How to Reduce your assessed value and Property Taxes: Some values have already been reduced. Check out this page from the County Assessors Office Decline in Property Value you can find your new assessed value. You can also request a review of your new assessed value from the County .You need to provide this information by November 30, 2009. The new assessments will be for the 2009 property tax bills. Sales cannot be later than March 31, 2009. Go to our Market Update site to see solds. This will help if you are appealing your reassessment.