Assessment

2 4 3 Secord Impoundment

5 6 9 Gladwin Harrison Smallwood Impoundment

10 11 12 8 21 Wixom Impoundment

S

Clare a g 14 in a 19 15 Sanford Impoundment w 20 B 22 13 ay 7 16 17 Midland 18 26 Mt. Pleasant

27 25 24 1 23 St. Louis Saginaw

Alma

05 10 20

Miles

1 – Tittabawassee River 15 – North Branch Salt River 2 – East Branch Tittabawassee River 16 – South Branch Salt River 3 – Middle Branch Tittabawassee River 17 – Carroll Creek Drain 4 – West Branch Tittabawassee River 18 – Chippewa River 5 – Sugar River 19 – North Branch Chippewa East River 6 – Molasses River 20 – Coldwater River 7 – Sturgeon Creek 21 – North Branch Chippewa West River 8 – Tobacco River 22 – West Branch Chippewa River 9 – Cedar River 23 – 10 – North Branch Tobacco River 24 – North Branch Pine River 11 – Middle Branch Tobacco River 25 – South Branch Pine River 12 – South Branch Tobacco River 26 – Pony Creek 13 – Salt River 27 – Bullock Creek 14 – Bluff Creek

Figure 1.–Tittabawassee River system and its watershed boundary. 103 Tittabawassee River Assessment

Headwaters

Secord Impoundment Middle Gladwin Smallwood Impoundment Harrison

S

Clare a g in a w Wixom Impoundment B ay Mouth Sanford Impoundment Midland

Mt. Pleasant

Saginaw River

St. Louis Saginaw

Alma

0 5 10 20

Miles

Figure 2.–Main stem valley segments of the Tittabawassee River. 104 Tittabawassee River Assessment

Bayport Limestone Coldwater Shale formation Marshal formation formation Red beds Secord Impoundment Saginaw formation

Gladwin Harrison Smallwood Impoundment

1 2 Wixom Impoundment

S

Clare a g in a Sanford Impoundment w B ay 5

Midland 6 7 3 Mt. Pleasant 9 4

Saginaw River

St. Louis Saginaw 8 Alma

05 10 20

Miles

Figure 3.–Bedrock geology of the Tittabawassee River watershed. 105 Tittabawassee River Assessment

12,500 BP

13,500 BP

Figure 4.–Glacial advance borders (hash marks) forming the Tittabawassee River watershed (modified from Farrand 1988). Advance borders (dark hash) along the western edge of the watershed occurred approximately 13,500 years before present (BP) and the borders (light hash) along the eastern edge of the watershed occurred approximately 12,500 years BP. 106 Tittabawassee River Assessment

High permeability Medium permeability

Secord Impoundment

Gladwin Harrison Smallwood Impoundment

Wixom Impoundment

S

Clare a g in a Sanford Impoundment w B ay

Midland

Mt. Pleasant

Saginaw River

St. Louis Saginaw

Alma

05 10 20

Miles

Figure 5.–Permeability of surficial deposits in the Tittabawassee River watershed. 107 Tittabawassee River Assessment

Secord Impoundment

Gladwin Harrison Smallwood Impoundment

1 2 Wixom Impoundment

S

Clare a g in a Sanford Impoundment w B ay 5

Midland 6 7 3 Mt. Pleasant 9 4

Saginaw River

St. Louis Saginaw 8 Alma

05 10 20

Miles

Figure 6.–United States Geological Survey gauge sites in the Tittabawassee River watershed. See Table 7 for gauge site descriptions. 108 Tittabawassee River Assessment

Secord Impoundment

Gladwin Harrison Smallwood Impoundment

Wixom Impoundment

S

Clare a g in a Sanford Impoundment w B ay

Midland

Mt. Pleasant

Saginaw River

St. Louis Saginaw

Alma

05 10 20

Miles

Figure 7.–Areas of groundwater recharge and discharge in the Tittabawassee River watershed. Areas where groundwater recharge is high are shown in grey and areas where groundwater discharge is high are shown in red. 109 Tittabawassee River Assessment

4500 Tittabawassee River at Midland 4000 Chippewa River at Midland Pine River at Midland 3500 Tobacco River at Beaverton Salt River at North Bradley 3000 /s) 3 2500

2000

Discharge (ft 1500

1000

500

0 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Month

Figure 8.–Mean monthly discharge for selected locations in the Tittabawassee River watershed for years 1963–71. Data from United States Geological Survey. 110 Tittabawassee River Assessment

3.0

Shiawassee River Sturgeon River 2.5 Tobacco River at Beaverton South Branch Tobacco River at Beaverton

2.0 ) 3 /s/mi 3 1.5

Yield (ft 1.0

0.5

0.0 5 20 35 50 65 80 95 Percent exceedence Figure 9.–Yield (ft3/s/mi2) exceedence curves for the Tobacco River (Tobacco River at Beaverton and South Branch of the Tobacco River at Beaverton). Comparison exceedence curves are given for the Shiawassee and Sturgeon rivers. Exceedence curve represents the frequency of a discharge exceeding a given rate. Data from the Unived States Geological Service for period of record.

3.0

Shiawassee River Sturgeon River 2.5 Chippewa River at Mt.Pleasant Chippewa River at Midland

2.0 ) 3 /s/mi 3 1.5

Yield (ft 1.0

0.5

0.0 5 20 35 50 65 80 95 Percent exceedence Figure 10.–Yield (ft3/s/mi2) exceedence curves for the Chippewa River (Chippewa River at Mt. Pleasant and Chippewa River at Midland). Comparison exceedence curves are given for the Shiawassee and Sturgeon rivers. Exceedence curve represents the frequency of a discharge exceeding a given rate. Data from the Unived States Geological Service for period of record. 111 Tittabawassee River Assessment

3.0

Shiawassee River Sturgeon River 2.5 Pine River at Alma Pine River at Midland

2.0 ) 3 /s/mi 3 1.5

Yield (ft 1.0

0.5

0.0 5 20 35 50 65 80 95 Percent exceedence Figure 11.–Yield (ft3/s/mi2) exceedence curves for the Pine River (Pine at Alma and Pine at Midland). Comparison exceedence curves are given for the Shiawassee and Sturgeon rivers. Exceedence curve represents the frequency of a discharge exceeding a given rate. Data from the Unived States Geological Service for period of record.

3.0

Shiawassee River Sturgeon River 2.5 Salt River at Bradley

2.0 ) 3 /s/mi 3 1.5

Yield (ft 1.0

0.5

0.0 5 20 35 50 65 80 95 Percent exceedence

Figure 12.–Yield (ft3/s/mi2) exceedence curves for the Salt River (Salt near North Bradley). Comparison exceedence curves are given for the Shiawassee and Sturgeon rivers. Exceedence curve represents the frequency of a discharge exceeding a given rate. Data from the Unived States Geological Service for period of record. 112 Tittabawassee River Assessment

3.0 Shiawassee River Sturgeon River 2.5 Tittabawassee River at Midland

2.0 ) 3 /s/mi 3 1.5

Yield (ft 1.0

0.5

0.0 5 20 35 50 65 80 95 Percent exceedence

Figure 13.–Yield (ft3/s/mi2) exceedence curves for the mouth segment (Tittabawassee River at Midland). Comparison exceedence curves are given for the Shiawassee and Sturgeon rivers. Exceedence curve represents the frequency of a discharge exceeding a given rate. Data from the Unived States Geological Service for period of record. 113 Tittabawassee River Assessment

2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 1-turbine operating range – 300 CFS to 450 CFS 0.4 — optimal 380 CFS

Mean daily discharge in CFS (thousands) 0.2 0.0 0% 20% 40% 60% 80% 100% Percent of time equalled or exceeded

Figure 14.–Percentage of operational times by mean monthly discharge for Secord Dam turbine. Mean annual discharge is indicated by a circle. Data are from FERC (1998a). Period of record is for water years 1977–91.

2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 1-turbine operating range – 500 CFS to 720 CFS 0.6 — optimal 600 CFS 0.4

Mean daily discharge in CFS (thousands) 0.2 0.0 0% 20% 40% 60% 80% 100% Percent of time equalled or exceeded

Figure 15.–Percentage of operational times by mean daily discharge for Smallwood Dam turbine. Mean discharge is indicated by a circle. Data are from FERC (1998a). Period of record is for water years 1977–91. 114 Tittabawassee River Assessment

2.6 2.4 2.2 2.0 1.8 1.6 2-turbine operating range – 900 CFS to 1,940 CFS 1.4 — optimal 1,600 CFS 1.2 1.0 1 or 2 turbine operations 0.8 1-turbine operating range – 450 CFS to 970 CFS 0.6 — optimal 800 CFS 0.4

Mean daily discharge in CFS (thousands) 0.2 0.0 0% 20% 40% 60% 80% 100% Percent of time equalled or exceeded Figure 16.–Percentage of operational times by mean daily discharge for (Wixom Lake impoundment) turbines. Mean discharge is indicated by a circle. Data are from FERC (1998a). Period of record is for water years 1977–91.

2.6 2.4 2.2 2.0 3-turbine operating range – 1,530 CFS to 2,190 CFS 1.8 — optimal 1,950 CFS 1.6 1.4 2-turbine operating range – 1,030 CFS to 1,470 CFS 1.2 — optimal 1,300 CFS 1.0

0.8 1-turbine operating range – 530 CFS to 750 CFS — 0.6 optimal 650 CFS 0.4

Mean daily discharge in CFS (thousands) 0.2 0.0 0% 20% 40% 60% 80% 100% Percent of time equalled or exceeded Figure 17.–Percentage of operational times by mean daily discharge for Sanford Dam turbines. Mean discharge is indicated by a circle. Data are from FERC (1998a). Period of record is for water years 1977–91. 115 Tittabawassee River Assessment

45,000

40,000

35,000

30,000 /s) 3 25,000

20,000

Discharge (ft 15,000

10,000

5,000

0

6:00 AM 6:00 PM 6:00 AM 6:00 PM 6:00 AM 6:00 PM 6:00 AM 6:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM Time

Figure 18.–Instantaneous discharge of the Tittabawassee River at Midland from September 10 to 13, 1986 and mean flow for the period of record 1936–2003. Data from United States Geological Survey. 116 Tittabawassee River Assessment

Erie-Huron lake plain Indiana and Ohio till plain and Wisconsin sandy drift plain Southern Michigan and Northern Indiana drift plain Western Michigan and Northeastern Wisconsin fruit belt

Secord Impoundment

Gladwin Harrison Smallwood Impoundment

Wixom Impoundment

S

Clare a g in a Sanford Impoundment w B ay

Midland

Mt. Pleasant

Saginaw River

St. Louis Saginaw

Alma

05 10 20

Miles

Figure 19.–Major land resource areas of the Tittabawassee River watershed. 117 Tittabawassee River Assessment

Agriculture Commercial Developed Grassland Secord Impoundment Open water Upland Gladwin Urban-recreation grasses Harrison Smallwood Impoundment Wetland

Wixom Impoundment

S

Clare a g in a Sanford Impoundment w B ay

Midland

Mt. Pleasant

Saginaw River

St. Louis Saginaw

Alma

05 10 20

Miles

Figure 20.–Land use types within the Tittabawassee River watershed. 118