Speaking

The Portland Water District (PWD) supplies water to 16-percent of Maine's population through over 1,000 miles of watermains. In 2024, PWD advanced its watermain risk management practices, adopting an AI-powered watermain break prediction and replacement planning tool. PWD also advanced its methodology for estimating the consequences of failure (COF) of watermain breaks to create monetized, triple-bottom line (TBL) risk costs associated with every watermain. The resultant advanced risk-cost values improved both the prioritization of watermain replacements and the determination of budgets for replacements to achieve level-of-service goals for water reliability.

Over 90-percent of watermain failures have predictable consequences: the direct financial cost of repairs to the utility ranges between $5,000 and $10,000 depending on location of the main (undeveloped vs. developed areas) and the regional cost of living. However, “hidden” costs can be 5-times higher than that due to traffic disruptions, service interruptions, property damage, surface restoration and other impacts. Where pipes are in proximity to roads, railroads, structures and waterbodies, TBL costs increase significantly. Additionally, COF can skyrocket if service interruptions impact critical customers and large users. For example, a 12-inch main break in Oregon once caused an estimated $5 million in TBL consequences.

For this project, PWD and its consulting team leveraged information from research agencies and other utilities to develop comprehensive TBL COF values for a variety of critical customers. Financial costs of breaks were estimated based on each pipe’s diameter and proximity to roadways, structures, water bodies and railroads. TBL costs were developed for hospitals, dialysis centers, nursing homes, schools, prisons, booster and pump stations, and treatment facilities. TBL COF analysis of select specific customers was also conducted for power plants and the region’s largest airport.

This presentation will share the methodology and tools utilized and provide advice on how to conduct a similar analysis. The presentation will share how Probability of Failure (POF) values we generated using an AI model and coupled with COF values to develop a risk profile for every watermain. 

Finally, PWD asked its consulting team to automate many of the processes used to develop the POF and COF values so that pipe risks could be updated periodically, allowing for updates of the watermain replacement program. Scripts were developed so this process could be accomplished cost effectively and consistently.