Large Diameter Water Main in a Congested Urban Environment Fort Worth East Side II 54" Water Main

Large-diameter pipeline design in a fully-developed urban environment presents many challenges. The designer has to work around or relocate existing obstacles while keeping water, sewer, and traffic disruptions at a minimum. This paper will discuss: (1) the design of the City of Fort Worth East Side II 54-inch Water Main (E-2); (2) how existing development presented multiple design challenges; and (3)how the design compensated for these challenges. The E-2 pipeline is a key component of the City's water transmission system. The pipeline supplies water from the City's Rolling Hill's Water Treatment Plant to northern sections of the City and several wholesale customer Cities. The current pipeline was built in multiple stages from 1972 to 1985. The E-2 is primarily a 54-inch pipeline. There is, however, a 42-inch section in the middle of the alignment that limits the full use of the entire line. The City of Fort Worth hired Freese and Nichols, Inc. to design a 54-inch replacement for this section of the line. The original concept was to construct the replacement 54-inch pipeline parallel to the existing 42-inch. However, the 42-inch alignment is very congested and an alternate route had to be developed. The E-2 pipeline runs through the heart of Fort Worth's east side, primarily along the Beach Street Corridor. The area has been developed for many years (in some cases over 100 years), and existing water, sewer, franchise utilities, and gas well sites occupy much of the open space and City Right-Of-Way. While selecting the route and designing the 54-inch line, the project team had to consider all of these potential conflicts as well as two major urban highway crossings, a railroad crossing, and a crossing of the Trinity River. The design also had to allow for keeping the existing 42-inch water line, a 36-inch water line and numerous smaller water and sewer lines in service, while keeping all major streets open during construction.