Highest City Of Gretna employee salary in year 2017 was $115,939. City Of Gretna employees number in year 2017 was 20. City Of Gretna average salary was $34,750 and median salary was $31,506. According to the last payroll, City Of Gretna average salary is 54 percent lower than USA average and 30 percent lower than Florida state average. City Of Gretna employee salaries are usually between $16,409 and $46,914. Top 10% of highest-earning employees have salaries ranging from $55,293 to $115,939.