Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
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?

### Inputs:
table_name: table, columns: ['Township', 'County', 'Pop. (2010)', 'Land ( sqmi )', 'Water (sqmi)', 'Latitude', 'Longitude', 'GEO ID', 'ANSI code']

### Response:
SELECT MAX Latitude FROM table WHERE Water (sqmi) > 0.518 AND Longitude < -99.830606 AND Pop. (2010) = 18