Because of an increased number of visitors to Hamilton Pool, Travis County commissioners have adopted changes that will require guests to make a reservation ahead of time and pay a higher fee for access to the pool.

Starting May 15, visitors will be able to make a reservation for two time slots: 9 a.m. to 1 p.m. and 2 p.m. to 6 p.m. In addition, the original $15 fee per car will increase to $26 because of a $10 online reservation fee and a $1 credit card processing fee. Visitors can either reserve a spot online or at the park reservations desk at 700 Lavaca St., Suite 540.

“Over the last few years, Hamilton Pool Reserve has gotten increased visitation at an exponential rate,” Dan Perry, the western district manager for the county’s parks system, said in an Austin American-Statesman article. “If you look on Google for anything about ‘10 best swimming pools in the U.S.,’ Hamilton Pool comes up.”

According to the Austin American-Statesman, the changes are expected to bring in more than $127,000 to county offices and cause up to a 20 percent decrease in the number of people who visit the pool each year.

There are 75 parking spots at Hamilton Pool — meaning if an average of three people come in each car during each of the two reservation times, 450 people would be able to visit the pool per day during the peak months, according to the Statesman article.

The changes will only apply during the peak season, from May through September. In recent years, more than 70 percent of people have been turned away from the pool during this time, according to the Statesman. The original $15 fee for cars will remain from October through April, and discounts and season passes will be honored year round.