When it's working, the giant concrete circle outside the Hennepin County Government Center is considered the crown jewel of the hulking facility.

That circle is the center's 44-year-old pool and fountain. A springtime repair to fix a "bubble" underneath the structure's surface has delayed this year's filling.

But fear not: Officials say the thirsty beast will be flowing with 12,000 gallons of the county's finest water after Memorial Day.

"Streets get potholes. We get bubbles," said Michael Sable, the county's director of facility services.

The fountain and surrounding plaza on the north side of the Government Center is a popular downtown gathering spot, and it hosts a food vendor and music during the warm months. A farmers market is held on Thursdays on the center's south plaza. More than 10,000 people walk through the center's skyway level each day.

Michelle McKinney came to the plaza for an outdoor break from her job at Ameriprise. She considered turning to Google to find out when the fountain might be turned on.

"This is not attractive," she said.

The county intended to fill the fountain a month ago, but on Tuesday workers discovered a bonding problem with material between a waterproofing membrane and the concrete surface of the pool. This doesn't appear to be related to a $3.5 million renovation of the fountain in 2016.

The fountain isn't leaking, but it will be tested and repaired next week, Sable said. He's now trying to determine if the repair is under warranty with the contractor, Shaw-Lundquist Associates Inc. in St. Paul. A senior project manager at the company couldn't be reached for comment Friday.

The renovation in 2016 was the second time such repair was done to the fountain. It involved a total replacement of the piping, pumps, and infrastructure underneath, as well as the waterproofing membrane. Officials said the repairs would last 30 years.

The county spends about $23,000 a year to maintain and operate the pool and fountain, which have caused problems for decades for the offices below. Leaks have regularly occurred on the circular glass "curtain wall" around the oculus, which receives the waterfall.

In 2012, a task force recommended removing the pool and waterfall and making other improvements, at a cost of $2.6 million. The panel considered turning the pool into a planter at a cost of $500,000, but that option left open the possibility of leakage below.

In 2015, officials discussed replacing or repurposing the pool, but they opted for repair work because it was less expensive and in keeping with the architect's original design.

David Chanen • 612-673-4465