زمزم
In pre-modern Mecca, the city used a few chief sources of water. The first were local wells, such as the Zamzam Well, that produced generally brackish water. The second source was the spring of 'Ayn Zubaydah (Spring of Zubaydah). The sources of this spring are the mountains of Jabal Sa'd and Jabal Kabkāb, which are a few kilometers east of 'Arafah/'Arafat or about southeast of Mecca. Water was transported from it using underground channels. A very sporadic third source was rainfall which was stored by the people in small reservoirs or cisterns. The rainfall, scant as it is, also presents the threat of flooding and has been a danger since earliest times. According to al-Kurdī, there had been 89 floods by 1965. In the last century, the most severe flood was that of 1942. Since then, dams have been built to ameliorate this problem.