Oak Creek-Frontal Lake Michigan TWA WQM Plan (2017)

Project Title

HUC: 040400020102, Monitored 2015
Craig Helker, SER Water Quality Biologist and Author


Study Purpose & Setting

Study Summary
The streams of the Oak Creek watershed tend to contain fish resembling a cool-warm thermal regime. The streams typically have five-to-ten species, most considered transitional or warmwater species, with the exception of Oak Creek below the South Milwaukee dam, where seasonal runs of trout and salmon from Lake Michigan occur. Small numbers of Iowa Darters were found in a few locations. These fish are intolerant of environmental degradation. However, most of the species found in the Oak Creek watershed are considered tolerant to environmental degradation and are therefore a reflection of the conditions of these historically manipulated waterways. These waterways have many sections that have been straightened to enhance drainage, which leads to degraded habitat within the individual streams and promotes sediment delivery downstream. Nine locations on Oak Creek (WBIC 14500) and tributaries (WBICs 14800 and 14900) were sampled for fish, qualitative habitat, and total phosphorus. An additional five Total Phosphorus samples were taken at the pour point location.

Purpose of Project
In 2015, the aquatic biological communities, chemistry and habitat of the Oak Creek � Frontal Lake Michigan Watershed was monitored to provide information for the Restoration Plan for the Oak Creek Watershed, currently being drafted by the Southeast Wisconsin Regional Planning Commission (SEWRPC). This HUC 12, located within the larger Root-Pike Basin, is the last watershed in the Basin without a watershed plan in place. The watershed was surveyed and assessed under Section 305(b) of the Clean Water Act; data gathered through the project was used to evaluate problems and determine impaired waters (CWA 303(d)). Finally, this monitoring study provides data to assess the overall watershed condition and to make recommendations for DNR and partner management actions.

Management Priorities

Watershed Goals
The overall goal of this plan is to improve and protect water quality in the basin. This Targeted Watershed Assessment monitoring project provided substantial data to analyze current conditions and to make recommendations for future management actions in the area. This plan is designed to present monitoring study results, identify issues or concerns in the area found during the project and to make recommendations to improve or protect water quality consistent with Clean Water Act guidelines and state water quality standards.

Management Priorities
1. Identify areas throughout the watershed where stream habitat can be restored and connectivity improved. Seek funds and programs to support these efforts.
2. Identify the primary sources of phosphorus and chlorides in the watershed and pursue local runoff management and river/stream grants to reduce phosphorous and chloride inputs into local water resources.
3. Identify potential partners and stakeholders to participate in an overall awareness and behavioral change program in the watershed that could result in reduced erosion and phosphorus inputs.

Restoration Goals
1. Work with partners and through grant programs to reduce overall nutrient loads to the watershed to protect existing conditions and reduce impacts to impaired or nearly impaired waters.
2. Expand aquatic life passage within the watershed.
3. Improve fish and aquatic life habitat.
4. Expand and improve existing wetlands.


Watershed Overview
The Oak Creek Watershed is located entirely within Milwaukee County. Oak Creek originates in the City of Franklin, with the majority of flow contributed by urban runoff. As it makes its way east, Oak Creek receives flows from the North Branch and Mitchell Field Drainage Ditch. In South Milwaukee, Oak Creek meanders through to Grant Park, and ultimately into Lake Michigan. The stream drains about 26 square miles. Principal land cover in the Oak Creek Watershed is a mix of urban and grassland (38% and 32% respectively). The remaining land uses include agriculture (11%), Forest (14%) and Wetland (3%). Oak Creek drains portions of the Cities of Greenfield, Franklin, Oak Creek, South Milwaukee, and Milwaukee. The one named lake found in this watershed is the Oak Creek Parkway Pond, an impoundment created by the Old Mill Dam, located in Grant Park in South Milwaukee. The Pond is 5 acres in size.

Population, Land Use, Site Characteristics
The Oak Creek watershed is 26.19 mi?. Land use in the watershed is primarily suburban (41%), urban (29%) and a mix of forest (12%) and other uses (17%). This watershed has 48.46 stream miles, 28.09 lake acres and 440.81 wetland acres.

