHOTOGRAPHS

BOSTON POND DAM, HOUGHTON COUNTY

DAM ID NO 00077

r

4lt

PHOTOGRAPH

PHOTOGRAPH 2-EROSION ADJACENT TO CONTROL STRUCTURE

BOSTON POND DAM, HOUGHTON COUNTY

DAM ID NO 00077

JTP

10-12-94

PHOTOGRAPH 3-DEBRIS IN INLET STRUCTURE

PHOTOGRAPH 4-CONCRETE CRACK IN HEADWALL

_-3131_3_

APPENDIX A-PHOTOGRAPHS

BOSTON POND DAM, HOUGHTON COUNTY

DAM ID NO 00077

JTP

10-12-94

2%

PHOTOGRAPH 5-OUTLET PIPE AND DOWNSTREAM SLOPE

PHOTOGRAPH

A r

I

1 11,4 -3

..1

H

· ;6 lc i

. 4

.6 ..' . r.fits

.P L fill r t.

f -,1 /.9

.\ i ·

F f i r i f

C rp w u m e t.-

.le li P

R

, *il r

I r l d

,4

P u

N D b A

M lb ld

i. , \U ffF yJakrt, .

li.> r

W L

41\ M i f

T O fl i C

/G ri 2r

N

U .L

K E

J A r= y u ,rv v .z

Z i lm

:W l

I i i g

-M

U L

:1 f f m

I r

S C

A L

E

N O

N E

A P

P R

O V

E D m Y

DRAW

N .Y Jr.7.1 D

A T

E ! 2

-9 -9

R E

V

ID

E O

20 570* P o•, 8 bA

N

H o o d

B T

O N

C -0

D

A D

A ff€

L O

C A

-T lt>

N M e f

D R

A W

IN

G

N U

M

IE

R

X

P a

'N

/8 O

N N

O . I€

C

L E

A R

,P a l• ,r i )F j 2,lk

13,st#J

/ Zes tk Q •4- 45: Au.2 ....LiI -F- t.- s#v'll'y S L,Cu

W·-444 (4*/ 6 074- to·,ve#- -Mu ¢&5210<4 1 ¥-444· 00*€U - 091 - h,s*ficit =r-keL 44- ar,1•-4 of- pi,_

/ 54¥11 6 7 -11'f.,1,1. DA 6 A-0,0.- 1, + f 06- A-,kd A,-# tl .

/ 5u.ai u..2 ,/4 ': . ' A rks•-·, 9,446461-A' ·f»104767·v-5- -- Ag· 4- 6° KE>4 16,4 k.00.- A ft) ry')*Av'- i=/ A-'i} 44.£.v,- PAP« o 't'*LE,---

574 of= - b.-0 '*'4CuL+01,c·C4, d"L s...V.c<

/ tted 42-0 2 7-,5- c I.c,6./ -6 f 4 00•-c r<·'- , vWAAJ -- r N

-kj/,194# i

/ 5' 4 CAP O#4 ri'<. - t,1-6+C- c-£>+¢-Al 001>21 , EA„vt \/7 r•··4.#-r 544 c4 1 + pu F,AL- & 3 -evel#- 601 - 4.6 prD61•* 4+ -this -6-4- U.L-c a 2 f .*' 4& U« / ¥tclt-& At

0 0

!O -t 1-'ZY

.Fl

BOSTON POND DAM, HOUGHTON COUNTY

DAM ID NO 00077

..192"ip

JTP

10-12-94

PHOTOGRAPH 1-CONTROL STRUCTURE AND UPSTREAM SLOPE OF EMBANKMENT

1L

PHOTOGRAPH 2-EROSION ADJACENT TO CONTROL STRUCTURE

e J

DAM ID NO 00077

JTP

10-12-94

1/ .1 im€,1,4 4 f 17:2(:4*44,1

9.4 7 , b.

PHOTOGRAPH 3-DEBRIS IN INLET STRUCTURE

t

E1

PHOTOGRAPH 4-CONCRETE CRACK IN HEADWALL

3 r

BOSTON POND DAM, HOUGHTON COUNTY

DAM ID NO 00077

JTP

10-12-94

PHOTOGRAPH 5-OUTLET PIPE AND DOWNSTREAM SLOPE

PHOTOGRAPH

DAM ID 77

BOSTON CREEK, PORTAGE LAKE BASIN

HOUGHTON COUNTY

SE 1/4, Section 7, T55N, R33W

OWNER/OPERATOR: Michigan Department ofNatural Resources Fisheries Division

427 U.S. Highway 41 North

Baraga, Michigan 49908 Telephone: 906-353-6651

HAZARD POTENTIAL

CLASSIFICATION: Low

INSPECTION DATE: October 6, 1997

REPORT DATE: December 17,1997

INSPECTED AND 14-

PREPARED BY: 1 3 T. Pawlosti, P.E Michigan Registration No. 34034 Dam Safety Unit

Land and Water Management Division Michigan Department of Environmental Quality 1985 U.S. Highway 41 West Ishpeming, Michigan 49849 906-485-1031

-2-2.3/I./-12---1

.. r

INTRODUCTION

The purpose of this inspection report is to evaluate the structural condition and hydraulic capacity of this dam as required by Part 315, Dam Safety, of the Natural Resources and

Environmental Protection Act, Act 451 of 1994, as amended. The report is limited to a discussion of observations based on a visual investigation and review of any previous inspection reports. plans, and data which are available. This report should not be considered an in-depth engineering investigation.

