The best commercial water leak detection system is the one that saves the most money in your building. That usually means two things: stopping the hidden leaks that inflate the water bill every month, and catching damaging leaks before they soak finishes, equipment, and operations. This guide explains the system types, the criteria that matter, how well-known vendors differ, and how to judge payback.
Why commercial buildings need water monitoring
Most occupied commercial buildings are already leaking. The water shows up first as a higher bill, then sometimes as damage. Cooling towers, irrigation, restrooms, kitchens, and process equipment all lose water in ways no one sees during a walkthrough.
Published NOWi results show the scale. Across 47 buildings in Los Angeles, 72% were leaking in the first week of data, about 794,000 gallons a month and about $190,000 a year. At one site, NOWi found 1,521 gallons per hour leaking, worth $24,092.64 a month, and triage took 2 hours. These results are summarized on our commercial water leak detection page.
PGW Solutions, which used NOWi data across its commercial work, put it this way: "NOWi's precise, high-resolution data proved invaluable in analyzing water savings across a diverse range of commercial properties we service, from bustling restaurants to large-scale manufacturing facilities."
Types of commercial water leak detection systems
Meter-level commercial water monitoring
A sensor reads the existing water meter and records flow continuously. Software flags patterns that don't match normal use, like flow that never drops to zero after hours. Because it sees all water entering the building, it catches leaks in walls, underground, in cooling towers, and in fixtures.
Strength: whole-building coverage from one device, and direct savings on the water bill.
Trade-off: it tells you that a building or zone is leaking. You need zone sensors or a walkthrough to find the exact source.
Pipe-level flow monitoring
Clamp-on ultrasonic sensors measure flow through a specific pipe: a riser, cooling tower makeup line, irrigation line, or fire sprinkler line. This breaks a building into zones so you can see which system is driving use.
Strength: targeted visibility without cutting pipe.
Trade-off: each sensor covers one pipe.
Point-of-leak sensors
Spot sensors detect water on the floor near water heaters, server rooms, mechanical rooms, and drain pans.
Strength: fast alerts at known high-risk spots.
Trade-off: they only see the spot they're on, and they don't catch water going down a drain or into the ground.
Automatic shutoff valves
A motorized valve on a supply line closes when the system detects a problem.
Strength: limits damage from a burst line automatically.
Trade-off: valves are installed in-line, which usually means a plumber, a water shutdown, and more upfront cost.
How to choose a commercial water leak detection system
Start with what the leaks cost you
Ask which loss is bigger for your building: wasted water every month, or the risk of a damaging event. For many occupied buildings, the hidden-leak savings pay for monitoring, and damage prevention is the added protection. The right system covers both.
Coverage
Does it see the whole building's water, or only certain spots? Meter-level monitoring covers everything that passes through the meter. Point sensors cover their location. Ask vendors to map coverage against your building's actual water systems: domestic, cooling towers, irrigation, and fire protection.
Installation
Ask what the installation requires. Cutting pipe means a plumber, permits in some areas, and shutting water off to an occupied building. Reading the existing meter or clamping onto a pipe avoids all of that. NOWi's Meter Monitor reads the existing meter with magnetic, pulse, or meter protocols, and the Pipe Monitor clamps on with ultrasonic sensing. Neither needs plumbing.
Connectivity
Meter rooms and basements often have weak or no Wi-Fi, and IT teams may not want new devices on the building network. Options include Wi-Fi, LoRaWAN with gateways, and cellular. Cellular devices connect directly, with no gateway to install or maintain. NOWi's monitors use cellular with no Wi-Fi and no gateway.
Data resolution
Daily or monthly data can show that use went up. Minute-level data shows when a leak started, what shape it has, and whether a repair actually stopped it. NOWi's Meter Monitor reports minute-level data.
Alerts and response
Ask who gets alerts, how they arrive, and whether a monitoring service is included. Some vendors staff a monitoring center. Others send alerts directly to your team. Pick the model that matches how your facilities staff works.
Power and maintenance
Ask about battery life, power requirements, and what happens when a device loses connection. NOWi's Meter Monitor runs on a 5+ year battery, so no electrician is needed.
Portfolio reporting
If you manage several sites, look for one dashboard across buildings, utilities, and states, so you can rank sites by waste and send staff where it matters.
Commercial water leak detection systems compared
These summaries come from each vendor's own public pages. Confirm current details with each vendor.
NOWi Sensors
Cellular meter-level and pipe-level water monitoring for occupied commercial buildings. The Meter Monitor reads existing meters, and the Pipe Monitor clamps onto pipes, including cooling tower and fire sprinkler lines. Both send minute-level data over cellular, with no Wi-Fi, gateway, or plumbing work. NOWi focuses on cutting wasted water and catching leaks before they become damage.
Eddy Solutions
Eddy describes a managed program that combines point-of-leak sensors, flow metering, automatic shutoff, and a 24/7 live monitoring center. Its devices run on Eddy's own LoRaWAN network, with gateways that backhaul over Ethernet or LTE cellular. Eddy positions the program from construction through operations.
Wint
Wint describes an AI-powered water intelligence platform. Its control units connect to meters and valves, learn normal water behavior for each system, and can shut off water automatically. Wint says the control units run detection and shutoff decisions locally, so they keep protecting when communication is down. It also connects with third-party valves, meters, and sensors.
Alert Labs
Alert Labs describes cellular sensors with battery backup and no Wi-Fi or wired network required, 24/7 automated phone call alerts, automatic shutoff valves for pipes up to 6 inches, and the AlertAQ analytics platform. It monitors leaks, temperature, humidity, and building power status.
Which approach fits which building?
