Impact of Urbanization on Portable Water in Sikkim, Himalayas.
Agenda 21 of the UN Department of Sustainable Development, 1992, has worked out the Dublin Principles for IWRM in more detail for urban areas. One of the objectives of Agenda 21 is to develop environmentally sound management of water resource for urban use. Meeting the increasing demand for water services, while sustainably managing the water resources, can be a tremendous challenge for many countries. Hence, proper water management is the need of the hour.
Gangtok, city of Sikkim state is facing the problem of inadequate water supply and demand due to urban sprawl. The urban population of Sikkim increased from 37006 in 1991 to 122487 in 2011 (Primary Census Abstract, 2011). It has risen by 153%, between 2001 and 2011. Therefore, the present study addresses the impact of urbanization on the potable water resources in Gangtok city of Sikkim state. The main aim of this study is to judge the water quality changes and the gap between water supply and demand, which is beneficial in deciding appropriate remedial measures for conservation of water resources.
The Study Area
Gangtok, the capital of Sikkim,is located at 27.33[degrees]N and 88.62[degrees]E and has 122487 persons. It is situated in the lower Himalayas at an altitude of 1800m. The sex ratio of Gangtok city is 912 females per 1000 males. The average literacy rate of the Gangtok town is 82%, which shows a good literacy rate. The city is surrounded on the East and West by two streams, i.e., Roro Chu and Ranikhola, respectively. Both the streams meet at Ranipool and flow south as the main Ranikhola before it joins the Teesta at Singtam. The West-East or Southerly facing slopes of Gangtok and its suburbs, forms part of the inner belt with low to medium grade metamorphic rocks, and few areas are covered with schist and Darjeeling gneisses. The main Gangtok town stands over the intrusive lingtse granite gneiss. Gangtok enjoys a mild, temperate climate all year round. The mean temperature of Gangtok city ranges from 22[degrees]C in summer to 4.3[degrees]C in winter.
The present study is based on both primary and secondary data sources. The secondary data was collected from various sources viz., local water supply authorities, Department of Public and Health Engineering, Department of Forest, Department of Agriculture, Department of Urban Development and Housing, Government of Sikkim, Census handbook of India, etc. The primary data was collected from different stakeholders at the household level, government institutions, commercial setups and hotels of Gangtok city through questionnaires, group interviews and field observations. Primary data was obtained with close-ended and open-ended types of questionnaires and interviews. Close-ended types of questionnaires relating to the consumers contained the demand and consumption pattern, i.e., seasonal fluctuation in water demand and supply, duration of water supply, distance travelled to fetch water, income and expenditure on water supply, etc. An open-ended type of questionnaire was based on management aspects only. Stratified random sampling was chosen and 10 households were selected from each ward. Table 1 represents the demographic information of the selected respondents.
Table 1- Detail information of selected respondents of Gangtok City, Sikkim Parameters Item Numbers Percent Gender Male 69 46 Female 81 54 Age 18-29 42 28 30-60 106 70 >60 2 1 Education Primary School 17 5 Middle School or above 133 87 No. of Family Members 1-2 persons 21 14 3-6 person 99 66 >6 persons 30 20 Source of Income Off-farm 138 92 Agriculture 12 8
Urbanization has been closely connected to industrialization in the major cities of the world. Urbanization has taken place in Gangtok not only city due to its being the state capital of Sikkim state, but also because it is the big commercial centre in the state, which attracted majority of the population for trade and employment. Over the years the population has been following an upward trend with the strengthening of the economic and commercial hub of the state. This led to the concentration of schools, colleges, university and health care facilities which act as a major pull factor in attracting people from rural areas. The population from 1991 to 2011 has increased fourfold, the number of the households has increased three times, with a growth percentage of 178: from 2001-2011. It reflects the spatial expansion and clearing of vegetative cover for construction purposes. The urban population growth rate in the last decade has been recorded highest (200%) in Gangtok city. This unprecedented growth has led to tremendous pressure on the limited urban resources. Rapid urban expansion has led to encroachment and development of unstable terrain and reduced green areas. Due to the unprecedented growth of urban population, Gangtok city generated about 390 grams per capita per day solid waste. The estimated waste generation per day in Gangtok and adjoining areas is approximately 45 metric tons per day (Government of Sikkim, 2007). Although incineration of unassailable waste is not recommended as a method of solid waste disposal, incineration of biomedical waste is however strongly recommended for maintenance of health of the citizens.
Water Supply and Demand Analysis
Water supply and demand are phenomena that are indispensable to the urbanization processes. The two main agencies viz., Public Health Engineering Department (PHED) and Municipal Corporation, Gangtok, are responsible for supplying drinking water in Gangtok city using surface water (rivers/streams and lakes). There are about 40 seasonal local springs which are utilized by the Rural Management and Development Department of Sikkim Government to supply water to outlying rural areas. The water distribution system was laid as early as in the year 1968 in the city (IEE, 2011). The source of water for Gangtok is Lake Tamze (3800m asl) which is 52km from Selep Water Treatment Plant. River Ratey Chu originates from Lake Tamze and serves as a tapping point for Gangtok water supply. The total water supply in the city is 25 MLD of actual raw water supply from Rateychu to Selep water treatment plant at Gangtok.