All references to "right" and "left" in this report are based on the observer facing downstream.

CONCLUSIONS AND RECOMMENDATIONS

The Boston Pond Dam is in fair condition. There were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway capacity under existing conditions.

The following recommended actions should be completed as soon as practical:

1. Remove rocks and debris from inside of spillway and outlet pipe.

2. Remove trees and brush from earth embankment.

The current low hazard rating is appropriate.

PROJECT INFORMATION

The Boston Pond Dam consists ofa 2500 foot long earth fill embankment that creates a normal head of 9 feet and an impoundment with a surface area of approximately 140 acres. The height of dam as defined by Part 315, Dam Safety, is 10 feet. The structural height of the dam is 12 feet. The normal storage in the impoundment is 500 acre-feet and the maximum storage is 670 acre-feet.

The dam was reportedly constructed in 1968 for recreational purposes. Copies of original design drawings are on file with the Dam Safety Unit.

The spillway consists of a reinforced concrete drop inlet with a single row of 5 foot long stoplogs. The inlet is connected to a 60 inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet and downstream slope of 2.5 horizontal to 1 vertical.

i - .....Illidil

Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

A 1994 inspection reported indicated erosion around the spillway inlet. Those areas have been successfully repaired with rock rip rap. No other recommendations for significant repairs were included in that report. An annual 2.5 foot drawdown has been implemented each fall since 1985 to reduce the potential for flooding upstream roads during spring runoff.

SITE INVESTIGATION

The following discussion of the physical condition of the dam and appurtenances is based on observations and photographs obtined on the date of the inspection.

The Boston Pond Dam is in fair condition. The concrete of the spillway inlet structure is in good condition. There is a crack in the headwall from the crown of the outlet pipe to the top of the wall, as shown is photograph 3. This crack has been observed during several previous inspections and does not present any problems at the present time. The stoplogs appear to be in good condition. The CMP outlet pipe is still in good condition, with some minor seepage at the first joint downstream from the inlet structure, as reported in previous inspections. The outlet pipe is shown in photographs 5 and 6.

Significant debris, including rocks and sticks continue to be a problem in this spillway and outlet pipe, as shown in photographs 4 and 7. It is likely that local vandals continue to contribute to this problem. All debris should be removed from the spillway as soon as practical.

The embankment is in fair condition. There are trees and brush along much of the embankment, as shown in photographs 1 and 2. All trees and brush should be removed as soon as practical. No further deficiencies were noted during the inspection.

STRUCTURAL STABILITY

Based on the conditions observed during the field inspection, the dam appears to be stable. No further structural stability analysis is warranted at this time.

-- I.

HYDRAULICS AND HYDROLOGY

The contributing drainage area of the Boston Creek at the dam is 2.6 square miles. The design discharge for this dam is the 1% chance (100-year) tlood discharge which is estimated to be 340 cubic feet per second (cfs). The existing spillway capacity is estimated to be 230 cfs, with no freeboard.

The design flood event was routed through the impoundment, considering storage in the impoundment and the existing spillway capacity. Based on this analysis, the design flood outflow was estimated to be 80 cfs, with a corresponding rise in the impoundment of approximately 1 foot, leaving 2 feet of freeboard. Therefore, the dam is considered to have adequate spillway and storage capacity. Hydraulic calculations are on file with the

Dam Safety Unit.

OPERATION AND MAINTENANCE

Operation of the dam is the responsibility of the owner or their designee. A written Operation and Maintenance (O&M) Plan is on file with the Dam Safety Unit.

EMERGENCY ACTION PLAN

No Emergency Action Plan (EAP) exists for this dam. Since the dam has a low hazard potential rating, an EAP is not required.

APPENDICES

Appendix A - Photographs Appendix B - Location Map

- I

. 0

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

APPENDIX A_- PHOTOGRAPHS

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

APPENDIX A -PHOTOGRAPHS

DAM ID NO. 77

October 6, 1997

JTP

Photograph 1 --Embankment and spillway viewed from left

Photograph 2--Embankment and spil[way viewed from right

APPENDIX A - PHOTOGRAPHS

DAM lD NO. 77

October 6, 1997

JTP

t

Photograph 3--Spillway headwall-note concrete crack

Photograph 4--Stoplog section-note debris

.r

DAM ID NO. 77

October 6, 1997 jTP

Photograph 5--Outlet pipe viewed from downstream

L · it

Photograph 6--Outlet pipe-close view e

.r- r

DAM ID NO. 77

October 6, 1997

]TP

i

Photograph 7--Outlet pipe interior view-note rocks and debris

Photograph --

. 0

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

APPENDIX B - LOCATION MAP

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

RETAIN THIS IMAGE

U

If

J,.1,11.4 r 1 ETT1 1% i ' 5%14*41.iLLL.&1. (biliN j.\L 1 1 '516 1 471 1- 51 - . 1 ...

