Situation

The Las Vegas Valley Water District (LVVWD) is responsible for providing a safe drinking water supply to more than 1.5 million residents from a sizable water system that includes more than 6,500 miles of transmission and distribution pipeline.

For the town that never sleeps, neither does the crew at the LVVWD – as they relentlessly protect the community’s underground water distribution network from water main failures and breaks. This long-standing commitment toward continuous improvement and self-assessment helps the utility maintain some of the lowest water loss rates in the nation with eight times fewer main breaks than a typical water utility.

To ensure ongoing water service reliability, the LVVWD is implementing its 10-year, $616 million Capital Improvement Plan (CIP), which came into effect in 2017. The plan focuses on infrastructure renewal and many other efforts, including the repair and replacement of facilities and aging pipes with an expansion initiative to increase system capacity.

Nevada is the driest state in the nation and one of the fastest-growing. Water conservation is also undeniably top-of-mind.

“When it comes to water conservation, our customers are already playing a tremendous role in reducing water waste. From a utility standpoint, we’re constantly looking at maximizing our system and providing reliable water service. Over the years, we’ve been successful at detecting leaks, assessing our critical infrastructure and repairing pipes before they reach the end of their remaining useful life. So our goal here is to continue to drive non-revenue water level to as low as possible,” explains Bronson Mack, District spokesman at the Las Vegas Valley Water District.

Action

To help track leaks down before they become a problem, apart from other proven technologies, the LVVWD uses an acoustic leak detection system that listens for water leaking underground and pinpoints where leaks are occurring. As a 24/7 town, the Water District understands that shutting down any water infrastructure may affect service to its customers. To ensure that impacts on any businesses or households are kept to a minimum, the Water District uses the LeakFinder-ST^TM for its non-invasive approach toward leak detection.

As an advanced Windows-based leak noise correlator, the LeakFinder-ST^TM works off an acoustic-based technique using cross-correlation to measure leak noise signals and determine the difference in the time delay between vibration signals measured on either side of a water leak. Together with the velocity of noise propagation, leak locations can be determined, if not pinpointed.

Results

One notable achievement was the successful detection of a 1” leak on the South Valley Lateral, the backbone transmission pipeline serving the city of Henderson and other areas throughout the valley’s southern region. The LeakFinder-ST^TM was set up on the 108” mortar-lined and coated steel pipeline, surveying a distance of 1,789ft. To access the sensor location and subsequently perform leak correlation, the field crew set up traffic control and the work began.

Using the LeakFinder-ST^TM and magnetic-based surface-mounted sensors, crews identified the location of a 300 gallon-per-minute leak and completed repairs without interrupting water services to the community. What the LVVWD had achieved here was the ability to minimize the amount of evacuation work needed and efficiently put ratepayers’ dollars to work.

“This technology allowed for a hassle-free deployment. We did not need to shut down the system temporarily to get inside the pipe. Instead, all we had to do was to connect the sensors above ground to existing connection points of the infrastructure. When correlating, we were able to get the reading between those two points which helps us to focus our effort on the leak location – preventing us from having to do any exploratory digging,” said Mack.

For a water system that has over 60% of its pipeline infrastructure still relatively new, the Water District’s leak detection efforts focus on mature and critical segments of the water system with historical records of leaks. The CIP program aims to ensure that those areas of the water system remain just as reliable as the newer areas and provide equity across the entire customer base. Hard work did not go unnoticed. In 2018, the LVVWD was honored by the Association of Metropolitan Water Agencies with a sustainable water utility management award. This success came at a time when changing economic and climatic conditions pose a threat to the sustainability of existing water supplies.

Critical to its water conservation efforts, to date, the LVVWD’s leak detection system has led to the discovery of more than 2,500 underground leaks and has saved more than 665 million gallons of water since 2004.