Dredging
Closest Town: Delafield
Lake Size: 283 Acres
Public Boat Access: West side of channel between Upper and Lower Nemahbin Lakes operated by Wauksha County.
Lake Notes: Specializing in Bluegill, Large & Smallmouth Bass. Walleye, Northern Pike and Crappie also caught. Connects to Lower Neshotah & Lower Nemahbin Lake.
| Size: (total) | ||
| Surface Area (Acres) | 283 | |
| Volume (Acre-Feet) | 8,377 | |
| Direct Tributary Drainage Area (Acres) | 1,734 | See Map 1* |
| Total Tribuatary Drainage Area (Acres) | 25,585 | See Map 3* |
| * Upper Nemahbin Lake Watershed Inventory Findings, Southeastern Wisconsin Regional Planning Commission May 1995 | ||
| Shape: | |
| Maximum Length (Miles) | 1.1 |
| Length of Shoreline (Miles) | 2.9 |
| Maximum Width (Miles) | 0.6 |
| Depth: | |
| Maximum (feet) | 60 |
| Mean Depth (Feet) | 29.6 |
Upper Nemahbin Lake Trends Over Time
Upper Nemahbin Lake Drainage Graph: Secchi Disk Measurments
Graph From the Wisconsin Department of Natural Resources
Secchi Averages for July and August 1986-2007
Data Taken From Wisconsin Department of Natural Resources
Upper Nemahbin Lake Trophic State Index (TSI) Graph
 = Secchi  = Chlorophyll  = Total Phosphorus |
| TSI(Chl) = TSI(TP) = TSI(Sec) | It is likely that algae dominate light attenuation. |
| TSI(Chl) > TSI(Sec) | Large particulates, such as Aphanizomenon flakes dominate |
| TSI(TP) = TSI(Sec) > TSI(Chl) | Non-algal particulate or color dominate light attenuation |
| TSI(Sec) = TSI(Chl) >= TSI(TP) | The algae biomass in your lake is limited by phosphorus |
| TSI(TP) > TSI(Chl) = TSI(Sec) | Zooplankton grazing, nitrogen, or some factor other than phosphorus is limiting algae biomass |
| TSI | TSI Description |
|---|---|
| TSI < 30 | Classical oligotrophy: clear water, many algal species, oxygen throughout the year in bottom water, cold water, oxygen-sensitive fish species in deep lakes. Excellent water quality. |
| TSI 30-40 | Deeper lakes still oligotrophic, but bottom water of some shallower lakes will become oxygen-depleted during the summer. |
| TSI 40-50 | Water moderately clear, but increasing chance of low dissolved oxygen in deep water during the summer. |
| TSI 50-60 | Lakes becoming eutrophic: decreased clarity, fewer algal species, oxygen-depleted bottom waters during the summer, plant overgrowth evident, warm-water fisheries (pike, perch, bass, etc.) only. |
| TSI 60-70 | Blue-green algae become dominant and algal scums are possible, extensive plant overgrowth problems possible. |
| TSI 70-80 | Becoming very eutrophic. Heavy algal blooms possible throughout summer, dense plant beds, but extent limited by light penetration (blue-green algae block sunlight). |
| TSI > 80 | Algal scums, summer fishkills, few plants, rough fish dominant. Very poor water quality. |
Report Taken From: Wisconsin Department of Natural Resources
Aquatic Plants Found in Upper Nemahbin Lake |
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Ranunculaceae |