With a little more than a week before opening day at the Lawrence Outdoor Aquatic Center, city officials only have about 40 percent of the lifeguards they need for the summer swim season.

City Hall leaders on Thursday were alerting the public that a dramatic uptick in lifeguard applications is needed, or else parts of the indoor and outdoor aquatic centers may be closed.

“We may have to close some areas of the pool down, like slides and diving board, throughout the day to maintain our level of swimmer safety,” said Jimmy Gibbs, the city’s recreation program manager.

So, what’s behind the shortage of lifeguards? For one, the economy is no longer sinking. Lifeguard positions have had a starting salary of $7.25 an hour, which is federal minimum wage. On Thursday afternoon, city officials announced the starting salary has been increased to $8.25 per hour.

“As things are starting to pick back up, they are finding different job opportunities that pay more,” said Lori Madaus, the city’s aquatics supervisor.

Madaus said the department likely will ask city commissioners to approve a budget increase for 2015 that will allow lifeguards to be paid a rate more competitive with area aquatic centers.

Madaus estimated that the city still has about 100 positions it needs to fill for this year. Lifeguard applicants must be at least 16 years old. To be hired, applicants must pass a lifeguard training course, which is taught by the city.

“It has been a challenge,” said Madaus, who said busy summer schedules of students also has helped fuel the decline in applications. “But once people take the class and become a lifeguard, they see how rewarding it can be. But right now, it is challenging to convince people of that.”

People interested in applying can do so at lawrenceks.org/jobs.

The Outdoor Aquatic Center, 727 Kentucky Street, is scheduled to open at 1 p.m. on May 24.