Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

Prepared in cooperation with the U.S. Environmental Protection Agency– Great Lakes Restoration Initiative

Scientific Investigations Report 2015–5115

U.S. Department of the Interior U.S. Geological Survey Front cover: A USGS crew prepares for an acoustic Doppler current meter discharge measurement on the South Branch of the Chicago River, part of the Chicago Area Waterway System. Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

By James J. Duncker and Kevin K. Johnson

Prepared in cooperation with the U.S. Environmental Protection Agency– Great Lakes Restoration Initiative

Scientific Investigations Report 2015–5115

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Sally Jewell, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2015

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod/.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.

Suggested citation: Duncker, J.J. and Johnson, K.K., 2015, Hydrology of and current monitoring issues for the Chicago Area Waterway System, northeastern Illinois: U.S. Geological Survey Scientific Investigations Report 2015–5115, 48 p., http://dx.doi. org/10.3133/sir20155115.

ISSN 2328-0328 (online) iii

Contents

Abstract...... 1 Introduction ...... 1 Purpose and Scope...... 3 Chronology of Construction and Regulation for the Chicago Area Waterway System ...... 3 Chicago Area Hydrology...... 5 Precipitation...... 5 Groundwater...... 6 Surface Water...... 9 North Shore Channel ...... 10 North Branch Chicago River ...... 12 Mainstem Chicago River ...... 14 South Branch Chicago River ...... 20 Southeast Fork of the South Branch Chicago River (Bubbly Creek) ...... 22 Chicago Sanitary and Ship Canal ...... 22 Summit Conduit...... 31 Calumet Sag Channel ...... 32 Little Calumet River ...... 40 Current Monitoring Issues for the Chicago Area Waterway System...... 40 Lake Michigan Diversion Accounting ...... 41 Regional Flooding ...... 41 Power Plant Thermal Load Modeling...... 42 Infrastructure Design ...... 42 Waterway Separation...... 45 Summary ...... 46 References Cited...... 47

Figures

1. Map showing the Chicago Area Waterway System study area, northeastern Illinois...... 2 2. Historical engineering drawings of the map, profile, and cross-sections of the Main Drainage Channel for the Chicago Sanitary District of Chicago, from Chicago to Joliet, Illinois...... 3 3. Map showing the Tunnel and Reservoir Plan service area, Chicago, Illinois...... 4 4. Schematic drawing of the hydrologic cycle...... 5 5. Maps showing A, pre-diversion, and B, post-diversion surface drainage in Chicago, Illinois, and vicinity...... 6 6. Map showing lines of equal precipitation pattern for the 2012 water year, Chicago, Illinois, and vicinity...... 6 7. Schematic cross-section diagram showing the elevations of the water table, local combined sewer invert, and Chicago Sanitary and Ship Canal water-surface elevation in the Pilsen neighborhood on the south side of Chicago, Illinois...... 7 iv

8. Map showing the potentiometric surface of the deep sandstone aquifers in the Chicago area, northeastern Illinois, fall 2007...... 8 9. Graph showing water-surface profile data for the Chicago Area Waterway System, Chicago, Illinois, and vicinity during an April 17–18, 2013, storm and the extent of drawdown of the water surface at points along the waterway...... 9 10. Map showing the Chicago Area Waterway System with the North Shore Channel, Chicago, Illinois, and vicinity...... 11 11. Graph showing mean daily discharge for the North Shore Channel at Wilmette, Illinois, for the 2003 water year, which is the last year of record...... 12 12. Map showing the Chicago Area Waterway System, including the North Branch Chicago River and U.S. Geological Survey streamflow-gaging stations, Chicago, Illinois, and vicinity...... 13 13. Graph showing mean daily discharge for the streamflow-gaging station (05536105) on the North Branch Chicago River at Albany Avenue, Chicago, Illinois, and vicinity, for the 2012 water year...... 14 14. Photograph showing the concrete control structure at the confluence of the North Branch Chicago River and the North Shore Channel, Chicago, Illinois, and vicinity...... 15 15. Map showing the Chicago Area Waterway System and the mainstem of the Chicago River, Chicago, Illinois...... 16 16. Data from acoustic Doppler current profiler measurements in the mainstem of the Chicago River near Columbus Drive in Chicago, Illinois showing: A, typical low-flow water velocity magnitude and B, direction; C, typical high-flow velocity magnitude and D, direction; E, reverse flow magnitude and F, direction...... 17 17. Graph showing gage heights for the Chicago River at Columbus Drive at Chicago, Illinois, streamflow-gaging station, hourly precipitation measured at the Chicago Lock, and gate settings at the Chicago River Controlling Works during the April 2013 storm...... 20 18. Map showing the Chicago Area Waterway System including the South Branch of the Chicago River and the Southeast Fork of the South Branch of the Chicago River, Chicago, Illinois, and vicinity...... 21 19. Graphs showing discharge and water-surface profiles for the Chicago Area Waterway, Illinois, during the April 17–23, 2013, storm: A, rising storm discharge hydrograph and canal drawdown, B, near peak of storm discharge and opening of the Chicago River Controlling Works, and C, the effect of flow reversal at the Chicago River Controlling Works on the water-surface elevation profile...... 23 20. Data from horizontal acoustic Doppler current profiler (H-ADCP) measurements May 25–27, 2009, for Bubbly Creek near 36th Street, Chicago, Illinois: A, water velocity, and B, discharge...... 25 21. Map showing the Chicago Area Waterway System including the Chicago Sanitary and Ship Canal and Calumet Sag Channel, Chicago, Illinois, and vicinity...... 26 22. Graphs showing discharge for the Chicago Sanitary and Ship Canal near Lemont, Illinois, for: A, a normal pool elevation with highly unsteady flow conditions, April–May 2013, B, a typical dry-weather pattern showing cycle of ponding and increased flows, October 12, 2013, and C, a wet weather pattern showing the pre-storm drawdown and subsequent flood wave, April–May 2013...... 27 23. Graph showing mean daily effluent discharge for the Metropolitan Water Reclamation District of Greater Chicago–Stickney Water Reclamation Plant, Chicago, Illinois, for the 2012 water year...... 28 24. Graph showing mean daily discharge for the Chicago Sanitary and Ship Canal near Lemont, Illinois, for the 2012 water year...... 28 v

25. Graph showing data from low-, medium-, and high-flow acoustic Doppler current profiler measurements in the Chicago Sanitary and Ship Canal near Lemont, Illinois, showing: A, low-flow cross-section water velocity contour; B, low-flow plan view of depth-averaged velocity magnitude and direction; C, medium-flow cross-section velocity contour; D, medium-flow plan view of depth-averaged velocity magnitude and direction; E, high-flow cross-section velocity contour; and F, high-flow plan view of depth-averaged velocity magnitude and direction...... 29 26. Photograph showing the entrance to the Summit Conduit and the location of the streamflow-gaging station...... 32 27. Graph showing mean daily discharge for the Summit Conduit at Summit, Illinois, for the 2012 water year...... 32 28. Map showing the Chicago Area Waterway System including the Calumet-Sag Channel, Chicago, Illinois, and vicinity...... 33 29. Graph showing mean daily discharge at the U.S. Geological streamflow-gaging station on the Calumet Sag Channel near Route 83 at Sag Bridge, Illinois, for the 2012 water year...... 34 30. Graphs showing data from low- and high-flow acoustic Doppler current profiler measurements in the Calumet Sag Channel near Route 83 at Sag Bridge, Illinois, showing: A, low-flow cross-section water velocity contour, B, low-flow plan view of depth-averaged velocity magnitude and direction, C, high-flow cross-section velocity contour, and D, high-flow plan view of depth-averaged velocity magnitude and direction...... 35 31. Graph showing mean daily effluent discharge for the Metropolitan Water Reclamation District of Greater Chicago Calumet Water Reclamation Plant in Illinois for the 2012 water year...... 37 32. Screen capture and schematic diagrams showing data from acoustic Doppler current profiler measurements in the Calumet River near the Thomas J. O’Brien Lock and Dam, Chicago, Illinois, showing: A, complex water velocity patterns adjacent to the lock and dam, B, circulation patterns in the Calumet River below the lock and dam, and C, the complex velocity patterns near the Calumet Water Reclamation Plant outfall...... 38 33. Graph showing daily mean discharge for Tinley Creek near Palos Park, Illinois, for the 2012 water year...... 41 34. Photograph showing the coal-fired power plant at Romeo Rd along the Chicago Sanitary and Ship Canal near Romeoville, Illinois...... 43 35. Map showing synoptic water temperature data from the upper Chicago Sanitary and Ship Canal collected February 2012 and the sharp increase in water temperature at the power plant discharge locations...... 44 36. Photograph showing construction of the river walk along the mainstem of the Chicago River...... 45 37. Map showing one of the waterway separation scenarios proposed by the U.S. Army Corps of Engineers Great Lakes and Mississippi River Interbasin Study...... 46

Tables

1. Summary of backflow events on the Chicago Area Waterway System, Chicago, Illinois, and vicinity, 2000–14...... 10 2. Long-term U.S. Geological Survey streamflow-gaging stations on the North Branch of the Chicago River and its tributary streams, Chicago, Illinois, and vicinity...... 12 vi

Conversion Factors

Inch/pound to International System of Units

Multiply By To obtain Length inch (in.) 2.54 centimeter (cm) inch (in.) 25.4 millimeter (mm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Flow rate foot per second (ft/s) 0.3048 meter per second (m/s) cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s) Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: °F=(1.8×°C)+32

Datum

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29) and Chicago City Datum (CCD), which is 579.48 feet above NGVD 29. Elevation, as used in this report, refers to distance above the vertical datum.

Supplemental Information

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C). Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

By James J. Duncker and Kevin K. Johnson

Abstract Introduction

The Chicago Area Waterway System (CAWS) consists of The Chicago Area Waterway System (CAWS) consists a combination of natural and manmade channels that form an of a combination of natural and manmade channels that form interconnected navigable waterway of approximately 90-plus an interconnected navigable waterway of approximately miles in the metropolitan Chicago area of northeastern Illinois. 90-plus miles (mi) in the metropolitan Chicago area (fig. 1) of The CAWS serves the area as the primary drainage feature, a northeastern Illinois. The CAWS is a principal component of waterway transportation corridor, and recreational waterbody. the regional hydrology of the Chicago metropolitan area. The The CAWS was constructed by the Metropolitan Water Recla- CAWS functions as an important waterway for both com- mation District of Greater Chicago (MWRDGC). Completion mercial and recreational transportation and as a conduit for of the Chicago Sanitary and Ship Canal (initial portion of the the discharge of wastewater effluent and stormwater runoff CAWS) in 1900 breached a low drainage divide and resulted from the region. Water levels and flows within the CAWS are in a diversion of water from the Lake Michigan Basin. A U.S. regulated through a series of control structures operated and Supreme Court decree (Consent Decree 388 U.S. 426 [1967] maintained by the Metropolitan Water Reclamation District of Modified 449 U.S. 48 [1980]) limits the annual diversion from Greater Chicago (MWRDGC). The CAWS was constructed in Lake Michigan. While the State of Illinois is responsible for response to the growing population and the need for improve- the diversion, the MWRDGC regulates and maintains water ments to the natural drainage system in the region. The physi- level and water quality within the CAWS by using several ography of the Chicago area prior to settlement consisted of a waterway control structures. The operation and control of low-lying region with sluggish streams and wetlands. water levels in the CAWS results in a very complex hydraulic The primary canals and infrastructure of the CAWS were setting characterized by highly unsteady flows. The complex- constructed from 1892 to 1939 (Hill, 2000). Since completion ity leads to unique gaging requirements and monitoring issues. of the CAWS, water levels and flows within the waterway This report provides a general discussion of the complex have been maintained on the basis of water levels at various hydraulic setting within the CAWS and quantifies this infor- points along the waterway. Theoretical equations were used mation with examples of data collected at a range of flow to estimate flows at the control structures. Following a 1980 conditions from U.S. Geological Survey streamflow gaging U.S. Supreme Court ruling (Consent Decree 388 U.S. 426 stations and other locations within the CAWS. Monitoring to [1967] Modified 449 U.S. 48 [1980]), the U.S. Geological address longstanding issues of waterway operation, as well as Survey (USGS) in 1984 installed an acoustic velocity meter current (2014) emerging issues such as wastewater disinfec- (AVM) streamflow-gaging station on the Chicago Sanitary and tion and the threat from aquatic invasive species, is included in Ship Canal at Romeoville, Ill. The AVM streamflow-gaging the discussion. station provided a means for the direct measurement and near real-time monitoring of streamflow within the CAWS. Analysis of the stage, velocity, and discharge data from the AVM streamflow-gaging station at Romeoville revealed the complex hydraulic setting that is present throughout the CAWS. Since the 1984 installation of the streamflow-gaging 2 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