Trout Waters
DNR uses three categories to classify the different types of trout streams throughout Wisconsin. These are evident in Wisconsin Trout Stream Maps, which provides a comprehensive list of trout streams and a set of trout stream maps covering the majority of the state. Efforts have been made to list all trout streams in the State of Wisconsin, but it is recognized that this listing in not exhaustive. While there are no officially listed trout waters within the Sauk Creek Watershed, the lower portions of Oak Creek do have populations of Lake Michigan run Rainbow and Brown Trout. Additionally, Oak Creek Parkway pond in South Milwaukee is occasionally stocked with Rainbow Trout to enhance urban fishery opportunities.

Species of Special Concern
Prairie Crayfish and the Plains Emerald dragonfly have been reported in the drainage area of Oak Creek. Least darters were historically reported, but have not been documented in recent times.

Impaired Waters
Every two years, Section 303(d) of the Clean Water Act requires states to publish a list of all waters that do not meet water quality standards. The list, also known as the Impaired Waters List, is updated to reflect waters that are newly added or removed based on new information. Impaired waters in this watershed are impaired for historical discharges, mine tailings, and runoff issues .

Aquatic Invasive Species
Lake Michigan hosts a variety of Aquatic Invasive Species, including the following: Eurasian Water Milfoil, Fishhook Waterfleas, Spiny Waterfleas, Zebra Mussels, Rainbow Smelt, and Round Goby

Ecological Landcapes

The Southern Lake Michigan Coastal Ecological Landscape is located in the southeastern corner of Wisconsin along Lake Michigan. The landforms in this Ecological Landscape are characteristic of glacial lake influence, with ridge and swale topography, clay bluffs, and lake plain along Lake Michigan. Further inland, ground moraine is the dominant landform. Soils typically have a silt-loam surface overlying loamy and clayey tills. The historic vegetation in the northern part of this Ecological Landscape was dominated by sugar maple-basswood-beech forests with some oak while the southern part was dominated by oak forest, oak savanna and prairies. Wet, wet-mesic, and lake plain prairies were common in this area. Black ash and relict cedar and tamarack swamps were found in this Ecological Landscape. Today, most of the area is dominated by dairy and cash grain agriculture and intense urban development. Only about 8% of the Ecological Landscape is forested. Maple-beech forests are about half of the remaining forest types with the remainder split equally between oak-hickory and lowland hardwood forest types. There are some areas of wet-mesic and wet prairie but only small preserves remain since the landscape is heavily disturbed and fragmented. Because of this isolation, fragmentation, and high level of disturbance, non-native plants are abundant.


The hydrologic cycle describes the various ways water is exchanged from one form or location to another. In Wisconsin, precipitation, in the form of rain, snow, and everything in-between, falls onto the earth surface. It either soaks into the ground or flows across the land. The water that soaks into the ground recharges the groundwater table, or flows laterally through the ground into a lake or stream. Water generally moves more quickly in coarse sand, sometimes as much as several feet per day. When precipitation infiltrates the more sandy soils in this watershed, the water quickly moves vertically through the soils into the shallow Sand and Gravel Aquifer. Oak Creek is a heavily developed watershed, characterized by limited wetland complexes and only one named lake.

Natural Communities

Most of the streams in the Oak Creek watershed are modelled as cool-warm transitional headwaters. The department has developed a method to determine whether or not the modeled natural community is accurate based on the fishery assemblage and climate conditions (Lyons, 2013). In most cases, the thermal composition of species (cold, warm, or transitional) indicated the sampled stream sites resemble cool-warm systems, with the exception of Mitchell Field Drainage Ditch (OC-03) (Table 3), where fish indicate a cool-warm warm community but historical manipulations point to a historical cool-cold community. Diversity of game and nongame fish species in the sampled sites was limited, with coldwater species almost entirely absent, except where access from Lake Michigan was possible.

Site Selection & Study Design

This 2015 study collected data on fish assemblage, qualitative habitat, and macroinvertebrates at nine sites (Figure 4 and Table 2). Phosphorus data was collected five times during the growing season from the pour point of the watershed, near the mouth of Oak Creek, as well as one time at each of the other sites. Data was collected during the field season (May to September) of the 2015 calendar year and was entered into the Fish Database and SWIMS.

