The Beneficial Option of Dam Removal
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A River Runs Through Them…Once Again! Presentation by: Deb Loiselle (Dam Bureau) Steve Landry (Watershed Assistance Section) How Many Dams are in New Hampshire? 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 Souhegan River Feasibility Phase Goldman Dam Milford Souhegan River Feasibility Phase Exeter River Great Dam Exeter Exeter River Feasibility Phase Macallen Dam Newmarket Lamprey River 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 Gulf of Maine Watershed Neighborhood Portsmouth, NH Maxwell Pond Dam Manchester, NH AtlanticOcean 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 Documenting Restoration of Designated Uses Dissolved Oxygen Saturation Pre-Removal Exceedances = 12 75 Average = 90% Dissolved Oxygen Concentration Pre-Removal Exceedances = 6 Dam Removal (February 2009) (February Removal Dam Average =8.30 mg/L 5 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) Aug-07 - -3 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) Aug-08 - -3 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 Dam 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 Dam Removal Dam 100 50 62 6 8 0 2007 2009 Total Fish Total Species Happy Fishing Macroinvertebrate Survey Water Quality Survey Thank You ! .