Junagadh means "Old Fort". Junagadh city has two rivers, the Sonrakh and the Kalwo, which is polluted from city sewers. The city has several lakes: Narsinh Mehta Sarovar, Damodarji, Sudarshan Lake, etc. Willingdon Dam, Hasnapur Dam, and Anandpur Weir are the main water sources for the city. Groundwater supply is widely available in the city, with wells throughout. Junagadh's soil is similar to that of the rest of Junagadh district. It is deep- to medium-black coastal alluvium, due to its proximity to the sea, long shoreline, and nearby mountain ridge. Because of many fault lines in the vicinity, Junagadh is in a seismically active zone. Junagadh lies in a Seismic Zone III region, which means earthquakes up to magnitude 6.5 on the Richter-scale may be expected.