THE IMPACT OF DAMS ON RIVER SYSTEMS

Transcription

1 THE IMPACT OF DAMS ON RIVER SYSTEMS G R O U P 6 / N R E / B E N S O N, J. ; H O R N B E C K E R, B. ; M C K I E R N A N, B. ; P O M E R A N T Z, J. ; R O B A C K, D. ; 4 / 1 9 / 1 1

2 THE NUMBERS There are approximately 85,000 dams in the U.S 765 just in Connecticut Average age is just over 51 years old

3 WHAT STARTED IT ALL? 1932,1955 Flood USACE Flood Reduction Act

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7 THE QUESTION How does the presence of dams affect the river systems that they lie in?

8 THE ECOLOGY OF THE SYSTEM Rivers without dams have a natural cycle of flooding which the fish and vegetation along the river rely on When not in a flood stage the river system is held at a constant height Water is let out of the backs of these dams at a rapid pace after a flood event Creates a dead zone beyond the dam due to scouring which strips away organic materials, sediment, vegetation, and macro invertebrates.

9 FISH SPECIES EFFECTED M A I N S T E M D A M S A R E C O N T R I B U T I N G T O T H E P R O B L E M S - H O L Y O K E D A M M I U P S T R E A M - T U R N E R F A L L S D A M M I U P S T R E A M I N A D E Q U A T E F I S H P A S S A G E S, O V E R F I S H I N G, A N D P O P U L A T I O N M A N A G E M E N T P R O B L E M S A L S O A F A C T O R A N A D R O M O U S A N D C A T A D R O M O U S F I S H : CT River Fish Species: Atlantic Salmon and American Shad, Lamprey, Blueback Herring, Alewifes, American Eel, etc.

10 ATLANTIC SALMON Spawn in the spring in cool fast flowing streams of the north. Live in those rivers for 2-3 years before returning to the ocean Ritual practiced unhindered for hundreds of years until about the 1800 s Settlers began to harness the power of the rivers

11 SALMON Indigenously extinct from CT and other parts of New England since 1800 s Turners Falls Dam in MA constructed in last spawning ran in effectively extinct the Salmon from New England. No historical population return numbers - NOAA study- probably exceeded 30,000/year

12 SALMON POPULATION CT River watershed council -since 1967 returns avg returned in 2009 Only native populations are in eastern Maine Rivers - Less than 10% needed to sustain survival are returning - Put on endangered species list in 2000.

13 AMERICAN SHAD Largest of the Herring species Popular commercial bait fish Increase in population until Holyoke Dam counted 720,000 - Avg. of 143,000 from ,000 counted in 2007 Annual Passage at Turner Falls Dam for the last decade is roughly 1%

14 OTHER ANADROMOUS FISH Blueback Herring: - 69 blueback herring were tallied at Holyoke in 2007, compared with 410,000 in Dams and failing passage along with over fishing and management problems. Alewifes: - Once rivaled the Herring, declines due to over fishing and tributary dams

15 LOCAL FISHWAY PROJECTS P A R T 2 J A C O B P O M E R A N T Z

16 CT RIVER WATERSHED 11,000 square miles of land through 4 states One of only 14 presidentially-designated American Heritage Rivers in the U.S. Begins at the outlet of Fourth Connecticut Lake in Pittsburg, N.H. Empties into Long Island Sound in Old Saybrook, CT Longest river in New England, it spans 410 miles

17 FISH LADDERS ALONG THE CONNECTICUT RIVER There are over 1,000 dams in the Connecticut River watershed Fish ladders have opened up more than 1,000 miles of migratory fish habitat in the Connecticut River watershed Very important habitat Largest watershed with the greatest amount of historical diadromous fish freshwater habitat in the southern New England Counting for: American Eel, American Shad, Atlantic Salmon, Blueback Herring, Gizzard Shad, Sea Lamprey, and Striped Bass