Methods & Procedures

The fisheries assemblage at each site was determined by electroshocking a section of stream with a minimum station length of 35 times the mean stream width. A stream tow barge with a generator and two probes was used at most sites, with a single-probe backpack shocker used at sites generally less than three meters wide. All collected fish were identified and counted, with gamefish measured for length. At each site, qualitative notes on average stream width and depth, riparian buffers and land use, evidence of sedimentation, fish cover and potential management options were also recorded. A qualitative habitat survey (Simonson, et. al., 1994) was also performed at each site. Macroinvertebrate samples were obtained by kick sampling using a D-frame net at these same sites in the watershed during the fall of 2015, and sent to the University of Wisconsin-Stevens Point for analysis.

Additionally, five water samples were collected once per month throughout the growing season by DNR staff at one site near the mouth of Oak Creek. One water sample was also collected at each fish sampling location in the watershed. All water samples were analyzed for Total Phosphorus (TP).

Study Results

Nine monitoring stations were sampled during the 2014 field season in the Oak Creek Frontal Lake Michigan TWA. Based on fish surveys (Table 4) in the watershed, the modeled natural communities at each of the nine monitoring stations were able to be verified (Table 3). Sauk Creek has a cool-warm transitional headwater natural community at eight of the nine monitoring stations. Fish surveyed at Station ID 10044098 indicate a cool-warm transition headwater natural community, not the modeled natural community of cool-cold transition headwater Table 3).

Water chemistry and biological parameters were taken at all nine monitoring stations. Six total phosphorus samples were taken at OC-01 (SWIMS Station ID: 10010371) throughout the growing season (May ? October) and one phosphorus grab sample was taken at the other 8 monitoring stations (Table 5). Total phosphorus concentrations ranged from 0.03mg/l at OC-06 to 0.172 mg/L at OC-05. Dissolved oxygen was taken once at each of the monitoring stations during 2015 and ranged from 4.1mg/L (OC-09) to 13.0mg/L (OC-04) (Table 5).

Fish Species Found
The majority of the species found during sampling in the Oak Creek watershed are species tolerant to low dissolved oxygen and/or disturbed habitat conditions. These were Brook Stickleback, Central Mudminnow, Common Carp, Creek Chub, Fathead Minnow, Green Sunfish, White Sucker, Black Bullhead, and Goldfish (Table 4). The only intolerant species found was the Iowa Darter, which were found at three locations.
Gamefish diversity was limited in the surveys upstream of Oak Creek Parkway pond, with the exception of Green Sunfish (found at most sites), Bluegill, and Pumpkinseed. Below Parkway Pond, White Crappie and Rainbow Trout were collected.

Index of Biological Integrity Findings
The fishery is only one environmental indicator of condition and for this reason, the quality of the resources should be looked at in the context of overall parameters, including habitat and macroinvertebrates. The cool water FIBIs (Lyons, 2012), when applied to the natural community indicated by the fishery assemblage, reveals a fishery ranging from poor to good. The good scores are generally related to the presence of Darter species or a lack of an overabundance of tolerant species such as White sucker.

The macroinvertebrate data varied at sites throughout the watershed (Table 6). The macroinvertebrate index of biotic integrity (MIBI) has shown the combination of watershed land cover and local riparian and in stream conditions strongly influence one another (Weigel, 2003). The MIBI scores in this watershed suggest challenging conditions resulting from watershed inputs and overall degraded channel conditions. The Hilsenhoff Biotic Index (HBI) scores indicate there is varied nutrient loading across the different sites, but significant enough, when combined with Total Phosphorus scores, to support Oak Creek listing on the Federal Impaired Waters List.

Study Discussion

Watershed Condition
The majority of the streams within the Oak Creek watershed have natural community classifications of cool-warm transition headwaters. Overall, the water quality of Oak Creek and tributaries ranges fromgood to poor. Fish and macroinvertebrate communities rated good to poor, with ratings varying at each site, depending upon the index used (Table 6).

Across the watershed, stream habitat is a limiting factor. Stream channelization, along with associated sedimentation from runoff and bank erosion impairs fish and macroinvertebrate populations. Conversely, some areas of Oak Creek have been hardened with concrete, leading to increased water velocities the scour away fish and macroinvertebrate habitat. Water chemistry monitoring was done in 2015 at all of the monitored sites and showed elevated concentrations for TP that exceed Wisconsin water quality standard for the majority of sample locations. Dissolved oxygen levels did not appear to be a problem at most sampling sites, with the exception of Mitchell Field Drainage Ditch. The DO reading here, as well as biological indicators of occasional anoxic conditions, suggests ongoing challenges with this tributary.

