Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_69 (latitude INTEGER, pop__2010_ VARCHAR, water__sqmi_ VARCHAR, longitude VARCHAR)

### Question ###
What is the highest latitude when there are more than 0.518 square miles of water, a longitude less than -99.830606, and a population of 18?

### Accurate SQL ###

SELECT MAX(latitude) FROM table_name_69 WHERE water__sqmi_ > 0.518 AND longitude < -99.830606 AND pop__2010_ = 18