14 +r m e

4if. 7,7Uf,.9 sr r ' 3/l.,1 'le,%/1.0

0./1,¢14 hy-ju

W

'MuLLE-6 .4$

' 3--

A -

-7 R 'f g , 9, r 'It

N r-

U

5,191 +9 t t

. E

R

3l¥a

4 pDAID Dka 4, 1214 1 1

U

APPROVED BY,

DRAWN BY 77 REVISED

eDo ·77

DRAWING NUMBER

8 t·,xII

PRINTED ON NO.,00OH CLEARPRINT.+1«# < . V'"',1 &4471 3 rt -7-r-rv'V 4 : 84, P,1 1.F#P a.-: i... ,, hi··'/ , r-rrt.-ft--···

RECEIVED

DEQ-GLMD

NOV 1 8 2002

DAM SAFETY INSPECTION REPORT GAYLORD

BOSTON POND DAM

DAM ID 77

BOSTON CREEK

HOUGHTON COUNTY

SE 1/4, Section 7, T55N, R33W

OWNER/OPERATOR: Michigan Department of Natural Resources Fisheries Division

427 U.S. Highway 41 North Baraga, Michigan 49908 Telephone: 906-353-6651

HAZARD POTENTIAL

CLASSIFICATION: Low

INSPECTION DATE: September 10, 2002

REPORT DATE: November 7,2002

INSPECTED AND lk fAw4ob;

PREPARED BY: 0a s T. Pawloski, P.E.

uam Safety Program Geological and Land Management Division Michigan Department of Environmental Quality 2100 West M-32

Gaylord, Michigan 49735 989-705-3443

2.1, 46

INTRODUCTION

The purpose of this inspection is to evaluate the structural condition and hydraulic capacity of this dam pursuant to the requirements of Parl 315, Dam Safety, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended, Section 31518. This inspection was conducted by the Department of Environmental Quality per the provisions of its Memorandum of Understanding with the Department of Natural Resources (DNR), the owner of the dam.

The report is limited to a discussion of observations based on a visual investigation and review of any previous inspection reports, plans, and data which are available. This report should not be considered an in-depth engineering investigation.

All references to "right" and "left" in this report are based on the observer facing downstream.

CONCLUSIONS AND RECOMMENDATIONS

The Boston Pond Dam is in fair condition. There were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway capacity under existing conditions.

The following recommended action should be completed during the 2003 construction season:

• Remove trees and brush from earth embankment.

The current low hazard rating is appropriate.

PROJECT INFORMATION

r The Boston Pond Dam consists of a 2500-foot long earth fill embankment that creates a normal head of 9 feet and an impoundment with a surface area of approximately 140 acres. The height of dam as defined by Part 315, Dam Safety, is 10.5 feet. The structural height of the dam is 12 feet.

The dam was reportedly constructed in 1968 for recreational purposes. Copies of original design drawings are on file with the Dam Safety Program.

The spillway consists of a reinforced concrete drop inlet with a single row of 5-foot long stoplogs. The inlet is connected to a 60-inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet and downstream slope of 2.5 horizontal to 1 vertical. Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

A 1997 inspection recommended removal of rocks and debris from the outlet pipe. No other recommendations for significant repairs were included in that report. An annual 2.5 foot drawdown has been implemented each fall since 1985 to reduce the potential for flooding upstream roads during spring runoff.

SITE INVESTIGATION

The following discussion of the physical condition of the dam and appurtenances is based on observations and photographs obtained on the date of the inspection.

The Boston Pond Dam is in fair condition. The concrete of the spillway inlet structure is in good condition, as shown in Photographs 2 and 4. There is a crack in the headwall from the crown of the outlet pipe to the top of the wall, as shown is Photograph 2. This crack has been observed during several previous inspections and does not present any problems at the present time. The stoplogs appear to be in good condition. The CMP outlet pipe is still in good condition, with some minor seepage at the first joint downstream from the inlet structure, as reported in previous inspections. The interior of the outlet pipe is shown in Photograph 6.

The embankment is in fair condition. There are trees and brush along much of the embankment, as shown in Photographs 1,3 and 5. All trees and brush should be removed during the 2003 construction season. No further deficiencies were noted during the inspection.

STRUCTURAL STABILITY

Based on the conditions observed during the field inspection, the dam appears to be stable. No further structural stability analysis is warranted at this time.

HYDRAULICS AND HYDROLOGY

The contributing drainage area of the Boston Creek at the dam is 2.6 square miles. The design discharge for this dam is the 1 -% chance (100-year) flood discharge which is estimated to be 570 cubic feet per second (cfs). The existing spillway capacity is estimated to be 230 cfs, with no freeboard.

The design flood event was routed through the impoundment, considering storage in the impoundment and the existing spillway capacity. Based on this analysis, the design flood outflow was estimated to be 155 cfs, with a corresponding rise in the impoundment of approximately 1.5 feet, leaving 1.5 feet of freeboard. Therefore, the dam is considered to have adequate spillway and storage capacity. Hydraulic calculations are on file with the Dam Safety Program.