88°15' 88°00' 87°45' 87°30' 42°15' EXPLANATION

Lake Michigan diverted watershed LAKE MICHIGAN Map area 05536101 U.S. Geological Survey (North Shore streamflow-gaging station, LAKE COUNTY ILLINOIS Channel at identifier, and name COOK COUNTY Wilmette) North Figure 12 Wilmette Pumping Control structure waterway Branch Branch Station section e Pans River Plaines Des 05536000 (North Branch Chicago River 05536101 at Niles) (North Shore Channel at Figure 10 Wilmette) waterway Willow section Chicago North 42°00' Shore Cr COOK COUNTY Channel DU PAGE COUNTY Salt 05536105 (North Branch Chicago 05536123 River at Albany (Chicago River River Creek Avenue at Chicago) at Columbus Drive at Chicago) 05536118 (North Branch Figure 15 waterway Chicago River at Grand section Avenue at Chicago) Chicago River Controlling Works Figure 7 waterway section South Branch Chicago River Canal Figure 18 05536890 Ship waterway (Chicago Sanitary section and Ship Canal near Lemont)

and 41°45' 05536700 Thomas J. O'Brien DU PAGE COUNTY (Calumet Sag Channel Lock and Dam WILL COUNTY near Rt. 83 at Sag Bridge) Sanitary 05536358 Calumet (Calumet River below 05536995 Sag O'Brien Lock and Dam at Chicago) Calumet R. (Chicago Sanitary and Ship Canal Chicago Channel Grand at Romeoville) Calumet R Little Calumet R.

Figure 21 Lockport waterway Controlling section Works Figure 28 waterway section Lockport Powerhouse and Lockport Lock and Dam

Des Plaines River

INDIANA ILLINOIS 41°30' Base from U.S. Geological Survey, 0 5 10 MILES 1:100,000-scale digital data Albers Equal-Area Conic Projection 0 5 10 KILOMETERS Standard parallels 45o and 33o, central meridian -89o.

Figure 1. The Chicago Area Waterway System study area, northeastern Illinois. (NB, North Branch) Introduction 3 station at Romeoville, the USGS has worked closely with Chronology of Construction and Regulation for local, State, and Federal partners to advance the understanding the Chicago Area Waterway System of the hydrology of the CAWS. The USGS, with support and cooperation from the U.S. Environmental Protection Agency– The CAWS was constructed from 1892 to 1939 to serve Great Lakes Environmental Restoration Initiative, compiled the Chicago region as an integral part of the region’s sanitation this report to describe the hydrology of the CAWS. system and as an important waterway for the transportation of bulk goods (fig. 2). The purpose of the CAWS monitoring sta- Purpose and Scope tions in the early days was initially very specific to operation and maintenance of the waterway. Water-level gages along The purpose of this report is to describe the hydrology the waterway recorded water-surface elevations, which were of the metropolitan Chicago area and the primary hydrologic used by engineers to maintain a water-surface slope towards components of the CAWS in quantifiable engineering terms. Lockport and away from the city of Chicago. Completion of The report was prepared in cooperation with the U.S. Envi- the Chicago Sanitary and Ship Canal (CSSC) in 1900 resulted ronmental Protection Agency’s Great Lakes Environmental in the diversion of water from the Lake Michigan Basin to the Restoration Initiative. Illinois River/Mississippi River Basin. A series of legal rul- The scope of this report is a description of the primary ings regarding the diversion resulted in a 1980 U.S. Supreme hydrologic components of the metropolitan Chicago area Court decree that mandates the State of Illinois to monitor the and specifically the CAWS. Recent focus on the CAWS with CAWS as a component of Lake Michigan Diversion Account- respect to a number of issues has highlighted the value of ing. This decree tasks the U.S. Army Corps of Engineers waterway data and an understanding of the complex hydro- (USACE) to maintain a Lake Michigan Diversion Accounting, logic and hydraulic setting. This report discusses issues facing which relies on the USGS for accurate streamflow monitoring decision makers at a time when, due to regional economic in the CAWS. In 1984, the USGS installed an AVM stream- conditions, the level of CAWS monitoring is at a historic low. flow-gaging station on the CSSC at Romeoville, Ill., to monitor flows for Lake Michigan Diversion Accounting.

Figure 2. Historical engineering drawings of the map, profile, and cross-sections of the Main Drainage Channel for the Chicago Sanitary District of Chicago, from Chicago to Joliet, Illinois. (Figs. 2 and 3 from Hill, 1896) 4 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

As environmental regulations developed in the 1960s In 1972 the MWRDGC, in order to comply with water- and 1970s, State and Federal water-quality standards were quality standards, adopted the Tunnel and Reservoir Plan established for the waterway (Copeland, 2010; Hines, 2012). (TARP), which is composed of a network of large under- The MWRDGC, as the operating agency for the waterway, ground tunnels (11–33 feet [ft] in diameter and referred to as installed a water-quality monitoring network along the water- “Deep Tunnel”) and several large storage reservoirs that con- way. Waterway operation procedures were modified to use the nect to the CAWS (fig. 3). The TARP system presents a major information from the water-quality monitoring network and change for regional hydrology and provides for flood control incorporate flows to help meet the water-quality standards. and the routing of combined sewer runoff in the region. The

88°00'

Lake COOK COUNTY Michigan

O'HARE UPPER DES PLAINES TUNNEL SYSTEM Evanston 87°40' O’HARE RESERVOIR 42°00'

EXPLANATION DES PLAINES TUNNEL Service area SYSTEM

Water reclamation plant Chicago MAINSTREAM Completed Deep Tunnel TUNNEL SYSTEM

Storage reservoir completed

Storage reservoir under construction Riverside

Pumping station

City

Mc COOK RESERVOIR 0 5 10 MILES

0 5 10 KILOMETERS CALUMET TUNNEL SYSTEM 41°40'

THORNTON RESERVOIR INDIANA ILLINOIS

Figure 3. The Tunnel and Reservoir Plan service area, Chicago, Illinois. Chicago Area Hydrology 5

Deep Tunnel system provides an outlet for combined sewer composed much of the city was surrounded by wetlands and runoff that otherwise would have overflowed to the CAWS. was drained by low-slope sluggish streams. The mouths of the The Deep Tunnel system provides some additional storage but Chicago and Calumet Rivers were open to the lake, and shift- is primarily designed to convey the combined sewer runoff to ing sandbars were present that affected the geometry of the storage reservoirs that are under construction. When com- river mouths. The diversion of water away from Lake Michi- pleted, the TARP system of tunnels and reservoirs will help gan initially began with the completion of the Illinois and mitigate flooding in the region. Michigan Canal in 1848 and continued with the completion of the CSSC in 1900 (fig. 5).

Chicago Area Hydrology Precipitation

The hydrologic cycle is depicted schematically (fig. 4) The climate of the Chicago area is classified as a humid to outline how the components interact with each other. In continental (Changnon and others, 2004). The Illinois State the relatively flat urban setting of Chicago, the primary fea- Water Survey (ISWS) operates a network of 25 rain gages tures of the hydrologic cycle include engineered structures. (fig. 6) in the Chicago area for Lake Michigan Diversion The engineered drainage system is designed to facilitate the Accounting (Westcott, 2013). Average precipitation from the rapid removal of excess stormwater from the area to prevent ISWS network (1990–2012) is 36.77 inches (in.). Long-term overland flooding, combined sewer overflows, and flooded average annual precipitation for the National Weather Service basements. rain gage at Chicago O’Hare Airport is 36.89 in. (1981–2010). Prior to the start of construction of the CSSC in 1892, the Most of this precipitation falls in the form of rainfall. Average natural drainage for much of the Chicago area was towards annual snowfall in the Chicago area is approximately 40 in. Lake Michigan. The relatively flat, low-lying area that per year (Changnon and others, 2004).

Figure 4. The hydrologic cycle (U.S. Geological Survey, 2014). 6 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

A 88°00' 87°40' PRE-DIVERSION

Lake 25 Lake Chicago Rivers Des Plaines River Michigan Michigan 23

42°00' COOK DUPAGE

25 27 29 27 31 33 29 33 Calumet 31 29 27 Rivers 25 29 27 B POST-DIVERSION - Circa 1920 41°40' 31 27  Lake

Chicago Rivers

Des Plaines River Michigan 27 27  EXPLANATION 25 25 Line of equal

precipitation, INDIANA in inches COOK ILLINOIS CSSC 27 WILL Raingage location

0 5 MILES

Calumet-Sag 0 5 KILOMETERS

Channel  Calumet Figure 6. Lines of equal precipitation pattern for the 2012 water year, Chicago, Illinois, and vicinity. (Data are from the Illinois State Rivers Water Survey dense rain gage network [Westcott, 2013])

Groundwater EXPLANATION 0 5 10 MILES Direction of flow 0 5 10 KILOMETERS The groundwater component of the hydrologic cycle in Control structure the Chicago area is composed of an interconnected pathway  Streamflow-gaging station of natural subsurface drainage consisting of groundwater flow through the soils and bedrock, but it also includes the subsur- Figure 5. A, pre-diversion, and B, post-diversion surface face sewer system to some extent. Precipitation infiltrates into drainage in Chicago, Illinois, and vicinity. soils and fill material to become shallow groundwater. Shallow Chicago Area Hydrology 7 groundwater moves through soils and fill material at vary- in the Chicago area are very old, brick-lined sewers that are ing rates controlled by the physical properties of the material susceptible to inflow and infiltration. Shallow groundwater (porosity and permeability) and hydraulic gradients (pressure monitoring wells in Chicago record a varying water-table sur- head). The soils and fill material may be connected to local face (piezometric surface) that for much of the year is above sewer systems to varying degrees. Many of the local sewers the elevation of the local sewer system (fig. 7).

