The Logistics of Large Diameter Waterline Shutdowns

With the aged infrastructure in many U.S. cities and the devastation caused by large diameter (i.e., greater than 24-inches) transmission main failures, the need for many cities and water utilities to perform an assessment of their system has intensified. The challenge in assessing these large transmission mains includes budgeting and manpower constraints. Even with the latest technology, assessment requires a delicate balance to physically shutdown critical mains while still supplying system demands and with as little public disruption as possible. The answer involves in planning, communicating, planning, testing, and planning some more. With limited time and other facility shutdowns required for construction or rehabilitation work, creative solutions are needed to formulate feasible shutdown solutions. This paper will discuss the preparation efforts and considerations taken by the City of Houston (City) in performing condition assessment of several of their large diameter water mains ranging in size from 48- to 84-inches.