Plugin seems to be broken as of Aug 3. FP added new convars to the WaterLevel.Test method.

Error while compiling: SurveyInfo.cs(214,32): error CS1501: No overload for method `Test' takes `1' arguments

I made this change to line 212 in the code, it compiles but not sure how it will affect survey charges thrown in water/beaches.

if (WaterLevel.Test(position, false, false, null))

Nope, the error you're encountering is actually from the previous month, and it has already been patched. It just seems like you haven't updated the plugin