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19 FEDERAL, STATE AND PRIVATE AGENCIES WORKING TOGETHER DEP State Department of Environmental Services National Park Service USDA Natural Resource Conservation Service U.S. Environmental Protection Agency U.S. Army Corps of Engineers U.S. Geological Survey U.S. Air Force National Marine Fisheries Commission National Fish and Wildlife Foundation Massachusetts Department of Fish and Wildlife Massachusetts Department of Marine Fisheries New Hampshire Department of Fish and Game University of New Hampshire Facilities Services Dufresne-Henry Inc., NH FishAmerica Foundation Trout Unlimited American Rivers Coastal Conservation Association Hackle and Tackle Club, NH Atlantic Salmon Federation Local Governments/Commissions

20 THE LEESVILLE DAM, SALMON RIVER, CT In Middlesex County Used for recreation purposes Construction was completed in Owned by the DEP 25 feet high with a length of 450 feet Fish Count: Atlantic Salmon.1 Sea Lamprey..881

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22 RAINBOW DAM, FARMINGTON RIVER, CT The first dam on the Farmington River, the largest tributary of the Connecticut River There are two fish passages, one for traveling upstream and one for traveling downstream Provides access to 52 miles of historic spawning habitat Owned by Farmington River Power Company Underwent large reconditioning in 2010 $5,139,000 Federal Funded Required Dam Safety Permit issued by the CTDEP/Inland Water Resources Division The CT Department of Environmental Protection manages the fish passages American Eel..889 American Shad Atlantic Salmon...4 Blueback Herring..25 Sea Lamprey...3,090

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24 ENFIELD DAM IN CT Built in 1827 to avoid the rapids and to divert water into the Windsor Locks Canal 1,500 feet long Fell into disrepair in the late 1970s Currently breached Owned by Ahlstrom-Windsor Locks Paper Company No interest in rebuilding it The Pioneer Valley Yacht Club of Longmeadow, Mass. would like to see the dam restored Argue present low water level is unsafe for boaters and a hindrance to emergency rescue craft Supported by several local police and fire departments

25 OPPOSITION TO DAM RECONSTRUCTION Department of Environmental Protection, U.S. Fish & Wildlife Service, and the nonprofit Connecticut River Watershed Council oppose reconstruction State-of-the-art fishways may not work effectively, because the short-nosed sturgeon, an endangered species and therefore the most heavily protected, is not adept at making use of such passageways There is no current plan to rebuild the dam

26 FISH COUNTING CT RIVER WATERSHED The Leesville Dam, Salmon River, CT Rainbow Dam in Windsor, Farmington River, CT West Springfield Dam, Westfield River, MA Holyoke Dam Fishlift, Holyoke Gas and Electric, Holyoke, MA Turners Falls Fish Ladder, FirstLight Power Resources Services, MA Vernon Dam, Vernon, VT Bellows Falls Dam Wilder Dam

27 2010 CONNECTICUT RIVER MIGRATORY FISH Total fish counts as of Thursday, January 27, 2011 American Eel.5,398 American Shad.168,436 Atlantic Salmon...51 ATS, Other 1 ATS, Released...10 Blueback Herring.102 Gizzard Shad Sea Lamprey..44,238 Striped Bass.298 The total number of Atlantic salmon returns listed above includes the number released.

28 HOLYOKE DAM, HOLYOKE, MA The first dam on the mainstream of the Connecticut River 87 miles upstream of the Long Island Sound. Built in the early 1900 s 30 feet high with a length of 1770 feet Owned by City Of Holyoke Gas And Electric Department (Hydroelectric) Robert E. Barrett Fishway was constructed in 1955 One of the first fishways in U.S.

29 ROBERT E. BARRETT FISHWAY American Eel.4,138 American Shad.164,439 Atlantic Salmon..41 ATS, Released...10 Blueback Herring 76 Gizzard Shad 370 Sea Lamprey...39,782 Striped Bass 98

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31 FISH LIFT Robert E. Barrett Fishway

32 PART 3: DAM REMOVALS A K E Y T O O L I N R I V E R A N D F I S H R E S T O R A T I O N N R E / G R O U P 6 : B E N S O N, J U D Y ; H O R N B E C K E R, B R I A N ; M C K I E R N A N, B R Y A N ; P O M E R A N T Z, J A C O B ; R O B A C K, D A N / A P R I L 1 9,

33 NATIONWIDE, THERE HAVE BEEN 450 DAM REMOVALS SINCE DESTRUCTION OF THE EDWARDS DAM ON THE KENNEBEC RIVER IN MAINE SPARKED THE MOVEMENT. THE PROJECT OPENED 17 MILES OF FISH HABITAT, BROUGHT BACK SHAD, STRIPED BASS AND HERRING TO THE WATERWAY AND TURNED THE AREA INTO A HUB FOR RECREATION.

