Roger Jordan, Ryan Benner, Greg Kodweis
Papers # 2018 Las-Vegas
The Las Vegas Valley Water District (District) delivers water to approximately 1.4 million residents within the City of Las Vegas and unincorporated Clark County. The District maintains more than 4500 miles of water pipeline ranging from 4-inches to 102- inches in diameter, as well as another 2,000 miles of small-diameter service laterals ranging from one-half inch to 4 inches in diameter. With an average infrastructure age of approximately 22 years, the District’s water distribution system is relatively young, with less than six percent non-revenue water losses and a break rate of 1.3 breaks/100 miles. The utility’s pipeline network primarily consists of PVC (52 percent) and concrete pipe (36 percent); steel and ductile iron comprise much of the remaining pipe material.
The District has embarked on a $600 million dollar, 10-year Capital Improvement Plan (CIP). Two-thirds of the CIP funds are allocated for the repair and replacement of aging infrastructure, including more than $200 million dedicated to replacing aging water pipelines. The District has developed a program to identify and replace aging and failing pipelines utilizing a methodology that focuses on field investigations, break history, material type, and other parameters.
The District utilizes a variety of technologies to determine the condition of pipelines. These include acoustic monitoring for leaks, direct assessment of pipelines, and utilizing data captured and compiled in the District’s Graphical Information System. District engineers utilize this and other data, such as hydraulics, to determine the likelihood, as well as potential impacts, of failure. An overall risk assessment ranking is then developed for each pipeline to identify and prioritize replacement schedules. This data-based, proactive method allows the District to proactively target its capital investments in the most cost-effective manner possible. This paper will summarize the District’s methodology to identify and replace aging pipe with new PVC pipelines.