Emergency Authorities Work to Keep Villagers Safe in Event of a Dam Failure

Featured Image: Firemen attendees at Cortez Dam Emergency Response Meeting (left to right) – Lieutenant Zach Sykora, Lieutenant Dakota Graves, Chief Jason Miller, Captain Jeremy Simmons, and Lieutenant Chase Egleston

This report is not meant to alarm anyone but to inform everyone that our first responders and POA staff are working diligently behind the scenes to keep villagers safe and protected in the event of a worst-case scenario—the failure of a village dam. While thinking about disasters and necessary planning for such situations might be unpleasant, it is sometimes required; this is what our emergency response teams are trained for.

Hot Springs Village has three dams with a high-risk rating. Although a recent meeting conducted by Hot Springs Village Fire Chief Jason Miller focused specifically on Cortez Dam, much of the planning is also applicable to the DeSoto and Balboa Dams. In 2023, DeSoto Dam was the focus, and it is anticipated that Balboa Dam will be the priority in 2025.

A high-risk rating for a dam is based on there being a significant population in the inundation area; it is not based on the condition of the dam. Hot Springs Village dams are well-maintained and inspected. Approximately 1/3 of dams in the U.S.A. are considered high-risk due to the large population that would be affected by a dam failure.

While a catastrophic failure of a Hot Springs Village dam is unlikely, authorities conducted a tabletop exercise to prepare for the remote possibility of a Cortez Dam breach. On Thursday, December 19, Hot Springs Village emergency responders, along with area authorities, emergency services, and POA staff, collaborated to discuss a hypothetical dam failure scenario and response plan. The objective of the planning session is to ensure that our community is well-prepared to respond effectively in the unlikely event of a dam failure. This “what if” exercise reviewed risk assessment, emergency response plans, possible evacuation procedures, communication strategies, and resource allocation.

Cortez Dam Failure Risk Assessment

Risk assessment involves understanding the potential impact of a dam break on our community and the surrounding areas.

A failure of Lake Cortez Dam would affect approximately 500 homes and 30 businesses within the village. Most of the impact from a Lake Cortez Dam failure would extend outside the village. Floodwaters would travel along the Middle Fork of the Saline River for approximately 22 miles over an estimated time of 8.5 hours. The floodwaters would stop approximately 2.5 miles west of Benton, AR, just before reaching I-30.

While a small portion of Garland County might be affected, the majority of the impact downstream would be in Saline County.

Within the village, the Mill Creek Wastewater Treatment Plant is located close to and above Cortez Dam and will be partially in the inundation area. This wastewater treatment plant is expected to be decommissioned within the next three years.

Let’s begin the tabletop exercise. As the scenario develops, it progresses in intensity from level 1 to levels 2 and 3, with level 3 representing a full-fledged dam failure. Please remember that the narrative below is purely hypothetical and was used solely for emergency planning purposes.

Possible Cortez Dam Failure Scenario

With the recent droughts, the Lake Cortez release valve is open to allow water to flow downstream, per a 50-year-old agreement with our Developer, John Cooper. The valve is a crank valve inside a locked door. Hot Springs Village Lakes Department possesses the key.

At approximately 9:30 a.m. on December 19, after a substantial amount of rainfall, Lakes Department staff were asked to shut the dam valve. While attempting to close the valve, they noticed it would not close. They then contacted the dam operator, stating the valve would not close.

Next, they go to the north side of the dam to look for the flow of water and notice a muddy spray approximately two feet high in the center of the dam, 20 yards northeast of the drainage pipe.

After detecting the event and assessing the situation, the Lakes staff rate the situation. At this point in the tabletop exercise, the situation is rated a level 1, which is a nonemergency event and is slowly developing. The situation is not normal but has not yet threatened the operation or structural integrity of the dam, but it possibly could if it continues. The appropriate authorities are contacted, and the situation is closely monitored. (Lists of required notifications are detailed in the HSV Emergency Action Plan – Cortez Dam.)

The situation quickly moves into a level 2 scenario, which is a potential dam failure situation rapidly developing when it is determined that there is a 2-foot spray coming 20 yards from the pipe. This is called “piping.”

Cortez Road is closed off, and a detour is made.

Significant erosion or head-cutting of the spillway is occurring, but the rate does not appear to threaten an imminent breach of the spillway crest that would result in an uncontrolled release of the reservoir.  Flow through the earth’s auxiliary spillway is causing flooding that is threatening people, homes, and/or roads downstream from the dam.

