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State Programs

Illinois Department of Natural Resources, Office of Water Resources

Flood Control Planning

The Flood Control Act of 1945, 615 ILCS 15, gives the Office of Water Resources (OWR) legal authority to participate in the improvement of the rivers of the State for the purpose of regulating and controlling flood and low-water flows. Criteria followed by the Office relating to flood control planning include:

• Assurance that the most severely damaged areas receive priority consideration and assistance from State and Federal sources.

• State water resource projects be designed to maximize economic efficiency at minimal environmental impact.

• State expenditures result in the maximum benefits for the least possible cost.

• Local interest and investment of funds be required as evidence of involvement in any project.

OWR, through its regular flood control program and in cooperation with local governmental sponsors, has provided over 5350 acre-feet of floodwater storage in eleven reservoirs, as well as improved channels at numerous locations throughout the Chicago Metropolitan Area.

OWR provides funding through its Small Projects Program to alleviate smaller, more easily solvable flood problems. Maximum OWR funding is currently $75,000 per Small Project. Additionally, OWR provides study/project support through field activities including the operation of a modernized water resources data collection network and the acquisition of field survey data.

OWR participates in Federal programs within the legal authority of State Statutes. OWR is an active sponsor, along with other regional and local agencies, of floodwater management plans developed with NRCS, MWRD, and Corps of Engineers assistance. Sponsor responsibilities include land acquisition needed for the structural measures and implementation of various non-structural programs and project operations and maintenance.

Stream Preservation Program

OWR assumed responsibility for the development of a stream preservation program as a part of the non-structural program of the Chicago Metropolitan River Basin Plans.

Stream Preservation refers to the management of a stream’s conveyance capacity and can include natural channels and environmental enhancements.

It includes the following goals and objectives:

• Keep debris, sediment, and restrictive vegetation out of rivers and streams.

• Convey floodwater safely through each community.

• Assure that flood control structural measures will perform as planned by maintaining unobstructed inflows and outflows.

• Provide for annual inspection and maintenance of the key rivers and streams in each watershed.

• Encourage each community to assume responsibility for maintenance of the stream portion within its jurisdiction.

• Provide assistance and advice to communities and other regional agencies when needed.

• Encourage environmental awareness of the general public.

The program has been implemented and coordinated through each respective watershed steering committee. Greater community compliance with this program would provide even greater results.

State Floodplain Regulations

The Rivers, Lakes, and Streams Act, 615 ILCS 5, gives the Office of Water Resources the authority to regulate construction activities within the floodway. The floodway is that portion of the floodplain required to store and convey floodwater. A permit is required to construct within the floodway. Construction that significantly raises the stage or velocity of the 100-year projected flood in the floodway is prohibited . Only appropriate uses are allowed.

The Office has compiled an official list of designated regulatory floodway maps. Information is available from the Office or from the local municipality.

Floodproofing and Flood Insurance Programs

The Office’s Floodplain Management Section is the State Coordinating Agency for the National Flood Insurance Program. This section provides advice and information concerning the flood insurance program as well as technical assistance.

Flood Mitigation Program

Illinois Revised Statutes, Chapter 19, para. 126d. gives the Office of Water Resources the authority to acquire floodplain property to convert to public use. This authority is used to acquire properties that cannot be protected by flood control structures, or where structural flood control measures are not practical or economically feasible. Only those communities participating in the National Flood Insurance Program may be considered for funding through this program. Currently, four communities in DuPage County (Addison, Elmhurst, Oak Brook, and Wood Dale) are receiving flood mitigation project funding. In Will County a mitigation project was funded by OWR as the result of the 1990 Plainfield tornado.

The Office of Water Resources also provides technical mitigation and floodproofing assistance to property owners through publications available free of charge.

Metropolitan Water Reclamation District of Greater Chicago

The first major modification of the natural drainage system in the Chicago Metropolitan Area was made by the Metropolitan Water Reclamation District (MWRD) in the late 1880’s. A series of canals were constructed to reverse the flow of the Chicago River and carry waste away from Lake Michigan.

The existing canal systems (Sanitary and Ship Canal, North Shore Channel, and Calumet-Sag Channel) provide a substantial volume of flood control storage and flow capacity. The water level in the waterways can be lowered in anticipation of a storm to provide stream bank storage of up to 4,600 acre-feet of additional capacity beyond normal operating water levels.

Flood Control Program

While MWRD does not have a specific statutory responsibility in the area of flood control, its involvement and expertise in the areas of water pollution control and drainage have led the MWRD to assume a flood control leadership role in the Metropolitan Area.

By the mid-1960’s, MWRD was involved in the design and construction of many flood control storage reservoirs and stream improvement projects. Melvina Ditch Reservoir, completed early in 1967 in Oak Lawn, was the first reservoir constructed. To date 30 reservoirs have been completed with MWRD participation. These reservoirs range in capacity from 24 to 1,089 acre-feet of stormwater detention and provide flood relief to thousands of people. Most of the reservoirs designed by the Water Reclamation District will accommodate a 5- to 6-inch rainfall storm event.

The maintenance and operation responsibility of approximately one third of the existing reservoirs has been fully undertaken by the local municipalities. MWRD shares this responsibility with a local public entity in one third, and the remaining one third are maintained solely  by the MWRD.

