Challenges to Restoring Watershed-Scale Ecological Connectivity Within Major Great Lakes Watersheds

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1 Challenges to Restoring Watershed-Scale Ecological Connectivity Within Major Great Lakes Watersheds LESSONS LEARNED FROM THE OZAUKEE COUNTY FISH PASSAGE PROJECT Dale Buser, PE, PH Principal Hydrologist, Bonestroo

2 What we ll cover in the next 15 minutes Myths and misconceptions Workable solutions a four dimensional model Experiences from the Ozaukee County Project Road/stream crossings Dam Removal/Modification Fishways Aquatic invasive species barriers a closer look at the Bridge Street Dam project

3 Myths and Misconceptions A FEW FUN AND FAVORITE QUOTES We re not near the ocean, so we don t need to worry about migrating fish. We ve cleaned up the river and removed the big dams what more do you want? We have plenty of the fish in the ocean to eat, who cares about these fish anyway. The only fish I care about is under cellophane. Chinook salmon are typical examples of migrating fish. I ve seen fish get through this structure, so we re OK. It s only a ditch. In fact, it doesn t even run when it s dry it s not important to fish. Can you guarantee the dam will never fail if you work on it? You guys got the grant because you convinced others that the dam was going to fail any day, and now you say it is structurally sound? There were more fish years ago before you guys started to remove dams. Now the fish can t get upstream. How dare we remove this beautiful dam that God gave us.

4 Successful projects require four independent ingredients, but a different recipe for each and every element Sound science, imagination, creativity... Collaboration Tolerance, nonpartisan open communication, not necessarily general agreement or knowledge... Trust Adequate compliance with regulations, standards, goals, and aspirations... Respect Affordable, both now and in the future... Pragmatism

5 Road/Stream Crossings Project Philosophy Essentially all water bodies matter small and large, perennial and intermittent, slow and fast all are ecologically important on a watershed scale Individual projects compartively small, but large collective effect

6 Road/Stream Crossings Ingrained Thought Processes What are the four functions of a well-designed road/stream crossing? Allow people and goods to safely and reliably reach the other side Pass water Allow unimpeded passage of aquatic organisms during all seasons and all life cycles Allow uninterrupted transport of sediment and debris Pop Quiz what is your personal rule of thumb when considering desirable water velocities in a typical road culvert? Imagine a 40-foot culvert passing a small perennial stream.

7 Road/Stream Crossings LOTS OF PEOPLE, LOTS OF ISSUES, SURPRISING OPPORTUNITIES Rural and suburban streams have similar numbers of impediments Long history of settlement and development adds to the list of unknowns Perceived competing priorities project benefits versus basic infrastructure needs Fragmented ownership and responsibility Mapped floodplains Utilities Good habitat and valuable resources present, even in urbanizing landscapes Excellent mutually beneficial use of County labor and equipment

8 An example before and after

9 Large Dam Modifications: PROJECT GATEWAYS IN SEVERAL RESPECTS Three distinct projects Mequon-Thiensville Fishway Lime Kiln Dam Removal Bridge Street Fishway/Dam Removal Evaluation Habitat portals Poorly understood histories, e.g., multiple structures Sediment Aquatic invasive species High visibility, emotionally charged, costly, and polarizing sets tone for entire project

10 Bridge Street Dam Fish Passage Design Process Several generations of conceptual design West side, 450 feet long, construction in the dry Removal and channel restoration considered East side, almost 650 feet long, dewatering required, partially enclosed Exposed bedrock, water depth variations, landowner concerns, structural issues, second older upstream dam AIS management

11 Bridge Street Dam Fish Passage and AIS Existing dam is first structure upstream of Lake Michigan considered by USFWS to be an effective lamprey barrier Despite desirable downstream habitat being accessible to Lake Michigan for up to 20 years, no lamprey yet identified Stop log structures and ongoing monitoring anticipated to adequately address issue Rapidly evolving Asian carp, VHS, and other AIS issues complicate management considerations

12 Bridge Street Dam AIS Barrier Function Questions Lamprey barrier function is specific to the habits and abilities of this species Other AIS have differing habits and abilities Questions regarding water profiles during high water periods Alternate water flow paths with gentler gradients/less leap height Additional study to determine AIS barrier performance

13 Bridge Street Dam Crest Versus Tailwater Elevations Detailed model needed for fishway design revised water elevation profiles for various annual recurrence interval flows Detailed model reveals much higher tailwater elevations Limited photographs and gaging station information generally corroborate findings Recurrence of various hydraulic separation distances

14 Bridge Street Dam AIS Evaluation Powerful swimmers/leapers may theoretically able to pass every year Weir an effective lamprey barrier, but alternate flow paths available Improbable barrier to VHS and possibly Asian carp Evaluate recurrence during the period when species of interest present, determine duration of opportunity windows Study channel form and hydrodynamics and their affect on leaping performance Evaluate alternate flow paths

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18 Questions? Thank you for your time!