Conservation Status Of Groundwater In Kathmandu Valley

Essay add: 22-10-2015, 20:34   /   Views: 237

The total 1.65 million population of Kathmandu valley in 2001 has been tremendously increased in 2010 (about 2.7 million) with the demand of 270 million liters of water per day, but the government could only provide about 10% of it. So there is significant water scarcity in the valley causing ground water consumption very high in recent years. Technicians and other concerned bodies says that 20 feet depth would be enough to extract water in the past but now there is difficult to find water even when digging 40feet (Ramtel, 2010). Groundwater resource is defined by shallow aquifer (water level up to 100m) and deep aquifer (more than 100m). The shallow aquifer water can be recharged more easily than the deep aquifer water.

The surface water infiltration and percolation recharge the shallow aquifer easily whereas the deep aquifer where the water has been stored since ages, called fossil water, cannot be recharged easily from the surface water infiltration. Different studies have revealed that the ground water extraction should not exceed 15 millions of liters per day (MLD) but in Kathmandu it is about 70 MLD and this trend decreasing the water level by 2.5m annually. So when the groundwater level reduces, there are chances of subsidence of the earth's surface, which leads to cracking and breaking down of physical infrastructure.

Other aspects of problem associated with the ground water extraction alarms that if this trend of water consumption continues, then the water will be sufficient only for 90 years (Adhikari, 2009).

1.1 Statement of problem

Every citizen wants to satisfy his/her needs. Needs in the developing countries like Nepal are fulfilled in the capital city. So the increased and increasing population is common. However this increase has also been highly influenced by the twelve years civil war since 1995-2006 (McMahon 2006).Whatever may be the reason for increasing population may be another part of the study but in present, the increased population has affected the basic needs i.e. air - polluted, water- scarce, food and commodities- expensive, shelter- land use pattern change to residents.Water is a basic need. A population of about 2.7 millions in Kathmandu valley is already beyond carrying capacity.

Establishing proper policy and guidelines for water supply was already a problem with a smaller population in the valley, but now this is out of control with this increased population. The over exploitation has also resulted in water contamination by the different pollutants reducing its usable potentiality. The pollutants get infiltrated through the polluted surface water like rivers in the shallow aquifer.

This has created pressure in the use of deep aquifer which has relatively good water quality. (Pathak, Hiratsuka et al. 2009). The high percolated amount of dissolved organic carbon, pathogens, nitrate, ammonia and other organic pollutants from different wastewater sources and septic effluents are highly influencing the water quality in the aquifer(Pant 2010).For the sustainable use extraction as well as recharge should be simultaneous. The data shows that increasing population density of the valley is 3150 to 4680 person per sq. km.

Besides the population density the number of hotels, restaurant has also tremendously increased in this decade contributing to the high consumption of ground water. Recent data shows that the extraction of ground water is 21.56 million cubic meter per year whereas the recharge is just 9.6 (Pandey, Chapagain et al. 2010).

Research Questions:

On the basis of these arguments regarding the ground water, two research questions have been derived:How is the dynamics and conservation status of resources?What are the existing regimes for water use in the Kathmandu valley?What can be the conservation strategy to solve the problem?

Analysis and Discussion

Dynamics and conservation status of resources:

Water is required for the drinking, religious, agricultural, industrial purposes as well as for the recreational activities. Until 1891, stone spouts, wells and rivers were the common water sources of the people in Kathmandu valley. Stone spouts were to be a very connected water supply system for the residence of Kathmandu.

It was considered to be the purest source for the drinking purposes. People used to depend on rivers (Bagmati and its tributaries) and dug wells for other purposes such as washing, bathing and agriculture. Therefore, indigenous people had natural water supply system that met the water demand of the valley (Amatya, 2010).Groundwater naturally supplies water flow to these spouts and wells. Besides this people at that time were skillful to recharge the groundwater through the water canal (locally called 'Rajkulo') through the ponds in the valley.

The connections of these ponds, water spouts, wells and canals were so efficient that it could provide both quantity and quality of water to the Kathmandu citizens(UN-HABITAT 2008).

Table 1: Traditional Stone Spout in the Kathmandu valley

Cities

Running

stone spout

Connected with main supply

Not working

Not Exist

Total

Kathmandu

9623433

165

Lalitpur

47077

61

Kirtipur

10001

11

Bhaktapur

3335181

87

Madhyapur Thimi

47693

65

Total

233

43

68

45

389

Source: NGOFUWS (2006) cited by: NGO Forum, 2010Table 1 shows the total number of stone spout in the Kathmandu valley with different status of operation. In Kathmandu 33 are in not existence while 34 is not working or dried up. Similarly 2 are connected with the city supply line whereas 96 are naturally working.The local communities (locally called Guthis) are involved in the maintenance of this water supply and in the festival called Sithinakha (consider as local water day) these guthis get involved in the cleaning of water canals, ponds and spouts.Fig 1: Traditional Stone SpoutThese indigenous methods of water supply and source conservation got ruined when there was introduction of piped water system a century ago.

Piped water supply was more convenient than the fetching to the stone spouts, hence people forgot about it. Also the population increment and uncontrolled urbanization demolished the ponds, canals which recharge the sources.As mentioned earlier, dug wells are common source of water for cleaning and other domestic purposes. Data revealed that about one thousand such dug wells are found in the valley. People with no pipeline supply mostly use the dug well for different purposes.http://t2.gstatic.com/images?q=tbn:ANd9GcTxAQfaHx1JeaighFtfjSQ4oamFg_uRcGAWfbzRNwB29hHPe4UXFig 2: A typical Dug WellThe water table in these dug wells has been receded due to the low recharge rate.

Population growth leading to the rapid urbanization has declined the water table and quality. The deposited soil in valley has very productive aquifer and the upper unconfined part of the aquifer serves as the source of water for these dug wells. These aquifers are getting pollutants and highly infected by the coli-form bacteria and other infectious bacteria especially in the monsoon season.

These pollutants also enter into the pipeline supply affecting the drinking water (Dixit and Upadhya 2005).

Time period

Amount (MLD)

Before 198071980-1990461990-to date70Ponds are the other connected source of water in the Kathmandu valley. These ponds helped to feed the dug wells and stone spouts in the valley. The rains in the monsoon are collected in these ponds making easier to get continuous and easy access of water in the dug wells and stone spouts in the dry season. Local people in their festival 'Sithinakha' clean up these ponds before the monsoon so that it could fill up with the debris and sediments.

The sediment filled in the pond is used as manure in the agricultural lands (Upadhya, 2009).



Article name: Conservation Status Of Groundwater In Kathmandu Valley essay, research paper, dissertation