How many number of lakes are there in the Valdez-Cordova (CA) area?
create table table_17978052_2 (_number_s_lake_and_gnis_query_link integer, borough_or_census_area varchar, PRIMARY KEY (_number_s_lake_and_gnis_query_link))
select min(_number_s_lake_and_gnis_query_link) from table_17978052_2 where borough_or_census_area = "valdez-cordova (ca)"