Police say Blanco Firefighter opened four hydrants in Johnson City and Blanco, putting the area's water supply in danger.

In the early morning hours on the Fourth of July, Blanco police say two men — one a firefighter — opened fire hydrants around the county, putting the City of Blanco's water supply in danger.

It's unclear whether the act was a prank or a deliberate attempt to deplete Blanco's water supply, but officials reported the incident to the governor's office as a possible terroristic threat.

Police charged Dustin Garrett, 19, and Stephen Howells, 18, with felony criminal mischief in connection with the incident Saturday, said Carl Bragg, the interim police chief in Blanco. Neither Garrett nor Howells could be reached for comment Wednesday.

Garrett was fired this week from his job at the Blanco Volunteer Fire Department, city officials said. Bragg said Howells and Garrett admitted opening the hydrants in statements to police. "An officer caught them and noticed some suspicious activity, and he started developing (the case) from there," Bragg said.

On Wednesday, Bragg would not release more details or provide copies of arrest warrants or affidavits, which are considered public documents, according to the Texas Code of Criminal Procedure. A request for the documents under the Texas Public Information Act was not answered Wednesday.

Howells posted bail and was released from jail, but Garrett remained in custody with bail set at $100,000, according to Blanco County Jail records. Bragg said the case is still under investigation and that more charges are possible.

The city's public works director received an alert early on July 4 that the water supply was dropping rapidly, Blanco Mayor Christina Gourley said. Two fire hydrants in Blanco and two in Johnson City had been opened and left flowing.

"We're in a two-year drought and (had already) implemented Stage 1 voluntary water restrictions," Gourley said. "Wells were going dry around town."

In addition to threatening the city's ability to fight fires, the loss of water pressure also threatened the safety of drinking water. Gourley reported the incident to the emergency hot line at the Texas Commission on Environmental Quality. Commission officials reported the incident to the governor's Division of Emergency Management because it involved a threat to a public water supply.

More than 200,000 gallons of water in Blanco and 150,000 gallons in Johnson City were drained from fire suppression systems, said Andrea Morrow, a spokeswoman for the state commission. "This is a significant loss of water," Morrow said.

By comparison, on Tuesday, the City of Austin lost about 5 million gallons of water, about 2 percent of that's city's daily production, before plugging a leak in a broken 54-inch water main.

As crews worked to replenish Blanco's water supply, the local fire marshal declared an emergency, Gourley said. City officials posted signs around town to alert people of the danger and to ask them not to use fireworks. Gourley said the fire department had no problems putting out fires over weekend.

Gov. Rick Perry's office reviewed the information but did not notify federal authorities, said Katherine Cesinger, a spokeswoman for the governor. "There was no indication terroristic or otherwise that would require any additional response than what was being done on a local level," she said

Bragg said the U.S. Department of Homeland Security was involved, but a spokeswoman with the federal agency was unable to verify this Wednesday afternoon.

By Andrea Lorenz, AMERICAN-STATESMAN