Sample Sites
Oak Creek (OC-01), located upstream of the mouth of Oak Creek, but downstream of the Oak Creek Parkway Pond dam, has a fish community that reflects the access from Lake Michigan. This section scores as ?Good? for fish, one of only two Good sites sampled (Table 6). Rainbow Trout were found, as were White Crappie. Unfortunately, the invasive Round Goby was also found in large numbers. Gobies are being found in a majority of Lake Michigan tributaries, and may present a risk to native Darte **7** r species. The macroinvertebrate community of Oak Creek scores as ?Poor?, perhaps reflecting the water?s channelized condition. However, the Hilsenhoff (HBI) macroinvertebrate score is ?Good?, suggesting some organic pollution. Total Phosphorus at this location was measured five times during the growing season, with two of those readings above 0.075 mg/L, indicating impaired conditions (Table 5).

The next assessed stream portion (OC-2) was 2.58 miles upstream of the mouth at 15th Street, near South Milwaukee High School. This section has a ?Poor? fishery. The macroinvertebrate community (MIBI) scores as ?Fair?, with a Hilsenhoff macroinvertebrate score (HBI) of ?Good?. The Total Phosphorus reading was 0.106 mg/L (Table 5).

Oak Creek at Pennsylvania Avenue (OC-3) is approximately 4.5 miles upstream of the mouth. This site has a ?Fair? fish community, with darter species in good numbers (Table 6). The macroinvertebrate community (MIBI) score of ?Good? was the second highest of sites surveyed with an equally high ?Good? HBI score for some organic pollution. The Total Phosphorus reading was 0.0.097 mg/L (Table 5).

Oak Creek at Puetz Road (OC-4) is 6.5 miles upstream of the mouth. This site was, like a majority of Oak Creek, historically ditched. It was the most heavily affected by sedimentation of sites visited and had a significant aquatic plant population. The fish community scored as ?Fair?, and had a significant population of Iowa and Johnny Darters. It had a ?Fair? MIBI score, and a ?Fairly Poor? HBI score suggesting significant organic pollution (Table 6). Total Phosphorus was 0.066 mg/L (Table 5).

Oak Creek at 13th (OC-5) is 10 miles upstream of the mouth, and is bordered on both sides by agricultural fields. It is deeply entrenched, and during the site visit, was inundated by backwater from an active beaver dam. The fish community scored as ?Poor?, as did the MIBI score. The HBI score of ?Good? suggests some organic pollution (Table 6). The Total Phosphorus reading was 0.172 mg/L, over the impairment threshold (Table 5).

The last sample site on the mainstem of Oak Creek is at Ryan Road (OC-6). This site has a ?Good? fish community, and scores ?Fair? for both macroinvertebrate indexes (Table 6). Total Phosphorus was 0.03 mg/L (Table 5).

OC-7 is a site on Mitchell Field Drainage Ditch, a tributary to Oak Creek approximately five miles upstream of the mouth. This site is classified as a Cool-Cold Natural Community and has a fish community considered ?Poor? (Table 6). The macroinvertebrate community under the MIBI scored as ?Good?, but with a ?Fairy Poor? HBI score, suggesting significant organic pollution. Measured Total Phosphorus was 0.150 mg/L, which exceeds the impairment threshold (Table 5).

The North Branch Oak Creek was sampled at two locations, one nearer the headwaters adjacent to 6th Street (OC-9), and one adjacent to the Oak Creek Public Works building on Puetz Road (OC-8).

OC-8 had the largest populations of fish of all sample sites, collecting just under a 1000 fish. However, the fish community scores a ?Poor?, due to the overabundance of fish tolerant of disturbed conditions. The macroinvertebrate scores were ?Fair? for both the MIBI and HBI. The Total Phosphorus reading was 0.089 mg/L (Table 5). OC-9 had the worst conditions of all sites sampled, scoring ?Poor? for all metrics. The HBI macroinvertebrate score suggests very significant organic pollution. The Total Phosphorus result was 0.160 mg/L (Table 5).