In the context of dams, a “head-cut” refers to “a localized area of intense erosion at the base of the water discharge, often happening when water flows over the dam crest during high water events.”

At this point, additional notifications of appropriate authorities must be made. (Lists of required notifications are detailed in the HSV Emergency Action Plan – Cortez Dam.)

E-blast notifications from Mindy Maxwell, Business Development and Client Relations Manager, will be sent out to villagers.

Code Red notifications will be sent out to those in the potentially affected area. Code Red notifications will contain evacuation site information, which is listed in the Emergency Action Plan.

The language used in the notifications is always coordinated so that the messages coming from different entities are all the same.

A command post is set up at the POA Administration Office.

Communications between appropriate authorities and POA staff will be through AWIN. AWIN stands for the Arkansas Wireless Information Network. It is a statewide, digital 700/800 MHz trunked communications system designed to provide reliable communication for public safety agencies.

At approximately 9:48 a.m., the dam operator arrives to assess the valve. The valve remains seized up and is unable to be closed. The lake employees mention that they see a spray on the north side of the dam. When the operator and employees go look at the spray, they notice that the spray has become more significant in diameter and is now spouting approximately 1 foot high and 12 inches in diameter. The situation has elevated to level 3, which is over 10 gallons/minute discharge.

Incident Command Posts will be set up both inside and outside the village.

An Emergency Operation Center will also be set up. This is the hub where everyone shares and gathers very important information that will be disseminated to the Incident Command Posts.

There is now a potential for evacuation downstream (outside the village).

At approximately 10:28 a.m., the spouting of water continues, and the operator notices a cavity forming, and the soil liquefies and settles on the back slope of the dam.

The situation has rapidly progressed, and there is no chance of preventing the catastrophic failure of the dam.

At approximately 10:33 a.m., the dam operator, as he is looking at Cortez Road over the dam, notices cracking at the edge of the road.  This cracking indicates that we have undermining. it is a good thing that Cortez Road has already been closed to traffic.

At approximately 1:58 p.m., the operator notices that the north side of the dam is seeping, and there is rapid erosion on the back slope of the dam. Cortez Road has now noticeably sunk.

Authorities ensure that everyone has evacuated as the dam breach is imminent.

At approximately 2:30 p.m., the dam engineers arrive at the scene. At this point, residents and businesses have been notified via Code Red, and communication with staff and also outside entities has been occurring. Mindy Maxwell has notified villagers via POA blast, and the press has also been notified with a uniform message.

Having a Public Information Officer is essential. Kevin Sexton, Director of Business Development, Public Affairs, and Land, is the appointed PIO for Hot Springs Village. Having a unified message is crucial. Mr Sexton works with Saline County and Garland County Office of Emergency Management for uniform information dissemination.

Cortez Dam Failure Incident Termination

A state of emergency can only be declared by a County Judge, Governor, or President of the United States.

Follow-up procedures will be conducted to include:

• Appropriate POA staff and, if on the scene, the state dam safety officer will inspect and assess the situation. If it is determined the dam is safe and in good enough condition to terminate the emergency, Emergency Action Plan guidelines will be followed.

• The POA Dam Operator is responsible for making sure all required paperwork is completed. The POA Dam Operator must make copies of the required paperwork and documentation, which are provided to the Arkansas National Resources Commission (ANRC) and the National Resources Conservation Services (NRCS). A dam failure is a costly event, and all activities must be documented for accounting and insurance purposes. It is unlikely the POA will receive recovery funds from county, state, or federal entities, but it is likely areas outside the gates will be eligible for assistance.

Conclusion

The Cortez Dam Emergency Action Planning session brought together local authorities, emergency services, and POA staff to collaboratively review a comprehensive response plan. Meetings of this type are crucial to ensure the safety and well-being of our community. While a catastrophic dam failure is not likely, those in the affected area can be assured that advance planning does occur.

Note: Your homeowners’ insurance policy may not cover flood damage. Flood insurance is a type of property insurance that can protect against financial losses from dam failure and other types of flooding. Flood insurance options may include purchase through your current home or property insurance company or through the National Flood Insurance Program. Flood insurance can also be purchased from a private flood insurance carrier.

I am not an expert on flood insurance, and it would be best if you reach out to your insurance agent or conduct your own research to determine if you are covered in case of flooding or dam failure. Thanks!

By Cheryl Dowden