The Satpula is a weir, or water dam, built by Ghyias al-Din Muhammad Shah II (Muhammad ibn Tughluq) (r. 1325-51) ca.1340 as part of the rampart walls of Jahanpanah, the fifth city of Delhi, which Tughluq laid out in 1326-27. The city created a link between the two then-established centers of Lal Kot and Siri Fort, enclosing a large area within its ramparts. The Satpula is one of the few surviving fragments of these ramparts, and forms part of the southeastern wall of the city, which can be traced along the Press Enclave Road today. It is located approximately 350 meters (1148 feet) east from the Khidki Mosque and village.
The Satpula is also one of the few surviving examples of waterworks created by the patronage of the Tughluq sultans, who built a number of dams, step wells, cisterns, aqueducts, bridges and canals during their reign in Delhi to facilitate irrigation of income-generating agricultural lands. Mohammed bin Tughluq is said to have built two water reservoirs during his reign: the first, located outside Delhi, was named Lalmish and provided potable water to the city. The second was a private reservoir built within the city of Jahanpanah, and the Satpula is associated with this reservoir. Folklore attributes healing properties to the water in the stream following ritual ablutions performed here by the Sufi Chisti saint Nasir-ud-din Mahmud (Roshan Chirag-i Dilli, "Lamp of Delhi"). He is buried approximately 900 meters (2953 feet) north of the Satpula along the same stream in the eponymous urban village of Chirag-i Dilli.
Scholars have described the Satpula as the most remarkable structure of the surviving sultanate waterworks, and interpreted 'Satpula' as 'the bridge with seven openings', 'seven arches', and literally, as 'seven bridges'. Two stories high, it is built in rubble masonry and comprises a dam and sluice structure with eleven arched openings. Of these, seven principal openings are at the lowest level. On either side of the dam, 12 meters to the south, are square bastion-like structures said to have housed a madrasa. As part of the Jahanpanah ramparts, the Satpula served as a defensive wall and a water dam.
The Satpula, 78 meters long and 15 meters deep, once extended approximately east-west across a stream flowing in from the south; however, the Archaeological Survey of India has since diverted the stream to run approximately 50 meters (164 feet) due east of the structure in order to protect it. The Satpula was apparently damaged by a flood at an earlier date, after which a rubble wall was added to its immediate south. Silt has built up against this wall, leading to a flat, terrace-like formation to the south of the Satpula. Although the Satpula no longer functions as a dam, it does retain a large, swamp-like pond in the low-lying areas to its north. The sluice gates in the Satpula were used to regulate the flow of water from the southern stream into an artificial water reservoir to the north within the rampart walls of Jahanpanah. Some scholars suggest this was a private reservoir while others claim it supplied water to the drier areas of Hissar, to the south. The approximate extents of this reservoir can be traced today to the low-lying area between the edges of Khidki, Chirag-i Dilli and Sheikh Sarai.
The massive lower story of the weir wall contains 11 barrel-vaulted openings running across its entire depth in the north-south direction that would have served as sluice gates for the dammed stream. Of these eleven, the seven central openings are at the lowest level, with two openings on either side stepping up to two successively higher levels. Except for the sluice openings the lower story is completely solid. The southern edge of the weir is a single two-story high, gently battered wall with 10 triangular buttresses protruding out of its surface in-between the 11 arched openings. It is approximately 1.7 meters (5.5 feet) in thickness and has an elevated walkway at the top. It contains 11 arched recesses in its north side that coincide with the 11 sluice gates below. The arched recesses align vertically with deep grooves in the inner surfaces of each of the eleven vaulted openings below, suggesting the presence of sliding wooden sluice gates to regulate the flow of water through the dam. The sides of these recessed arches contain grouted metal rings for fastening or anchorage. Small holes are found on the elevated walkway above either side of each recessed arch. The working of the sluice gates cannot be understood completely due to recent preservation works and concrete having been laid on the floors; in addition, much of the lower story has been badly damaged.
Although the weir wall is two stories high, when viewed from the Press Enclave Road to the south it appears to be single-storied due to the sloping earth that rises up for an entire story. This earth is retained by a rubble retaining wall that precedes the weir wall to the south by approximately 4 meters (13.1 feet). It has an L-shaped profile in plan, starting at the eastern bastion wall, running west parallel to the weir wall, and then turning north after 7 arched openings and joining the weir wall at a ninety-degree angle.
Behind the two-story high weir wall, the rest of the Satpula structure to the north is single-storied. The massive barrel-vaulted lower story of the weir structure supports a series of flat terraces. The terrace levels correspond to the heights of the vaulted openings, with the lowest terrace at the center spanning across the seven lowest vaults. A small terrace raised by approximately 1.8 meters (5.9 feet) spans the intermediate-level vaults and another terrace further raised by approximately 1.8 meters (5.9 feet) spans the highest vault and the rest of the structure. The raised terraces are accessed by short flights of stairs. Each of the 4 vertical planes of the stepped terraces contains a small door leading to a narrow chamber where the working of the sluice gate is visible. Today, these terraces are considerably damaged, and a large crescent-shaped portion has collapsed completely. The highest terrace at the eastern end has also partially collapsed.
The two rooms contained within the square bastion-like structures are accessed via the highest terraces on the east and west through a large arched portal on the north with a pointed arched profile deeply recessed within a large rectangular frame. The frames are newly plastered in the characteristic pink plaster of the Archaeological Survey of India preservation works. Adjacent to each frame and rising towards it is a straight flight of steps leading to the elevated walkway over the weir wall and continuing up to the roof of the square bastion-like structure. The archway leads into a vaulted vestibule-like space with a small arched niche on either side. To the south of this vestibule an arched doorway leads into an inner room. Scholars have often described this room as octagonal and 5.97 meters (19.5 feet) in diameter. The room is actually square, with each of its four corners leading into smaller circular rooms. These rooms have a number of tall narrow slit-like openings at various levels and directions piercing through the walls of the square bastion-like structure. The sides of this square room have large deeply recessed niches that also have similar openings. It contains a few remnants of plaster decoration. These remnants indicate that the rooms may have been plastered and decorated in incised plaster.
The Satpula is a fine example of Tughluq engineering, one which marked great improvements in local irrigation technology and which continues to be of great significance in understanding the history of water management in the Delhi region.
Peck, Lucy. Delhi: A Thousand Years of Building – An Intach Roli Guide. New Delhi: The Lotus Collection, Roli Books Pvt. Ltd., 2005. 55-59, 71.