Decline of the Indus Valley Civilization

Nearly two-thirds of the 1,500 archaeological sites related to the Indus Valley Civilization, occur on the dried up banks of the present-day Ghaggar river.

Around 1900 B.C.E., one of the major rivers of the Indus Valley, the Ghaggar-Hakra (also called the Saraswati), began to shift its course and eventually dried up, leaving many sites without a viable subsistence base. These communities would have migrated to other farming regions or to cities such as Mohenjo Daro and Harappa, resulting in overcrowding and civic disorder.

1500-2000 years before Christ, the Indus Valley civilization witnessed large scale deurbanization, population decrease, abandonment of many established settlements, lack of basic amenities, interpersonal violence and disappearance of the Indus Valley script.

Previously scholars argued that the Indus cities were suddenly abandoned around 1750 B.C.E., but recent work at Harappa has clearly demonstrated that during its late phase, from 1900 to 1300 B.C.E., Harappa was indeed inhabited. 

In fact, signs that drains and city walls were not maintained provide proof of crowding and a breakdown of civic order. The remains suggest that the ruling elites were no longer able to control the day-to-day functioning of the urban center. This loss of authority must have eventually led to a reorganization of society, not just in Harappa but throughout the entire region that the upper classes had dominated for 700 years. Similar changes were occurring at the other big cities, such as Mohenjo Daro to the south and Dholavira in western India.

The crisis led to a cessation of the hallmarks of Indus elite culture. The distinctive pottery with ritual motifs and Indus script and traditional square seals with unicorn and other animal motifs disappeared. Cubical weights for taxation and trade fell into disuse, and the international trade networks began to deteriorate. Shells from the coastal regions no longer made their way to the northern sites, and lapis lazuli from the north failed to reach the sites in the plains. In Mesopotamia the texts that had recorded ongoing trade with a region called Meluhha, which is probably the Indus Valley, no longer mentioned it.

The First Great Urbanized Culture in the World...

A distinct urban stamp

Distinct characteristics ofurban planning from remains of the cities of Harappa, Lothal, Dholavira, and Mohenjo-daro in the Indus Valley Civilisation (in modern-day northwestern India and Pakistan) lead archeologists to interpret them as the earliest known examples of deliberately planned and managed cities. The streets of many of these early cities were paved and laid out at right angles in a grid pattern, with a hierarchy of streets from major boulevards to residential alleys. 

Secondary streets are about half the width of the main streets; smaller alleys are a third to a quarter of the width of the main streets. The street layout shows an understanding of the basic principles of traffic management, with rounded corners to allow the turning of carts easily. The drains are covered. 

Drainage at Lothal / Vu2sga / CC-BY-SA 3.0

Archaeological evidence suggests that many Harrapan houses were laid out to protect from noise and to enhance residential privacy; many also had their own water wells, probably both for sanitary and for ritual purposes. These ancient cities were unique in that they often had drainage systems, seemingly tied to a well-developed ideal of urban sanitation.

Harappans demonstrated advanced urban architecture with dockyards, granaries, warehouses, brick platforms, and protective walls. These massive walls likely protected the Harappans from floods.

Harappans were among the first to develop a system of standardized weights and measures. The consistency of brick size across cities also suggests unity across the various urban areas, which is evidence of a broader civilization. The cities across a million+ square kms were interlinked by trade and economic activities, religious beliefs and social relationships, apart ofcourse from a shared high standard of living where sanitation, hygiene and an orderly life in the city was concerned. 

Although some houses were larger than others, Indus civilization cities were remarkable for their apparent egalitarianism. For example, all houses had access to water and drainage facilities. One gets the impression of a vast middle-class society.

From the big to the small

Dholavira, part of sandstone pillar, 2500 BC
/ Rahul Zota / CC-BY-SA 4.0

Urbanism in the Indus Civilisation is associated with the development of five large settlements considered by archaeologists as cities, and numerous smaller urban settlements. Three of these cities are in present day Pakistan – Mohenjo Daro, Harappa, Ganeriwala; and Dholavira and Rakhigarhi in India.

These were cities of monumental dimensions like Mohenjodaro, Harappa, Dholavira and Rakhigarhi that stand out on account of their size (more than 100 hectares each).

The intermediate tier of the urban hierarchy was made up of sites that in several features recall the layout of the monumental cities of the civilization but are smaller in size. Kalibangan, Lothal, Kot Diji, Banawali and Amri are some of them and they can be considered as provincial centres.

Dancing Girl of Mohenjo Daro /
Joe Ravi / C_BY_SA 3.0

The third tier of the Harappan settlement hierarchy is made up of small urban sites. These show some evidence of planning but no internal sub-divisions. Notwithstanding their size and structurally unprepossessing character, they had urban functions. Allahadino in Sind is one such site, which had a diameter of only 100 metres but was an important metalcrafting centre. Similarly, Kuntasi in Gujarat is a small Harappan fortified settlement where semi-precious stones and copper were processed.

Finally, urban centres were supported by and functionally connected with rural hinterlands of sedentary villages and temporary / semi-nomadic settlements. 

Sanitation in the Indus Valley Civilization

The world's first urban sanitation systems can be seen in the Indus Valley Civilization. Within the city, individual homes or groups of homes obtained water from wells. From a room that appears to have been set aside for bathing, waste water was directed to covered drains, which lined the major streets. 

The ancient Indus systems of sewage and drainage developed and used in cities throughout the Indus region were far more advanced than any found in contemporary urban sites in the Middle East and even more efficient than those in many areas of Pakistan and India today. 

Great Bath of Mohenjo Daro /
Usman_Ghani / CC-BY-SA 3.0

Mohenjo Daro’s Great Bath, built 2500 years before the roman baths, is the earliest public water tank in the world ! Drains and water chutes in the upper storeys of buildings were often built inside the wall with an exit opening just above the street drains. Tapered terracotta drainpipes were used to direct water out to the street (something we see again in the Roman Empire 2500 years later..). Many houses had distinct toilets, separate from bathing areas. Commodes were large sump pots sunk into the floors. Garbage bins were provided along the major streets as were manholes, to clean the drains.