34 River herring PROJECTS TYPICALLY INVOLVE PARTNERSHIPS OF STATE, FEDERAL AND LOCAL GOVERNMENT AGENCIES WITH SPORTSMEN AND CONSERVATION GROUPS. REMOVING OBSOLETE DAMS THAT CREATE BARRIERS FOR HERRING, EELS AND OTHER WILDLIFE, AS WELL AS FOR FISHING, KAYAKING AND OTHER RECREATIONAL USES IS A TANGIBLE ENVIRONMENTAL GOAL THAT CAN ATTRACT BROAD-BASED SUPPORT. American eel

35 SEVERAL MAJOR DAM REMOVALS PLANNED IN 2011 Three in Washington state, including one on the Elwha River. Two dams on the Penobscot River, Maine, slated to be demolished.

36 ORIGINALLY, PRIMARY MOTIVATION WAS FOR ENVIRONMENTAL BENEFITS: - IMPROVED WATER QUALITY (REMOVES SEDIMENT TRAP) - FISH PASSAGE - IMPROVED PUBLIC SAFETY WAS A SECONDARY BENEFIT. - NOW THE REVERSE IS TRUE. The biggest issue now is public safety, said Brian Graber, Northeast river restoration program director for American Rivers. Our general feeling is that removal is the most cost-effective solution.

37 DAMS LEFT IN DISREPAIR ARE A HAZARD TO PEOPLE AND PROPERTY, ESPECIALLY DURING FLOODS. Blue Pond dam in Hopkinton, R.I., after collapse during 2010 floods.

38 CONNECTICUT DAM REMOVALS: Nine since 1999 First were three on the Naugatuck River Six more are slated for removal, and several others are in early stages. Significant recent projects include removal of two dams on the Rippowam/Mill River in Stamford as part of a larger river restoration project.

39 Rutan dam on Anguilla Brook, Stonington - Slated to come down this summer - Partnership of DEP, Avalonia Land Conservancy, U.S. Fish & Wildlife Service, dam owners; stream used by migratory eels and herring - Cost $163,000 grant funded - Dam in disrepair; downstream neighborhoods evacuated during floods

40 ZEMKO DAM ON EIGHTMILE RIVER, SALEM, REMOVED IN THIS IS THE SITE A YEAR LATER.

41 Costs of removal can range from tens of thousands to hundreds of millions, depending on size, whether contaminated sediments are present and many other variables. Ed Bill s Pond dam and fish ladder on Eightmile River in Lyme; Nature Conservancy is pursuing removal.

42 There are hundreds of dams in Connecticut that could be candidates for removal, so state chooses dam removal projects based on: Greatest benefit for conservation goals for particular fish species Amount of habitat that would be opened Willing owners Public-private partnerships (best chance of getting grants) No or limited dredging required to remove contaminated sediments

43 BEFORE THE DEMOLITION STARTS, MULTIPLE STEPS: DEP, Army Corps permits Notify neighbors Test sediments Engineering plans for demolition Stabilize stream banks Draw down pond when water lowest Begin stepby-step demolition. The Lower Shannock Falls dam on the Pawcatuck River in Richmond, R.I., was removed in 2010.

