Sustainable Mountain Development No. 56, ICIMOD, Winter 2009
optimal use of rainwater. If just 10% of the Kathmandu tubewells, and recharge pits to recharge shallow
Valley area was to be used for rainwater harvesting, aquifers. Pond restoration and channelling rainwater
128 million cu.m per/year could be recharged. To into the ponds also supports the recharging of shallow
implement such a plan, investigation is required to groundwater aquifers.
identify suitable recharge techniques and locations.
A recent groundwater recharge initiative of UN-Habitat
and the Centre for Integrated Urban Development (CIUD)
Artifi cial groundwater recharge in the
in a community in Patan resulted in increased fl ow from
Kathmandu Valley
the stone spouts and increased water levels in dug wells
A recent study indicates that the Valley’s sub-surface in the area. Rainwater from roofs and surface runoff
geology is favourable for assisted recharging of from houses, courtyards, and surrounding areas was
groundwater. Although several areas have high collected and channelled to a recharge pit (Figure 3).
groundwater infi ltration rates because of favourable With the success of this initiative, UN-Habitat has agreed
geological formations, natural infi ltration is generally to provide further fi nancial and technical support for
ineffective due to the sealing of the ground’s surface groundwater recharge, in partnership with Lalitpur Sub-
(NGOFUWS/ UNHABITAT 2008). Several methods are Metropolitan City and Bottlers Nepal Limited, through a
currently available for assisted groundwater recharge. public-private community partnership model.
These include recharge trenches and permeable
pavements that promote the percolation of water through
Time to start harvesting
soil strata at shallower depths; and recharge wells that
allow rainwater to seep to greater depths. Figure 2
The water shortage in the Kathmandu Valley will not
shows the potential areas for shallow aquifer recharge.
be solved in the near future. It is now time to tap
The north and northeastern parts of Kathmandu have
alternative sources of water. Rainwater harvesting has
great potential (Shrestha 2001) for deep aquifers. Past
been successfully practised in many parts of the world
studies and research recommend dug wells, shallow
and was a major source of water in the Kathmandu
Figure 2: Potential recharge zone in the Kathmandu Valley showing the infi ltration rate during the monsoon season
(NGOFUWS/UN-HABITAT 2008)
Legend
Infi ltration Rate
High (>0.6 cm/min)
Moderate (>0.06 & <0.6 cm/min)
Low (<0.06 cm/min)
Formation
Quaternary
Recent alluvial soil
Residual soil
Colluvial soil
Alluvial fan deposit
Plio-Pleistocene
Tokha Formation
Gokarna Formation
Chapagoan Formation
Kalimati Formation
Kobgaon Formation
Lukundol Formation
Basal boulder bed
Precambrian to Devonian
Godawari limestone
Chitlang Formation
Chandragiri Formation
Sopyang Formation
Tistung Formation
Markhu Formation
Kulekhani Formation
Sheopuri gneiss
General
Drainage
River and River Bank
Main Road
Sub Road
Spot Height (in metres)
Map source: based on engineering and environmental geological map published by DMG in cooperation with BGR
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