organizing for clean and affordable water
TRANSCRIPT
River Raisin Watershed and AOC
River Raisin Dam Remediation Project Raisin AOC presents a unique opportunity for potential
delisting (and therefore attractive for potential Ph.2 funds)
EPA dredging combined with this project, along with SterlingState Park and other habitat restoration work could lift habitatimpairments
Dam project will potentially be accomplished in two phases by2013 and create fish and small boat access from Lake Erie toDundee (~23 miles)
MDEQ working on strategies for other impairment delistings,recognizing that Monroe will remain an important shippingport for the forseeable future
Raisin AOC delisted 2015-2016?
Monroe Dams
City’s six low head dams (2.5-ft to 3-ft high) constructed by the Works Progress Administration –early to mid-1930’s
Used to carry sanitary sewer over the river’s unique limestone bedrock and “beautify” downtown
Currently, only 4 dams carry active sanitary sewer
Waterloo Dam (owned by City) and Grape Dam (privately owned) are 5-ft to 6-ft high
Phase 1 Project AreaDams 6, 1, 2, 3 (reconnect 3.5 Miles)
LakeErie
Phase 2 Project AreaDams 4, 5, Waterloo, Grape (another 19.5 Miles)
LakeErie
DAM 6 DAM 1
DAM 2 DAM 3
Ecological Survey
Mussels
Did not find large presence of mussels
184 individual mussels were collected (11 species)
Low population is likely a result of impacted water quality and lack of suitable habitat
One state listed species of concern – Elktoe
Greatest occurrence upstream of Dam 6 and Dam 3
Most of the specimens were of larger size which suggests reproduction success is not great
Ecological Survey (cont.)
Macroinvertebrates
In general, macro density was low
Samples are in the process of being identified
Field biologists believe higher quality taxa were present downstream of Dams 2 & 3 (more favorable substrate)
Aquatic Vegetation
No rare, threatened, or endangered species
Exotic/Invasive species present - Flowering rush & Purple loosestrife
Natural Channel Design for Dams
Reconnecting Rivers by Luther Aadland, Minnesota DNR
http://www.dnr.state.mn.us/eco/streamhab/reconnecting_rivers.html
Benefits of Rock Arches Varying velocities and water depths
Increased variety of habitat
Deep pools of water for habitat
Creates flow patterns that minimize capture of ice and woody debris
Nashville Dam, Michigan
Rock Arches
Dimondale Dam, Michigan
W-Weir
Proposed Structure – Dam 6
Proposed Structure – Dam 1
Section/Profile
Visualization of Rock Arch Rapids in Monroe
BEFORE…AFTER…
Four Critical Issueswith Dam Remediation Projects
1. Public perception
2. Sediment
3. Hydraulics
4. Invasive species
Public Perception Has not been a major issue in City of Monroe
Active groups
River Raisin Public Advisory Council (PAC)
River Raisin Institute (RRI)
River Raisin Watershed Council (RRWC)
Monroe Commission on the Environment (COTE)
Ongoing communication
Public meetings
Updates to Monroe COTE
Project Website: www.ci.monroe.mi.us/RRP_description.cfm
Sediment Has not been an
issue in City of Monroe
Little or no sediment behind the low-head dams
Bedrock bottom
“Numasepee” –River of Sturgeon
Hydraulics
Critical issue in City of Monroe
Perceived flooding concerns – existing vs. proposed
Dam 1 – HEC-RAS model shows 0.25-ft increase in 100-year water surface elevation (WSE)
Dam 6 – HEC-RAS model shows 0.01-ft increase in 100-year WSE
Modeling proposed conditions
Obstructions
Ineffective flow areas
1-D vs. 3-D
Modeling Plan Refine flood plain sections with LIDAR (light detection
and ranging – high resolution mapping)
Non-destructive testing to see if we can partially notch top of dam without damaging sewer
Expert opinion (Army Corps and Dr. Hubert Chanson) -HEC-RAS may not appropriate model for these structures
Problems simulating energy loss in 1D, both for proposed and existing conditions
Developing 3D model of existing and proposed conditions
Invasive Species Will this be an issue in City of Monroe?
Risks vs. benefits
Create passage for desired species
Restore river to more natural condition
Increase in species diversity
Potential to allow passage of invasive species
Ongoing research – so far, consensus that positives outweigh the negatives
Breakout Session – Critical Issues
How might these four critical issues apply to projects across the Great Lakes?
Are there additional concerns not already mentioned that might be associated with these issues?
What are some potential solutions?
1. Public perception2. Sediment3. Hydraulics4. Invasive species
Questions?Dan Stefanski
Monroe County
734- 240-3101
Barry LaRoy, PE
City of Monroe
734-384-9122
Scott Dierks, PE
Cardno JFNew
734-222-9690
Michelle LaRose, PE
Cardno JFNew
734-222-9690
Richard Micka
River Raisin PAC
734-242-0909