44 Engineers try to take flow measurements as the stream channel is reopened during demolition of the Lower Shannock Falls dam. LIKE REPAIRING A CLOGGED ARTERY

45 PART 4: FISHWAY DESIGN AND EFFECTIVENESS

46 FISHWAYS Provide a method for fish to independently or mechanically bypass dams, hydroelectric power plants, or some obstruction There are two different kinds of fishways: Fish ladders Nature-like (bypass)

47 TYPES OF FISH LADDERS Pool and Weir Used for species of fish that tend to jump Average Slope: 10% Streaming flow may be used so the non-jumpers can swim over the obstacle, however, this hinders jumping species

48 TYPES OF FISH LADDERS Denil Weir is angled upstream and has an opening that allows fish to swim at different depths to pass Slope: 10-25% Greater flow rate creates need for resting pools Prone to debris blockage

49 TYPES OF FISH LADDERS Vertical slot Cross between pool and weir and denil ladders Step system with open weirs Slope: 10% Fish must exert extra effort to pass to the next stage Hydraulically self-regulating

50 TYPES OF FISH LADDERS Hybrid: Combine various features of different fish ladders Alaska Steeppass: Prefabricated fish ladder Slope: Up to 33% Cannot be used by hydroelectric dams because it is not hydraulically self-regulating Fish Lifts: Mechanically transport fish past dams. Flow independent Over-crowding can be a problem

51 OTHER OPTIONS Nature-like (bypass): a secondary stream that runs around dam and creates a natural looking setting for the fish Initially more expensive than typical fish ladders, but requires little to no maintenance Allows all organisms to pass obstruction Most fish ladders are species specific

52 IMPORTANT CONSIDERATIONS: Fishway entrance: Proper flow required to draw fish Fishway Exit: Need to be placed in areas of consistent flow in order to prevent fish disorientation Fishway: Need to identify which species are going to use fishway. Each is developed to allow certain species to pass

53 CONCLUSIONS / KEY POINTS: Dams create man-made river systems in regards to flood control but are not ecologically friendly. Spawning rituals of catadromous and anadromous fish were unhindered until the beginning of the Industrial Revolution at the beginning of the 19th century. Main stem dams such as the Holyoke and Turner Falls dams are contributors to the population declines. Inadequate fish passages, over fishing, and population management problems also are factors in declines. State and federal agencies are continuing their futile attempts to re-stabilize the key species populations. Connecticut river watershed is a very important habitat that must be protected. Many different departments working together regulate area. Limiting factor = money. Funding for fish ladders can be from federal, state, or private supporters. Removal of obsolete dams has become a key tool in the river and fish restoration field. Projects can attract broad support for environmental and public safety benefits. Connecticut has an ongoing dam removal program. There are multiple steps in dam demolition. Two different kinds of fishways: fish ladders and bypass Fish ladders are typically made of man-made materials and species limiting Bypass is made to replicate a natural setting and allow all species to pass

54 SOURCES: PART 1: htm PART 2:

55 PART 3: American Rivers website, State Department of Environmental Protection website, Wood-Pawcatuck Watershed Association website, Phone or in-person interviews with Steve Gephard, supervising fisheries biologist, DEP; Duncan Schweitzer, vice president, Avalonia Land Conservancy; Brian Graber; Northeast river restoration program director for American Rivers; William and Linda Rutan, Stonington, CT; Adam Whelchel, director of conservation programs for the Connecticut chapter of the Nature Conservancy. Robbins, Jesse Lance and Lewis, Lynne Y., Demolish It and They Will Come: Estimating the Economic Impacts of Restoring a Recreational Fishery, Journal of the American Water Resources Association, Dec. 2008, Vol. 44, No. 6, pages Sondergaard, Marin and Jeppesen, Erik, Anthropogenic impacts on lake and stream ecosystems, and approaches to restoration, Journal of Applied Ecology, 2007, Vol. 44, pgs Lewis, Lynne Y.; Bohlen, Curtis; and Wilson, Sarah; Dams, Dam Removal and River Restoration: A Hedonic Property Value Analysis, Contemporary Economic Policy, April 2008, Vol. 26, No. 2, pgs Kocovsky, Patrick M.; Ross,, Robert M.; and Dropkin, David S.; Prioritizing Removal of Dams for Passage of Diadromous Fishes on a Major River System, River Research and Applications, May 2008, Vol. 25, pgs Kemp, P.S. and O Hamley, J.R.; Procedures for evaluating and prioritizing the removal of fish passage barriers: a synthesis, Fisheries Management and Ecology, 2010, Vol. 17, pgs PART 4: