Elevation = ~390 km (1279' MSL)

A_o = 16.6 ha (41 acres)

A_w = 85.4 ha (211 acres)

Z_max = 16.1 m

Z_mean = 7.0 m

V = 1.16 x 10⁶ m³

A_w:A_o = 5.1 : 1

Shoreline = 1.6 km

Littoral area = 32%

HRT = 2.6 ± 0.9 yrs (30 year record)

11% Urban (6 storm sewers)

35% Wetland/Water

54% Forest

<1% Grassland/Shrubs

<1% Other

Summer Epilimnion
May through September
(1998 means, ±sd, range)

Secchi = 3.4 ± 0.8 m (2.2 - 4.3 m)
Chlorophyll a = 1.4 ± 0.6 ppb (<1 - 4.7)
TP = 9 ± 1 ppb (7 - 10 ppb)
NO₃-N = 5 ± 6 ppb (<5 - 14 ppb)
NH₄-N = 8 ± 6 ppb (<5 - 11 ppb)
TN = 432 ± 44 ppb (387 - 502 ppb)
Alkalinity = 45 (low, but not acid sensitive)
pH = 6.5 - 8.3
EC = 114 µS/cm

Summer Hypolimnion
May through September
(1998 means, ±sd, range)

TP = 35 ± 13 ppb (21 - 50 ppb)
NO₃-N = 40 ± 35 ppb (<lod - 14 ppb)
NH₄-N = 217 ± 96 ppb (78 - 296 ppb)
TN = 760 ± 124 ppb (587 - 881 ppb)

28 perennial
(17 1st tier, 11 2nd tier)

0 summer
all on city sewer

Stratified in summer; limited spring mixing in 1998 and 1999

Ice Out dates:
April 11, 1998
April 9, 1999

1983
Bluegill
Sunfish
Bullhead
Northern Pike

42 (mesotrophic)

Elevation = 0.39 km

A_o = 51.4 ha

A_w = 853 ha (2107 acres)

Z_max = 19 m

Z_mean = 9.1 m

V = 4.7 x 10⁶ m³

A_w:A_o = 16.6 : 1

Shoreline = 4.80 km

Littoral area = 26%

HRT ~ 20 yrs (?)

20% Urban

12% Wetland/Water

33% Forest

24% Grassland/Shrubs

11% Other

Summer Epilimnion
(1998 means)

Secchi = 3.4 - 5.0 m
Chlorophyll a = 1 - 1.5 ppb
TP = 5 - 14 ppb
NO₃-N = 10 - 16 ppb (1981 datum)
NH₄-N = < 5 ppb (1981 datum)
TN = 360 ppb
Alkalinity = 125 (moderate)
pH = 8.1

anoxic by July @ >12 m
anoxic under ice

41 perennial
0 summer

Stratified in summer

37 (meso-oligotrophic)

Elevation = ~305 km (1100' MSL)

A_o = 216 ha (533 acres)

A_w = 4968 ha (12,271 acres)

Z_max = 46.6 m (153 ft)

Z_mean = 21.7 m (71.3 ft)

V = 46.95 x 10⁶ m³

A_w:A_o = 23 : 1

Shoreline = 7.84 km (4.87 mi)

Littoral area = 13.4%

HRT = ~4 years

1% Urban

48% Wetland/Water

27% Forest

17% Cultivated

7% Pasture/Open

Summer Epilimnion
(2000 means, ±sd, range)

Secchi = 4.0 ± 0.9 m
Chlorophyll a = 3 ± 1.6 ppb (2.1 - 6.1 ppb)
TP = 9 ± 3 ppb (7 - 11 ppb)
NO₃-N = ppb
NH4-N = 18 ppb (n = 1)
TN = 405 ± 6 ppb (401 and 409 ppb)
Alkalinity = 48 (low, but not acid sensitive)
pH = 7.5 - 8.6
EC = 95 µS/cm
Color = 33 Pt-Co units

Summer Hypolimnion
(2000 means, ±sd, range)

TP = 11 ± 3 ppb (8-14ppb)
NO₃-N = 150 ppb (1 datum)
TN = 454 ± 30 ppb (430-487ppb)

1993
43 permanent
63 seasonal
none sewered

Stratified in summer; remains oxic (~5 ppm DO) as deep as 33 m

2 story

1st Warm Water
Bullheads
centrarchids
Northern Pike

2nd Cold Water
Trout

45 (mesotrophic)

Elevation = ~411 km (1400' MSL)

A_o = 950 ha (2347 acres)

A_w = 26,900 ha (66,500 acres)

Z_max = 14.6 m (48 ft)

Z_mean = 5.25 m (17.2 ft)

V = 53 x 10⁶ m³

A_w:A_o = 29

Shoreline = 34km (includes 5.15 km island shore) (21 mi)

Littoral area = 30 %

HRT = ~1 yr (2 mos-2 yrs)

1969 data

2 % Urban

11 % Wetland/Water

75 % Forest

5 % Cultivated

7 % Pasture/Open

Summer Epilimnion (1998 epilimnetic data)

Secchi = 2.9 m
Chlorophyll a = 9.1 ppb (max 26 ppb)
TP = 22 ppb
NO₃-N = ?? ppb
TKN = 400 ppb
Alkalinity = 32 mg CaCO3/L
pH = 7.9 SU
EC = 89 µS/cm
Color = 18 Pt-Co units

1999
142 homes & cottages
1985 - 91
1966 - 44

Stratified in summer;

Walleye, white sucker, and yellow perch

47 (mesotrophic)

Elevation = ~291 km (954' MSL)

A_o = 344 ha (850 acres)

A_w = 1946 ha (4807 acres)

Z_max = 17.7 m

Z_mean = 5.5 m

V = 18.9 x 10⁶ m³

A_w:A_o = 5.6 : 1

Shoreline = 11.4 km

Littoral area = ~50%

5% Urban

17% Wetland/Water

6% Parkland (Hennepin County Baker Park)

72% Agricultural

Summer Epilimnion
June and August only
(1998 means, ±sd, range)

Secchi = 1.1 ± 0.1 m (2.2 - 4.3 m)
Chlorophyll a = 17 ppb (1 datum)
TP = 44 ± 2 ppb (42 - 45 ppb)
NO₃-N = 15 ppb (1 datum)
NH₄-N = 30 ± 5 ppb (26 - 33 ppb)
TN = 1134 ± 9 ppb (1121 - 1148 ppb)
Alkalinity = 123 (moderate)
pH = 8.4 - 8.5
EC = 348 µS/cm

Summer Hypolimnion
June and August only
(1998 means, ±sd, range)

TP = 159 ± 28 ppb (139 - 179 ppb)
NO₃-N = 14 ± 2 ppb (12 - 15 ppb)
NH₄-N = 1265 ± 570 ppb (861 - 1668 ppb)
TN = 2008 ± 452 ppb (1688 - 2388 ppb)
pH = ~7.1
EC = 372 µS/cm

192 perennial
??? summer
all on city sewer

Stratified in summer; complete spring mixing in 1998 and 1999

Ice Out dates:
March 29, 1998
March 29, 1999

Northern Pike
Walleye
Yellow Perch
Bluegill
Sunfish

54 (mesotrophic)

Elevation = ~0.283 km (928.6 MSL)

A_o = 220 ha (544 acres)

Z_max = 10.98 m (36 feet)

Z_mean = 3.96 m (13 feet)

V = ~8.62 x 10⁶ m³

Shoreline = 11.75 km (7.3 mi)
Littoral Area = 66%
Hydraulic Retention Time = not available

Summer Epilimnion
May - October
(2000 means, ±sd, range)

