A River Runs Through Them…Once Again!

Presentation by: Deb Loiselle (Dam Bureau) Steve Landry (Watershed Assistance Section) How Many Dams are in ?

National Inventory of Dams (NID) = 625

NID + Remaining Active Dams = 2,621

NID + Active + Inactive Dams = 5,176

Source: NH Dam Bureau Database NHDES – Dam Bureau

Operations and Maintenance Engineering and Construction Dam Safety and Inspection

NH Dam Safety Program Partnerships

Project Partner Team NH RRTF Members

Dam Engineer USFWS American Rivers NOAA E3 Engineering, Economic, Emotion Historic Issues

1936 photo

Archaeological test pit

2008 Photo Sediment Quantity and Quality

TR-S1

TR-S2 TR-S3

TR-S4 Aesthetic Concerns

Days after removal

9 months after removal To Remove or Not Remove?

Is there financial and technical What are my options? assistance available?

What will it look like if I remove it? How much will it cost to repair and maintain the dam?

Remove the dam?

Retain the dam?

It is the Dam Owner’s Decision

Current NH Projects McLane Dam Milford Feasibility Phase

Goldman Dam Milford Souhegan River Feasibility Phase Great Dam Exeter Exeter River Feasibility Phase Macallen Dam Newmarket Feasibility Phase

Gonic Dam Rochester Cocheco River Design/Eng/Permit Gonic Sawmill Dam Rochester Cocheco River Design/Eng/Permit Lower Sawyer Mill Dam Dover Bellamy River Design/Eng/Permit

Upper Sawyer Mill Dam Dover Bellamy River Design/Eng/Permit

Anne Jackson Camp Dam Wilton Unnamed Construction Removed 2012 Stream McQuade Brook Dam Bedford McQuade Brook Construction Removed 2012

Haydens Reservoir Dam Hollis Witch Brook Construction Removed 2012

Beaver Lake Dam Derry Beaver Brook Permit - approved Est Removal 2012 Two River Restoration Projects in the Watershed Neighborhood

Portsmouth, NH

Maxwell Pond Dam

Manchester, NH Atlantic Ocean Atlantic

Merrimack Village Dam

Merrimack, NH

Merrimack River

Nashua, NH

Lawrence, MA

Lowell, MA The Maxwell Pond Dam removal/Black Brook restoration project (the rest of the story…)

Presented by: Stephen C. Landry – NHDES Maxwell Pond Dam

Grade Control Maxwell Pond Dam - 1900 Front Street Ice House - 1952 Safety – Administrative Order from DES Dam Bureau.

Economics – About $1 million to dredge and repair or $40K to remove and restore Black Brook.

Flooding – Front street was destroyed and local businesses were Evacuated in 2006 and 2007. Utility infrastructure was compromised.

Restoration of impaired waters – Maxwell Pond was on the 303(d) list of impaired waters since 2004 for failure to support aquatic life use due to insufficient dissolved oxygen. #5 Yea!

Sweet!! If you “un-build” it, they will come… Summer 2008 Drawdown – September 2008 February 24th 2009 Morning March 9th 2009 March 10th 2009 - Morning June 29th 2009 July 27 , 2010 September 29, 2011 July 20, 2012 Lost & Found

Pre- and Post- Monitoring at MPD Pre- and Post- Monitoring at MPD Monumented Photo Points

H-1 E-1

2008 2008

H-2

2008

2012 2012

2012 PreLongitudinal-removal slope = 0.43% and Cross Section Surveys

Post-removal slope = 1.03% 2008 2011

Former Impoundment (Maxwell Pond) Rapid Bioassessment Aquatic Macroinvertebrate Surveys Black Brook Rapid Bioassessment Aquatic Macroinvertebrate Surveys 2002 – 2012 Within Former Impoundment 7

6 43 (Excellent) 36 (Good) 5 36 (Good) 4

3

2 Number of Major Groups of Number

1

0 2010 (Oct) 2011 (Nov) 2012 (Aug)

Senstive Somewhat Sensitive Tolerant Fish Population Surveys Black Brook Fish Population Surveys 2002 – 2012