FEET 595

SMH-1 SMH-2 Leavitt Paulina PZ1-BI

PZ3s-JH PZ3-JH 590 PZ4-CC SMH-3 (Infiltration PZ2-CE Basin)

585

580

Bubbly Creek Elevation, in feet above Chicago City Datum

575

570 EXPLANATION

PZ Piezometer identifier SMH Street-level manhole identifier Fill

Material below fill

Sewer shaft

Sewer pipe

Top of well or sewer Water level Top of screen Bottom of screen

Figure 7. Schematic cross-section diagram showing the elevations of the water table, local combined sewer invert, and Chicago Sanitary and Ship Canal water-surface elevation in the Pilsen neighborhood on the south side of Chicago, Illinois. 8 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

The thickness of the glacial till varies across the Chicago shallow bedrock groundwater aquifer. Sandstone and dolomite area (Piskin and Bergstrom, 1975). Silurian-age carbon- bedrock of Cambrian and Ordovician age form a deep bedrock ate bedrock underlies the glacial till throughout the Chicago aquifer (Burch, 2008; fig. 8). area (Kolata and Nimz, 2010). The Silurian dolomite forms a

Figure 8. The potentiometric surface of the deep sandstone aquifers in the Chicago area, northeastern Illinois, fall 2007. (From Burch, 2008) Chicago Area Hydrology 9

Beneath the city streets of Chicago lies a vast network industrial withdrawals, and commercial and recreational boat of sewers that facilitates the drainage of the metropolitan traffic all contribute to the unsteady flow characteristics found area. This network of sewers consists of local and intercep- throughout the CAWS. Water-quality conditions during dry tor sewers that convey sanitary and stormwater runoff in weather are affected by the large volume of treated wastewater addition to industrial discharges. Underlying the Chicago effluent in the channel, which can exceed 70 percent of the metropolitan area at a much greater depth (110–330 ft below total volume of flow at times. the land surface) is the MWRDGC Deep Tunnel (fig. 3). The During wet weather, when storms are forecast for the Deep Tunnel is the tunnel portion of MWRDGC’s TARP. The Chicago area, the MWRDGC uses control structures (Lock- 100-plus mi network of four tunnel systems was completed in port Powerhouse and Lockport Controlling Works) near 2006 and lies between 70 and 300 ft below the land surface. the downstream end of the waterway near Lockport, Ill., to The tunnels were excavated in bedrock and, when the TARP proactively draw down the water-surface elevation and cre- project is completed, will drain combined sewer overflows and ate storage space within the CAWS channel for the influx of stormwater to three large storage reservoirs. The water in the stormwater. Navigation depth requirements and the hydraulic reservoirs will then be pumped to wastewater-treatment plants properties of the CAWS channels limit the amount of draw- before being treated and discharged to area waterways. down that is possible from the downstream control structures. Although the drawdown near the Lockport control structures (River mile 291) may reach 10–11 ft below the normal pool Surface Water elevation when all of the control structures are open, the drawdown near Sag Junction (River mile 302) may only be 3 ft, The dominant features of the hydrology for the Chi- and the effect near the lakefront may not be noticeable (fig. 9). cago area are the surface-water components that make up the At times during extreme wet weather, the stormwater CAWS. These consist of a combination of natural channels inflow to the CAWS channel may exceed the channel’s capac- and manmade canals that form the primary surface-drainage ity. When this occurs, water levels within the CAWS may features. During dry weather, the hydraulic conditions found increase rapidly and approach flood levels. In order to prevent within the CAWS are typically a low-velocity setting with flooding, the MWRDGC then opens the lakefront control water levels maintained by control structures to facilitate navi- structures and backflows the river water into Lake Michi- gation. During dry weather much of the waterway is affected gan. The MWRDGC has backflow capability at each of the by diurnal wastewater-effluent discharges. The navigable three lakefront control structures. The MWRDGC maintains reaches of canal and river channels exhibit very unsteady flow records of backflow events, backflow duration, and estimated characteristics. Many of the flow characteristics described by backflow volumes. Table 1 shows the MWRDGC record of Jackson and others (2011) are found throughout the CAWS. backflow events at the lakefront control structures since 2000. Lockages, variable-flow control structures at the lakefront and downstream, wastewater-effluent discharges, power-plant and

5 4 3 2 1 0 Grand (USGS) Western (MWRD) Western Sag Junction (MWRD) Chicago Lock Lake Michigan(USGS) -1 Stickney (USGS) -2

-3 Lemont (USGS) -4 -5

-6 Columbus (USGS) Water-surface elevation, Water-surface Romeoville (USGS)

-7 Chicago Lock (USGS)

in feet above Chicago City Datum -8 -9 Lockport CW (USGS) -10 Lockport (USGS) -11 290 295 300 305 310 315 320 325 330 River mile

Figure 9. Water-surface profile data for the Chicago Area Waterway System, Chicago, Illinois, and vicinity during an April 17–18, 2013, storm and the extent of drawdown of the water surface at points along the waterway. (MWRDGC, Metropolitan Water Reclamation District of Greater Chicago; USGS, U.S. Geological Survey) 10 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

Table 1. Summary of backflow events on the Chicago Area North Shore Channel Waterway System, Chicago, Illinois, and vicinity, 2000–14. The North Shore Channel (NSC; fig. 10) is a tributary to [From Metropolitan Water Reclamation District of Greater Chicago (2014)] the North Branch of the Chicago River and receives flow from the MWRDGC Wilmette Pumping Station (WPS; a lakefront Total volume Number of control structure at Wilmette, Ill.) and effluent discharge from Year (in millions of backflows the MWRDGC Thomas J. O’Brien Water Reclamation Plant gallons) (OWRP; formerly known as the North Side Water Reclama- 2000 0 0.0 tion Plant). During summer months, in dry weather, the WPS diverts lake water into the NSC to dilute the effluent discharge 2001 3 1,189.0 from the OWRP. During large storms, the NSC receives combined sewer overflows (CSOs) at numerous CSO outfall 2002 1 1,751.8 locations along the NSC. Also during large storms, the WPS may be used to backflow excess water to the lake to mitigate 2003 0 0.0 flooding. During winter months, the channel in the vicinity of 2004 0 0.0 the OWRP outfall is often free of ice cover owing to the effluent discharge. 2005 0 0.0 The USGS operated and maintained a streamflow-gaging station (05536101) on the NSC (approximately ¼ mi from 2006 0 0.0 the WPS) from 2000 to 2003 as part of the Lake Michigan Diversion Accounting Program. The streamflow data from 2007 1 224.0 this gage (fig. 11) provided accurate monitoring of the water that was diverted through the WPS; the data also were used 2008 2 11,509.9 to calculate flow volume during storm-related backflows to 2009 3 413.6 Lake Michigan. The data collected during the time that the streamflow-gaging station was in operation show unsteady 2010 1 6,534.9 flow conditions and periods of reverse flows, which likely were the result of the variable input from the NSWRP. The 2011 2 2,327.5 range in stage measured at the streamflow-gaging station during the period of data collection was -2.84 to 6.91 ft Chicago 2012 0 0.0 City Datum (CCD). The range in daily mean discharge during this same period was estimated to be from -58 to 245 cubic 2013 1 10,719.5 feet per second (ft3/s). 2014 1 525.0 Data collection at the USGS streamflow-gaging station 05536101 was discontinued in 2003. The USACE had completed a study (USACE, n.d; referred to as “Lakefront Accounting”) of monitoring the diversion near the three Several factors influence the frequency and magnitude of lakefront control structures. The Lakefront Accounting study backflow events. The timing and distribution of precipitation, resulted from the U.S. Department of Justice mediation efforts the hydraulic properties of the channels, and the regulation and to reconcile mid-1990s disputes among Great Lakes states operation of control structures may impact backflows. resulting from the State of Illinois’ noncompliance with the The general discussion of CAWS hydrology and flow 1980 U.S. Supreme Court mandate. In May 2013, streamflow- regulation gives an overall view of the complex hydraulic set- gaging station 05536101 was reestablished with funding ting and flow characteristics found in the CAWS. The follow- support from the MWRDGC. The streamflow-gaging station ing sections of this report will focus on individual reaches of provides flow data useful to the MWRDGC for allocation of the CAWS and describe in detail some of the hydraulic charac- diversion water, maintenance of water-quality standards for teristics of those sections. These descriptions are supported by the NSC, and measurement of backflow volumes. Recent stud- data whenever possible to validate the setting. ies on waterway separation by the Great Lakes Commission and the Great Lakes and St. Lawrence Cities Initiative (Great Lakes Commission, 2012) and the USACE (USACE, 2014) have proposed barrier locations that would reroute the OWRP effluent discharge directly to Lake Michigan. The complex, unsteady flow that would result from the proposed waterway separation scheme would warrant monitoring to determine flow direction and contaminant loading to the lake that would occur if the waterway separation plan were implemented. Chicago Area Hydrology 11

87°44' 87°42' 87°40' 87°38' 42°06' EXPLANATION City boundary

USGS streamflow-gaging station and identifier Pumping station

Wilmette Wilmette Pumping Station 05536101 (NORTH SHORE CHANNEL 42°04' AT WILMETTE, IL)

(41

Evanston Lake Michigan

North Shore Channel Channel Shore Shore North North

Skokie 42°02'

Lincolnwood

Chicago (41 42°00'

(14 (14

05536105 (NORTH BRANCH CHICAGO North RIVER AT ALBANY AVENUE (41 Branch AT CHICAGO, IL)

Chicago

41°58'

River

Base from U.S. Geological Survey, 0 0.5 1 MILE 1:100,000-scale digital data Albers Equal-Area Conic Projection 0 0.5 1 KILOMETER Standard parallels 45o and 33o, central meridian -89o.

Figure 10. The Chicago Area Waterway System with the North Shore Channel, Chicago, Illinois, and vicinity. (USGS, U.S. Geological Survey) 12 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

300

250

200

150

100

Daily mean discharge, in cubic feet per second 0

-50 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2002 2003

Figure 11. Daily mean discharge for the North Shore Channel at Wilmette, Illinois, for the 2003 water year, which is the last year of record.

Table 2. Long-term U.S. Geological Survey streamflow-gaging stations on the North Branch of the Chicago River and its tributary streams, Chicago, Illinois, and vicinity.

