Flood Warning System Frequently Asked Questions

The GRFWS will be delivered in two main phases to ensure thoughtful planning, efficient deployment, and long-term reliability. 

The first phase of the project focuses on providing sirens to support flash flood alerts for youth camps and surrounding areas on the North Fork and South Fork Guadalupe River in west Kerr County. Efforts have included hiring an engineering firm specialized in flood warning systems, procuring siren equipment from a reputable siren vendor, working with youth camp operators to determine where and how to install sirens, and coordinating with local and state agencies for funding and permits.  Our next steps are to install the sirens (in mid-May), update County emergency action plans to include when, why, and how sirens will be activated, conduct public outreach and education to help the community understand what it means when a siren is activated, and deploy a watershed dashboard, RiverHub, that provides the public real-time information on river and rainfall conditions. 

The second phase will include expansion of siren coverage to other critical flash flood risk areas in Kerr County, installation of additional river and rain gauges, development of software to help predict flooding, and broader public outreach and education.

Phase one is expected to be completed by the end of summer 2026, though most efforts are on-track to be completed by May. Phase two is planned to continue through the summer of 2027. 

Not only are there weekly project updates on our webpage, but we also post information on social media on a regular basis. We held a Town Hall meeting in May, see the slides here, and we will continue with additional Town Halls in the future. We also shared information on Flood Awareness Week from the Texas Floodplain Management Association, and some materials UGRA has created. We are currently working on creating print materials to be shared with the community later in June 2026. 

The sirens are currently designed to alert the nearby population of immediate flooding and not other hazards such as fire or hail. Activation may be triggered by National Weather Service Flood and Flash Flood Emergency Warnings, observed river water levels and/or rainfall, and/or manually by County Emergency Management. The sirens will also be activated for regular monthly testing during a scheduled time and day. The County is determining the procedure for activating and testing sirens and will provide more information in June.

Kerr County sirens are a Federal Signal modulator style siren. The siren includes a group of speakers mounted on a 50-foot pole, is high powered with 360-degree coverage, can broadcast various alerts and messages, and has backup power and communications.

Sirens can be controlled remotely and at the siren. The sirens use two forms of communications for redundancy, including the new Lower Colorado River Authority (LCRA) private cellular network being installed across Kerr County and a radio network (VHF) dedicated to the sirens. Authorized emergency management personnel can control the sirens at the Sheriff’s Office and Courthouse for redundancy, as well as on their phones and through a website. Information from the UGRA watershed dashboard, RiverHub, will automatically communicate with the sirens to ensure emergency managers have the information they need to make the right decision at the right time.

The map below shows the general coverage area of the outdoor warning sirens that are currently installed.

The sirens and control software for phase 1 are made by Federal Signal in Illinois. Federal Signal was founded in Chicago, Illinois in 1901 and is one of the largest siren manufacturers in the world.

You may have heard of a company called OmniWarn related to this project. OmniWarn is a Federal Signal representative, installer, and service provider.

The County Emergency Management is currently reviewing alert tones and voice messages to use for this summer. We will provide examples you can listen to once a decision is made.

The distance the sound will travel depends on many things, including the weather and the wind. Initially, the sirens are being installed at or near youth camp locations and the manufacturer says they may be heard within approximately one mile from the siren. Their sound may be reduced in areas blocked by terrain, buildings, and/or dense trees.

While you may hear a siren from inside your home, do not count on hearing it. Sirens are generally a last resort warning that goes off when immediate action is required. Be sure you have enabled County and National Weather Service alerts and are monitoring the UGRA watershed dashboard, RiverHub, and weather updates during severe weather so you are aware and informed.

River and rain gauges monitor conditions at a location and report those conditions to an offsite location using the LCRA private cellular network.  The new LCRA network was funded through the Texas Middle Mile Grant in cooperation with Kerrville Public Utility Board.  The gauges will also use a satellite network as backup. They are powered by solar panels and batteries and designed to operate during floods. River gauges monitor the depth of water while rain gauges monitor the amount of rain that has fallen at a point. Together, gauges provide emergency managers and the public a picture of whether flooding is likely to occur or is actively occurring.

The GRFWS will include new gauges to support existing gauges in Kerr County. These gauges may also monitor other environmental conditions that can support recreational and agricultural activities, such as water quality, water temperature, air temperature, and windspeed.

There are currently over 20 rain gauges and 9 river gauges in Kerr County that support the GRFWS and will be viewable on the UGRA watershed dashboard, RiverHub. These gauges are operated by the United States Geological Survey (USGS), the Guadalupe-Blanco River Authority (GBRA), the Texas Department of Transportation (TxDOT), and other partners. Future gauges installed as part of this project will be owned and operated by UGRA.

The River Sentry system is privately owned; for more information see their website.

The Guadalupe River Flood Warning System (GRFWS) is publicly owned and operated as a multilayered system to support emergency response across Kerr County.

Testing will be performed in accordance with state guidance and requirements along with industry best practices. At a minimum, sirens will be tested silently daily to confirm functionality and audibly monthly. The final schedule and protocols are being developed and will be shared here in Summer 2026.

Yes, the sirens have backup power in the form of solar panels and batteries. Here are photos of what that looks like.

The state has established strict guidance for maintenance of sirens and for gauges used to activate sirens. A maintenance plan is currently being developed based on state requirements, best practices, and vendor recommendations. The County, UGRA, and cities are currently discussing who will maintain which components of the GRFWS and how maintenance will be funded.

Kerr County Emergency Management will specify the protocols for activating sirens. The actual activation of sirens is an emergency management function and defined roles, responsibilities, and protocols will be developed and documented. This will include signed memorandums of understanding to ensure transparency and clarity.

While this is the regular schedule, if the weather is bad and sounding the sirens could confuse the public, the siren test will be postponed. It will be rescheduled to occur after severe weather passes and announced on social media and on the UGRA website.