Many great cities and civilisations in world history have collapsed, their populations forced to relocate, when their water systems ran dry. But in Kathmandu Valley, the hiti water supply systems built centuries ago were so robust that its cities never suffered a shortage.
In the 6th century CE, Kathmandu was the only city in the world that had mastered the technology to sustainably provide drinking water to its inhabitants deep in core residential areas. Free flowing, safe drinking water was available in the city round the clock, throughout the year.
Read more: Saving Nepal’s hiti heritage, Nepali Times
Generations of rulers, merchants and community leaders built a network of ponds, canals, underground filtration systems and artistic hiti conduits as a public service. Since ancient times, kings to common citizens regarded water as a public utility.
Making water accessible to all living beings, human, plant and animal, was considered a social and religious duty. Many mandatorily offered water to the gods as part of the daily ritual worship.
Kathmandu Valley, surrounded by a densely forested rim of mountains, provide the ideal geographical condition for natural flow of water downwards from vast rainwater catchment zones.
The hiti system taps into natural subsurface aquifer deposits, and channels that water to the end-point conduit. The system takes advantage of elevation difference for natural purification and a controlled flow of water based on gravitational force alone.
“Considering that 70% of the terrain in Nepal is mountainous, the geography of the hills and valleys is naturally suitable for a water supply technology that depends on gravity alone, not requiring the input of any form of external energy,” explains civil engineer and researcher Hrishav Raj Joshi. “This was leveraged to its fullest when our ancestors designed the hiti system more than 1,500 years ago.”
This indigenous technology reached its peak during the Lichhavi period (ca. 200-879 CE). The Mallas (1200-1769 CE) largely expanded the hiti system. One of the oldest documented hiti, Mani Hiti in Mangal Bazar, built in 570 CE by an influential Bharavi, is still functioning today with very little maintenance and human intervention.
Sushil Shrestha, who has two decades of experience in restoring hiti and ponds, explains why the system lasts many centuries, with minimal cleaning and minor periodic maintenance requirements.
He says, “All components of the hiti system were built using locally available skills and materials like soil, wood, bricks and stone. This ensured self-sufficiency, sustainability and longevity.”
The builders applied an ingenious biological intervention to keep the channels and spouts running sustainably over centuries. The drainage, when blocked, was cleaned with live frogs and snakes were sent down the narrow drains, and their wriggling motion as they forced their way out of the lower end of the drain, would clear up the obstruction.
Public open spaces played an important socio-cultural role in Kathmandu’s urban fabric. The classic Nepal Bhasa song Rajamati Kumati, mentions three different hiti in Kathmandu. The beautiful Rajmati slips and falls while fetching water from one of these stone spouts.
Adding beautiful images of different gods to the hiti gave it aesthetic value, as well as religious significance. This protected the structure from intentional harm.
Most hiti had an intangible support system called guthi – an association of individuals and families from a community created to undertake a specific social and cultural activity – that took care of its annual cleaning and maintenance of the water supply network.
The Guthi usually had a large endowment of agricultural land, the returns from which payed for its activities adequately. Unfortunately, most Guthis have died away, also leading to the disappearance of many hiti.
The uncontrolled and unplanned urbanisation Kathmandu in the last few decades is threatening the existence of this age-old system. Most public open spaces in and around the Valley that functioned as the rainwater catchment areas are now encroached upon or heavily concretised. The underground structures for piping in and filtering the water have mostly been destroyed by haphazard construction.
This led to the rapid deterioration and dysfunction of the stone spouts, resulting in an acute water shortage in neighbourhoods. This is further underscored by the recent natural disaster in the headworks of the Melamchi drinking water supply mega project, construction of which began about 20 years ago at a cost of $464 million (in year 2000 US dollars.
Supriya Shrestha, the current Miss Nepal Earth, has been working on the restoration of an ancient hiti in Dhobi Chaur in Kathmandu in collaboration with the local government. The numerous spouts there were a source of livelihood for the Dhobi community, whose traditional occupation is laundry.
Says Shrestha, “Reviving a few hiti in Dhobi Chaur can lead to a massive movement across Kathmandu Valley so communities rehabilitate hiti in their own areas. This can eventually lead to a shift of public opinion to preserve the remaining spouts, restoring the ones that have dried up, and building new ones as a sustainable, cost-effective solution to Kathmandu’s worsening drinking water problem. Reviving the hiti can supplement the city’s modern water supply system, which has fallen short of the demand manifold for a long time.”
The author is a conservation activist.
Read more: Water of the ages, Alok Siddhi Tuladhar
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