[USGS, U.S. Geological Survey]

USGS station Station name Period of record number 05535000 Skokie R. at Lake Forest, IL 1951–present 05535070 Skokie R. near Highland Park, IL 1966–present 05534500 N. Br. Chicago R. at Deerfield, IL 1952–present 05535500 WF N. Br Chicago R. at Northbrook, IL 1951–present 05536000 N.Br. Chicago R. at Niles, IL 1950–present 05536105 N. Br. Chicago R. at Albany Avenue at Chicago, IL 1989–present 05536118 N. Br. Chicago R. at Grand Avenue at Chicago, IL 2002–present

North Branch Chicago River the NBrCR receives CSOs at numerous CSO outfall locations along the NBrCR. Dry weather flows consist primarily of The North Branch of the Chicago River (NBrCR) is trib- wastewater effluent from treatment plants and base flow from utary to the CAWS and joins the NSC (fig. 12); the combined shallow groundwater. streamflow represents most of the flow from the north side of The NBrCR and its tributaries are currently (2014) gaged Chicago and the northern metropolitan area. The NBrCR is at several locations. Streamflow-gaging station 05536105 near composed of a mostly natural channel that is relatively shal- the confluence of the NBrCR and the NSC quantifies the flows low and nonnavigable for motor vessels. During large storms, entering the CAWS from the NBrCR (table 2). Chicago Area Hydrology 13

87°52' 87°48' 87°44' 87°40' 87°36'

Lake Forest EXPLANATION Lincolnshire City boundary

USGS streamflow-gaging station and identifier Highwood 42°12' Pumping station Bannockburn

Highland Deerfield Park

LAKE COUNTY Lake Michigan COOK COUNTY

42°08' Glencoe Northbrook

Winnetka Northfield Kenilworth Wilmette Pumping Station 05536101 Wilmette (NORTH SHORE CHANNEL Glenview 94 42°04' AT WILMETTE, IL) 294

Morton Evanston Grove North Shore Channel

Niles Skokie 05536000 (NORTH BRANCH CHICAGO RIVER Park Ridge AT NILES, IL) Lincolnwood 42°00' 05536105 (NORTH BRANCH CHICAGO RIVER AT ALBANY AVENUE 90 North AT CHICAGO, IL) 190 Branch Harwood Heights

05536123 Chicago 90 (CHICAGO RIVER AT COLUMBUS DRIVE 41°56' AT CHICAGO, IL) Chicago Chicago River River Controlling Works 05536118 Oak Park (NORTH BRANCH CHICAGO RIVER AT GRAND AVENUE AT CHICAGO, IL)

Base from U.S. Geological Survey, 0 2 MILES 1:100,000-scale digital data Albers Equal-Area Conic Projection 0 2 KILOMETERS Standard parallels 45o and 33o, central meridian -89o.

Figure 12. The Chicago Area Waterway System, including the North Branch Chicago River and U.S. Geological Survey streamflow-gaging stations, Chicago, Illinois, and vicinity. (USGS, U.S. Geological Survey) 14 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

The USGS streamflow-gaging station (05536105) on conductance was installed in 2002 to document the density the NBrCR is approximately 400 ft upstream from a concrete currents in this reach. The range in water temperature during control structure that regulates the flow of the NBrCR as the the period of data collection was 0.0–27.0 degrees Celsius flow combines with the NSC. Mean daily discharge at this (˚C). The range in specific conductance during the period of streamflow-gaging station is shown in figure 13. The control data collection was 264–5,420 microsiemens per centimeter structure consists of a multilevel concrete weir structure, wing at 25 ˚C. walls, and abutment that constrain the flow at low, medium, and high stages (fig. 14). The range in stage measured at the streamflow-gaging station during the period of data collection Mainstem Chicago River was 1.00–7.86 ft. Discharge during this same period ranged The mainstem of the Chicago River is a relatively short 3 from 3.6 to 3,580 ft /s. reach of channel (1.6 mi) that connects Lake Michigan to the The USGS streamflow-gaging station (05536118) on the confluence of the North and South Branches of the Chicago NBrCR at Grand Avenue is approximately ¼ mi upstream River (fig. 15). The channel is characterized by vertical from the confluence of the NBrCR and the mainstem of the sheet-pile or concrete walls through the high-rise corridor of Chicago River at Wolf Point (fig. 15). The flow in this reach downtown Chicago. The channel is primarily rectangular in is a combination from the NBrCR and the NSC. The channel cross section with depths in the 15- to 23-ft range when the through this reach is approximately 150 ft wide and 15–20 ft water level is at –2.0 ft CCD. The flow through this reach has deep with vertical sheet piling walls. The range in stage been monitored since 1996 for the Lake Michigan Diver- measured at streamflow-gaging station (05536118) during the sion Accounting Program and lakefront accounting of direct period of data collection was –4.32 to 5.00 ft CCD. The range diversions. The AVM data combined with data from a vertical in daily mean discharge during this same period was from string of probes that measured water temperature and spe- 3 –20 to 14,100 ft /s. Negative daily mean discharges occur as a cific conductance at the Columbus Drive streamflow-gaging result of regulation or the effects of upstream and downstream station (05536123) were used to define the complexity of (bidirectional) flow from density currents. A vertical string flows in this reach. Leakage of Lake Michigan water into the of six probes that measured water temperature and specific Chicago River was first quantified using discharge data from

900

800

700

600

500

400

300

200 Daily mean discharge, in cubic feet per second 100

0 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012 Figure 13. Daily mean discharge for the streamflow-gaging station (05536105) on the North Branch Chicago River at Albany Avenue, Chicago, Illinois, and vicinity, for the 2012 water year. Chicago Area Hydrology 15

Figure 14. The concrete control structure at the confluence of the North Branch Chicago River and the North Shore Channel, Chicago, Illinois, and vicinity. (Photograph by Shawn Cutshaw, U.S. Geological Survey)

this station, which resulted in the use of several infrastructure in this reach. Water-quality assessments of the Chicago River projects to reduce the leakage. Bidirectional flows, driven by may underestimate (or overestimate) the impairment of the density contrasts between the Lake Michigan water and the river because standard water-quality monitoring practices Chicago River water, were also first identified from monitor- do not account for density-driven underflows (or overflows) ing at this location (Jackson and others, 2008). Density differ- (Jackson and others, 2008). The range in stage measured at the ences driving the flow primarily arise from salinity differences Chicago River at Columbus Drive streamflow-gaging station between the NBrCR and the mainstem of the Chicago River; (05536123) during the period of data collection was from water temperature is secondary in the creation of these cur- -4.52 ft to 4.72 ft CCD owing to regulation. The range rents. Deicing salts appear to be the primary source of salinity in daily mean discharge during this same period was from in the NBrCR. These salts enter the waterway in direct -2,450 to 1,370 ft3/s. Typical low- and high-flow velocity runoff and in runoff entering the combined sewer system that direction and magnitude data from discharge measurements becomes effluent from water-treatment plants. Knowledge of at the streamflow-gaging station are shown in figure A–D16 . the complex flows in this reach helped to account for prob- Velocity magnitude and direction data for a reverse flow event lematic variability in long-term monitoring of water quality are shown in figure 16E–F. 16 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

87°38' 87°37' 87°36'

EXPLANATION USGS streamflow-gaging station 41°54' and identifier

05536118 (NORTH BRANCH CHICAGO RIVER AT GRAND AVENUE AT CHICAGO, IL)

Wolf Point Chicago River 05536123 (CHICAGO RIVER AT COLUMBUS Chicago River DRIVE AT CHICAGO, IL) Controlling Works

41°53' South

Branch

Lake Shore Drive Columbus Drive Lake Michigan

Chicago

River

Roosevelt Road 41°52'

Base from U.S. Geological Survey, 0 0.25 0.5 MILE 1:100,000-scale digital data Albers Equal-Area Conic Projection 0 0.25 0.5 KILOMETER Standard parallels 45o and 33o, central meridian -89o.

Figure 15. The Chicago Area Waterway System and the mainstem of the Chicago River, Chicago, Illinois. (USGS, U.S. Geological Survey) Chicago Area Hydrology 17

A 0

0.35

5 0.3

0.25

10 0.2 Depth, in feet 0.15 15

0.1

0.05 20 Riverbed magnitude (streamwise and transverse), in feet per second Velocity

100 50 0 Distance, in feet

4637590 0.14

0.12 4637585

0.1

4637580 0.08

0.06 UTM Northing, in meters 4637575 0.04 EXPLANATION Velocity vectors—length and color of vectors show magnitude (see 0.02 color scale at right) and orientation 4637570 shows direction Depth-averaged velocities, in feet per second, averaged over total depth 448520 448525 448530 448535 UTM Easting, in meters

Figure 16. Data from acoustic Doppler current profiler measurements in the mainstem of the Chicago River near Columbus Drive in Chicago, Illinois showing: A, typical low-flow water velocity magnitude and B, direction; C, typical high-flow velocity magnitude and D, direction; E, reverse flow magnitude and F, direction. (UTM, Universal Transverse Mercator) 18 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

C 0

0.4

0.35 5

0.3

0.25 10

0.2 Depth, in feet

15 0.15

0.1

20 0.05 Velocity magnitude (streamwise and transverse), in feet per second Velocity Riverbed

0 0 50 100 Distance, in feet

4637590

0.25

4637585

0.2

4637580

0.15 UTM Northing, in meters 4637575 EXPLANATION 0.1 Velocity vectors—length and color of vectors show magnitude (see color scale at right) and orientation 4637570 shows direction Depth-averaged velocities, in feet per second, averaged over total depth 448520 448525 448530 448535 UTM Easting, in meters

Figure 16. Data from acoustic Doppler current profiler measurements in the mainstem of the Chicago River near Columbus Drive in Chicago, Illinois showing: A, typical low-flow water velocity magnitude and B, direction; C, typical high-flow velocity magnitude and D, direction; E, reverse flow magnitude and F, direction.—Continued (UTM, Universal Transverse Mercator) Chicago Area Hydrology 19

E 0

3.5

10 3 Depth, in feet 2.5 15

2 20 Velocity magnitude (streamwise and transverse), in feet per second Velocity Riverbed 1.5

0 50 100 Distance, in feet

F 4637590

4637585 3.5

4637580 3 UTM Northing, in meters 4637575 2.5 EXPLANATION Velocity vectors—length and color of vectors show magnitude (see color scale at right) and orientation 4637570 shows direction 2 Depth-averaged velocities, in feet per second, averaged over total depth 448520 448525 448530 448535 UTM Easting, in meters

Figure 16. Data from acoustic Doppler current profiler measurements in the mainstem of the Chicago River near Columbus Drive in Chicago, Illinois showing: A, typical low-flow water velocity magnitude and B, direction; C, typical high-flow velocity magnitude and D, direction; E, reverse flow magnitude and F, direction.—Continued (UTM, Universal Transverse Mercator) 20 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

Even prior to the potential changes associated with lockages. The regulated flows are part of the MWRDGC’s waterway separation, recent declines in the water level of allocation of Lake Michigan water and are classified as a Lake Michigan have been changing the hydraulic setting of direct diversion. In most years, the MWRDGC uses its alloca- this reach. At times, record low lake levels can affect the direct tion between April 1 and October 31 to dilute treated wastewa- diversion (by gravity through existing sluice gates) of lake ter effluent and maintain the waterway “in a reasonably satis- water into the river at the Chicago River Controlling Works factory sanitary condition” (U.S. Supreme Court, 1980). The (CRCW; fig. 1). The USGS established river- and lake-level direct diversion of Lake Michigan water during the warmer gages at the CRCW in August 1997 to evaluate sluice gate months of the year helps to maintain dissolved oxygen levels flow ratings and leakage through the structure. The USACE in the waterway. In most years, there is no direct diversion also uses the streamflow data for operations during storms. during November 1–March 31. During winter months, flow At times, during extreme precipitation events, the water level in the mainstem of the Chicago River is very low, consisting of the mainstem of the Chicago River approaches a thresh- mainly of leakage through the control structures and occasion- old flood elevation (+3.5 ft CCD). This elevation triggers a ally through lockage. The mainstem of the Chicago River can response from the MWRDGC and USACE to mitigate immi- have variable ice cover during winter months; ice thickness nent flooding by opening the CRCW to backflow the river generally is greatest close to the lake. water to Lake Michigan. The backflow occurs as sluice gates in the control structure are opened and the river water (at an elevation near +3.5 ft CCD) flows by gravity into the lake. If South Branch Chicago River opening the sluice gates does not immediately lower the river The South Branch of the Chicago River (SBrCR) is the water-surface elevation, the gates to the lock chamber may section of channel from the confluence with the NBrCR and be opened for increased backflow capacity. A large backflow mainstem Chicago River at Wolf Point south and southwest event in April 2013 required the use of sluice gates and lock to the start of the CSSC near South Damen Avenue (fig. 18). chamber gates to mitigate potential flooding (fig. 17). USGS Flow through this reach is generally to the south, then south- field crews made discharge measurements to verify backflow west into the CSSC; however, at the mouth of southeast fork capacity and volumes. of the SBrCR, locally known as Bubbly Creek, the flow may Flow in the mainstem of the Chicago River is heavily become complex during storms. The high flows discharg- affected by the regulated flows coming through the CRCW. ing from Bubbly Creek are the result of combined sewer These flows include the flow through sluice gates and the

