Stream ecosystems are impacted by anthropogenic changes on the land surface. Stream-water quality and the quality of biological communities in urban-stream corridors are complex issues that drive research, regulation, and the use of rivers and streams. Personnel from Federal, state, and local agencies and universities involved with such issues in southeastern Wisconsin have worked cooperatively to assess the recent history of urban streams and to use that knowledge to evaluate future stream-improvement projects. This collaboration will help the various parties to determine the likely success of proposed projects prior to implementation and will allow projects with greatest potential to receive priority. With the expertise of professionals from the planning, regulatory, and nonregulatory fields, as well as academicians and engineers, the Milwaukee Metropolitan Sewerage District (MMSD) Corridor Study has taken a broad-based approach to promote sound, resource-based management decisions (Schneider and others, 2004).

The MMSD Corridor Study is a three-phase project designed to improve the understanding of water resources in the MMSD planning area (fig. 1). This study is a collaborative effort by MMSD, the Wisconsin Department of Natural Resources (WDNR), the Southeastern Wisconsin Regional Planning Commission (SEWRPC), the U.S. Geological Survey (USGS), the University of Wisconsin-Milwaukee, Marquette University, and Wisconsin Lutheran College. The Corridor Study is designed to evaluate the quality of water resources and biological communities of stream corridors within the MMSD planning area and to provide information to assess the potential success of current and future projects.

Figure 1.  Locations of sites sampled during Phase II in the Milwaukee Metropolitan Sewerage District (MMSD) planning area, Wis. Site abbreviations listed in table 1.

An MMSD stream corridor is defined as the land between a natural or artificial channel and either (1) the SEWRPC primary or secondary environmental-corridor¹ boundary, (2) the 100-year regulatory floodplain boundary, (3) the edge of an adjoining wetland, or (4) a distance of 75 feet, whichever is the greatest distance from the stream channel or shoreline.

¹ Areas of concentrated natural resources (for example, lakes, streams, undeveloped shorelands, and floodplains) delineated by SEWRPC and used to make development recommendations to local governments (University of Wisconsin—Extension and Southeastern Wisconsin Regional Planning Commission, 2004).

The objectives of the MMSD Corridor Study are the following:

1. Evaluate historical results and assess potential effects of planned MMSD projects. Types of projects to be evaluated include, but are not limited to, historical and planned flood-control projects that involve the modification of stream channels and (or) their corridors by deepening, widening, or enclosing; the placement or removal of material or structures on the channel or its corridor; habitat enhancements; structure removal; land purchases for conservation purposes; and water-pollution-abatement projects.
2. Create a comprehensive inventory of corridor conditions. Develop an improved understanding of the interrelationship of stream physiographic, hydrologic, hydraulic, biologic, water-quality, sediment-quality, habitat, and land-use variables.
3. Establish a baseline assessment of existing stream and corridor conditions. Detect impairments for each reach.
4. Determine the existing and potential water-use objectives for stream reaches.
5. Evaluate the success of flood-control, habitat, and water-quality improvement or protection projects; evaluate current technologies; and identify adjustments for future projects.
6. Implement long-term surveillance of stream and corridor conditions to quantify project results, track changes in impaired and unimpaired reaches, provide additional inventory information, and facilitate early detection of newly impaired reaches. (Schneider and others, 2004)

The Study was designed to be completed in three phases. Phase I was a data compilation, review, and summary effort that involved the development of a database to store data collected in the stream corridors of the MMSD planning area from 1970 through 2002. No additional data were collected as part of Phase I. The MMSD Corridor Study database contains data from MMSD, USGS, WDNR, and the U.S. Environmental Protection Agency (USEPA). A report prepared as part of Phase I summarized data in the database by subwatershed and identified data gaps in the planning area (Schneider and others, 2004; Southeastern Wisconsin Regional Planning Commission, 2002b).

Phase II consisted of an intensive data-collection effort intended to fill in the data gaps identified in Phase I, including the prevalence of emerging contaminants not previously investigated (Schneider and others, 2004), to create a baseline assessment of stream corridor conditions in the MMSD planning area. Data collected during Phase II has been incorported into the MMSD Corridor Study database. Additional data sets, including some supplied by local universities and volunteer groups, continue to be incorporated into the database as they become available. The MMSD corridor database is available to those within the cooperating agencies to assist in informal decision-making processes.

Phase III will involve data-collection efforts at a subset of the Phase II sites, focusing on specific investigations related to selected constituents. In addition, Phase III will continue to monitor the quality of biological communities to document changes in overall stream corridor condition.

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Purpose and Scope

This report summarizes the data collected as part of Phase II of the MMSD Corridor Study at 15 stream sites and 6 harbor sites in the MMSD planning area from February 2004 through September 2005. The objectives of Phase II were:

1. Identification of stream and harbor sites for data collection;
2. Collection of discharge data for selected streams within the MMSD planning area;
3. Collection of additional water-quality data;
4. Computation of chloride, total phosphorus, and suspended sediment loads at four streams in the MMSD planning area; and
5. Collection of biological-community and habitat data at wadeable stream sites.

Descriptions of Phase II study design, field and analytical methods, patterns of response to hydrology and seasons, and general comparisons to Phase I data summaries are also provided in this report.

Water-chemistry data were collected at all stream and harbor sites, and included measurements of chloride, nutrients, chlorphyll a, suspended sediment, mercury, indicator and pathogenic organisms, pesticides, and wastewater compounds. Sediment chemistry data were collected at all 15 stream sites, and included total polychlorinated biphenyls (PCBs), total phosphorus, particle-grain size, arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc. Biological data (fish-, macroinvertebrate-, and algal-community surveys; and habitat measures) and physical data (discharge) were collected at the 14 wadeable stream sites. In addition to data collected in conjunction with the Phase II sampling effort, data for semi-permeable membrane devices (SPMDs) were collected in 2004 at or near 7 of the Phase II sites by the USGS National Water-Quality Assessment Program Effects of Urbanization on Stream Ecosystem study.

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