OPERATION AND MAINTENANCE

Operation of the dam is the responsibility of the owner or their designee. A written Operation and Maintenance (O&M) Plan is on file with the Dam Safety Unit.

EMERGENCY ACTION PLAN

No Emergency Action Plan (EAP) exists for this dam. Since the dam has a low hazard potential rating, an EAP is not required.

APPENDICES

Location Map and Photographs

4'quill

S r.\11: 01· M H-lin{.AN

DEPARTMENT OF ENVIRONMENTAL QUALITY

1.ANS IN«j

JOHN ENGLER

GOVERNOR

RUSSELL J. HARDING

DIRECTOR

October 31, 2002

TO: Kelley D. Smith, Chief, Fisheries Division Department of Natural Resources

FROM: Harold R. Fitch, Chief

Geological and Land Management Division

SUBJECT: Dam Safety Inspection Report

Enclosed is the Dam Safety Inspection Report and recommendations for the Boston Pond Dam, Dam ID 77, Houghton County.

The Boston Pond Dam is in fair condition. There were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway capacity under existing conditions.

The following recommended action should be completed during the 2003 construction season:

• Remove trees and brush from earth embankment.

Jim Pawloski of our Dam Safety Program, Gaylord Field Office, is available to discuss any questions or concerns you may have with the inspection report. He can be reached at 989-705-3443.

-0#*27»<C:27*z:r_ Enclosure cc: Lower Peninsula Field Deputy, DNR Lake Superior Management Unit, Fisheries Division, DNR Arthur R. Nash Jr., Deputy Director, DEQ Jim Pawloski, DEQ

CONSTITUTION HALL • 525 WEST ALLEGAN STREET • PO. BOX 30458 • LANSING, MICHIGAN 48909-7958

¥mw.michtgan.gov• (517) 373-1170

-1.

HOUGHTON COUNTY

DAM ID NO. 77

d f

AL c

10> fLak« 2-

- UL

1/Goughten Cq -4 1 -•2b.>6•m )3,.1 3

1\JVH

.k-'-7-i.JUA'-f\.?ffjift*63113333

HOUGHTON COUNTY

DAM ID NO. 77

it

Photograph 1-Embankment viewed from left r

Photograph 2-Spillway inlet viewed from upstream

DAM ID NO. 77

tt

Photograph 3-Outlet channel

2.--\t'b

4 -: B -

Ir·

-.1FFE

Rit-

Photograph 4-Spillway inlet

L

HOUGHTON COUNTY

DAM ID NO. 77

t t tly f r.¥.

Photograph 5-Embankment viewed from left abutment

J

Photograph G-Interior of outlet pipe

DAM ID 77

BOSTON CREEK

HOUGHTON COUNTY

SE 1/4, Section 7, T55N, R33W

OWNER/OPERATOR: Michigan Department of Natural Resources Fisheries Division

427 U.S. Highway 41 North Baraga, Michigan 49908 Telephone: 906-353-6651

HAZARD POTENTIAL

CLASSIFICATION: Low

INSPECTION DATE: October 9,2007

REPORT DATE: October 16,2007

INSPECTED AND AMI.Rld &4 PREPARED BY: J m s-

Da SE

r. Pawloski, P.E.

ifety Program Land and Water Management Division Michigan Department of Environmental Quality 2100 West M-32

Gaylord, Michigan 49735 989-705-3443

'fof MICH/n .,4

2 ,·· JAMES T

g *E PAWLOSK}

,-- { ENGINEER

NO.

'4*.7UFESS\0*AL„-

J I .1 .

The purpose of this inspection is to evaluate the structural condition and hydraulic capacity of this dam pursuant to the requirements of Part 315, Dam Safety, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended, Section 31518.

This inspection was conducted by the Department of Environmental Quality per the provisions of its Memorandum of Understanding with the Department of Natural Resources (DNR), the owner of the dam.

The report is limited to a discussion of observations based on a visual investigation and review of any previous inspection reports, plans, and data which are available. This report should not be considered an in-depth engineering investigation.

All references to "right" and "left" in this report are based on the observer facing downstream.

CONCLUSIONS AND RECOMMENDATIONS

Conditions have changed very little since the 2002 inspection of the Boston Pond Dam.

Therefore, much of the language in this report is similar or identical to the 2002 report.

The Boston Pond Dam is in fair condition. There were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway capacity under existing conditions. The current low hazard rating is appropriate.

The following recommended action should be completed during the time frame specified:

1. Remove debris from spillway riser as soon as possible.

2. Remove trees and brush from earth embankment during the 2008 construction season. This recommendation was also included in the 2002 inspection report, but nothing appears to have been done to date.

PROJECT INFORMATION

The Boston Pond Dam consists of a 2,500-foot long earth fill embankment that creates a normal head of 9 feet and an impoundment with a surface area of approximately 140 acres. The height of dam as defined by Part 315, Dam Safety, is 10.5 feet. The structural height of the dam is 12 feet.

6 The dam was reportedly constructed in 1968 for recreational purposes. Copies of original design drawings are on file with the Dam Safety Program.