4 0 EXPLANATION Sector gates 50% opened Chicago River 3 1 South Sluice gates opened Lake Michigan North Sluice gates opened Sector gates 100% opened Hourly precipitation 2 2 Sector gates 100% opened 1 3 North and South Sluice gates closed 0 4 Sector gates 0% opened Sector gates 0% opened -1 5

-2 6 Gage height, in feet above Chicago City Datum City Chicago above feet in height, Gage

-3 7 hour per inches in Lock, Chicago at Precipitation

-4 8 17 12:00 PM 18 12:00 AM 18 12:00 PM 19 12:00 AM 19 12:00 PM April 2013

Figure 17. Gage heights for the Chicago River at Columbus Drive at Chicago, Illinois, streamflow-gaging station, hourly precipitation measured at the Chicago Lock, and gate settings at the Chicago River Controlling Works during the April 2013 storm. Chicago Area Hydrology 21

87°41' 87°40' 87°39' 87°38' 87°37' 87°36'

05536123 (CHICAGO RIVER AT COLUMBUS 05536118 DRIVE AT CHICAGO, IL) (NORTH BRANCH CHICAGO RIVER AT GRAND AVENUE AT CHICAGO, IL) River Chicago Chicago Lock and Chicago River 41°53' 90 Controlling Works

South

290

Branch

Lake Michigan

Chicago

41°52'

River

South Damen Avenue

41°51'

Western Avenue

Bubbly

41°50' 94

35th Street Creek

36th Street

41°49' EXPLANATION

USGS streamflow-gaging station and identifier

Control structure

Base from U.S. Geological Survey, 0 0.5 1 MILE 1:100,000-scale digital data Albers Equal-Area Conic Projection 0 0.5 1 KILOMETER Standard parallels 45o and 33o, central meridian -89o.

Figure 18. The Chicago Area Waterway System including the South Branch of the Chicago River and the Southeast Fork of the South Branch of the Chicago River (Bubbly Creek), Chicago, Illinois, and vicinity. (USGS, U.S. Geological Survey) 22 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois overflows from the MWRDGC’s Racine Avenue Pumping The USACE is currently (2014) studying the feasibility Station (RAPS). These flows enter the SBrCR perpendicular to of stream restoration for Bubbly Creek. The stream restora- the flow in the SBrCR. Results of hydraulic modeling stud- tion plans would benefit from additional flow data for Bub- ies indicate that during high flows from the RAPS, hydrau- bly Creek. Waterway separation scenarios include designs lic mounding may be likely at the confluence and that it is to locate a waterway barrier in the vicinity of the mouth of possible for a portion of the Bubbly Creek discharge to flow Bubbly Creek; the exact location depends on whether or not upstream to the northeast. A profile of the water-surface eleva- the discharge from RAPS is to go to Lake Michigan or to the tion for an April 2013 flood (fig. 19A–B) from the MWRDGC CSSC. Monitoring of Bubbly Creek would provide measured Lockport Powerhouse to the CRCW (Chicago Lock) reveals flows for evaluation of waterway separation barriers and miti- interesting aspects of the CAWS hydraulic setting. This storm gation strategies for the effects of these flows on the receiving produced approximately 4–5 in. of rainfall across much of the water bodies (SBrCR, mainstem Chicago River, and Lake Chicago area on April 17–18, 2013 (N.E. Westcott, ISWS, Michigan). written commun., 2013). A water-surface profile was produced for this storm event based on USGS and MWRDGC Chicago Sanitary and Ship Canal streamflow-gaging station data. Animating this profile over time shows definite reversal of the water-surface slope as the The CSSC consists of approximately 30 mi of manmade MWRDGC opened the gates (backflow) at the CRCW. With canal excavated into the bedrock and glacial material from the outlet to the lake open and with backflow conditions, the Lockport Powerhouse to Damen Avenue in Chicago (fig. 21). water-surface profile shows a hydraulic mound or divide near The CSSC was constructed from 1892 to 1900 and effectively Stickney. This condition persisted for several hours, routing reversed the flow of the Chicago River by capturing the flow the flows from a portion of the upper CSSC, Bubbly Creek, and draining it away from Lake Michigan. The CSSC varies and the South Branch and Branches of the Chicago River to in width from approximately 160 to 200 ft and in depth from Lake Michigan. Field discharge measurements document the approximately 18 to 22 ft (at normal pool elevation) for most backflows on the mainstem of the Chicago River at Columbus of its reach. Drive, but no discharge measurements have been made to Flow within the CSSC is highly regulated by downstream verify the mounding or upstream flows in the upper reaches of control structures (Lockport Controlling Works, Lockport the CSSC or SBrCR. These observations and measurements Powerhouse, and the Lockport Lock and Dam) (fig. 22A). Dur- may factor into discussions about locating proposed barriers ing dry weather, water levels are maintained for navigation, for waterway separation in this reach of the CAWS. and discharge through the control structures is regulated to During winter months, the SBrCR is usually free of ice balance the inflow to the waterway. At times, power genera- cover. The large amount of effluent in the NBrCR and minimal tion at the MWRDGC Lockport Powerhouse is timed to maxi- flows from the mainstem would keep ice from forming. Until mize power generation when utility rates are favorable. This its closing in 2012, the thermal discharge from the Fisk Gener- results in a cycle of “ponding” of water for a period of time ating Plant also contributed to keeping this reach free of ice. and subsequent increased flows as water is released through turbines (fig. 22B). During wet weather, prior to a storm, and in anticipation Southeast Fork of the South Branch Chicago of potential regional flooding, water levels within the CSSC River (Bubbly Creek) are drawn down to increase storage capacity within the channel (fig. 22C). The drawdown is accomplished by opening The Southeast Fork of the South Branch of the Chicago gates at the downstream control structures. These gates con- River is more commonly referred to by its local name Bubbly tinue to be operated during a storm to manage water levels and Creek (fig. 18). Bubbly Creek received its local name when it mitigate flood effects. Measured flows recorded at the USGS drained the Chicago Stockyards and areas of the meat pack- streamflow-gaging stations since 1986 show a maximum dis- ing industry. Today (2014), Bubbly Creek is a relatively short charge for the CSSC of approximately 20,000 ft3/s. reach of channel (1.4 mi) that is primarily stagnant during dry The MWRDGC Stickney Water Reclamation Plant dis- weather but receives discharge from the MWRDGC RAPS, charges treated effluent directly to the CSSC near Stickney, Ill. stormwater runoff, and a few smaller combined sewer over- (fig. 21). This treatment plant is one of the largest wastewater- flows during storms. Pumps within RAPS are capable of a treatment plants in the world with a design capacity of 1,200 3 combined discharge of almost 6,000 ft /s. During dry weather, million gallons per day (https://www.mwrd.org/irj/portal/ there is essentially no flow entering Bubbly Creek channel. anonymous/stickney). Water within Bubbly Creek rises and falls as levels in the During most years, the CSSC is ice free due to the CSSC fluctuate. A short-term streamflow-gaging station was thermal loads of the large wastewater-treatment plants, power operated near 36th Street from 2009 to 2010, which deployed plants, and industrial discharges. During extended periods a side-looking acoustic Doppler velocity profiler (ADCP) to of extreme cold weather, portions of the CSSC above Sag record stage and velocity for verification of a hydraulic model Junction have become ice covered. Below Sag Junction, the (fig. 20). During winter months, the Bubbly Creek channel can authors have never seen ice cover on the CSSC, even during be completely covered by ice. extended periods of subzero air temperatures. Chicago Area Hydrology 23

A 20 15 10 5 Discharge, per second of cubic feet in thousands 0 17 18 19 20 21 22 April 2013 5 4 3 2 1 0 Chicago Lock Lake Michigan (USGS) Grand (USGS) Western (MWRDGC) Western Sag Junction (MWRDGC) -1 Stickney (USGS) -2

-3 Lemont (USGS) -4 -5

-6 Columbus (USGS) Water-surface elevation, Water-surface

-7 Romeoville (USGS) in feet above Chicago City Datum

-8 Chicago River Controlling -9 Lockport Controlling Works (USGS) Lockport Controlling Works -10 Works and Chicago Lock (USGS) Works Lockport Powerhouse (USGS) -11 290 295 300 305 310 315 320 325 330 River mile

B 20 15 10 5 Discharge, per second of cubic feet in thousands 0 17 18 19 20 21 22 April 2013 5 4 3 2 Chicago Lock (USGS) Sag Junction (MWRDGC) 1 0

-1 Grand (USGS)

-2 Stickney (USGS)

-3 Columbus (USGS) Western (MWRDGC) Western Lemont (USGS)

-4 Romeoville (USGS) -5

-6 Chicago Lock Water-surface elevation, Water-surface

-7 (USGS) Lockport Controlling Works Lockport Powerhouse (USGS) Lake Michigan(USGS) in feet above Chicago City Datum -8 -9 -10 -11 290 295 300 305 310 315 320 325 330 River mile

Figure 19. Discharge and water-surface profiles for the Chicago Area Waterway, Illinois, during the April 17–23, 2013, storm: A, rising storm discharge hydrograph and canal drawdown, B, near peak of storm discharge and opening of the Chicago River Controlling Works, and C, the effect of flow reversal at the Chicago River Controlling Works on the water-surface elevation profile. (USGS, U.S. Geological Survey; CRCW, Chicago River Controlling Works; MWRDGC, Metropolitan Water Reclamation District of Greater Chicago) 24 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

C 20 15 10 5 Discharge, per second of cubic feet in thousands 0 17 18 19 20 21 22 April 2013 5 4 3 Sag Junction (MWRD) 2 Grand (USGS) 1

0 Chicago Lock (USGS) -1 -2 Stickney (USGS) -3 (MWRD) Western Lemont (USGS) -4 Romeoville (USGS)

-5 Columbus (USGS)

-6 Chicago Lock Water-surface elevation, Water-surface -7 Lockport CW (USGS) Lockport (USGS)

in feet above Chicago City Datum -8 Lake Michigan(USGS) -9 -10 -11 290 295 300 305 310 315 320 325 330 River mile

A 0 Top Q

12 Depth, in feet Bottom Q Riverbed 16

20 10,883 10,979 11,076 11,172 11,268 Ensemble number

EXPLANATION

0.000 1.000 2.000 3.000 4.000 Velocity magnitude, in feet per second, referenced to the bottom

B 2.5 2.5

Gage height is not Chicago City Datum, but range to surface of vertical beam

2 2 Range to surface of vertical beam, in meters

1.5 1.5

1 1

0.5 0.5

0 0 Velocity, in meters per second per meters in Velocity,

-0.5 -0.5

-1 -1

-1.5 -1.5 25 26 27 May 2009 EXPLANATION Horizontal acoustic Doppler current meter (H-ADVM) Gage height Cell 1 Cell 4 Cell 7 Cell 2 Cell 5 Cell 8 Cell 3 Cell 6 Cell 9

