Bottling a Rainstorm

This article appeared in the GAO Review, Vol. 14, Issue 4, Fall 1979. The Chicago Tunnel and Reservoir Project (TARP) is designed to alleviate the flooding and waterway pollution problems in the Chicago metropolitan area and eliminate backflow of the Chicago River into Lake Michigan. When completed, the tunnel will extend for 131 miles, its diameter of 30 to 35 feet will permit three locomotives to fit across it, and its depth of 200 to 300 feet will be equivalent to buildings that are from 14 to 21 stories high. TARP will have three below-ground, open-pit reservoirs which will also be 200 to 300 feet deep, and the tunnels and reservoirs will hold 44 billion gallons of water. The Metropolitan Sanitary District (MSD) of Greater Chicago believes the project will cost $3 billion, but GAO insists it will cost in excess of $11 billion by 1983. The $3 billion figure cited by MSD includes only their estimates of building the tunnel and reservoirs, whereas GAO believes that it will be necessary to include as well the cost of associated projects. The State of Illinois has said that, to meet its water quality standards, it will require instream aeration at a cost of $32 million, and GAO believes these costs should be included. Other costs to be considered are: treatment plant upgrading, increased sludge capacity, ship channel and navigational work, and estimated future inflation. The Environmental Protection Agency and Illinois cannot agree on whether the first phase of TARP will meet its goals; therefore, the cost-effectiveness of the project should be considered.