RICHMOND -- In the wake of county Assessor Gus Kramer canceling a scheduled appearance at a special West Contra Costa school board meeting Wednesday night, district trustees began looking into strategies to encourage Kramer to reassess properties to reflect a rebounding housing market.

Schools Superintendent Bruce Harter and trustees say they think higher assessed valuations will be key to the success of the district program financed by voter-authorized school bond sales to rebuild and replace district schools.

Kramer and other assessors statewide lowered assessed values of properties during the real estate downturn, enabling underwater owners to pay lower taxes.

According to board member Charles Ramsey, there was an 18.8 percent decline in assessed valuations in the district from 2009 to 2011.

"That's really fatal for a public entity," Ramsey said after the meeting. "That kind of decline is really difficult to overcome."

These downward assessments were allowed under Proposition 8, a 1978 initiative designed to fill a hole in Proposition 13, said San Francisco attorney Sean Absher, whom trustees invited to speak after Kramer canceled.

However, Prop. 8 also requires that the lowered assessments be re-evaluated annually and raised as home prices rise until the reassessed properties once again reach the levels allowed under Prop. 13, Absher said.

About 186,000 Contra Costa properties received property tax reductions from 2008 through 2011, but only 2,837 have had those valuations fully restored, according to John Whitehurst, a political campaign strategist hired by the district to promote the board's stance on the issue.

"The assessor is misunderstanding his duties under Prop. 8," Absher said. "He has a mandatory obligation each year to raise assessments (to reflect the market)."

Absher suggested some strategies the district could take, including going to court to prove that Kramer has not followed Prop. 8 mandates.

The district's case could be proved in court through the use of the assessor's records and expert testimony, he said.

"If examples of 50 properties could be found where there was a 15 to 20 percent disparity between (an independent appraisal and Kramer's), that evidence could be compelling to a judge," Absher said.

Even so, a satisfactory outcome under this procedure, known as a writ of mandate, could be "difficult to obtain," he said.

A more effective approach might entail gaining access to Kramer's assessment records through the Public Records Act and using that information as a tool for mediation, Absher said.

Kramer did not return a call seeking comment.

Harter said Kramer agreed to meet with the district two months ago "to provide general information about how assessed values are arrived at."

Harter said he received a letter Tuesday from the assessor saying he would not be attending Wednesday's meeting but that he would be available for questions on his latest valuations after they are published July 1.

Harter said Kramer apparently misunderstood the information the district was seeking at the meeting.

"Seeking all value numbers, specific information would have been inappropriate at this time," he said.

Following the discussion, board President Madeline Kronenberg said she was disappointed that the issue seems to have become "an adversarial thing."