Figure 20. Data from horizontal acoustic Doppler velocity profiler measurements May 25–27, 2009, for Bubbly Creek near 36th Street, Chicago, Illinois: A, water velocity, and B, discharge. 26 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

88°04' 88°00' 87°56' 87°52' 87°48' 87°44' 87°40'

Damien MWRDGC Stickney Avenue 88 Water Reclamation Plant Stickney Canal 414757087490401 55 (SUMMIT CONDUIT AT SUMMIT, IL) 41°48' Ship

DUPAGE COOK River

355 and

294 41°44' 83

55 Sanitary

Des Plaines05536700 (CALUMET SAG CHANNEL NEARNR RT ROUTE83 AT SAG 83 AT BRIDGE, SAG BRIDGE, IL) IL) Sag Junction Calumet-Sag 05536890 (CHICAGO SANITARY AND SHIP Chicago CANAL NRNEAR LEMONT, LEMONT, IL) IL) 41°40' Lemont Romeoville Channel

05536995 (CHICAGO SANITARY AND SHIP CANAL AT ROMEOVILLE, IL)

WILL 57

41°36' Lockport Controlling Works

Lockport 80 294

Lockport Powerhouse and Lockport Lock and Dam

Base from U.S. Geological Survey, 0 1 2 3 45 MILES EXPLANATION 1:100,000-scale digital data Albers Equal-Area Conic Projection 0 1 2 3 45 KILOMETERS USGS streamflow-gaging station Standard parallels 45o and 33o, central meridian -89o. and identifier Control structure

Figure 21. The Chicago Area Waterway System including the Chicago Sanitary and Ship Canal and Calumet Sag Channel, Chicago, Illinois, and vicinity. (USGS, U.S. Geological Survey; MWRDGC, Metropolitan Water Reclamation District of Greater Chicago) Chicago Area Hydrology 27

A 4,500

4,000

3,500

3,000

2,500

2,000

1,500

1,000

500

-500 3H 6H 9H 12H 15H 18H 21H 3H 6H 9H 12H 15H 18H 21H 3H 6H 9H 12H 15H 18H 21H 3H 6H 9H 12H 15H 18H 21H 30 1 2 3 April 2013 May 2013

B 5,000

4,000

3,000

2,000

1,000

Discharge, in cubic feet per second -1,000

-2,000 4H 8H 12H 16H 20H 4H 8H 12H 16H 20H 4H 8H 12H 16H 20H 4H 8H 12H 16H 20H 4H 8H 12H 16H 20H 4H 8H 12H 16H 20H 5 6 7 8 9 10 October 2012

C 25,000 22,500 20,000 17,500 15,000 12,500 10,000 7,500 5,000 2,500

0 -2,500 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2 3 April May 2013

Figure 22. Discharge for the Chicago Sanitary and Ship Canal near Lemont, Illinois, for: A, a normal pool elevation with highly unsteady flow conditions, April–May 2013, B, a typical dry-weather pattern showing cycle of ponding and increased flows, October 12, 2013, and C, a wet weather pattern showing the pre-storm drawdown and subsequent flood wave, April–May 2013. 28 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

The daily mean discharge of effluent for the 2012 water diversion. In 2006, construction at the USACE electric fish year is shown in figure 23. The treatment-plant effluent barrier necessitated that the USGS remove the streamflow- discharge greatly increases the flow within the CSSC at the gaging station and establish a new streamflow-gaging station MWRDGC Stickney Water Reclamation Plant. Dry-weather approximately 5 mi upstream near Lemont, Ill. flows within the CSSC are highly unsteady. The USGS streamflow-gaging station on the CSSC near The USGS operated an AVM streamflow-gaging sta- Lemont, Ill., is the primary measurement point for determin- tion at Romeoville, Ill., from 1984 to 2005. The information ing the State of Illinois’ Lake Michigan diversion. The mean from this gage was used for the State of Illinois’ compliance annual flow computed from the data collected at this stream- with a U.S. Supreme Court decree (Consent Decree 388 U.S. flow-gaging station (fig. 24) is used by the USACE Lake 426 [1967] Modified 449 U.S 48 [1980] on Lake Michigan Michigan Diversion Accounting Program.

2,500

2,000

1,500

Figure 23. Daily mean effluent discharge for 1,000 the Metropolitan Water Reclamation District of Greater Chicago–Stickney 500 Water Reclamation Daily mean discharge, in cubic feet per second Plant, Chicago, Illinois, for the 2012 water year. 0 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012

8,000

7,000

6,000

5,000

4,000

3,000 Figure 24. Daily 2,000 mean discharge for the Chicago

Daily mean discharge, in cubic feet per second Sanitary and Ship 1,000 Canal near Lemont, Illinois, for the 2012 0 water year. Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012 Chicago Area Hydrology 29

Water velocity throughout the CAWS, especially in in contrast, winds from the north or northeast can provide an the lower reach of the CAWS, is susceptible to the surface added push to the surface layer in the downstream direction. layer being affected by wind-driven flow. Winds from the Discharge measurements and velocity profiles document the south or southwest can effectively push the surface layer of effects of wind on the water velocities (fig. 25). water against the predominant downstream flow direction;

A 0 0.4

5 0.3

0.2

0.1

Depth, in feet 15 0 Streamwise velocity, in feet per second Streamwise velocity, -0.1 20

-0.2 Riverbed 25 0 50 100 Distance, in feet

B 4615940 EXPLANATION Velocity vectors—length and color 0.2 of vectors show magnitude (see 4615935 color scale at right) and orientation shows direction

4615930 0.15

4615925

4615920 0.1

4615915 UTM Northing, in meters

4615910 0.05

4615905

Depth-averaged velocities, in feet per second, averaged over total depth 419810 419815 419820 419825 UTM Easting, in meters

C 0

0.6 5

0.5 10

Depth, in feet 0.4

15 Streamwise velocity, in feet per second Streamwise velocity,

0.3

Riverbed

0.2 0 50 100 Distance, in feet

4615935 0.55 EXPLANATION Velocity vectors—length and color 4615930 of vectors show magnitude (see color scale at right) and orientation shows direction 4615925 0.5

4615920

4615915 0.45

4615910 UTM Northing, in meters

0.4 4615905

4615900

0.35 Depth-averaged velocities, in feet per second, averaged over total depth 419795 419800 419805 UTM Easting, in meters

E 0 5.5

5 5

4.5 10

15 Depth, in feet 3.5

20 Streamwise velocity, in feet per second Streamwise velocity, 3

25 2.5 Riverbed

0 50 100 Distance, in feet

EXPLANATION 5 4615930 Velocity vectors—length and color of vectors show magnitude (see color scale at right) and orientation shows direction 4615925

4.5 4615920

4615915

4 4615910 UTM Northing, in meters

4615905

4615900 3.5 Depth-averaged velocities, in feet per second, averaged over total depth 419,795 419,800 419,805 419,810 UTM Easting, in meters

Figure 25. Data from low-, medium-, and high-flow acoustic Doppler current profiler measurements in the Chicago Sanitary and Ship Canal near Lemont, Illinois, showing: A, low-flow cross-section water velocity contour; B, low-flow plan view of depth-averaged velocity magnitude and direction; C, medium-flow cross-section velocity contour; D, medium-flow plan view of depth-averaged velocity magnitude and direction; E, high-flow cross-section velocity contour; and F, high-flow plan view of depth-averaged velocity magnitude and direction.—Continued (UTM, Universal Transverse Mercator) 32 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois Summit Conduit The Summit Conduit is a manmade concrete-lined tunnel structure that routes the flows from a drainage ditch on the northwest side (right bank) of the Des Plaines River under- neath the Des Plaines River and discharges the flow into the CSSC (fig. 21). At the time of construction, the drainage area consisted primarily of a low-lying portion of the Des Plaines River floodplain. The ditch was excavated to permit the floodplain to be farmed. The Summit Conduit structure enables the flow within the ditch to be discharged directly into the CSSC. As the immediate area developed, the farmland disappeared and the drainage area consists of a large quarry operation and light industry. A USGS streamflow-gaging station was established at the entrance to the Summit Conduit in 2010 (fig. 26). Analysis of discharge data from the streamflow-gaging station confirms the regulation of flows within the ditch (fig 27). A relatively high sustained base flow and the occasional sud- den increase or decrease of water levels are likely related to a nearby quarry operation. The limestone quarries in the area periodically utilize pumps to dewater sections of the quarries as part of routine quarry operations. The pumping is permitted through the Illinois Environmental Protection Agency.

Figure 26. The entrance to the Summit Conduit and the location of the streamflow-gaging station.

10 Daily mean discharge, in cubic feet per second

0 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012

Figure 27. Daily mean discharge for the Summit Conduit at Summit, Illinois, for the 2012 water year. Chicago Area Hydrology 33

Calumet Sag Channel Mill Creek, Stoney Creek, and Tinley Creek; the channel drains flow away from the natural outlet into Lake Michigan. The Calumet-Sag Channel consists of approximately The USACE Thomas J. O’Brien Lock and Dam, constructed 16 mi of manmade canal connecting the Little Calumet River in 1965, separates the Little Calumet River from Lake Michi- to the CSSC (fig. 28). It was completed in 1922 and widened gan at a point approximately 6.8 mi inland from the lake. in 1960. The channel is approximately 220–270 ft wide and Flows within the Calumet-Sag Channel (fig. 29) are 12–16 ft deep at normal pool elevation. The Calumet-Sag highly regulated. Water levels within the Calumet-Sag Channel captures flows from the Little Calumet River, Grand Channel and the lower part of the Little Calumet River up to Calumet River, and several small tributary streams, including O’Brien Lock and Dam are regulated by downstream control

87°56' 87°52' 87°48' 87°44' 87°40' 87°36' 87°32'

55 Canal

DUPAGE COUNTY River Lake Michigan

COOK COUNTY Ship 41°48' and

Des Plaines Sanitary

94 90

41°44' 294 Chicago Lake Calumet 05536700 (CALUMET SAG Creek CHANNEL NEAR ROUTE 83 05536358 AT SAG BRIDGE, IL) Stoney (CALUMET RIVER BELOW O'BRIEN LOCK AND DAM AT CHICAGO) 05536890 Calumet-Sag (CHICAGO SANITARY AND SHIP MWRDGC Calumet Water Mill Reclamation Plant 41°40' CANAL NEAR LEMONT, IL) Creek Channel

Little Acme Bend Tinley Creek 57 Thomas J. O'Brien Lock and Calumet Dam

41°36' River

294 80

COOK COUNTY 80 WILL COUNTY

41°32'

INDIANA ILLINOIS

Control structure

Figure 28. The Chicago Area Waterway System including the Calumet-Sag Channel, Chicago, Illinois, and vicinity. (USGS, U.S. Geological Survey) 34 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois structures at Lockport (Lockport Lock and Dam, MWRDGC made during the April 2013 backflow event were negative Lockport Powerhouse, and Lockport Controlling Works). The (going out to the lake), -7,409 ft3/s through the lock cham- O’Brien Lock and Dam diverts Lake Michigan water into the ber and -5,573 ft3/s through the sluice gates for a total of Little Calumet River during lock operations and direct diver- -12,982 ft3/s. These measurements document the conveyance sion through sluice gates. of the channel, and lock and dam structure, during one of the The range in stage measured at the Calumet River relatively rare backflow events. downstream from O’Brien Lock and Dam streamflow-gaging The USGS installed a short-term streamflow-gaging sta- station during the period of data collection (1997–2003 water tion on the Calumet-Sag Channel near Route 83 (fig. 21) in years) was from -3.01 to 3.64 ft CCD. The range in daily mean 2011 to characterize the flow contribution of the Calumet-Sag discharge during this same period was estimated to be from Channel to the CSSC (fig. 30). The data at this location were 844 to 1,069 ft3/s. Velocity data and ADCP discharge measure- collected primarily for a modeling study related to the moni- ments downstream from the O’Brien Lock and Dam define a toring of flows for the Lake Michigan Diversion Accounting complex hydraulic setting (fig. 30). Discharge measurements Program.