- Occupied buildings with high water bills: meter-level monitoring first. It installs without disrupting tenants and targets the bill.
- Sites with cooling towers, irrigation, or sprinkler systems: add pipe-level monitoring on those lines.
- Buildings with critical equipment rooms: add point sensors where water on the floor would be costly.
- New construction: shutoff valves are simplest to add before walls close.
Cooling tower monitoring: where commercial water savings hide
In many commercial buildings, the cooling tower uses more water than anything else. It's also where some of the largest savings sit, because a tower can lose money in two ways: through the sewer bill and through problems nobody sees on the roof.
Makeup and blowdown metering
A tower takes in fresh makeup water to replace what evaporates, and drains blowdown water to flush out the minerals that build up as water evaporates. Makeup minus blowdown is roughly the water lost to evaporation. NOWi's cooling tower page calls makeup and blowdown "the heart beat of your cooling tower." Metering both is how you know whether the tower is running the way it should.
Evaporation credits from your utility
Most utilities bill sewer based on the water coming into the building, on the assumption that most of it goes down the drain. Water that evaporates from a cooling tower never reaches the sewer, but without metering you usually pay sewer charges on it anyway. Many utilities offer an evaporation or sewer credit if you can show how much water evaporated, which usually means metering makeup and blowdown and reporting the numbers. Rules differ by utility: some adjust billing once, and others want regular reports. NOWi's cooling tower page says owners can "save $1,000s per month on sewer or evaporation credits," and NOWi helps manage the reporting with the local utility. Read more about cooling tower credits.
How blowdown problems waste water and chemicals
Most tower waste comes from the controls, not from a broken pipe:
- Stuck blowdown valves. A valve stuck open drains treated water continuously, so the tower keeps adding makeup water and treatment chemicals to replace it.
- Overflow. A failed float or fill valve can send makeup water straight out the overflow.
- Poor cycles of concentration. If the tower blows down too often, it wastes water and chemicals. If it blows down too little, minerals build up and scale forms.
- Conductivity controller faults. A fouled probe or bad set point can make the controller blow down at the wrong times.
Scale is the other cost. NOWi's cooling tower page calls it the biggest enemy of cooling towers because it cuts efficiency and damages the equipment. NOWi has also reported that cooling towers average 2 to 3 issues a year, each wasting 100,000 to 300,000 gallons of water (source).
Why continuous monitoring catches tower problems
A stuck valve or an overflow can run for weeks before anyone notices on the water bill. Minute-level makeup and blowdown data shows the change the day it starts: blowdown that never stops, makeup that runs at night when the load is low, or a ratio that drifts away from normal. NOWi's Meter Monitor and clamp-on Pipe Monitor install in minutes on cooling tower lines with no plumbing, and alerts flag stuck valves, bad set points, and early signs of scale. See NOWi's cooling tower monitoring.
How to calculate ROI on commercial water monitoring
- Gather 12 months of water and sewer bills for each site.
- Flag sites with high or rising use that no one can explain.
- Estimate the leak share. In NOWi's LA portfolio, leaks were about 8.5% of use. In San Francisco, 11 of 24 buildings were leaking $11,040 a month, with ROI under two months. Your numbers may differ, and monitoring will show them.
- Add avoided damage from your own claims and repair history.
- Compare against total cost: hardware, subscription, installation labor, and any downtime for plumbing work.
A system that doesn't need plumbing starts producing data the day it's installed.
A practical rollout for commercial portfolios
- Start with the sites with the highest water costs.
- Put a meter monitor on each main meter.
- Review the first week of minute-level data for after-hours flow.
- Send facilities staff to the worst sites first, and confirm each repair in the data.
- Add pipe monitors on cooling towers, irrigation, or sprinkler lines where the data points.
- Roll out across the portfolio and rank sites by waste each month.
Frequently asked questions
What is the best commercial water leak detection system?
There isn't one best system for every building. The best fit sees the water losses that cost you most, installs without disrupting tenants, connects reliably, and gives your team data detailed enough to act on. For many occupied buildings, that starts with meter-level monitoring.
What is commercial water monitoring?
Commercial water monitoring is continuous tracking of a building's water use, usually at the meter or on key pipes, to catch leaks, waste, and abnormal use as it happens instead of on the next bill.
Do commercial leak detection systems need Wi-Fi?
Not all of them. Some use Wi-Fi, some use LoRaWAN with gateways, and some use cellular. NOWi's monitors use cellular with no Wi-Fi and no gateway.
Do I need a plumber to install one?
In-line meters and shutoff valves usually do. NOWi's Meter Monitor reads the existing meter and the Pipe Monitor clamps onto the outside of the pipe, so no plumbing work is needed.
Can it monitor cooling towers and fire sprinklers?
Yes. NOWi's clamp-on monitors can watch cooling tower lines and fire sprinkler lines for leaks without cutting pipe or shutting off water to install.
What is a cooling tower evaporation credit?
An evaporation credit, also called a sewer credit, is a reduction in sewer charges for water that evaporates from a cooling tower instead of going down the drain. To claim it, you usually meter the tower's makeup and blowdown water and report the evaporated volume to your utility. The rules vary by utility, so check with yours. NOWi can help with the metering and reporting.
Should I get automatic shutoff?
Shutoff valves limit damage from sudden bursts, but they need in-line installation. Many owners start with monitoring to cut waste and find problem sites, then add valves where the risk justifies the cost.
See what your commercial buildings are leaking
NOWi helps commercial owners and facilities teams cut wasted water and catch leaks before they become water damage. Cellular, no plumbing, no Wi-Fi. See NOWi's commercial water leak detection, or contact us to start with your highest-cost sites.