Jun. 23—EAU CLAIRE — A splash of water on sidewalks outside of 16 downtown Eau Claire establishments will reveal hidden images over the next few months for a contest organized by a local service club.

Eau Claire Morning Rotary's Rainworks Bingo — a scavenger hunt-like competition that encourages people to explore downtown and patronize businesses there — is free to participate in and starts Monday.

Organizers decided to bring back the contest after it had a good turnout in 2021.

"We had over 100 families participate last year," said Aaron Libner, past president of Eau Claire Morning Rotary.

More downtown businesses joined in to sponsor this year's contest and host one of the hidden images near their doorsteps.

"This year we have a full card of business participants," Libner said.

Starting next week, Bingo cards for the contest will be available at The Local Store, the Family Resource Center at Oakwood Mall and the downtown businesses taking part in Rainworks.

Those interested in taking part in the contest will need to find the 16 hidden designs on concrete sidewalks near the entrances of those participating businesses.

Earlier this month, volunteers used stencils and sprayed concrete sealer to put the invisible designs near the buildings' entrances. The sealer prevents water from seeping into the concrete, making the designs visible when the pavement gets wet.

Numerous contestants last year let mother nature take care of revealing the images for them.

"Some people waited 'til it rained admittedly," Libner said.

But others used spray bottles, squirt guns and splashes from water jugs to dampen sidewalks so they could spot the hidden designs.

After uncovering a waterproof image, participants must take a photo of it using a smartphone or other device, then go into the business to show that photo to an employee who will hand over a Rotary sticker to mark that spot on the Bingo card.

Stickers are required to fill 13 of the 16 spots on the Bingo card. The final three spots are "free spaces" where no stickers will be given.

Completed Bingo cards then must be mailed before Oct. 15 to the Eau Claire Morning Rotary address printed on them to be entered in prize drawings.

The grand prize is a family portrait session from Giles Photography, including an 11"x14" print. The second place prize is a free quart of ice cream each month for a year from Ramone's Ice Cream Parlor. Other winners will also be drawn, receiving prizes or gift cards from downtown businesses.

Before Rainworks became a contest last year, it was started in 2020 by local Rotarians as a way to simply raise people's spirits and encourage walking during the COVID-19 pandemic. Following favorable responses from people who enjoyed seeing positive messages and gleeful designs appear on sidewalks, the club decided to turn it into a annual event to promote downtown.

The hidden designs wear off about three to four months after the concrete sealer is applied, Libner said.