3,500

3,000

2,500

2,000

1,500

1,000

500 Daily mean discharge, in cubic feet per second 0

-500 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012

Figure 29. Daily mean discharge at the U.S. Geological streamflow-gaging station on the Calumet Sag Channel near Route 83 at Sag Bridge, Illinois, for the 2012 water year. Chicago Area Hydrology 35

A 0

0.3

0.2 5

0.1

Depth, in feet 0 10

-0.1 in feet per second Streamwise velocity,

Riverbed -0.2 15

0 50 100 150 Distance, in feet

EXPLANATION Velocity vectors—length and color of vectors show magnitude (see 4616505 0.2 color scale at right) and orientation shows direction

4616500 0.15

4616495 0.1 UTM Northing, in meters 4616490

0.05

4616485 Depth-averaged velocities, in feet per second, averaged over total depth 421770 421780 421790 421800 421810 UTM Easting, in meters

Figure 30. Data from low- and high-flow acoustic Doppler current profiler measurements in the Calumet Sag Channel near Route 83 at Sag Bridge, Illinois, showing, A, low-flow cross-section water velocity contour, B, low-flow plan view of depth-averaged velocity magnitude and direction, C, high-flow cross-section velocity contour; and D, high-flow plan view of depth-averaged velocity magnitude and direction. (UTM, Universal Transverse Mercator) 36 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

C 0

2.5

Depth, in feet 1.5

10 Streamwise velocity, in feet per second Streamwise velocity,

12 1 Riverbed 14

0 50 100 150 Distance, in feet

2.6 EXPLANATION 4616550 Velocity vectors—length and color of vectors show magnitude (see color scale at right) and orientation 2.4 shows direction 4616540 2.2

4616530 2

4616520 1.8 UTM Northing, in meters

4616510 1.6

4616500 1.4 Depth-averaged velocities, in feet per second, averaged over total depth 421610 421620 421630 UTM Easting, in meters

Figure 30. Data from low- and high-flow acoustic Doppler current profiler measurements in the Calumet Sag Channel near Route 83 at Sag Bridge, Illinois showing: A, low-flow cross-section water velocity contour, B, low-flow plan view of depth-averaged velocity magnitude and direction, C, high-flow cross-section velocity contour, and D, high-flow plan view of depth-averaged velocity magnitude and direction. (UTM, Universal Tranverse Mercator)—Continued Chicago Area Hydrology 37

The flow in the Calumet-Sag Channel is characteristic of its length. Barge traffic during winter months breaks the ice of the unsteady conditions in the CAWS. This reach of the cover in the navigation channel. Calumet-Sag Channel is also affected by the complex hydrau- The regulation of flows, control structures, low water lic setting just downstream at Sag Junction, the confluence slope, and channel characteristics all combine to produce of the Calumet-Sag Channel and the CSSC. During storms, a very complex hydraulic setting. The USGS operated and flow at the complex hydraulic setting at the confluence of the maintained an AVM streamflow-gaging station on the river Calumet-Sag Channel and CSSC forms eddies that collect a side of O’Brien Lock and Dam from 1997 to 2003 as part of lot of floating debris, and at times, visible contrasts in sedi- the Lake Michigan Diversion Accounting program. The AVM ment loads were observed. A USGS multibeam echosounder streamflow-gaging station was located at the end of the lock survey in this reach mapped the change in streambed eleva- guidewall approximately 1,000 ft from the lock and dam on tions between the Calumet-Sag Channel (shallower) and the the river side. Flow data from the AVM streamflow-gaging sta- CSSC. Discharge measurements made with an ADCP were tion and ADCP discharge measurements made in the channel used in this reach to document complex velocity and flow reach near the lock and dam document the complex hydraulic direction related to density contrasts between the Calumet-Sag setting (fig. 32A). A series of ADCP discharge measurements Channel and the CSSC. in the channel reach near the I–94 bridge (fig. 28) were made The discharge hydrograph for the 2012 water year at in May 2010 prior to a rapid-response effort for Asian carp the MWRDGC Calumet Water Reclamation Plant (WRP) is control (Asian Carp Regional Coordinating Committee, May shown in figure 31. The bending channel and variable outflow 2010). These measurements document the variability of water of wastewater effluent produce a complex hydraulic setting velocity and flow direction in this reach and further document in the reach near Acme Bend. During winter months, the the complex hydraulic setting (Jackson and Lageman, 2014; Calumet-Sag Channel (fig. 21) can be ice covered over much fig. 32B–C).

500

450

400

350

300

250

200

150

100

50 Daily mean effluent discharge, in million gallons per day

0 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012

Figure 31. Daily mean effluent discharge for the Metropolitan Water Reclamation District of Greater Chicago Calumet Water Reclamation Plant in Illinois for the 2012 water year. 38 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

Figure 32. Data from acoustic Doppler current profiler measurements in the Calumet River near the Thomas J. O’Brien Lock and Dam, Chicago, Illinois, showing: A, complex water velocity patterns adjacent to the lock and dam, B, circulation patterns in the Calumet River below the lock and dam, and C, the complex velocity patterns near the Calumet Water Reclamation Plant outfall. (WRP, water reclamation plant; from Jackson and Lageman, 2014) Chicago Area Hydrology 39

B Sluice gates

O’Brien Lock and Dam Lock bay

Eddies

EXPLANATION Depth-average velocity, in feet per second General circulation 5.00 2.50 2.35 2.21 2.06 1.91 1.76 1.62 1.47 1.32 1.18 1.03 0.88 Grand Calumet 0.74 River 0.59 0.44 0.29 0.15 0.00 No data

Marinas General circulation direction

Railroad bridge ±

0 570 1,140 FEET

0 110 220 METERS

Figure 32. Data from acoustic Doppler current profiler measurements in the Calumet River near the Thomas J. O’Brien Lock and Dam, Chicago, Illinois showing: A, complex water velocity patterns adjacent to the lock and dam, B, circulation patterns in the Calumet River below the lock and dam, and C, the complex velocity patterns near the Calumet Water Reclamation Plant outfall. (WRP, water reclamation plant; from Jackson and Lageman, 2014)—Continued 40 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

C Sidestream elevated Calumet Water pool aeration (SEPA) Reclamation Plant (WRP) outfall Outfall station discharge 300 ft3/s

Acme Bend

± Stagnation line April 29, 2005 EXPLANATION Depth-average velocity, in feet per second Outfall 1.50 General circulation discharge 1.42 555 ft3/s 1.33 Industrial outfall 1.25 1.17 1.08 1.00 0.92 0.83 0.75 May 21-22, 2010 0.67 Calumet WRP outfall February 17, 2005 0.58 discharge 0.50 465-564 cubic feet 0.42 per second Outfall 0.33 (ft3/s) discharge 0.25 414 ft3/s 0.17 0.08 0.00 No data

General circulation direction

0 500 1,000 FEET Railroad bridge 0 100 200 METERS March 30, 2002

Figure 32. Data from acoustic Doppler current profiler measurements in the Calumet River near the Thomas J. O’Brien Lock and Dam, Chicago, Illinois showing: A, complex water velocity patterns adjacent to the lock and dam, B, circulation patterns in the Calumet River below the lock and dam, and C, the complex velocity patterns near the Calumet Water Reclamation Plant outfall. (WRP, water reclamation plant; from Jackson and Lageman, 2014)—Continued Current Monitoring Issues for the Chicago Area Waterway System 41

Little Calumet River channel streamflow-gaging stations are located at South Hol- land, Ill., and at Hammond, Highland, and Munster, Indiana. The Little Calumet River watershed upstream from Several small tributary streams flow into the Calumet- the confluence with the Calumet-Sag Channel drains to the Sag Channel, including Tinley Creek, Stoney Creek, and Mill Calumet-Sag Channel. After completion, the Calumet-Sag Creek. During dry weather the combined flows of these tribu- Channel intercepted the flow from the Little Calumet River taries represent a relatively small fraction of the flow within and diverted the flow away from Lake Michigan. the Calumet-Sag Channel. Daily mean discharge for Tinley During dry weather, the flows are affected by wastewater- Creek is shown in figure 33. effluent discharge from the Thorn Creek Sanitary District treatment plant (not shown) along the tributary Thorn Creek. The Little Calumet River receives stormwater runoff from the heavily urbanized parts of the watershed and combined Current Monitoring Issues for the sewer overflows during wet weather. During winter months, Chicago Area Waterway System the Little Calumet River is often completely ice covered. The southwest-northeast orientation of the channel of the Little The CAWS is presently a focal point for several impor- Calumet River at the confluence with the Calumet-Sag Chan- tant issues that require an understanding of the complex nel contributes to the complex hydraulic setting in this reach. waterway, such as The USACE constructed several flood control projects in the Little Calumet River drainage basin. A control structure • Lake Michigan Diversion accounting, near the mouth of Hart Ditch (not shown) regulates the flows • long-term regional water supply, and restricts westward flow during large storms. A natural drainage divide in the area around the mouth of Hart Ditch • invasive species, produced variable flow directions in this reach of the channel prior to the flood control projects. The Little Calumet River is • waterway separation, gaged at four locations along the main channel and at mul- • regional waterway transportation, and tiple streams tributary to the Little Calumet River. The main • local and regional flood control issues.

