Riverside County builds California’s first new tax system in 40 years

California's 10th largest county is modernizing the way it keeps track of .5 billion in property assets.

SACRAMENTO, Calif. — Riverside County is developing a new property tax system technology that officials hope other municipalities in California could eventually adopt.

The technology will create a billing and collection system for the city, and will assist in disbursement to incorporated cities as well. It acts a bit like a bank, keeping track of $250 billion in property assets and redistributing the taxes collected to the appropriate programs. The system could go live as soon as July, Riverside’s Chief Information Officer Steve Reneker told StateScoop.

“It is literally the last application that is running on an IBM mainframe in our county,” he said. “We’re trying to modernize it, we are trying to get it off a hardware platform that’s, needless to say, end of life and something we want to save some money on.”

Counties across California have been slow to move away from decades-old technologies for assessing property and state taxes — even as they update other systems. That’s because, as a result a 1978 measure known as Proposition 13, municipalities are required to keep comprehensive records of historical property values, which dictate how much officials can increase assessed values and property tax rates each year.


Moving that volume of data to a new system can be a challenge — particularly for Riverside County, which must calculate $250 billion in property values a year, said Kan Wang, property tax system IT officer of Riverside County. This creates an output of about $2.5 billion in revenue for the state’s tax income.

“When we deal with a system that requires historical data to operate on a daily basis or annually, that means we have to figure out how to get all the data into the modern technology because we can’t just pick a time point and cut off and make the calculations with less history,” Wang said.

But he said sticking with the current system presented its own challenges.

“The public tax system we have has been around for over 40 years,” Wang said. “You can see the mainframe technology and the programming language, they are all obsolete so it does take a lot of effort and a legacy skill set to keep the system up and running — and still make all the necessary changes to make sure we are in compliance of any new laws and regulations in our operation. It becomes a risk when all those people started to retire and we’re losing the ability to have enough talent to keep it up and running.”

The county began investigating a new system a decade ago. After going through two cycles of requests for proposals, Riverside County contracted with Megatron, bought by Thompson Reuters, to develop the technology.


“It’s modern, it’s Microsoft technology with the normal broadband application programming language and single database, so it’s a well-established baseline of technology,” Wang said. Though he said the technology would need to be tailored to the county’s needs.

Other counties are taking notice of Riverside’s efforts. Sacramento County is considering the new system, depending on Riverside’s success, according to the county’s CIO Rami Zakaria. San Diego County is also creating a new tax system and has been working with Riverside to exchange ideas.

“We’re leading the charge ahead of them by a few months so we do keep each other informed, as far as the lessons learned,” Reneker said.

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