How to Purchase Sewer Atlas Information
 

The Engineering Department maintains three (3) atlases: TARP and Flood Control, Sewer, and Combined Sewer Area. The MWRD atlases have been deemed exempt from disclosure in accordance with Section 7(1)(k) of the Freedom of Information Act. However, if you’d like to make a request for a specific, narrowed location within the atlas, we will consider release of those records after weighing potential security risks. Requests are made through the Office of Public Affairs, in compliance with the Freedom of Information Act (FOIA). For FOIA procedures and fee schedules, click here.

1. TARP and Flood Control Atlas (31 oversized pages)

The Tunnel and Reservoir Plan (TARP), also referred to as the Deep Tunnel, shows the underground tunnels used to intercept stormwater overflow and convey it to large storage reservoirs. TARP is comprised of four major subsystems: Mainstream, Calumet, Des Plaines and O’Hare (Upper Des Plaines).

Maps in this atlas show the following:

  1. Boundary of MWRDGC service area

  2. Location and size of MWRDGC TARP Tunnels

  3. Location of drop shafts, connecting structures and interceptor connections

  4. Location of flood control projects

  5. Location of MWRDGC channels

  6. Flood control projects location plans

2. Sewer Atlas (31 oversized pages)

In order to collect wastewater from local sewer systems and convey it to the treatment plants, the District has constructed 547 miles of intercepting sewers, including force mains.

Maps in this atlas show the following:

  1. Boundary of MWRDGC service area

  2. Location and size of MWRDGC plants, and pumping stations

  3. Location, size and depth of MWRDGC sewers

  4. Location of MWRDGC channels

  5. Local sanitary districts

  6. Facility planning areas (service basins)

3. Combined Sewer Area Atlas (31 oversized pages)

The combined sewer system is designed to collect a mixture of rainfall runoff, domestic and industrial wastewater in the same pipe for conveyance to wastewater treatment plants.

Maps in this atlas show the following:

  1. Boundary of MWRDGC service area

  2. Location of MWRDGC combined sewers