The Paper describes the performance of a 28 m high compacted earthfill dam for water supply in Northeast Brazil. For mainly economic reasons, the dam was founded, in part, over soft to very soft silty clays to a depth exceeding 8 metres. Large diameter sand drains were provided to accelerate consolidation in the foundation during construction. Maximum construction settlements of approximately 240 cm were recorded. Results of settlement of spillway structures, pore pressure measurements in the fill and long term settlements, are described in this paper. Transverse cracking of fill occurred as a result of large deformations in the compressible sediments. The cracks were repaired, and the dam is currently operating satisfactorily
