The Tomar king Anangpal's city of Dhilli was founded around 1020 AD, near the present Surajkund in Haryana, 5 km from Tughlaqabad in Delhi. Having a semi-circular shape and called Surajkund because it had a sun temple, the tank had a stepped stone embankment. Its purpose was to impound the rainwaters of the Aravalli hills. During the Sultanate period that followed, several cities were built in the terrain of the Aravalli hills. All these cities had extensive water harvesting systems, which enabled the people to meet their daily needs.

Sultan Iltutmish (1210-1236 AD) built a large tank known as Hauz-e-Sultani or Hauz-e-Iltumish. Alauddin Khilji and Feroz Shah Tughlaq later had the tank repaired. In the regime of Feroz Shah Tughlaq, the channels supplying water to the tank were blocked by miscreants. The sultan ordered the cleaning of the water channels and the reservoir was filled with water. This tank, measuring 200 m x 125 m, is still used by pilgrims visiting the Dargah of Kaki Saheb. The tank has recently silted up and its catchment area has been encroached upon by private builders and the Delhi Development Authority (DDA)

Besides tanks, sultans and their nobles built and maintained many baolis (stepwells). These baolis were secular structures from which everyone could draw water. Gandak-ki-baoli (so named because its water has gandak or sulphur) was built during the reign of Sultan Iltutmish. The water of this beautiful rock-hewn baoli is still used for washing and bathing. Adjacent to this, there are the ruins of other baolis like Rajon-ki-baoli, a baoli in the Dargah of Kaki Saheb, and a caved baoli behind Mahavir Sthal. During this period baolis were built in other parts of the city too.

Muhammad-bin-Tughlaq (1325-51 AD) inherited Delhi with three competing habitations, and added a fourth one to it - Jahanpanah - which means the shelter of the world. The Satpula (meaning seven spans) was built to regulate water supply for irrigating the area falling outside the city. Built across the southern wall of Jahanpanah, it is a dam towering 64.96 m above ground level. Its seven principal spans were sluices that controlled the water in an artificial lake.)

Emperor Shahjahan (1627-58 AD) first shifted the city from the Aravalli hills towards the plains of the Yamuna. But he made sufficient arrangements to meet the water needs of the new palace, the army, and the common people. His system of Shahjahani canals and dighis was probably the
best creation of the time.

Shahjahan ordered Ali Mardan Khan and his Persian artisans to bring the waters of the Yamuna to the city and to his palace. Ali Mardan Khan not only brought Yamuna waters to the palace, but also linked this canal with another from Sirmaur hills, presently located on the Delhi border near Najafgarh. The new canal, Ali Mardan canal, channelled the waters of the Sahibi river basin to merge into the old canal.

In the main city, the canal charged dighis and wells. A dighi was a square or circular reservoir of about 0.38 m x 0.38 m with steps to enter. Each dighi had its own sluice gates. People were not allowed to bathe or wash clothes on the steps of the dighi. However, one was free to take water for personal use. People generally hired a kahar or a mashki to draw water from the dighis. Most of the houses had either their own wells or had smaller dighis on their premises. In the event of canal waters not reaching the town and the dighis consequently running dry, wells were the main source of water. Some of the major wells were Indara kuan near the present Jubilee cinema, Pahar-wala-kuan near Gali-pahar-wali, and Chah Rahat near Chhipiwara (feeding water to the Jama Masjid).

In 1843, Shahjahanabad had 607 wells, of which 52 provided sweetwater. Today 80 per cent of the wells are closed because the water is contaminated by the sewer system.