12 
A NEW METHOD OF ESTIMATING STREAM-FLOW 
OUTFLOW FROM LAKE MICHIGAN-HURON (/^ 
The outflow from Lake Michigan-Huron into Lake St. Clair through the St. 
Clair River was computed from the formula 
Discharge of ] 
fn* c^ft^per =3 > 820 [(#'-567.50) + 1.135 (A- 567.50)] (H'-h)i (5) 
second 
in which H' is the elevation above sea-level at the Harbor Beach gage, and h the 
elevation at the St. Clair Flats Canal gage. (See "Diversion of Water from the 
Table 3. — Rainfall stations, adjacent areas, and factors for converting rainfall in inches of depth to units of 
0.0001 fool rise of surface of Lake Michigan-Huron 
Station 
Lake area 
adjacent 
to station 
Factor 
Station 
Lake area 
adjacent 
to station 
Factor 
(sq. mi.) 
946 
612 
1,195 
601 
614 
143 
745 
189 
872 
402 
801 
619 
1,592 
86 
829 
723 
120 
2,472 
248 
360 
3,130 
1,662 
344 
212 
229 
303 
918 
1,072 
17.4 
9.4 
22.0 
9.2 
11.3 
2.6 
13.8 
3.6 
16.0 
7.4 
14.7 
11.4 
29.3 
1.6 
15.3 
13.3 
2.2 
45.5 
4.6 
6.6 
67.6 
30.6 
6.3 
3.9 
4.2 
6.6 
16.9 
19.7 
Jeddo, Mich 
(sq. mi.) 
505 
232 
669 
1,008 
698 
39 
1,059 
3,302 
46 
367 
216 
394 
2,184 
1,201 
974 
244 
240 
817 
361 
2,319 
921 
281 
102 
765 
600 
901 
793 
609 
1,047 
9.3 
4.3 
12.3 
18.6 
12.8 
0.7 
19.5 
60.8 
0.8 
6.8 
4.0 
7.2 
40.2 
22.1 
17.9 
4.5 
4.4 
15.0 
6.6 
42.7 
16.9 
6.1 
1.8 
14.0 
10.9 
16.5 
14.5 
11.1 
30.2 
Sarnia, Canada 
Clinton, Canada 
Point Clark, Canada 
Ganges, Mich 
Holland, Mich 
Saugeen, Canada 
Grand Haven, Mich 
Wiarton, Canada 
Owen Sound, Canada 
Hart, Mich 
Meaford, Canada 
Collingwood, Canada 
Midland, Canada 
Frankfort, Mich 
Parry Sound, Canada 
Bruce Mines, Canada 
Detour, Mich 
Traverse City, Mich 
Old Mission, Mich 
St. Ignac, Mich 
Escanabe, Mich 
Menominee, Mich 
Plum Is., Wis 
Sturgeon Bay, Wis 
Oconto, Wis 
East Tawas, Mich. . . 
Green Bay, Wis 
Bay City, Mich. . . 
Sheboygan, Wis 
Pt. Austin, Mich 
Milwaukee, Wis 
Racine, Wis 
Total 57 St 
45,333 
833.3 
Note — In the above table, Factor = a/A x , in which a is the lake area adjacent to a rainfall station, 
12 
A is the area of Lake Michigan-Huron, viz, 45,314 square miles, and the factor is to convert the observed rainfall 
at the station in inches of depth to units of 0.0001 foot rise of surface of Lake Michigan-Huron. 
This area was obtained from Report of International Waterways Commission on the Regulation of Lake 
Erie (1910), page 9, and was the best value then available. The area given in "Diversion of Water from Great 
Lakes and Niagara River" (1921), page 367, is 45,410 square miles. 
Great Lakes and Niagara River," Letter from the Secretary of War, Government 
Printing Office, 1921, page 355.) In the units used in the observation equation, 
Discharge of St. 
Clair River in 
0.001 ft. depth on 
Lake Michigan- 
Huron 
= 0.262 
[V- 
567.50) + 1.135 (h -567.50) (H'-h)i 
(6) 