The spillway consists of a reinforced concrete drop inlet with a single row of 5-foot long stoplogs. The inlet is connected to a 60-inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet and downstream slope of 2.5 horizontal to 1 vertical. Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

A 1997 inspection recommended removal of rocks and debris from the outlet pipe. No other recommendations for significant repairs were included in that report. An annual 2,5-foot drawdown has been implemented each fall since 1985 to reduce the potential for flooding upstream roads during spring runoff.

SITE INVESTIGATION

The following discussion of the physical condition of the dam and appurtenances is based on observations and photographs obtained on the date of the inspection.

The Boston Pond Dam is in fair condition. The concrete of the spillway inlet structure is in good condition, as shown in Photographs 3 through 5. There is a crack in the headwall from the crown of the outlet pipe to the top of the wall, as shown is Photograph 5. This crack has been observed during several previous inspections and does not present any problems at the present time. The stoplogs appear to be in good condition. The CMP outlet pipe is still in good condition. The outlet pipe is shown in Photograph 6.

The embankment is in fair condition. There are trees and brush along much of the embankment, as shown in Photographs 1 and 2. Trees and brush provide cover for burrowing animal and obstruct the view of the embankment during an inspection. For these reasons, all trees and brush should be removed during the 2008 construction season. No further deficiencies were noted during the inspection.

STRUCTURAL STABILITY

Based on the conditions observed during the field inspection, the dam appears to be stable. No further structural stability analysis is warranted at this time.

HYDRAULICS AND HYDROLOGY

The contributing drainage area of the Boston Creek at the dam is 2.6 square miles. The design discharge for this dam is the 1 percent chance (100-year) flood discharge, which is estimated to be 570 cubic feet per second (cfs). The existing spillway capacity is estimated to be 230 cfs, with no freeboard.

The design flood event was routed through the impoundment. Routing takes into consideration the amount of storage available in the impoundment and may reduce the outflow from a dam in the event of a flood. In simple terms, the peak flood waters enter the impoundment, some of the water is stored in the impoundment, the water level of the impoundment rises to a certain level, and the remainder of the water passes through the spillways. As the flood inflows recede, the water level in the pond drops, and the water passing through the spillway is also reduced.

Based on this analysis, the design flood outflow was estimated to be 155 cfs, with a corresponding rise in the impoundment of approximately 1.5 feet, leaving 1.5 feet of freeboard. Therefore, the dam is considered to have adequate spillway and storage capacity. Hydraulic calculations are on file with the Dam Safety Program.

OPERATION AND MAINTENANCE

Operation of the dam is the responsibility of the owner or their designee. A written operation and maintenance (0&M) plan is on file with the Dam Safety Unit.

EMERGENCY ACTION PLAN

No emergency action plan (EAP) exists for this dam. Since the dam has a low hazard potential rating, an EAP is not required.

Location Map and Photographs are attached.

DAM ID NO. 77

ly Or t - if

/ 4

,/46*1 /1 fxi-- - , 9. 1 -14

5%-fi f oughoin Ce

MI",LAkport j

Fi M

DAM ID 77

.%13<.-

Photograph 1 - Embankment viewed from left abutment

Photograph 2 - Embankment viewed from centerline of spillway to right

-IT ,wir-- -

J

Photograph - Spillway riser

Photograph 4 - Debris in spillway

Photograph 5 - Historic crack in spillway headwall

07=.

.A·

...<AL

t %7<.ۥ

7,€

• .1-*Mt.

Photograph 6 - Outlet pipe viewed from downstream

DAM ID NO. 77

V t At - -

RJ.

I : ti,121 r i.

Photograph 1 - Embankment viewed from left abutment

Photograph 2 - Embankment viewed from centerline of spillway to right

Photograph - Spillway riser

J>,7,€

Photograph 4 - Debris in spillway

Photograph 5 - Historic crack in spillway headwall r t."3.f..6£#- 4,A ' -

Photograph 6 - Outlet pipe viewed from downstream i '

The purpose of this inspection is to evaluate the structural condition and hydraulic capacity of this dam pursuant to the requirements of Part 315, Dam Safety, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended, Section 31518.

This inspection was conducted by the Department of Environmental Quality (DEQ) per the provisions of its Memorandum of Understanding with the Department of Natural Resources (DNR), the owner of the dam.

The report is limited to a discussion of observations based on a visual investigation and review of any previous inspection reports, plans, and data that are available. This report should not be considered an in-depth engineering investigation.

All references to “right” and “left” in this report are based on the observer facing

The Boston Pond Dam is in satisfactory condition. This means that there are no recognized existing dam safety deficiencies. Furthermore, there were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway and storage capacity for the design flood event under existing conditions. The current low hazard rating is appropriate.

The following recommended actions should be completed during the time frame specified:

1. Remove debris from spillway riser and outlet pipe as soon as possible.

2. Remove trees and brush from earth embankment during the 2013 construction season.

3. Repair the eroded area on the upstream slope of the embankment adjacent to the spillway riser.

PROJECT INFORMATION

The Boston Pond Dam consists of a 2,500-foot long earth fill embankment that creates a normal head of 9 feet and an impoundment with a surface area of approximately 140 acres. The height of the dam as defined by Part 315, Dam Safety, is 10.5 feet.

