Audit: Nassau reassessment relied on 'flawed data'

A yearlong audit of former Democratic Nassau County Executive Laura Curran's property reassessment faulted her staff for relying on "flawed data" and allocating too little time for the overhaul, but contained no criticism of the overall accuracy of the massive program.

The report by County Comptroller Elaine Phillips, released Thursday, asserted Curran's reassessment relied on "flawed" data that was out of date, and reduced the value of some 23,000 properties at the last minute without justifying the changes.

The audit noted that Nassau's primary reassessment consultants had recommended the Department of Assessment strengthen "data weaknesses prior to performing a reassessment."

Two outside valuation firms had told Curran's Department of Assessment there were significant errors in how it estimated the market value of its property inventory that needed correction before implementing the reassessment.

The firms warned that the county's list of property sales data — needed for the most precise valuations — were outdated.

Also, homes with multiple parcels were inaccurately coded and Nassau's commercial property database was rife with errors that could affect the accuracy of the reassessment.

Most changes weren't implemented, comptroller auditors wrote, and in all, the Curran administration "did not allocate sufficient time to correctly perform the reassessment."

"We have data errors that were clearly pointed out before the reassessment began, that were never corrected," Phillips, a Republican, told Newsday Wednesday. 

"We have a time frame to conduct the reassessment that was so condensed that no one was able to do any type of quality control," Phillips said. "We have thousands and thousands of unexplained changes with no audit trail … And we have no analysis of the results of the reassessment or its impact on people's taxes."

"The first step in doing good analysis is to make sure that the information is accurate," Phillips said. "The data was not accurate."

But despite Phillips' criticism of Curran, the comptroller acknowledged that reassessments must occur more frequently.

Phillips said the decision by former County Executive Edward Mangano, a Republican, to freeze tax rolls in 2011 had led to "significant appreciation" reflected in the 2020-2021 reassessment.

David Moog, who served as county assessor under Curran, told Newsday, "the tax roll that we put out was judged as one of the most accurate tax rolls in New York State."

Curran, a Democrat, declined to comment Thursday.

Phillips' audit of Curran's reassessment came at the request of Nassau County Executive Bruce Blakeman, a Republican who defeated Curran in 2021.

Blakeman argued on the campaign trail that Curran's reassessment was "error-riddled," even as experts said the roll was highly accurate.

Curran, in her 2017 campaign for county executive, called the tax system under Mangano "broken" and filled with inequities.

She argued that because of the nearly decade-long freeze, many homes were not being assessed at their true value.

During the freeze, many homeowners who grieved their property tax bills received automatic assessment reductions, shifting their tax burdens onto property owners who had not grieved their taxes.

Phillips' report also criticized "unilateral" valuation reductions that Curran staffers made with members of the Information Technology department two weeks before the new assessment roll was published in early 2019. 

Auditors said, "The appraised value of a property should emanate from the set of values that the [computer assisted mass appraisal] model has computed. There should be minimal, if any, need to override or replace model-produced values. However, should changes to valuations be necessary, the method of adjustment must be documented."

But Moog said: "At the end it was the most accurate tax roll with those changes. Those changes made it more accurate. It was all input from taxpayers and staff."