Businesses and Rainwater Harvesting/Recharge

-Tyler McMahon, SMART PAANI

Kathmandu’s groundwater problem is compounded by several factors. More than 50 billion liters
are blocked from recharging the ground, instead running off paved surfaces carrying pollutants
into the Bagmati and preventing shallow aquifers (inaar) from being recharged.

Additionally by 2009, deep borewells were over-extracting the deep aquifer at more than 3 times the sustainable
rate (Pandey et al 2012), since no new supply has been added this is likely more than 4 times
currently. The below paper presents case studies of businesses sustainable managing their water
to combat the problem, while also saving money in the process. These are cases only, however
this example is relevant for houses, schools, and businesses all across Kathmandu Valley.
The first is one of Smart Paani’s oldest clients, Thaguchhen, a boutique guesthouse in Bhaktapur.
SmartPaani was involved from the construction period and as a result the project was very cost-
effective. Thaguchhen originally was going to rely on municipal water, with SmartPaani
rainwater harvesting, biosand filtration for all water, and greywater recycling for flushing toilets.
However, like many municipal areas in Kathmandu Valley, the municipal supply was unreliable,
forcing the guesthouse to rely primarily on tanker water purchases. With the rainwater harvesting
systems Thaguchhen saves tanker water purchases for a good part of 5 months of the year, while
water recycling for toilet flushing saves 20 percent or more of their demands year-round. Given
they purchase as many as 3 water tankers in a week, this is a significant amount of water and
financial savings over the past 5 years. The systems have paid for themselves multiple times
while reducing water consumption from deep boring, municipal supply and the burden on the
non-functional municipal wastewater treatment systems.
Honda and SmartPaani have worked together for the past 4 years and the partnership continues
to evolve. It started with a car workshop, where rainwater is harvested, recharged and shallow
groundwater filtered via biosand. Previously the workshop/showroom had to purchase one
12,000 liter tanker each week, now the purchases are minimal if required at all. Another
showroom, the main one, harvests rainwater for normal use, reducing their demand on the deep
borewell in the premises by at least 40 percent. At this same site, a groundwater recharge system
for all the rainfall in the premises not collected by the system is being designed to help restore
nearby historical water infrastructure and reduce the flood burden of the premise.
Standard Chartered is the only international bank operating in Nepal. In line with their global
goals, they are pushing to become more sustainable in Nepal and one of the local branches
initiatives was water. SmartPaani successfully pushed the bank, which already had global
environmental goals, to also consider water as a sustainability strategy. For this, SmartPaani
designed a solution and long-term partnership for them. The first phase was a system installation
at their flagship branch in Lazimpat, allowing them to collect almost 400,000 liters of rainwater
annually, reducing their demand on the deep boring by 25 percent. They also recharge 2.3
million liters, or most the remaining rainwater on their property, back into the shallow aquifer.
In the second phase, in their headquarters in Baneshwor, they installed a system that collects
over 1 million liters of rainwater a year, reducing their demand by nearly 40 percent.


Simultaneously, they arranged educational sessions for employees on the importance of
sustainable water management conducted by SmartPaani, and 5 employees have adopted similar
systems at their homes. In the final phase, they went back and added the final bit of area in their
Lazimpat branch to their rainwater collection system, bringing the collection there to nearly
700,000 liters, more than 40 percent of their yearly demand. The integration of these systems in
their major offices and encouraging employees to do the same multiplies their initiative and is a
perfect example for others to replicate.
There are a lot of people who question the economics of retrofitting for rainwater, especially in
hotels. Thamel Eco Resort in Thamel is an example of how this is not the case. The resort had a
well, however didn’t use it and instead purchased water tankers. They had a borewell that dried
up as well. SmartPaani installed rainwater harvesting, surface water recharge, biosand filtration
for well water and our ultrafilter for on demand drinking water in the new Yeti Craft Beer Bar
and Coffee bar. Due to the reduced tanker purchases they pay back their rainwater harvesting,
recharge and biosand filter in less than 2 years and since they no longer will purchase mineral
water for rooms, the ultra-filtration system pays back in 1.5 years. Next will be water recycling,
which will also pay back in a similar timeframe. It has a business benefit and multiple
environmental benefits reducing plastic, reducing deep groundwater consumption, and
replenishing the shallow well and reducing flood and storm water pollution.
These cases are not in isolation. SmartPaani has done many more in Kathmandu, the customer
saves money with a return in less than 3 years (25% IRR) and at the same time has a tangible
environmental benefit. Even businesses who buy water 9 months a year can pay back the systems
rapidly as the rainfall from April-May and September to October is significant.
Since data on groundwater extraction and recharge is still limited and uncertain, offsetting
extraction and recharging the shallow aquifer are simple ways to work towards a sustainable
water supply. People are still skeptical of the potential of rainwater harvesting and its feasibility,
however these cases illustrate that it not only has a positive impact for now and potentially future
generations, but also generates significant financial savings. SmartPaani has the tools to work
with businesses not only for the installation but forecasting the financial benefits to replicate the
above cases across Kathmandu Valley and beyond.


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