SCHEMA:
CREATE TABLE table_26609958_1 (groundwater_discharge__million_m_3__ INTEGER, hydrographic_basin VARCHAR)
USER:
When cabarita river is the hydrographic basin what is the lowest groundwater discharge (million m 3)?

QUERY:
SELECT MIN(groundwater_discharge__million_m_3__) FROM table_26609958_1 WHERE hydrographic_basin = "Cabarita River"