1.It was constructed by Pushyagupta, the Governor of Saurashtra region during Chandragupta Maurya
2.Tushaap constructed a darn on the lake during Ashoka Maurya
3.First reconstruction was undertaken by Governor Suvishakh during Saka satrap Rudradaman and 2nd by Chakrapalit during the reign of Skandgupta
4.All of the above