Rawa Pening (literally meaning 'Clear Swamp', from the Javanese Bening) is a lake in the Ambarawa Basin in Central Java, Indonesia.

[4] Numerous species of aquatic plants live in Rawa Pening, including Panicum repens,[7] Eichhornia crassipes, Salvinia cucullata,[8] and Hydrilla verticillata.

[9] According to Soenarto Hardjosuwarno, P. repens is one of the main contributors to the formation of floating islands in the lake,[7] with M. Soerjani noting that E. crassipes and S. cucullata also contribute.

[10] According to Tri Retnaningsih Soeprobowati, a researcher at Diponegoro University in Semarang, Rawa Pening could become dry by 2021 due to increasing sedimentation.

She reports a total rate of deposition of 270 to 880 kilograms (600 to 1,940 lb) per day, averaging 780 tonnes yearly,[2] with the water level dropping 29% since 1989.