How the county calculates tax district values each year

(a) Upon or after creation of a tax increment district, the director of finance of the county in which the district is situated shall certify the assessment base of the tax increment district and shall certify in each year thereafter the amount by which the assessment base has increased or decreased as a result of a change in tax exempt status of property within the district, or reduction or enlargement of the district. The amount to be added to the assessment base of the district as a result of previously tax exempt real property within the district becoming taxable shall be equal to the assessed value of the real property as most recently assessed or, if the assessment was made more than one year prior to the date of transfer rendering the property taxable, the value which shall be assessed by the director of finance at the time of such transfer. The amount to be added to the assessment base of the district as a result of enlargements thereof shall be equal to the assessed value of the additional real property as most recently certified by the director of finance as of the date of modification of the tax increment financing plan. The amount to be subtracted from the assessment base of the district as a result of previously taxable real property within the district becoming tax exempt, or a reduction in the geographic area of the district, shall be the amount of assessment base initially attributed to the property becoming tax exempt or being removed from the district. If the assessed value of property located within the tax increment district is reduced by reason of a court-ordered abatement, stipulated agreement, or voluntary abatement made by the director of finance, the reduction shall be applied to the assessment base of the district when the property upon which the abatement is made has not been improved since the date of creation of the district, and to the assessment increment of the district in each year thereafter when the abatement relates to improvements made after the date of creation. (b) The director of finance shall certify the amount of the assessment increment to the county and redevelopment agency each year, together with the proportion that the assessment increment bears to the total assessed value of the real property within the tax increment district for that year.