The water level of Lake Kinneret, which supplies some 25 percent of Israel's drinking water, dipped below the Lower Red Line on Monday morning, according the Water Authority. The level of the lake stood at 213 meters below sea level - the lowest level in five years. According to the water company, the last time levels reached this lower red line was in Summer 2003. The Water Authority marks three threshold lines on the lake: The Upper Red Line, the Lower Red Line and the Black Line. The Upper Red Line is 208.9 meters below sea level; when the lake reaches the upper line the Deganya Dam is opened to allow greater flow into the Jordan River and prevent the lake from overflowing; if the level reaches the the Lower Red Line, the concentration of pollutants rises to undesirable levels and pumping water from the lake is prohibited.