Secchi = 1.3 m ± 1.0

chlorophyll a = 49 µg/L ± 28.6

total phosphorus = 100 µg/L ± 28.6

NO3-N = no data
NH4-N = no data

total nitrogen-N = 1970 µg/L ± 410

Alkalinity = (moderate)

pH = ~8.2

EC = ~370 µS/cm

chloride = 30 mg/L ± 3

139 permanent
4 seasonal

Stratified in summer but mixes periodically during storm events

Hypereutrophic

Total phosphorus TSI-74
chlorophyll a TSI-71
secchi TSI-59

mean TSI-68

Elevation = ~0.283 km (928.6 MSL)

A_o = 355.9 ha (879 acres)

Z_max = 25.6 m (84 feet)

Z_mean = ~6.71 m (22 feet)

V = ~23.3 x 10⁶ m³

Shoreline = 7.41 km (4.6 mi)
Littoral Area = 27%

Hydraulic Retention Time = not available

Summer Epilimnion
May - October
(2000 means, ±sd, range)

Secchi = 3.0 m ± 1.2

chlorophyll a = 5.1 µg/L ± 3.7

total phosphorus = 26 µg/L ±10

NO3-N = no data
NH4-N = no data

total nitrogen-N = 871 ± 176 µg/L

alkalinity = no data

pH = ~ 8.3

EC = ~350 - 370 µS/cm

chloride = 34 mg/L ± 2

67 permanent
24 seasonal

Stratified in summer

Mesotrophic

total phosphorus TSI = 53
chlorophyll TSI = 49
secchi TSI = 46

mean TSI = 49

Stream length = 288 km (179 miles)

Watershed drainage area = 9412 km² (3634 mi²)

Total watershed river and stream miles = 4053 km (2519 miles); 3800 km continuously flowing

Z_max = 8.2 m (in dredged channels)

Littoral area = high

HRT = short

1% Urban

81% Forest

50% Cultivated/Pasture

(overlapping, sum is > 100%)

Secchi = 0.75 m
Chlorophyll a = < 12 ppb
TP = ~30 - 150 ppb
NO₃/NO₂-N = 100 - 300 ppb
NH₄ = ~20 - 100 ppb
TN = ~ 500 - 1200 ppb
Turbidity = ~5 - 50 NTU (high)
Alkalinity = 100 (moderately soft)
pH = ~8
EC = ~110 µS/cm
Color = highly colored
DO > 5 mg/L throughout

Non-stratified; mixed water column

~30% dredged

suspended sediment-dominated

Remnant Great Lakes coastal wetlands

Heavy industry; shipping; sewage disposal (~40 mgd)

Non-point source pollution; sediment contaminated

Relatively high N and P; algal growth light-limited, due to root beer-colored water and often high turbidity

light development

Population in the watershed (1990): 142,502

Walleye
Northern Pike
Perch
River Ruffe
Goby

not applicable

Elevation = ~100m MSL

A_o = 379 ha (936 acres)

Z_max = 14.9 m (49 feet)

Z_mean = ~4.9 m (16 feet)

V = ~18.4 x 10⁶ m³

Shoreline = XXX km (XXX mi)
Littoral Area = ~ 47 %

Hydraulic Retention Time = not available

35% Residential

17% Agricultural/vacant

14% Commercial/industrial

10% Parkland/public

2.8% Major highways

Summer Epilimnion (2000)

Secchi = 2.0 m ± 1.3 (n=9)

chlorophyll a = 18.8 µg/L ± 8.1

total phosphorus = 51µg/L ± 23

NO3-N = no data
NH4-N = no data

total nitrogen-N = 1157 µg/L ± 563

alkalinity = ~140

pH = ~ 8.2

EC = ~554 µS/cm

XXX permanent
XXX seasonal

Stratified in summer

Ice Out dates:

Panfish (bluegill/black crappie)
northern pike

Fish Consumption Advisory

Eutrophic

mean TSI = 63