Najafgarh drain bird sanctuary (proposed) and wetland ecosystem is composed of the wetland ecosystem and wildlife habitat on several kilometres of the Najafgarh drain or nallah which passes through rural southwest Delhi in India's capital territory. It includes the portion draining the depression or basin area that formed the once famous but now completely drained Najafgarh lake or Najafgarh jheel.
Within the National Capital Territory of Delhi (NCT) this water-way, which is misclassified and misnamed as a mere drain (Najafgarh drain or nallah) is, in fact, the continuation of Sahibi River and an elongation of the Najafgarh jheel Lake. It is a tributary to River Yamuna in which it outfalls here. It becomes a refuge to thousands of migratory waterbirds every winter. The winter months are the best time to visit it to see many flocks of wintering waterbirds. It is currently classified as a Protected Forest and Recorded Forest (Notified Forest Areas in Delhi) as "M. P. Green area Najafgarh Drain (Tagore garden)", "Afforestation M.P.Green Area Najafgarh Drain (DDA)" and "Chhawla or Najafgarh drain city forest (29.64 Acre)".
The wetland ecosystem and wildlife habitat on several kilometres of less polluted Najafgarh drain in rural Delhi before entering the main city, including the former Najafgarh lake or Najafgarh jheel area, is very important habitat to migratory waterbirds as well as local wildlife. It has been earmarked to be declared a bird sanctuary for Delhi. The area came to be recognised as an important wildlife habitat after a local naturalist studying the area during 1986 to 1989 called attention to it, recommending it to be conserved as a bird sanctuary. After this, the Delhi wildlife department posted 16 guards in the area to control illegal bird hunters, including diplomats from various international embassies located in Delhi, India's capital. Delhi Administration officials were tasked with declaring about 25 km stretch of the drain in rural Delhi, including where it passes through the core area of the now drained Najafgarh Lake or jheel, protected under the Wildlife Act after Lt. Governor of Delhi Mr. H.L. Kapur was invited to the area for touring the site where he also heard accounts of local villagers about the rampant illegal hunting of waterbirds that went on here every year. The existing staff of the Flood Control and Irrigation Department, numbering about 40, were also given the additional responsibility of protecting the wildlife on and around the drain.