The structural height of the dam is 12 feet.

The dam was reportedly constructed in 1968 for recreational purposes. Copies of the stoplogs. The inlet is connected to a 60-inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet, and downstream slope of 2.5 horizontal to 1 vertical. Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

A 1997 inspection recommended removal of rocks and debris from the outlet pipe. No other recommendations for significant repairs were included in that report. An annual 2.5-foot drawdown has been implemented each fall since 1985 to reduce the potential for flooding upstream roads during the spring runoff. Previous inspection reports were used as references in the preparation of this report.

SITE INVESTIGATION

The following discussion of the physical condition of the dam and appurtenances is based on observations and photographs obtained on the date of the inspection.

The Boston Pond Dam is in fair condition. The concrete of the spillway inlet structure is in good condition, as shown in Photographs 3 through 6. There is a crack in the headwall from the crown of the outlet pipe to the top of the wall, as shown in Photograph 6. This crack has been observed during several previous inspections and does not present any problems at the present time. The stoplogs appear to be in good condition. The CMP outlet pipe is still in good condition. The interior of the outlet pipe is shown in Photograph 7. There is debris in the bottom of the pipe, as shown in the photograph. This debris should be removed as soon as possible.

The embankment is in fair condition. There are trees and brush along much of the embankment, as shown in Photograph 1. Trees and brush provide cover for burrowing animal and obstruct the view of the embankment during an inspection. For these reasons, all trees and brush should be removed during the 2013 construction season.

There is also an eroded area on the upstream slope of the embankment immediately adjacent and to the left of the spillway riser. This area should be repaired during the 2013 construction season. No further deficiencies were noted during the inspection.

STRUCTURAL STABILITY

design discharge for this dam is the 1 percent chance (100-year) flood discharge, which is estimated to be 500 cubic feet per second (cfs). The existing spillway capacity is estimated to be 230 cfs, with no freeboard.

The design flood event was routed through the impoundment. Routing takes into consideration the amount of storage available in the impoundment and may reduce the outflow from a dam in the event of a flood. In simple terms, the peak flood waters enter the impoundment, some of the water is stored in the impoundment, the water level of the impoundment rises to a certain level, and the remainder of the water passes through the spillways. As the flood inflows recede, the water level in the pond drops, and the water passing through the spillway is also reduced.

Based on this analysis, the design flood outflow was estimated to be 140 cfs, with a corresponding rise in the impoundment of approximately 1.5 feet, leaving 1.5 feet of freeboard. Therefore, the dam is considered to have adequate spillway and storage capacity. Hydraulic calculations are on file with the Dam Safety Program.

OPERATION AND MAINTENANCE

Operation of the dam is the responsibility of the owner or their designee. A written Operation and Maintenance Plan (O&M Plan) is on file with the Dam Safety Unit.

No Emergency Action Plan (EAP) exists for this dam. Since the dam has a low hazard potential rating, an EAP is not required.

A Location Map and Photographs are included with this report.

DAM ID NO. 77

Photograph 1 – Embankment viewed from left abutment.

Photograph 2 – Eroded area adjacent to left of spillway.

Photograph 3 – Spillway riser.

Photograph 4 – Historic crack in spillway headwall.

Photograph 5 – Left spillway wall.

Photograph 6 – Right spillway wall.

Photograph 7 — Interior view of outlet pipe. Note debris in pipe.

BOSTON CREEK

SE 1/4, SECTION 7, T55N, R33W

OWNER/OPERATOR: Michigan Department of Natural Resources Fisheries Division 427 U.S. Highway 41 North Baraga, Michigan 49908 Telephone: 906-353-6651

HAZARD POTENTIAL

CLASSIFICATION: Low

INSPECTION DATE: August 8, 2017

REPORT DATE: August 10, 2017

PREPARED AND INSPECTED BY:

James T. Pawloski, P.E.

Dam Safety Program Water Resources Division Department of Environmental Quality 2100 M-32 West Gaylord, Michigan 49735 989-370-1528

The purpose of this inspection is to evaluate the structural condition and hydraulic capacity of this dam pursuant to the requirements of Part 315, Dam Safety, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended, Section 31518.

This inspection was conducted by the Department of Environmental Quality (DEQ) per the provisions of its Memorandum of Understanding with the Department of Natural Resources (DNR), the owner of the dam.

The report is limited to a discussion of observations based on a visual investigation and review of any previous inspection reports, plans, and data that are available. This report should not be considered an in-depth engineering investigation.

All references to “right” and “left” in this report are based on the observer facing

The Boston Pond Dam is in satisfactory condition. This means that there are no recognized existing dam safety deficiencies. Furthermore, there were no deficiencies observed during the inspection that would lead to failure of the dam. The dam has adequate spillway and storage capacity for the design flood event under existing conditions. The current low hazard rating is appropriate.

The following recommended actions should be completed during the time frame specified:

1. Remove debris from spillway riser and outlet pipe as soon as possible.

2. Remove trees and brush from earth embankment during the 2017 construction season.

The Boston Pond Dam consists of a 2,500-foot long earth fill embankment that creates a normal head of 9 feet and an impoundment with a surface area of approximately 140 acres. The height of the dam as defined by Part 315, Dam Safety, is 10.5 feet.

