With a total length of 120 km. It discharges into the Orontes River at the confluence with the Afrin River north of Antakya (see Overview Map). The annual flow volume of the Karasu is approximately 40 MCM/yr.” Precipitation in the basin ranges from around 300 mm/yr (the mean annual rainfall at Aleppo, Syria, is 332 mm) to around 800 mm/yr,'2 with highs in December and January and lows in June and July (Figure 3).