What a difference a decade makes: Wivenhoe Dam then and now We’re sorry, this service is currently unavailable. Please try again later. Dismiss Normal text size Very large text size Wivenhoe Dam reached its highest-ever level on January 11, 2011 – a day like no other for the main supplier of Brisbane's drinking water. On that fateful day, Seqwater, the manager of Wivenhoe and Somerset dams, was urgently juggling the rate of dam water releases to prevent a major flooding problem for Ipswich and Brisbane. Water being released from Wivenhoe Dam on January 11, 2011. The dam reached its highest-ever level on this day.