Haleji Lake is situated 70 kilometers (43 miles) from Karachi in District Thatta of Sindh, Pakistan. Being Asia’s largest bird sanctuary the lake is a paradise for bird lovers. Every winter between November to February thousands of migratory birds come from as far as Siberia to this lake to find refuge. It is regarded as one of the most important wintering areas of migratory waterfowl in Eurasia. Total area of Lake Haleji is about 19 kilometers (12 miles). The main water reservoir covers an area of 10.59 square kilometers (6.58 square miles) and maximum depth being 5.18 meters (17 feet).
Haleji Lake along-with nearby Hudero Lake and Keenjhar Lake forms a very large complex of waterfowl habitat. These lakes are now home of divers, dabblers, surface and deep water feeders and fresh and brackish water lovers. All these find this strange salt and fresh water mix a fascinating place to suite their moods and requirements. As many as 223 bird species has been recorded in environs of Haleji Lake. The government of Sindh provided legal cover to preserve ecology of the region and Haleji has been declared as wildlife sanctuary.
The lake was initially a small one. It was a salt water lake formed by seasonal water, collecting in a depression. During World War II, the government of Sindh decided to increase the aptitude of this lake by having a tributary stream from River Sindh, in order to provide water to thousands of British and American troops stationed in Karachi. All salt water of the lake was depleted and a dike was built around the lake, which was fed by a canal of fresh water. As a result Haleji turned into one of the important water source to the increasing population of Karachi as well as exquisite site for waterfowl.