Management Recommendations

Management Goals
1. Work with local area experts and multiple program DNR staff to identify areas throughout the watershed where stream habitat can be restored and connectivity improved.
2. Work with partners and state pass through grant programs to encourage local entities to seek funds to support habitat restoration and corridor continuity.
3. Through monitoring, investigations and possibly modeling identify the primary sources of phosphorus and chlorides in the watershed.
4. Based on the results of the phosphorus and chlorides surveys, investigate and pursue local runoff management and river grants to help initiate management actions that reduce inputs of these pollutants into water resources.
5. Identify potential partners and stakeholders to participate in an overall awareness and behavioral change program in the watershed that result in reduced erosion and phosphorus inputs.

Management Recommendations
1. Provide input and support for the on-going development of the ?Restoration Plan for the Oak Creek Watershed?, currently being drafted by the Southeastern Wisconsin Regional Planning Commission with support from the surrounding communities and the Fund For Lake Michigan. Support Plan findings and recommended projects as appropriate, including partnering on and promoting grant eligible projects.
2. Federal, state, local governments, and the agricultural community should continue working to improve water quality by decreasing sedimentation, nutrient loads, chloride addition, and stormwater runoff to Oak Creek and tributaries.
3. Recruit Citizen-Based Stream Monitors to assist with on-going Watershed monitoring
4. Minimize runoff from agricultural areas in the watershed. Goals should include reducing soil erosion, runoff, and meeting nutrient management requirements. Stream bank buffers should be encouraged, as well as relaxing the slope of existing entrenched stream banks.
5. Map Invasive Species.
6. Continue to expand fishing opportunities within the Watershed, as well as work to remove fish passage impediments, including drop structures, channel blocking woody debris, and beaver dams where documented and appropriate.
7. The Department should encourage all communities to continue construction site erosion and stormwater management ordinance enforcement to minimize polluted runoff in developed areas.
8. Review wastewater and stormwater discharges in the watershed for compliance.

Monitoring Recommendations

1. Continue to support continued Citizen Based Monitoring volunteer efforts to track TP and Chlorides in Oak Creek and tributaries.
2. Monitor DO conditions on Mitchell Field Drainage Ditch.
3. Water quality biologists should continue to monitor Oak Creek and tributaries to document existing conditions as well as track potential improvements from BMP installations.

Partner Recommendations

1.The watershed communities should continue effective implementation of their stormwater programs.
2. Continue information and education programs within the municipalities bordering Oak Creek and tributaries.
3. Facilitate and provide incentives for increased management by private landowners, organizations, businesses, municipalities and agencies to monitor and control the invasion of non-native species in the watershed.
4. Restore and manage wetlands, woodlands, and shorelands in the watershed.
5. DNR and community partners should continue to promote stream bank buffers along Oak Creek and tributaries, including lowering stream banks to increase hydraulic connectivity to wetlands.
6. DNR and community partners should continue to work on and promote habitat improvement projects on Oak Creek and tributaries, including pursuing the removal of concrete channels, where appropriate. Additionally, where land and partners are available, pursue re-meandering straightened sections of Oak Creek and tributaries.

Monitoring and Planning

This Water Quality Management Plan was created under the state�s Water Quality Management
Planning and Water Resources Monitoring Programs. The plan reflects Water Quality Bureau and Water
Resources Monitoring Strategy 2015-2020 goals and priorities and fulfills Areawide Water Quality
Management Planning milestones under the Clean Water Act, Section 208. Condition information and
resource management recommendations support and guide program priorities for the plan area.
This plan is hereby approved by the Wisconsin DNR Water Quality Program and is a formal update to the
Southeast Areawide Water Quality Management Plan and Wisconsin�s Statewide Areawide Water
Quality Management Plan. This plan will be forwarded to USEPA for certification as a formal plan


Craig Helker, Primary Author and Investigator, Eastern District, Wisconsin DNR
Victoria Ziegler, Program Support, Water Quality Bureau, Wisconsin DNR
Lisa Helmuth, Program Coordinator, Water Quality Bureau, Wisconsin DNR


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Lyons, John. 1992. Using the Index of Biotic Integrity (IBI) to Measure Environmental Quality in Warmwater Streams of Wisconsin. United States Department of Agriculture. General Technical Report NC-149.

Lyons, John. 2006. A Fish-based Index of Biotic Integrity to Assess Intermittent Headwater Streams in Wisconsin, USA. Environmental Monitoring and Assessment 122: 239-258.

