Au Sable River near Red Oak Ontonagon River Near Rockland Mainstem Thunder Bay River below Four Mile Dam (near Alpena) St. Joseph River at Three Rivers Grand River at Lansing 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Pere Marquette River at Scottville Mainstem Thunder Bay River 3.8 mi up from North Branch Paint River near Alpha Flint River near Otisville Shiawassee River at Owosso Pine River near Hoeyville Mainstem Thunder Bay River near Hillman Dowagiac River at Sumnerville Middle Branch Escanaba River near Princeton Battle Creek at Battle Creek South Branch Flint River near Columbiaville St. Joseph River at Burlington 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Low-flow yield (ft 3 s -1 mi -2 ) -2 Figure 7. Low-flow yield (90% eceedence flow divided by catchment area) epressed as ft3 s-1 mi for three mainstem Thunder Bay River catchments with USGS streamflow data. Each panel depicts comparisons of low-flow yield at a Thunder Bay River gauge to that of other Michigan Streams with similar-sized catchments. Note that some flow regulation occurs upstream of gauges on the Ontonagon, St. Joseph, Grand, Paint, Flint, and Middle Branch Escanaba rivers. 122
Pine River Near Rudyard River Rouge at Detroit North Branch Thunder Bay River near Bolton Mill Creek near Avoca 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 Low-flow yield (ft 3 s -1 mi -2 ) -2 Figure 8. Low-flow yield (90% eceedence flow divided by catchment area) epressed as ft3 s-1 mi for the North Branch Thunder Bay River near Bolton, compared to low-flow yields for other Michigan Streams with similar-sized catchments (United States Geological Survey). 123
Pine River near Hoeyville Mainstem Thunder Bay River near Hillman Dowagiac River at Sumnerville Middle Branch Escanaba River near Princeton Battle Creek at Battle Creek St. Joseph River at Burlington South Branch Flint River near Columbiaville 0 1 2 3 4 5 6 7 8 Ratio of 10% to 90% eceedence flow Figure 9. Flow stability (epressed as the ratio of 10% and 90% eceedence flows) of Michigan streams having catchments comparable in size to the mainstem Thunder Bay River near Hillman, MI (25 feet up from M-32 Bridge). Note that some flow regulation occurs upstream of the gauge on the Middle Branch Escanaba River. Data from United States Geological Survey. 124
Paint River near Alpha Pere Marquette River at Scottville Mainstem Thunder Bay River 3.8 mi up from North Branch Flint River near Otisville Shiawassee River at Owosso 0 2 4 6 8 10 12 14 Ratio of 10% to 90% eceedence flow Figure 10. Flow stability (epressed as the ratio of 10% and 90% eceedence flows) of Michigan streams having catchments comparable in size to the mainstem Thunder Bay River near Bolton, MI (3.8 miles upstream from confluence with the North Branch Thunder Bay River) (United States Geological Survey). Note that some flow regulation occurs upstream of the gauges on the Paint and Flint rivers. 125
Au Sable River near Red Oak Mainstem Thunder Bay River below Four Mile Dam Ontonagon River Near Rockland St. Joseph River at Three Rivers Grand River at Lansing 0 2 4 6 8 10 12 Ratio of 10% to 90% eceedence flow Figure 11. Flow stability (epressed as the ratio of 10% and 90% eceedence flows) of Michigan streams having catchments comparable in size to the mainstem Thunder Bay River below Four Mile Dam, near Alpena (United States Geological Survey). Note that some flow regulation occurs upstream of the gauges on the Ontonagon, St. Joseph, and Grand rivers. 126
Boardman River near Mayfield Grand River at Jackson Upper South Branch Thunder Bay River near Lachine Lower South Branch Thunder Bay River near Hubbard lake 0 5 10 15 20 25 30 Ratio of 10% to 90% eceedence flow Figure 12. Flow stability (epressed as the ratio of 10% and 90% eceedence flows) of Michigan streams having catchments comparable in size to the Upper and Lower South Branch of the Thunder Bay River (United States Geological Survey). 127
Pine River Near Rudyard River Rouge at Detroit North Branch Thunder Bay River near Bolton Mill Creek near Avoca 0 5 10 15 20 25 30 35 40 45 Ratio of 10% to 90% eceedence flow Figure 13. Flow stability (epressed as the ratio of 10% and 90% eceedence flows) of Michigan streams having catchments comparable in size to the North Branch Thunder Bay River near Bolton, MI. (United States Geological Survey). 128
0 5 10 Miles Alpena Hillman Atlanta Thunder Bay Lake Huron Figure 14. Road-stream crossings in the Thunder Bay River watershed. Data are from a MIRISbased 24,000 scale map clipped to the Thunder Bay River watershed (Michigan Geographic Data Library 2002). 129
Wetland (34%) Eposed Bedrock (<1%) Water (2%) Forest Land (64%) Figure 15a. Percent land use and land cover in the Thunder Bay River watershed in 1800 (Austin et al. 2000). Agricultural Land (20%) Wetland (18%) Barren Land (1%) Water (3%) Urban or Built-Up Land (1%) Forest Land (57%) Figure 15b. Percent land use and land cover in the Thunder Bay River watershed in 1983 (United States Geological Survey National Mapping Program 1994). 130
Thunder Bay River Assessment 0 5 Miles 10 Alpena Thunder Bay Atlanta Lake Huron Hillman Forest Land Water Wetland Figure 16. Land use and land cover in the Thunder Bay River watershed in 1800 (Austin et al. 2002). 131