However, after Israel built the National Water Carrier in 1953 and diverted water from Lake Tiberias to Israel's coastal plains and southern desert, the flow of the Lower Jordan River dropped significantly. The 50 MCM/yr that Israel provides from Lake Tiberias as part of the 1994 peace treaty was meant to compensate for this loss. A 2010 study found that the Lower Jordan River has been reduced to 2% of its historic flow.[24] Water quality has also deteriorated sharply, with high levels of salinity and pollution from agricultural fertilizer and untreated wastewater upstream in Israel and the West Bank.[25]