Lyons, John. 2008. Using the Wisconsin Stream Model to Estimate the Potential Natural Community of Wisconsin Streams (DRAFT). Wisconsin Department of Natural Resources Fish and Aquatic Life Research Section. November, 2008.

Lyons, John. T. Zorn, J. Stewart, P Seelbach, K Wehrly, and L. Wang. 2009. Defining and Characterizing Coolwater Streams and Their Fish Assemblages in Michigan and Wisconsin, USA. North American Journal of Fisheries Management. 29:1130-1151.

Lyons, John. 2012. Development and Validation of Two Fish-based Indices of Biotic Integrity for Assessing Perennial Coolwater Streams In Wisconsin, USA. Ecological Indicators 23 (2012) 402-412.

Lyons, John. 2013. Methodology for Using Field Data to Identify and Correct Wisconsin Stream �Natural Community� Misclassifications. Version 4. May 16, 2013. IN DRAFT.

Simonson, Timothy D., J. Lyons, and P.D. Kanehl. 1994. Guidelines for Evaluating Fish Habitat in Wisconsin Streams. U.S. Department of Agriculture. Forest Service. General Technical Report NC-164.

Sims, Bradd. 2013. Ludden Lake, Iowa County. 2013 Comprehensive Fisheries Survey. Wisconsin Department of Natural Resources. December, 2013.

WDNR. 2003. The State of the Sugar and Pecatonica River Basins. Wisconsin Department of Natural Resources.

WDNR. 2013. Wisconsin 2014 Consolidated Assessment and Listing Methodology (WisCALM). Clean Water Act Section 305(b), 314, and 303(d) Integrated Reporting. Wisconsin Department of Natural Resources. Bureau of Water Quality Program Guidance. September, 2013.

Weigel, Brian. 2003. Development of Stream Macroinvertebrate Models That Predict Watershed and Local Stressors in Wisconsin. Journal of the North American Benthological Society. 22(1): 123-142.


BMP: Best Management Practice. A practice that is determined effective and practicable (including technological, economic, and institutional considerations) in preventing or reducing pollution generated from nonpoint sources to a level compatible with water quality goals.

DNR: Department of Natural Resources. Wisconsin Department of Natural Resources is an agency of the State of Wisconsin created to preserve, protect, manage, and maintain natural resources.

FIBI: Fish Index of biological integrity (Fish IBI). An Index of Biological Integrity (IBI) is a scientific tool used to identify and classify water pollution problems. An IBI associates anthropogenic influences on a water body with biological activity in the water and is formulated using data developed from biosurveys. In Wisconsin, Fish IBIs are created for each type of natural community in the state?s stream system.

HUC: Hydrologic Unit Code. A code or sequence of numbers that identify one of a number of nested and interlocked hydrologic catchments delineated by a consortium of agencies including USGS, USFS, and Wisconsin DNR.

MIBI: Macroinvertebrate Index of biological integrity. In Wisconsin, the MIBI, or macroinvertebrate Index of biological integrity, was developed specifically to assess Wisconsin?s macroinvertebrate community (see also Fish IBI).

Natural Community. A system of categorizing waterbodies based on their inherent physical, hydrologic, and biological assemblages. Both Streams and Lakes are categorized using an array of ?natural community? types.

Monitoring Seq. No. Monitoring Sequence Number, refers to a unique identification code generated by the Surface Water Integrated Monitoring System (SWIMS), which holds much of the state?s water quality monitoring data.

SWIMS ID. Surface Water Integrated Monitoring System (SWIMS) Identification Code is the unique monitoring station identification number for the location where monitoring data was gathered.

TWA: Targeted Watershed Assessment. A statewide study design a rotating watershed approach to gathering of baseline monitoring data with specialized targeted assessments for unique and site specific concerns, such as effectiveness monitoring of management actions.

WATERS ID: The Waterbody Assessment, Tracking and Electronic Reporting System Identification Code (WATERS ID) is a unique numerical sequence number assigned by the WATERS system, also known as ?Assessment Unit ID code?.

WBIC: Water Body Identification Code. WDNR?s unique identification codes assigned to water features in the state. The lines and information allow the user to execute spatial and tabular queries about the data, make maps, and perform flow analysis and network traces.