The Deep Tunnel System was created to ameliorate the sewer and pollution problems of storm runoff events. Most of it has been built under existing waterways where storm sewers and other runoff sources already converge, resulting in a discontinuous network as a whole. Such waterway locations, publicly owned, also simplified construction. The system is designed to collect excess stormwater into reservoirs for later treatment and gradual release.

Author: Dennis McClendon
Source: Newberry Library