For the third straight year, Dallas County and the city of Selma combined to fund a river level gauge on the Alabama River.

The United States Geological Survey picked Selma as one of several river gauges to defund three years ago, but offered Selma and Dallas County a chance to keep the gauge operation if they could come up with $6,500, Dallas County Emergency Management director Rhonda Abbott said.

“Without the gauge it would be really hard for us to detect when the river is going to flood,” Abbott said. “We measure the river and then can determine when we have to start contacting the sheriff and evacuating people.”

Selma Mayor George Evans presented Abbott with $3,250 to fund the gauge during the city council’s Wednesday work session. The county provided its portion last month.

The gauge, located under the Edmund Pettus Bridge provides more than a local measurement. The National Weather Service uses a system of gauges across the state to create a complete river-level forecast, meteorologist Michael Garrison said.

“We definitely could not do a quality forecast for the city of Selma without the gauge on the Alabama River,” Garrison said. “We use all of our gauges to develop a complete forecast for the state. We look at what is happening upstream, where rainfall is occurring and take the river flow into account to determine what river levels might look like downstream.”

For example, a storm that drops several inches of rain in Birmingham may not cause local flooding, but could cause a river-level rise in Selma once water flows southward.

The National Weather Service and emergency management agencies break up river levels into phases.

Once the Selma gauge measures 30 feet — the caution action stage — low lying pastureland begins to flood. At 45 feet — the flood stage — some low-lying areas in Selma and Selmont begin to see flooding.

“That 45-foot mark is critical,” Abbott said. “That is the point when we have to begin evacuations.”

On Friday afternoon, the Alabama River in Selma measured 18 feet, which is average, according to Abbott.