An emergency drill closed Lake View Park on Grapevine Lake while crews practiced a lake rescue.
More than 10 emergency crews from around North Texas dove into Grapevine Lake as part of a training exercise to save 10 people from a plane crash.
The run-through included quickly pulling people out of the water, getting them on land to assess their injuries and then rushing them to the hospital.
"This skill could be utilized on any highway that we have, in any building that we have, where there's a large amount of people," Grapevine Fire Deputy Chief Mark Ashmead said.
The skills responders practiced could also be used if a charter boat, which can carry 50 to 70 people, sank or collided with another boat.
The emergency responders who participated in the training said they are confident they can apply what they learned to almost any emergency.
They said they welcomed Thursday's rain because it required them to adjust to changing conditions.
"The environment is what we have to work in, so to test the capabilities in extreme conditions certainly adds to the realism and the problems that we would encounter in any type of exercise like this," Ashmead said.