The Sultan of Delhi who is reputed to have built the biggest network of canals in India was

Feroz (Firuz) Shah Tughlaq is credited with the largest programme of canal construction and restoration among Delhi Sultans. Contemporary summaries and modern accounts highlight his vigorous public‑works policy of digging new canals, refurbishing older channels, and promoting irrigation to expand cultivable land and agrarian revenue. Scholarly treatments note that he commissioned canals from rivers such as the Yamuna, Ghaggar and Sutlej and built associated regulators and embankments, extending an integrated irrigation network across his territories. Institutional histories of the Sultanate also single out Firuz Shah’s state‑sponsored canal systems and waterworks as a distinctive legacy of his reign and a major contribution to medieval Indian irrigation infrastructure [1].

Sources

1. [1] https://fmuniversity.nic.in/getdata?dir=deptnotice&rid=notice2087_12620251749710563789.pdf