WATERLOO, Iowa  — The Isle of Capri casino in Waterloo has joined a casino in Riverside in contributing to a group opposing a proposed casino in Cedar Rapids.

The Iowa Racing & Gaming Commission made a document public Monday that shows Isle Casino Hotel Waterloo has signed a contract with the Just Say No Casino campaign, which aims to defeat a March 5 referendum in Linn County on casino gambling.

The Waterloo-Cedar Falls Courier  reported the contract shows the casino could provide up to $150,000 for the effort. The document’s public release comes after the state commission released a report Friday that shows the Riverside Casino and Golf Resort plans to spend up to $1.5 million on the campaign.

The Riverside casino opened in 2006, and the Waterloo casino followed in 2007. Owners argue their business will be hurt if a Cedar Rapids casino is built. The newspaper reported the Black Hawk County Gaming Association also shares those concerns. The nonprofit organization holds the Isle’s license and distributes casino funds for community projects.

The association said it is not involved in the campaign, but will reach out to the state commission if the referendum passes.

It’s possible the Meskwaki Bingo Casino Hotel also may contribute to the campaign, said Steve Gray, a leading investor in the Cedar Rapids casino proposal. The Indian casino is not required to report expenditures of more than $100,000 to the state commission, like the Waterloo and Riverside casinos.

Get news headlines sent daily to your inbox

If the measure passes in March, developers still need state approval for the $80 million to $100 million project. Investors said the casino should be located in an area across the Cedar River from either downtown or the Quaker Oats plant.