Wetlands are nature’s wastewater treatment facilities. The KKL-JNF imitates natural wetlands by constructing artificial ones. In the 1950's the JNF of South Africa financed the draining of the Hula swamps. In the 1990's it became evident that the land could not be farmed due to peat soil which had developed. Consequently the area was re-flooded and turned into the Hula Nature Reserve which is one of the most important bird sanctuaries in the Northern Hemisphere.
The Constructed Wetlands Project in Hod Hasharon is one of the most important ecological projects being implemented in Israel today. Purified effluents from the Hod Hasharon and the Kfar Saba wastewater treatment facility undergo a special process in the constructed wetlands and are then conducted to the Yarkon Stream to actually improve its water quality.