By Tim Gaynor

TUCSON, Arizona (Reuters) - Anyone with cash in their pockets and a concern about security on the porous Arizona-Mexico border can make a donation to help the state build its own fence as of Wednesday.

An Arizona law that went into effect July 20 allows the desert state to build the barrier, provided it can raise enough private donations and persuade public and private landowners to let them build it on their land.

Steve Smith, the Republican state senator who sponsored the law, hopes to raise $50 million. Donations are being taken through a website -- --- which went live at midnight.

"It's out. We're getting a lot of traffic and calls already, so it's doing pretty well," Smith said, adding that it had taken some $10,000 in donations in the first few hours of Wednesday.

Smith said an advisory committee would determine what type of fencing would be built with donated funds, and where it would be erected along the desert state's 370-mile border with Mexico.

"It's an American problem, not just an Arizona problem," said Smith, highlighting the border state's role as an entry point for smugglers and illegal immigrants crossing from Mexico.

"Those people don't just stay in Arizona, they infiltrate the rest of the country, and the rest of the country has to understand the peril that we exist in if we do not address just the outright disaster happening on this border," he added.

Smith said the project seeks to use cheap convict labor to build fencing on the border, which abuts federal, tribal and private lands.

The project is not supported by the U.S. federal government, which is responsible for securing the nation's borders.

In May, after the law was passed, the U.S. Department of Homeland Security responded noting that the federal government had committed unprecedented levels of personnel, resources and technology to secure the southwest border.

During a visit to Arizona earlier this month, Homeland Security Secretary Janet Napolitano noted that gun, drug and bulk cash seizures along the southwest border had increased in the previous two years, while the number of illegal immigrants was down "substantially."

The law has also drawn a mixed response in Arizona. An organization representing cattle ranchers said in May that, while it welcomed the state's efforts to secure the border, there was very little private land to build the fence on.

Tony Estrada, the sheriff of Santa Cruz county which flanks a heavily trafficked stretch of the border south of Tucson, said he thought the additional fencing the state seeks was costly and unnecessary.

"There's ample manpower and infrastructure and technology right now at the border, at least here in Santa Cruz county, to deal with what's coming across the border," Estrada told Reuters.

"If the state wants to tackle it, go for it. But it's a very expensive project, and I can think of better things that that money can be used for," he added.

(Editing by Jerry Norton)