The structural height of the dam is 12 feet.

The dam was reportedly constructed in 1968 for recreational purposes. Copies of the stop logs. The inlet is connected to a 60-inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet, and downstream slope of 2.5 horizontal to 1 vertical. Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

A 1997 inspection recommended removal of rocks and debris from the outlet pipe. No other recommendations for significant repairs were included in that report. An annual 2.5-foot drawdown has been implemented each fall since 1985 to reduce the potential for flooding upstream roads during the spring runoff. Previous inspection reports were used as references in the preparation of this report.

SITE INVESTIGATION

The following discussion of the physical condition of the dam and appurtenances is based on observations and photographs obtained on the date of the inspection.

The Boston Pond Dam is in satisfactory condition. The concrete of the spillway inlet structure is in good condition, as shown in Photographs 3 through 6. There is a historic crack in the headwall from the crown of the outlet pipe to the top of the wall, as shown in Photograph 6. This crack has been observed during several previous inspections and does not present any problems at the present time. The stop logs appear to be in good condition. The CMP outlet pipe is still in good condition. The interior of the outlet pipe is shown in Photograph 7. There is debris in the bottom of the pipe and in the inlet structure, as shown in Photographs 7 and 8. This debris should be removed as soon as possible.

The embankment is in satisfactory condition. There are trees and brush along much of the embankment, as shown in Photographs 1 and 2. Trees and brush provide cover for burrowing animals and obstruct the view of the embankment during an inspection. For these reasons, all trees and brush should be removed during the 2017 construction season. No further deficiencies were noted during the inspection.

design discharge for this dam is the 1 percent chance (100-year) flood discharge, which is estimated to be 500 cubic feet per second (cfs). The existing spillway capacity is estimated to be 230 cfs, with no freeboard.

The design flood event was routed through the impoundment. Routing takes into consideration the amount of storage available in the impoundment and may reduce the outflow from a dam in the event of a flood. In simple terms, the peak flood waters enter the impoundment, some of the water is stored in the impoundment, the water level of the impoundment rises to a certain level, and the remainder of the water passes through the spillways. As the flood inflows recede, the water level in the pond drops, and the water passing through the spillway is also reduced.

Based on this analysis, the design flood outflow was estimated to be 140 cfs, with a corresponding rise in the impoundment of approximately 1.5 feet, leaving 1.5 feet of freeboard. Therefore, the dam is considered to have adequate spillway and storage capacity. Hydraulic calculations are on file with the Dam Safety Program.

OPERATION AND MAINTENANCE

Operation of the dam is the responsibility of the owner or their designee. A written Operation and Maintenance Plan is on file with the Dam Safety Unit.

No Emergency Action Plan (EAP) exists for this dam. Since the dam has a low hazard potential rating, an EAP is not required.

A location map and photographs are included with this report.

Photograph 1 – Embankment viewed from left abutment

Photograph 2 – Embankment viewed from right abutment

Photograph 3 – Spillway riser

Photograph 4 – Spillway headwall

Photograph 5 – Left spillway wall

Photograph 6 – Right spillway wall

Photograph 7 – Interior view of outlet pipe Note debris in pipe

Photograph 8 – Debris at base of inlet structure

Photograph 9 – Outlet end of spillway pipe

Boston Pond Dam – Dam ID No. 77

Boston Creek Houghton County – Section 7, T 55N, R 33W

OWNER(S)/OPERATOR(S):

MDNR Fisheries Division - Western Lake Superior Management Unit

Baraga Operations Service Center 427 US 41 North Baraga, MI 49908

(906) 293-5131

HAZARD POTENTIAL

CLASSIFICATION: Low

INSPECTION DATE: August 29, 2022

REPORT DATE: December 2, 2022

PREPARED AND INSPECTED BY:

Micheal Size, E.I.T. Mitchel K Thelen, P.E.

Dam Safety Unit Dam Safety Unit Water Resources Division Water Resources Division Dept. of Environment, Great Lakes, and Energy Dept. of Environment, Great Lakes, and Energy 2100 West M-32 P.O. Box 30458 Gaylord, Michigan 49735 Lansing, Michigan 48909 989-619-4295 517-280-5866

The purpose of this inspection was to evaluate the structural condition and hydraulic capacity of the Boston Pond Dam, as required by Part 315, Dam Safety (Part 315), of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended.

This inspection was conducted by the Department of Environment, Great Lakes, and Energy (EGLE) per the provisions of its Memorandum of Understanding with the Department of Natural Resources (DNR), the owner of the dam. The report is limited to a discussion of observations based on a visual investigation and review of any available previous inspection reports, plans, and data. This report should not be considered an in-depth engineering investigation. All references to “right” and “left” in this report are based on the observer facing downstream.

