Updated 08/02/13 – 11:19 a.m.

CHICAGO (CBS) — Heavy rain overnight and early this morning turned Grant Park into a muddy mess just hours before the start of Lollapalooza.

CBS 2’s Vince Gerasole reports about 100,000 people a day are expected to pack onto the lawns at Hutchinson Field to watch their favorite bands, but didn’t seem deterred that the mosh pits could be more like mudholes for the third straight year at the festival.

“Of course not, that makes it more fun,” said Emily Spurgeon, of Indianapolis.

The first performances began at 11:30 a.m., and fans were ready to pack into Grant Park, rain or shine.

Fans already decked out for a good time said they’re prepared for the possibility of more rain.

“I have a rain jacket, she has a poncho,” said Chaye Heiwig, from Carmel, Ind. “I don’t know, we might just party in the rain.”

WBBM Newsradio’s Mike Krauser reports rain was a problem for the three-day music festival for the previous two years, leaving the turf badly torn up by the time the festival ends. With scattered showers and thunderstorms on Friday, muddy conditions could be a problem again.

Grant Park will be crowded with about 100,000 people a day through Sunday.

The big crowds in 2011 and 2012 left Grant Park’s grass torn up, due to the muddy conditions.

The storms were so severe in 2012, organizers were forced to halt Lollapalooza and evacuate tens of thousands of fans from Grant Park for nearly three hours on the second day of last year’s festival.

This year, organizers are posting information about weather updates, safety conditions, and potential evacuations on the Lollapalooza website and on mobile phone apps.

Lollapalooza marketing manager Lindsay Hoffman said organizers don’t believe the wet conditions should force the cancellation of any shows this year.

“We do monitor weather on-site, and we try to keep everybody informed,” she said.

Last year, the damages from the muddy conditions required $350,000 in repairs; in 2011, repairs cost about $1 million.

Luckily for Chicago taxpayers, promoters have had to pay the tab for those repairs.

Grant Park Conservancy president Bob O’Neill said possible damage was the first thing he thought about when the rain started falling early Friday.

O’Neill said he was leery of Lollapalooza when it first came to Grant Park in 2005, but he said, over the years, Grant Park and other city parks have become dependent on the event’s promoters to finance improvements.

For example, Lollapalooza paid for most of Sir Georg Solti Garden, which was created in 2006, near Orchestra Hall in Symphony Center, where he was music director from 1969 to 1991, and music director laureate from 1991 to 1997.

“There’s a lot of things that people don’t realize that Lollapalooza has really done for this park, and probably most importantly is that Grant Park now is marketed to people around the world,” he said.

The damage in 2011 and 2012 prompted the installation of higher-quality turf that is more resilient.

In addition, O’Neil said since it’s been pretty dry lately, there’s a good chance the water will drain enough to prevent widespread damage, depending on how much rain falls.