20-Year Anniversary of Tucson Water’s Pipeline Protection Program (PPP)

The city of Tucson is a Sonoran Desert community in southern Arizona with a population of nearly 750,000 people and one million people, including the metropolitan areas. “Tucson Water”, a department of the city of Tucson, is a large, complex groundwater system receiving a Colorado River water allocation of approximately 148,000 acre-feet, which the city recharges in a vast recharge and recovery system west of the community. In February of 1999, the city’s largest potable water transmission line, a 96-inch diameter (4,000 mm) prestressed concrete cylinder pipeline (PCCP), failed catastrophically, releasing a flood of water, mud, rock, and debris, crashing into a neighborhood, knocking down block walls, trapping people in homes, floating vehicles out of driveways, and causing extensive damage to private property and homes within the community. This one failure of a pipeline just 11 years old, cost the city approximately five million dollars in private property damage, collateral damage, and litigation, and forced the city to revert back to pumping native groundwater for months, until the transmission line was restored to service. The forthcoming white paper will demonstrate how one water utility recovered from the catastrophic failure of its most critical water transmission line, progressed to one of the most forward-thinking water utilities, and implemented one of the most advanced and longest running asset management programs for PCCP in North America. This “snapshot” presentation of Tucson’s asset management program entitled “Pipeline Protection Program” (PPP), will give a brief overview of the various challenges Tucson faced and highlight the various strategies, tools, and technologies applied, that have collectively prevented any additional catastrophic failures for more than 20 years and counting.