Restoring Minnesota Falls after a Century of Submergence

Transcription

1 University of Massachusetts - Amherst ScholarWorks@UMass Amherst International Conference on Engineering and Ecohydrology for Fish Passage International Conference on Engineering and Ecohydrology for Fish Passage 2014 Jun 11th, 2:10 PM - 2:30 PM Restoring Minnesota Falls after a Century of Submergence T. MacDonald University of Wisconsin - Madison Follow this and additional works at: MacDonald, T., "Restoring Minnesota Falls after a Century of Submergence" (2014). International Conference on Engineering and Ecohydrology for Fish Passage This Event is brought to you for free and open access by the The Fish Passage Community at UMass Amherst at ScholarWorks@UMass Amherst. It has been accepted for inclusion in International Conference on Engineering and Ecohydrology for Fish Passage by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact scholarworks@library.umass.edu.

2 restoring Minnesota Falls after a century of submergence

3 location

4 location Granite Falls Minnesota Valley Power Plant Minnesota Falls

5 area geology glacial Lake Agassiz glacial River Warren ancient gneiss outcrops

6 Minnesota Falls site history town platted 1871 first dam 1872 for sawmill and grist mill flood, then fire in 1881 officially vacated 1901

7 site history Dakota presence

8 site history dam constructed in 1905 for hydropower longest dam on the Minnesota River: 600 x 15 high NSP (Xcel) purchased the dam in 1917 NSP operated the hydroelectric plant until 1958

9 site history hydroelectric facilities demolished in 1961 dam impounded water for cooling at Minnesota Valley power plant until 2004

10 recent dam history DNR and Xcel inspected routinely, minor repair as needed 2008 DNR report rated dam High Hazard DNR required Xcel Energy to remove, repair or modify the dam Xcel began studying options in late 2008

11 primary spillway

12 stop log abutment

13 stop log structure

14 west canal wall

15 project objectives improve site safety reduce liability minimize maintenance cost (ratepayers) create attractive site provide ecological benefit

16 project timeline feasibility study 2009 decision to remove June 2010 legal review 2010 to 2012 EAW fall 2010 to fall 2011 permitting January to December 2012 construction Dec Feb (6 weeks)

17 feasibility study (2009) channel bottom mapping sediment sampling HEC RAS flow modeling impacts investigation wells, etc cultural/archaeological scoping study cost comparison of alternatives trial pool drawdown

18 channel bathymetry

19 sediment sampling

20 stakeholder impacts Granite Falls Energy, LLC Water Intake Granite Run Golf Course Irrigation System City of Granite Falls Hydro Plant shallow wells (two identified)

21 granite falls energy water intake plant intake

22 bedrock elevation not precisely known

23 expected lowering - low flow Granite Falls

24 sediment budget 1.5 MTY Mankato from Payne, USGS, 1994

25 cost comparison of alternatives

26 environmental review & permitting Environmental Assessment Worksheet (EAW) DNR Work in Waters/Dam Safety Permit U.S. Army Corps of Engineers Sections 10 and 404 MPCA Clean Water Act Section 401 Water Quality Certification MPCA NPDES Construction Storm Water Permit MPCA NOI Dredge Material Permit County (Chippewa and Yellow Medicine) Fill and Grading Permits Yellow Medicine SWCD WCA (Wetland) Certification

27 cultural, historical and archaeological worked with two specialty firms documented affected upstream sites SHPO determined dam ineligible for National Register of Historic Places archaeological investigations performed fall of 2010, 2011 and 2012 bank inspections, staging area, access consultation with Upper Sioux community one finding of significance

28 construction (finally!) dredging December 2012 demolition January February 2013 restoration summer 2013

29 water quality monitoring: continuous monitoring suspended due to winter ice grab samples collected instead Turbidity, DO, ph, Ammonia

30 time lapse video VmAnmDyGA&feature=youtu.be

31 May 2013

32

33 site restoration summer 2013

34 gully restoration fall 2013

35 post-removal

36 post-removal

37 May 2014

38 May 2014

39 recovery The most unique habitat in the entire Minnesota River is right here and it is going to be exposed, said Chris Domeier, Minnesota Department of Natural Resources assistant fisheries supervisor in the Ortonville office. Domeier said the dam s removal will provide tremendous angling opportunities that will extend well beyond the site itself. The spawning habitat that will be restored will benefit a wide variety of game fish, including walleye and sauger, and attract fish such as lake sturgeon and paddle fish from as far as the Mississippi River. - West Central Tribune, January 13, 2013

40 fish monitoring (DNR): returned species sauger black buffalo smallmouth buffalo longnose & shortnose gar highfin carpsucker mooneye paddlefish shovelnose sturgeon longnose gar

41 acknowledgements Xcel Energy Agency staff Matt Peterson site design, etc Ron Koth permitting

42 thank you!