250

200

150

100

50 Daily mean discharge, in cubic feet per second

0 Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. 2011 2012

Figure 33. Daily mean discharge for Tinley Creek near Palos Park, Illinois, for the 2012 water year. 42 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

As of 2014, the purpose of CAWS monitoring has expanded that did not rely on complex modeling to complete the annual to address many issues beyond the monitoring needs of computations. An alternative monitoring network to the Rome- 1900. The demands on the CAWS have increased over time. oville streamflow-gaging station was proposed by the Third Navigation and wastewater discharge regulations have become Technical Review Committee on Lake Michigan Diversion increasingly stringent and require more detailed monitoring (Espey and others, 1994). These recommendations resulted in to effectively meet the regulatory needs. Waterway operations the installation of three additional AVM streamflow-gaging must balance increasing demands for water quality, commer- stations in close proximity to the lakefront control structures. cial and recreational navigation, regional flood control, and These streamflow-gaging stations (fig. 1) are located at (1) newer issues such as wastewater disinfection and the threat North Shore Channel at Wilmette, Ill., (2) Chicago River at from aquatic invasive species. Overall there continues to be Columbus Drive at Chicago, Ill., and (3) Calumet River below a regional recognition of Lake Michigan water as a valuable O’Brien Lock and Dam at Chicago, Ill. Streamflow data col- resource. These needs emphasize that, more than ever before, lected at these three gaging stations helped define the distribu- there is an increased need for CAWS monitoring. tion of direct diversion flow within the CAWS, seasonal tim- There are several issues pertinent to the CAWS that are ing of direct diversion into the CAWS, and detailed timing and dependent upon or directly benefit from accurate waterway flow of storm-related backflow events. Although the USACE monitoring data. A primary reason for monitoring flows within Lake Michigan diversion accounting program has ended the the CAWS is to maintain compliance with the U.S. Supreme alternative monitoring network concept, the data collected Court decree on Lake Michigan Diversion accounting. Moni- from the three streamflow-gaging stations has contributed to a toring water levels at various points within the CAWS insures better understanding of the CAWS. appropriate depths for navigation within the waterway. The waterway is also a critical component of a regional flood- control program, which is dependent on waterway monitor- Regional Flooding ing. The monitoring of flow within the waterway is a critical As the primary outlet for stormwater in the region, flow component to maintaining compliance with State and Federal within the CAWS is managed by the MWRDGC to prevent water-quality standards. Flow monitoring provides critical flooding during storms. The CAWS is an important component information for several power plants and industries located of MWRDGC’s regional flood control program. As storms along the CAWS that use the CAWS for cooling water. approach the region, the MWRDGC actively manages water levels within the CAWS to provide for more channel stor- Lake Michigan Diversion Accounting age of stormwater within the channel. The MWRDGC TARP system of sewers, tunnels, and reservoirs works together to The USGS streamflow-gaging station (05536890) on the capture stormwater and combined sewer flows. During large or CSSC near Lemont, Ill., functions as the primary measurement intense storms, the capacity of the system is exceeded and the point for Lake Michigan diversion accounting. Long-term excess flow is diverted directly to the CAWS. Control struc- monitoring of the CAWS at this location meets the require- tures at Lockport, the Wilmette Pumping Station, the CRCW, ments of the 1980 U.S. Supreme Court decree (Consent and the T.J. O’Brien Lock and Dam are used to prevent flood- Decree 388 U.S. 426 [1967] Modified 449 U.S. 48 [1980]) ing. As new TARP reservoirs are completed, the hydrology of and provides a long-term continuous record of discharge for the CAWS is likely to change to reflect the additional storage the CAWS. The value of the long-term streamflow-gaging and delayed release of reservoir water to the CAWS. The near station is that it allows engineers and scientists to analyze the real-time data from the AVM streamflow-gaging stations on flow records for trends. Implementation of water-conservation the CAWS is used to monitor the water levels within the sys- measures and repairs made to the critical infrastructure in the tem and evaluate the routing of flood hydrographs. Operators Chicago area can be detected in the flow records when they at the control structures use the data during floods for opera- are evaluated over an extended period. The single streamflow- tion of water-level control. The USGS has worked closely gaging station at the lower end of the CAWS (fig. 1; Rome- with the USACE and the MWRDGC to provide near real-time oville 1984–2006, then Lemont 2006–present) records the data for waterway operations. cumulative effects of changes within the hydrology of the Discharge data are also critical for the calibration of entire Chicago area. hydraulic models that engineers use in regional flood control The 1980 U.S. Supreme Court decree mandates that the projects. The USACE has recently completed (2011) the flood USACE Lake Michigan Diversion Accounting Program be protection features for a major flood control project along the reviewed by an independent technical review committee every Little Calumet River. The levees, floodwalls, pump stations 5 years. The technical review committees recognized that and flow control structures will provide 200-year level of flood data from the single streamflow-gaging station at Romeoville/ protection to more than 9,500 homes and businesses in the Lit- Lemont were not adequate to address questions regarding the tle Calumet River watershed and prevent nearly $11 million in distribution of flows near the lakefront structures and leakage average flood damage. Flood control projects like the USACE through the lakefront control structures. The committee was Little Calumet River Project rely on accurate waterway gage also interested in a simpler approach to diversion accounting data for the design of flood control measures. Current Monitoring Issues for the Chicago Area Waterway System 43

Power Plant Thermal Load Modeling power plant discharge location (fig. 35), and elevated water temperatures are observed downstream from the power plants. Several major coal-fired power plants (Midwest Gen- Power plant operators currently rely on the real-time flow data eration Plants-Will County, Fisk, and Crawford) are located from the USGS AVM gaging station on the CSSC near Lem- along the CAWS and rely directly on the volume of flow in ont gaging station to meet waterway thermal regulations. the CAWS for cooling water (fig. 34). Two of the three power plants (Fisk and Crawford) have recently closed or are in the processing of closing operations (as of 2014). Each of these Infrastructure Design plants operate or operated as “once-through” cooling systems Flow data are routinely used by engineers to design infra- where water is withdrawn directly from the waterway, absorbs structure components along waterways. Bridge piers, loading heat from cooling coils, and is returned to the waterway. The terminals, outfalls, and other structures that extend into the water withdrawals of these plants directly impact the local water require water level and flow data for proper design. flows within the CAWS. The USGS studied this reach in detail Increased demands for recreational use of the CAWS brings in 2010 (Jackson and Lageman, 2014) using Rhodamine dye more people in close contact with the waterway, from new as a tracer. The dye data defined a low-velocity stagnant river-walk paths and facilities to new boathouses for human- zone of water between power plant intake and return chan- powered craft; the associated facilities and structures that are nel. The thermal loading from these withdrawals also impacts built along the waterways are designed and constructed using the water-quality conditions throughout the CAWS. A sharp water level and flow data (fig. 36). increase in water temperature is observed at the warm water

Figure 34. The coal-fired power plant at Romeo Rd (135th Street) along the Chicago Sanitary and Ship Canal near Romeoville, Illinois. 44 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois 87°38' 87°40' MILES 2 87°42' KILOMETERS 2 1 1 Orthography from the USDA Farm Service Agency, Orthography from the USDA Farm Service Agency, Aerial Photography Field Office 2012 National Agriculture Imagery Program (NAIP) Natural Color Imagery for Illinois, accessed in 2014 at http://gis.apfo.usda.gov/arcgis/services 0 0 87°44' 5.01 to 6.00 6.01 to 7.00 7.01 to 8.00 8.01 to 9.00 9.01 to 10.00 10.01 to 11.00 11.01 to 12.00 12.01 to 13.00 13.01 to 14.00 14.01 to 15.00 15.01 to 16.00 EXPLANATION Temperature, in degrees Celsius 87°46' Lake Michigan River

Chicago Channel

North Branch COOK and Ship Canal Ship and

River

Des Plaines Cal-Sag Sanitary

87°48' Chicago WILL EXPLANATION DUPAGE Sampling location on the Chicago Area Waterway Sampling location shown Synoptic water temperature (near surface) data from the upper Chicago Sanitary and Ship Canal collected February 2012 s harp increase in

41°54' 41°52' 41°50' 41°48' Figure 35. temperature at the power plant discharge locations. Current Monitoring Issues for the Chicago Area Waterway System 45

Figure 36. Construction of the river walk along the mainstem of the Chicago River. 46 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

Waterway Separation waterways is the threat that invasive Asian carps may pose to the sport fishing industry in the Great Lakes. Concurrent stud- Construction of the CAWS provided an important water- ies by the Great Lakes Commission (Great Lakes Commission, way link between the Lake Michigan Basin and the Illinois 2012) and the USACE (U.S. Army Corps of Engineers, 2014) River/Mississippi River Basin. While this link is important to are evaluating the feasibility and technical issues of waterway transportation of bulk goods in and out of the region and the separation. Several separation scenarios and separation loca- reduction of wastewater discharge to Lake Michigan, it also tions have been evaluated (fig. 37). The physical placement is an open pathway for the movement of aquatic invasive spe- of a barrier or multiple barriers in the waterway represents a cies. In 2002, the USACE constructed an electric fish barrier radical change in the hydraulics and hydrology of the CAWS. in the lower reaches of the CAWS to prevent the movement Each scenario and location has positive and negative aspects of invasive species through the waterway. Recent movement with regards to transportation, flooding, water quality, and of several species of Asian carps up the Illinois River (not costs. The effects of the barriers at different scenario locations shown) towards the CAWS spurred discussions on a complete will be addressed through engineering studies using hydraulic waterway separation of the CAWS to permanently sever the model simulation. Addressing the data requirements for proper waterway link between Lake Michigan and the Illinois River/ calibration of the hydraulic models is just one type of short- Mississippi River Basins. A major concern for separating the term use of waterway data.

EXPLANATION Mid-system separation CAL SAG open control technologies with buffer zone Alternative features Project

Mitigation

Project and mitigation

Conveyance tunnel

Water reclamation plant outfall tunnel

Sediment remediation

Buffer response zone

Water reclamation plant

Figure 37. One of the waterway separation scenarios proposed by the U.S. Army Corps of Engineers Great Lakes and Mississippi River Interbasin Study. (From U.S. Army Corps of Engineers, 2014; GLMRIS, Great Lakes and Mississippi River Interbasin Study; ANS, aquatic nuisance species; CAL SAG, Calumet Sag Channel; WRP, water reclamation plant) Summary 47

Summary the CAWS. The implementation of near real-time telemetry to streamflow-gaging stations on the CAWS helps to reduce the The hydrology of the Chicago Area Waterway System amount of missing record in the operation and maintenance (CAWS) can be characterized as a low-slope natural drainage of the streamflow-gaging stations. The many issues affecting system that has been highly modified to facilitate the drain- the CAWS reinforce the need for detailed hydraulic data to age of a large metropolitan area. The construction of man- understand the complex hydraulic setting. made canals, water-control structures, tunnels, and reservoirs Since its construction in 1900, the CAWS has served to interrupt the natural drainage patterns and convey water several important functions for the Chicago region, including away from Lake Michigan has produced a complex regulated a long-term regional water supply/wastewater diversion func- hydraulic setting. This report describes the hydraulic charac- tion that provides municipal water supply for approximately teristics of the different reaches of the CAWS and presents 9 million people and helps maintain water quality in Lake examples of the flow measurement data over a wide range of Michigan, a regional waterway for transportation, and local flow conditions. Examples of flow measurement data through and regional flood control. Recently, the CAWS has become a range of flow conditions including low, medium, high, and the focal point for several important regional issues. Proposed in some locations, reverse flow are presented. The unsteady changes to the State of Illinois’ diversion of Lake Michigan flow characteristics found throughout the CAWS are evident in water, water supply needs for projected growth in the popula- the data and presented graphically. The detailed hydraulic data tion of the Chicago metropolitan area, protection from and collected by the U.S. Geological Survey at streamflow-gaging control of invasive species that threaten the ecology of both stations throughout the CAWS provide engineers and scien- the Great Lakes and Illinois River, regional flood control tists with an understanding of how this complex waterway functions, infrastructure design, and cooling water demands system operates and contribute to a more efficient operation for power plants are just some of the issues that currently or of the CAWS. The use of hydroacoustic flow measurement will potentially impact the CAWS in the near future. Increased instruments like acoustic velocity meters and acoustic Dop- levels of waterway monitoring can provide scientists and engi- pler current profilers has advanced the understanding of the neers a better understanding of CAWS hydrology and the data complex hydraulic setting characteristic of many reaches of to address current and future uses for the CAWS. 48 Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois References Cited

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Duncker and Johnson—Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois—Scientific Investigations Report 2015-5115 ISSN 2328-0328 (online) http://dx.doi.org/10.3133/sir20155115