Mill Creek, Mill and Blue Mounds Creek Watershed (LW15)
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Mill Creek, Mill and Blue Mounds Creek Watershed (LW15)
Mill Creek (1242200)
15.78 Miles
0 - 15.78
Natural Community
Cool-Cold Mainstem, Cool-Warm Mainstem, Coldwater
Year Last Monitored
2024
Poor
 
This river is impaired
Impairment Unknown
Total Phosphorus
 
Iowa
Trout Water 
No
Outstanding or Exceptional 
No
Impaired Water 
Yes

Fish and Aquatic Life

Current Use
Restricted Aquatic Life
Attainable Use
Default FAL
Designated Use
Default FAL

Overview

Mill Creek is a tributary to the Wisconsin River at Tower Hill State Park. It is a Class II trout
stream for 4.5 miles of its length. One 4-mile section of trout water is downstream from Twin
Valley Lake, the other 0.5 mile stretch is downstream from the mouth of Trout Creek. Below
the last stretch of trout water, Mill Creek is considered a warm water sport fishery stream. A
rare aquatic species has been found in the creek in past surveys. The stream historically had
problems with flooding as a result of intensive agriculture and lumbering. Flood control
structures were put into place in the watershed to help lessen the problem. Two of these
structures formed Twin Valley and Cox Hollow Lakes in the upstream portion of Mill Creek.
These lakes are used primarily for fish, wildlife and recreational purposes. The creek below
the lakes and upstream from Trout Creek can have problems with cattle grazing and in-stream
sedimentation appears to be a problem.

From: Ripp, Coreen, Koperski, Cindy and Folstad, Jason. 2002. The State of the Lower Wisconsin River Basin.
PUBL WT-559-2002. Wisconsin Department of Natural Resources, Madison, WI.

Date  2002

Author  Cynthia Koperski

Historical Description

Mill Creek is a tributary to the Wisconsin River at Tower Hill State Park. It is a Class II
trout stream for 4.5 miles of its length (WDNR, 1980). Below the last atretch of trout
water it is considered a warm water sport fishery stream (Schlesser, 1991-1992). In-
stream sedimentation appears to be a problem (WDNR, 1991). There are areas of
excessive cattle grazing in the upper reaches of the stream between Trout Creek and
Twin Hollow Lake (WDNR, 1991)

Date  1994

Author   Surface Water Inventory Of Wisconsin

Historical Description

Mill Creek - Mouth location T8N R4E Section 20 -12, Gradient = 11.1 feet per mile, Total alkalinity = 240.0 mg/l, Volume of flow = 35.2 cfs.
The basic source of water of Mill Creek is springs on the Niagara escarpment of the Southwestern Uplands, but it also receives a considerable amount from runoff and ground seepage. Originally it began at springs in Cox Hollow (now Cox Hollow and Twin Valley Lakes) about 2.5 miles north of Dodgeville and flowed in a northeasterly direction to the Wisconsin River. The past history of this watershed shows that flooding was common and costly for farmers, the stream fishery, roads, and the soils of the basin. Pre-settlement times saw most of the watershed forested. The chief industry of early settlers, who moved into the area shortly after the Indian wars about the mid-nineteenth century, was lumbering.
Soon after, lumbering gave way to farming, first, in the form of wheat and then dairying. Cheese factories became common until modern transporation and refrigeration enabled milk to be safely transporated to distant markets. As of 1961 only one sawmill and four cheese factories remained. With the advent of intensive farming the choice land was cleared for crops and serious erosion followed. This was a common occurrence until recently when the Twin Parks Watershed plan was prepared by the Iowa Co. Soil Conservation District with the assistance of the USDA, USDI, and WDNR. The basic objectives of this plan included the installation of 10 floodwater structures and 4.5 miles of channel improvements. Eight of these are designed specifically for erosion control and three for fish and wildlife -Twin Valley, Birch, and Cox Hollow Lakes. Three others maintain a permanent pool deep enough to support a fishery but this is incidental to their primary purposes of flood control. Other works of improvement include land treatment measures such as contour farming and strip cropping, waterways, streambank protection and grade stabilization structures. The practices and structures completed to date have reduced severe flooding in this watershed. Some of the structures have reduced or eliminated the trout fishery in several tributary streams but the erosion control brought about by reduced flooding should enhance the fishery assets of the mainstream.
Principal tributaries include two of the best trout streams in the county in Love and Trout Creeks. Other streams of importance are Cutler, Ryan, and Hubbard Creeks. The total flow of these streams contributes about 56 percent of the base flow of Mill Creek. The most prized fishery in the watershed is for trout; however, the mainstream is managed for smallmouth bass and channel catfish. Other game fish species also present are largemouth bass, northern pike, rainbow trout and brown trout. Panfish include brown bullheads and bluegills. Forage and rough fish species include hornyhead
and creek chubs; redbelly and blacknose dace; stoneroller and fathead minnows; emeral shiners, carp, quillback carpsuckers, redhorse, white suckers, and sheepshead. There are at least 12 farm ponds in the watershed which support either largemouth bass-panfish or trout fisheries and are a major contributor to the overall fisheries resources of the area.
Aquatic game assets consist of ducks and beaver in lower sections and muskrats throughout its length.
Public access is available from Governor Dodge State Park but otherwise public lands are absent throughout the immediate drainage basin. Limited access is possible from 16 public road crossings.

From: Piening, Ronald and Threinen, C.W., 1968. Lake and Stream Classification Project. Surface Water Resources of Iowa County, Wisconsin Department of Natural Resources, Madison, WI.

Date  1968

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.
Fish and Aquatic Life communities are not fully supported in this ecosystem.
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.