Kathmandu has a population of about 0.8 million and is a historic capital
city, commercial and cultural centre with a small industrial base (carpets).
It is growing at 5% per annum and tourism is economically important. and
the population is expected to double by 2020. About 60% of the city is
sewered and the remainder is being progressively connected to sewer. The
population density is low and the city covers an area of more than 700
km2.
Intermontane basin with unconsolidated sediments (Plio-Quat) up to 500
m thick. Upper, unconfined aquifer with recharge in N of basin, contains
originally good-quality water but now 60% of wells are polluted. Lower
aquifer is confined by thick clay bed and contains dissolved iron, ammonia
and methane and needs treatment. Discharge unknown, basal aquifer may be
stagnant.
Municipal water supply about 14 million cubic m per year which is 50% groundwater.
In addition private wells supply an estimated 6 million cubic m. Waste
disposal and sewerage systems are inadequate.
The ultimate capacity of the groundwater system to supply future growth
of the city, is doubtful, and a future major water source will have to
be sought outside the basin.
Pollution of shallow aquifer by sewage and industrial effluent is serious.
Rivers, hich connect with unconfined aquifer, are heavily polluted. The
deeper, confined, aquifer requires treatment for domestic use.
Khadka, M.S., 1993. The groundwater quality situation in alluvial aquifers
of the Kathmandu valley, Nepal. AGSO Journal of Australian Geology &
Geophysics, 14, 207-211.
Gerry Jacobson and John Bauld of AGSO are carrying out a joint project
with the Nepal Groundwater Resources Board, to investigate groundwater
quality in Kathmandu, under the auspices of the Australian technical assistance
program.
