Why Is ALERT2 the Wave of the Future for Flood Alerts?

When flooding happens, every second matters. Intense rainfall can quickly cause rivers to rise above flood stage, and the difference between property damage and a life saved often comes down to the speed and reliability of your warning system. While the original Automated Local Evaluation in Real Time (ALERT) protocol has provided reliable real-time data for flood warning and environmental monitoring, evolving technology and network demands call for modernized communications standards.

That’s where the ALERT2 protocol comes in. Developed to modernize and expand on the original ALERT protocol used since the 1970s, ALERT2 provides a more reliable, faster, and scalable foundation for real-time flood warning systems and is used by forward-looking agencies across the world. With devices like our AL200X ALERT2 Modem and Sensor Interface, it’s even easier for you to adopt this new protocol.

What makes ALERT2 different?

ALERT2 isn’t just a modest upgrade; it’s a leap forward in how flood warning networks communicate. One of the most important improvements is its use of time division multiple access (TDMA) architecture, which organizes radio transmissions across a network so that each station gets a dedicated time slot to broadcast. This eliminates the message collisions and data loss common in older systems, especially during peak storm conditions when reliable communications matter most.

Another key advancement is built-in forward error correction (FEC). This technique ensures that even if a signal weakens during heavy rain or from obstruction, the message still gets through accurately. Combined with GPS-based synchronization—which keeps every station operating on the same precise schedule—ALERT2 creates an efficient system capable of transmitting more data in less time with fewer errors. For emergency managers, this means better situational awareness with data that are timely, complete, and reliable—even when cellular networks go down or communications channels are saturated.

Lessons from the Field

The value of ALERT2 isn’t theoretical. It has already proven itself in high-stakes situations.

During Hurricane Harvey in 2017, Campbell Scientific ALERT2-based systems in the Houston area provided continuous, real-time flood data even as mobile networks faltered under the strain of the storm. That uninterrupted stream of rainfall and water-level information allowed emergency managers to make informed, localized evacuation decisions, protecting communities when it mattered most.

Agencies such as the Sacramento Area Flood Control Agency (SAFCA) have completed a full transition from legacy ALERT to ALERT2 networks. In the case of SAFCA, the upgrade resulted in higher-resolution data and better system reliability during critical events. 

In Australia, the ALERT2 protocol has been a cornerstone in Brisbane’s efforts to improve disaster resilience. Following the 2022 floods, a city-commissioned review emphasized the importance of expanding early warning systems and telemetry to strengthen emergency coordination. While not naming specific protocols, the report’s recommendations reflect many of the capabilities ALERT2 already offers. 

Making ALERT2 Deployment Easy with the AL200X

Campbell Scientific’s AL200X is designed specifically to simplify ALERT2 deployment in the field.

The AL200X is a modem and sensor interface built to work in the harshest conditions. It supports a wide range of sensors, including rainfall, water level, and pressure. It is fully compliant with ALERT2 specifications, including TDMA, GPS sync, and FEC. It’s compact, rugged, and easy to integrate into existing infrastructure, whether you're upgrading a single site or modernizing an entire regional network. It is also built from the ground up with parts that are designed to last.

For emergency managers, this means less time configuring hardware and more time focusing on what matters: preparing your community, interpreting incoming data, and coordinating response efforts with confidence.

Modernize with Confidence

Flood events are becoming more frequent, more severe, and less predictable. A modern flood warning system is no longer a luxury; it’s a necessity. ALERT2 offers the speed, reliability, and flexibility emergency managers need to stay ahead of the storm. And with tools like the AL200X, adopting this technology is now well within reach.

Find out more about the AL200X and how it can be central to faster warnings and smarter responses for your flood warning system on our AL200X product web page.

Credits: Brett Hansen of Campbell Scientific, Inc. contributed to this article.