MWRD has sought Federal, State, and local participation in its flood control efforts. MWRD was one of the principal sponsors of the floodwater management plans developed by the Natural Resources Conservation Service. These plans address flood control on a regional basis, and most of the reservoirs delineated by these plans have been completed and are operating.

MWRD, as a local sponsor of the NRCS watershed projects, was responsible for the acquisition of land rights and contract administration. Since the inception of this program, MWRD has expended more than $10,000,000 in land rights acquisition for five reservoirs (Structures 2, 3, 4, 5, and 6) in the Upper Salt Creek Watershed,  more than $15,000,000 for three reservoirs (Structures 32, 53, and 143) in the Little Calumet River Watershed, and more than $2,000,000 for two reservoirs (Structures 86 and 102) in the lower Des Plaines Watershed. As contracting agent, MWRD has administered the construction of ten reservoirs with NRCS funding.

In 1974, MWRD adopted ‘‘Flood Control Program Guidelines’’ (amended January 1981), which established certain criteria for MWRD’s participation in proposed local flood control reservoir projects (projects not addressed in the regional NRCS plans). These criteria included such items as the requirement for a local sponsor to share the costs of reservoir implementation, a requirement that the proposed reservoir be of at least 100 acre-feet capacity, that the flooding problem be of long standing, and that the project has a favorable benefit/cost ratio.

The January 1981 amendment requires a ‘‘Strategic Planning Study for Flood Control’’ to be conducted by the Illinois Office of Water Resources (OWR). This OWR study is required for possible State and MWRD funding of the project and is used to define a cost effective project. The cost of a State and MWRD study is borne equally by the local sponsor and the Water Reclamation District. The Flood Control Program Guidelines ensure that public funds are expended only in situations where serious flooding problems exist and adequate justification of expenditures is made.

State legislation is currently being considered that would name the MWRD as the Regional Stormwater Management Agency for Cook County. The MWRD would be involved in the planning and design of flood control facilities and provide low interest loans for approved projects.

MWRD Sewer Permit Ordinance

Since 1972, detention of stormwater runoff has been a requirement of the sewer permits within the service area of the MWRD. This area includes most of Cook County.

The intent of the ordinance is to require local governments and developers to jointly provide detention storage. This eliminates excessive runoff during heavy storm periods and promotes comprehensive community-wide programs for flood control. The MWRD ordinance requires that the release rate of stormwater runoff from a development not exceed stormwater runoff from the area in its undeveloped state.

Infiltration/Inflow Corrective Action Program (ICAP)

The Clean Water Act enacted by Congress mandated that all sanitary sewer systems in the USA be rehabilitated to eliminate excessive stormwater.

In the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) area, regional sewer conferences were convened. As a result of these conferences, a Sewer Summit Agreement was created which was acceptable to all municipalities. The Sewer Summit Agreement enabled the local municipalities to meet the requirements of the Clean Water Act without creating a financial burden on the local taxpayers.

The purpose of ICAP, as developed by the local communities, is to remove excessive Infiltration and Inflow (I/I) from sanitary sewers in order to meet the following goals:

• Eliminate basement sewer backups and other conditions that cause health hazards or financial losses.

• Prevent pollution of the waterways.

On November 21, 1985, the MWRDGC’s Board of Commissioners approved adoption of the Sewer Summit Agreement and authorized an amendment to article 6-5 of the Manual of Procedures for the Administration of the Sewer Permit Ordinance, creating ICAP.

Sanitary sewers are designed and intended to convey only sanitary wastewater. The major sources of stormwater entering a sanitary sewer system are excessive I/I. Infiltration is the stormwater entering a sanitary sewer system through defective pipes, pipe joints, pipe connections, and manhole walls. Inflow is the stormwater discharged into a sanitary sewer system through roof leaders, cellar drains, yard and area drains, foundation drains, cooling water discharges, drains from springs and swampy areas, manhole covers, and cross connections from storm sewers and combined sewers.

Excessive I/I overloads sewers. Overloaded sewers cause basement flooding, health hazards, financial losses, and inconvenience to residents and businesses. Excessive I/I also results in additional sewage treatment costs to the public.

Tunnel and Reservoir Plan (TARP)

The Chicago Metropolitan Area has two different methods for collecting sewage. Flood problems in areas serviced by these two systems must be resolved differently. In most areas, except the central basin, sewage and storm- water are collected in different sewers. One system of sewers collects stormwater, and the other system of sewers collects sewage. These areas are commonly called ‘‘separate sewer’’ areas. Surface flood retention reservoirs, mentioned previously, are provided only in separate sewered areas. In the central basin, sewage and stormwater are collected in the same sewer and the areas served are called ‘‘combined sewer’’ areas. Combined sewer areas comprise 375 square miles of the total 872 square mile area under the jurisdiction of the Water Reclamation District. Flood and pollution problems in these areas are handled with combined sewers by the Tunnel and Reservoir Plan (TARP). The TARP service area includes the City of Chicago and 51 suburban municipalities.

TARP consists of two phases. Phase I of the Plan is primarily a water pollution control project. Phase II is associated primarily with urban flood control.  Virtually all excess combined sewage will be captured by the ultimate tunnel-reservoir system. In addition, waterway stages will be controlled, reducing overbank flooding, basement flooding, and bypassing of raw sewage to Lake Michigan.