A $115-million flood relief bill has been signed by Gov. George Deukmejian. The emergency measure provides up to an additional $5,000 each to individuals and families who were flood victims. It also provides $80 million to 36 counties for repair and renovation of public property. Reclamation districts get $5 million to fix levees. It allows homeowners to delay payment of April 10 property tax installments until damaged residences can be appraised, and permits individuals and businesses to carry forward casualty losses for five years.