The 26m high embankment dam was constructed in 1885 and has a stepped concrete spillway with approximately 650kl/sec capacity. However, some deficiencies have restricted its operation at the full design capacity. At least 50 homes lie downstream of the dam, which reportedly has seepage and stability problems.
The report, prepared last year by Brisbane Water, said questions about the dam's safety had been raised in 1966 when wet patches were detected on the downstream side of the dam wall due to possible low strengths in the clay core of the dam.
The Queensland Department of Natural Resources has directed Brisbane Water to prepare an Emergency Action Plan, repair and upgrade the dam by December. Repairs are expected to cost millions of dollars.
