Recent hydrogeological studies suggest that the Dan may have a much larger actual subsurface recharge basin area of more than 1,320 km2 (compared to an estimated 520 km2 for the Banias) as the Dan Springs emerge from a deep and productive Jurassic limestone aquifer with outcrops in Lebanon and Syria.'* This transboundary aquifer is recharged by rain and snow-melt, especially along the slopes of Mount Hermon. A combination of the surface water catchments of the Hasbani and Dan or even of all three headwaters results in more realistic estimates with a required effective rainfall of 489 or 512 mm/yr over the respective catchments. Israel (Figure 5) flows into Lake Tiberias.