120 Within Former Impoundment 100 109 99 80 60

40 47

20 8 9 19 4 5 0 2009 (June) 2009 (August) 2010 2012

Total fish Total species 75 5

Documenting Restoration of Designated Uses Designated of Restoration Documenting Dissolved Oxygen Concentration Oxygen Dissolved Pre - Removal Exceedances = 6 ExceedancesRemoval = Pre DissolvedOxygen Saturation - Removal Exceedances = 12 ExceedancesRemoval =

Dam Removal (February 2009)

Average =8.30 mg/L Average =8.30 Average = 90% Average =

Fish Watson Park

Merrimack Village Dam

Quick Facts  Dam present since 1700s associated with mill buildings  Height = 20 ½ feet Width = 180 feet  Constructed with granite blocks overlayed in concrete with concrete apron  Dam owned by Pennichuck Water Works since 1964  Dam was barrier to anadromous & resident fish  Dam deficiencies  Pennichuck considered repair vs removal  Feasibility study- Phase I completed in 2004  Dam offered to town-voted not to take over ownership, Pennichuck pursued removal

If you dismantle it, they will come…

Team MVD Dam Cam

Merrimack Village Dam Archaeological & Architectural Surveys

 Project Area Form

 Individual Inventory Form

 Phase IA and Phase IB

Development of an MOA

Watson Park

 Interpretive signage  Brass plaque  HAER documentation (written and photo)  10 granite blocks from the dam transferred to Watson Park  Notification of unidentified historic resources

Pre- and Post- Monitoring Cross Section MVD03

Pre-Removal

Post-Removal Cross Section MVD06

Information provided by NOAA and Boston College

MVD06

Information provided by NOAA and Boston College

Upstream – MVD06

1

0 island

-1

-2

pin (m) -3

-4 ht rel to L -

-5

-6 Aug-07 <100% impounded sediment remaining -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0 island

-1

-2

pin (m) -3

-4 ht rel to L -

-5

Aug-07 -6 June-08

100% impounded sediment remaining water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0

-1

-2

pin (m) -3

-4 ht rel to L -

Aug-07 -5 June-08

water line -6 Aug-08 71% impounded sediment remaining water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0

-1

-2

pin (m) -3

-4 ht rel to L - Aug-07

June-08 -5 water line Aug-08

-6 water line Oct-08 51% impounded sediment remaining water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0

-1

-2

pin (m) -3 Aug-07

June-08 -4 ht rel to L - water line

Aug-08

-5 water line

Oct-08

-6 water line Jul-09 ~40% impounded sediment remaining water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0

-1

-2

pin (m) -3 Aug-07 June-08 water line -4 ht rel to L - Aug-08 water line Oct-08 -5 water line Jul-09 -6 water line 40% impounded sediment remaining Aug-09 water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0

-1

Aug-07 -2 June-08

water line

pin (m) -3 Aug-08 water line Oct-08 -4 ht rel to L - water line Jul-09 -5 water line Aug-09

-6 water line May-10 22% impounded sediment remaining water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0

Aug-07 -1 June-08 water line -2 Aug-08

water line Oct-08 pin (m) -3 water line Jul-09 -4 ht rel to L - water line Aug-09 -5 water line May-10

-6 water line 11-Jun 22% impounded sediment remaining water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m) Upstream – MVD06

1

0 Aug-07 June-08 -1 water line Aug-08

-2 water line

Oct-08 water line pin (m) -3 Jul-09 water line -4 Aug-09 ht rel to L - water line May-10 -5 water line 11-Jun -6 water line 19% impounded sediment remaining 12-Jul water line -7 0 10 20 30 40 50 60 70 80 90 100 distance rel to L-pin (m)

Cross Section MVD06

Information provided by NOAA and Boston College

Summer Fun Vegetation Community Survey

Fish Population Surveys (Pre) Fish Population Surveys (Post) Souhegan River Fish Population Surveys 2007 – 2009

1000 Downstream of Dam

100 125 129 93 Removal Dam

14 10 13 11

1 2007 2008 2009

Total Fish Total Species Souhegan River Fish Population Surveys 2007 – 2009

250 Within Former Impoundment

200 210

150 Removal Dam 100

50 62

6 8 0 2007 2009 Total Fish Total Species Happy Fishing  Macroinvertebrate Survey

Water Quality Survey

Thank You !