CONCLUSIONS AND RECOMMENDATIONS

The Boston Pond Dam is in Fair condition. No existing dam safety deficiencies are recognized for normal loading conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. The following recommended actions are listed by priority:

Primary Spillway Outlet: Begin process to replace outlet pipe as the life expectancy has been surpassed for corrugated metal pipes (~50 years) Upstream Slope Vegetation Action: Remove vegetation by December 31, 2023 Downstream Slope Tree Action: Remove trees by December 31, 2024 Downstream Slope Animal Burrow Action: Monitor embankment for development of other animal burrows and fill them as necessary Downstream Slope Seepage Action: Monitor seepage area for sediment transportation and boils

The dam’s current Low hazard potential rating remains appropriate.

The Boston Pond Dam consists of a 2,500-foot long earth fill embankment that creates a normal head of 9 feet and an impoundment with a surface area of approximately 140 acres. The hydraulic height of the dam as defined by Part 315, Dam Safety, is 10.5 feet, while the structural height of the dam is 12 feet.

The dam was reportedly constructed in 1968 for recreational purposes. Copies of the original design drawings are on file with the Dam Safety Program.

The spillway consists of a reinforced concrete drop inlet with a single row of 5-foot long stop logs. The inlet is connected to a 60-inch diameter corrugated metal pipe (CMP) outlet pipe through the embankment.

The embankment consists of unclassified earth fill with an upstream slope of 3 horizontal to 1 vertical, top width of 12 feet, and downstream slope of 2.5 horizontal to 1 vertical. Soil boring logs are provided on the drawings and generally indicate muck and topsoil overlying sands and gravels. Apparently, some sort of an embankment existed prior to construction. Notes on the drawings indicate that all debris was to be removed and muck excavated prior to placing fill.

An annual 2.5-foot drawdown has been implemented each fall since 1985 to reduce the potential for flooding upstream roads during the spring runoff.

A Dam Safety inspection was previously completed in 2017. A copy of that inspection report is on file with the Dam Safety Program. The 2017 inspection report prepared by the Dam Safety program of EGLE was used as a reference for this report.

SITE INVESTIGATION

The following discussion of the dam’s physical condition and appurtenances is based on observations and photographs obtained on the inspection date.

In addition to the specific findings listed below, it is important to continue good maintenance practices. These practices include regular inspection of the dam embankments and hydraulic structures for any deficiencies. Some of the more common issues that are found include growth of trees and brush, development of erosion areas, and animal burrows.

If woody vegetation is allowed to mature, it could develop an extensive root system.

These root systems can lead to piping failure or if the brush and trees are uprooting in a storm, can cause extensive deterioration of the embankment. Embankments should be clear of woody vegetation and mowed 10 feet past the toe of the embankment.

Similarly, animal burrows and surface erosion, can propagate into increased seepage and potentially piping failure, as well as lead to slope stability issues.

The following data was collected on the date of the inspection and includes deficiencies observed during the inspection and necessary actions for remediation of the observed deficiencies.

Upstream Slope Upstream slope ground cover Brush, riprap, grass

Slope Protection What types of slope protection are used? Riprap, Vegetation

Average diameter of riprap Type C (6"-18")

Condition of riprap Adequate

Trees/Woody Vegetation Density of vegetation Dense

Location of vegetation Entire Upstream Slope

Action required for vegetation Maintenance

Describe action required Remove Vegetation

Crest

Approximate width of crest (ft) 10

Approximate freeboard (ft) 5

Crest ground cover Road gravel

Downstream Slope

Downstream slope ground cover Grass, vegetation, trees

What issues are present on the downstream slope?

Trees

Trees/Woody Vegetation Number of trees Dense

Tree DBH (in) 6-12"

Location of trees Downstream Slope Toe

Action required for trees Maintenance

Describe action required Remove trees

Downstream slope ground cover Grass, vegetation, trees

What issues are present on the downstream slope?

Trees

Seepage Location of Seepage Downstream Slope, near right abutment (see photo #4)

Action required for trees Monitor

Describe action required Monitor seepage area for sediment transportation and boils

Animal Burrow Location of Burrows Downstream Slope, near offroad trail access (see photo #10)

Action required for trees Monitor

Describe action required Monitor embankment for development of other animal burrows and fill them as necessary

Principal Spillway What type of spillway is present? Concrete Riser and Stoplogs

What is the primary material used in the spillway? Concrete, Wooden Stoplogs and CMP outlet

Which components are present? Low-Level Outlet

What issues are present with the primary spillway?

Deteriorating Materials

Material Deterioration What materials are deteriorating in the spillway? CMP Outlet

What issues are noted with the components? Rusted, Pitted, Separated from Concrete

Where are the issues located? Throughout

Action required for concrete components of the spillway

Maintenance

Describe action required Begin process for designing outlet replacement

Erosion Control / Energy Dissipation What type of erosion control structure is in place? Rock-Lined Channel

Are there any issues with the outlet erosion control structure?

None

Does the outlet erosion control structure include any drains?

No

The above monitoring and maintenance items should be addressed in accordance with the Conclusions and Recommendations section of this report.

Based upon observations during the inspection, there were no indicators of any conditions that represent an immediate threat to the dam’s stability. No further structural stability analysis is warranted at this time.

HYDROLOGY AND HYDRAULICS

The contributing drainage area of the Boston Creek at the dam is 2.6 square miles.