Upper Nemahbin Lake, Bark River Watershed (LR13)
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Upper Nemahbin Lake, Bark River Watershed (LR13)
Upper Nemahbin Lake (827100)
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276.86 Acres
Natural Community
Two-Story
Year Last Monitored
2024
Excellent
 
Waukesha
Trout Water 
No
Outstanding or Exceptional 
No
Impaired Water 
No

Fish and Aquatic Life

Current Use
Two-Story
Attainable Use
Default FAL
Designated Use
Default FAL

Overview

Rock River Water Quality Management Plan, Lower Rock River Appendix. WT-668-2002. South Central Region, WDNR.

Upper Nemahbin Lake is a natural mesotrophic drainage lake on the Bark River. This lake also has a good warm water sports fishery and heavy recreational use. Water quality problems are due to nutrient and sediment loading from upstream; surrounding agricultural runoff; and urban runoff and erosion from construction sites. Septic systems in non-sewered areas may also be a water quality threat. The lake has good water clarity, though algae have been a problem in the past. Eurasian water milfoil, purple loosestrife and fluctuating water levels have also been problematic.

Date  2002

Author   Aquatic Biologist

Historical Description

Source: 1963, Surface Water Resources of Waukesha County Upper Nemahbin Lake T7N, R17E, Sections 13 and 24

One of a chain of lakes bordering terminal moraine parallel to the interlobate moraine. The water is clear and much of the bottom is marl. The Bark River enters from Nagawicka Lake and exits unimpounded to Lower Nemahbin Lake. Pan fish, northern pike, largemouth bass and walleyes are common in the fishery. Carp are present but are not a use problem. The lake has at times had an algae problem. Swimming is prohibited at a public beach by order of the town board. Public access is afforded by a beach on the south end and by a launching site on the outlet channel. There are no adjoining wetlands of value to wildlife.

Surface Acres = 283, S.D.F. = 1.23, Maximum Depth = 61 feet

Date  1963

Author   Surface Water Inventory Of Wisconsin

Natural communities (stream and lake natural communities) represent model results that use predicted flow and temperature based on landscape features and related assumptions. Ranges of flow and temperature associated with specific aquatic life communities (fish, macroinvertebrates) help biologists identify appropriate resource management goals. Wisconsin Natural Communities.
This is the most recent date of monitoring data stored in SWIMS. Additional surveys for fish and habitat may be available subsequent to this date.
Trout Waters are represented by Class I, Class II or Class III waters. These classes have specific ecological characteristics and management actions associated with them. For more information regarding Trout Classifications, see the Fisheries Trout Class Webpages.
Wisconsin has designated many of the state's highest quality waters as Outstanding Resource Waters (ORWs) or Exceptional Resource Waters (ERWs). Waters designated as ORW or ERW are surface waters which provide outstanding recreational opportunities, support valuable fisheries and wildlife habitat, have good water quality, and are not significantly impacted by human activities. ORW and ERW status identifies waters that the State of Wisconsin has determined warrant additional protection from the effects of pollution. These designations are intended to meet federal Clean Water Act obligations requiring Wisconsin to adopt an 'antidegradation' policy that is designed to prevent any lowering of water quality - especially in those waters having significant ecological or cultural value.
A water is polluted or 'impaired' if it does not support full use by humans, wildlife, fish and other aquatic life and it is shown that one or more of the pollutant criteria are not met.
The use the water currently supports. This is not a designation or classification; it is based on the current condition of the water. Information in this column is not designed for, and should not be used for, regulatory purposes.
Shallow headwater lake describes the depth and location of the lake in a watershed. These variables affect the lakes response to watershed variables.
The use that the investigator believes the water could achieve through managing "controllable" sources. Beaver dams, hydroelectric dams, low gradient streams, and naturally occurring low flows are generally not considered controllable. The attainable use may be the same as the current use or it may be higher.
Fish and Aquatic Life - Default Waters do not have a specific use designation subcategory but are considered fishable, swimmable waters.
This is the water classification legally recognized by NR102 and NR104, Wis. Adm. Code. The classification determines water quality criteria and effluent limits. Waters obtain designated uses through classification procedures.
Fish and Aquatic Life - Default Waters do not have a specific use designation subcategory but are considered fishable, swimmable waters.