The Selep water treatment plant was constructed in 1976 with a capacity of 4.5 MLD. The maintenance of raw water mains is severely affected due to landslides and hostile conditions of the approach road. The Gl main from Selep to RateyChu was last changed in 1994 and had reached the age of 25 years with its carrying capacity of 200 Ips. By the end of 2042, the demand for drinking water would rise to 40.34 MLD. Thus, if no additional Raw Water Mains are added by the year 2042, Gangtok will face an acute shortage of treated water. Hence, the replacement of raw water mains and augmentation of the existing facility at Selep Water Treatment Plant would be needed to meet the demand.
Water demand for Gangtok has been estimated based on the guidelines laid down in the Manual of Water Supply and Treatment published by the Ministry of Urban Development, Government of India. The Recommendation as per the Central Public Health and Engineering Organization is presented in Table 2.
Table 2- Recommendations as per the CPHEEO S. Classification of Towns and Cities Recommended No. Maximum Water Supply (Ipcd) 1 Towns provided with piped water supply but without a 70 sewerage system 2 Cities provided with piped water supply and with 135 existing/contemplated sewerage system 3 Metropolitan and Megacities provided with piped water supply 150 and where the sewerage system is existing/contemplated
Table 3 shows the consumption of water after the CPHEEO guideline of 135 Ipc daily at present and the projected water consumption for three decades in the future, considering the population trend that has been projected with the base of the current population growth rate and the projected water in MLD. The above population projection shows an increase in the population in the wards of Development area, Diesel Powerhouse, Lower M.G. Marg, Upper Sichey and Deorali followed by a proportional water use of 1.58 MLD in Development area and Diesel Power House, 1.48 MLD at Lower M.G. Marg and 1.29 MLD at Deorali.
Table 3- Ward wise projected water demand in Gangtok City Name of Ward Projected Population Water demand @135 Ipcd (MLD) 2027 2042 2012 2027 2042 Burtuk 14455 18580 1.40 1.95 2.51 Upper Sichey 15775 20276 1.53 2.13 2.74 Lower Sichey 11030 14177 1.07 1.49 1.91 Chandmari 10260 13188 0.99 1.39 1.78 Development Area 16337 20999 1.58 2.21 2.83 Diesel Power House 16301 20952 1.58 2.20 2.83 Arithang 10617 13646 1.03 1.43 1.84 Lower M.G. Marg 15318 19689 1.48 2.07 2.66 Upper M.G. Marg 12213 15698 1.18 1.65 2.12 Tibet Road 11708 15049 1.13 1.58 2.03 Deorali 13352 17161 1.29 1.80 2.32 Daragaon 5918 7607 0.57 0.80 1.03 Tadong 9821 12623 0.95 1.33 1,70 Ranipool 7475 9608 0.72 1.01 1.30 TathangchenSyari 9919 12750 0.96 1.34 1.72 Total 180500 232000 17.48 24.37 31.32 Source: NERCCDIP Report
Water Supply Distribution System
The purpose of the distribution system is to deliver water to the consumer with appropriate quality, quantity, and pressure. The distribution system is used to describe collectively the facilities used to supply water from the source to the point of usage. The water supply system in Gangtok follows a gridiron system which maintains the proper circulation of water due to an absence of dead ends and in the case of a breakdown in some section; water is available from some other direction. The existing water distribution system that caters to the Gangtok Municipal Area comprises of (i) primary network, about 34km existing and (ii) secondary network about 43km existing. The present distribution system consists of bunches of 20 or 25mm Gl pipes drawn from the main service reservoirs or distribution tanks to each consumer. This system needs to be replaced by a looped system with proper hydraulic zoning, which will ensure an equitable supply with adequate and equal terminal pressure. Water for each zone will be supplied from a zonal tank.
The provision and management of efficient pricing systems vary with different states. Tariff rates are basically set by the water or sanitation provider or by the national or local governments through national or state policy. The state governments are responsible for establishing an urban water tariff structure, and the result is a wide variety of practice. Average tariffs in India are low, relative to the cost.
The proposed tariff and revenue generation is based on the assumption that 80% of the population will pay water charges at the initial stage, 90% will pay at the middle stage and 100% population will pay at the ultimate stage with the measure of Increasing Block Tariff. The rates fixed are also not revised frequently to reflect the general costs, widening the gap between the cost of production and tariff charged. Water connection charges are collected from the users based on the number of connections per building. The tariff charge is collected based on the number of taps provided as presented in Table 4. Lack of metering is an issue in Sikkim, and this also leads to a lot of water going undetected and unaccounted. Further, the lack of pricing and regulation of water contributes to the overuse of water resources. Therefore, it is suggested that water regulators should properly price the water for household, industries, and irrigation.
Table 4- Tariff chart in Gangtok City, Sikkim Tap-based tariff Domestic Commercial Number of Taps 1 to 3 Rs. 80/- per month Rs. 160/- per month 4 to 7 Rs. 130/- per month Rs. 260/- per month 8 to 12 Rs. 225/- per month Rs. 350/- per month Volumetric tariff Domestic Rs. 5/- per 1000 litres Commercial Rs. 10/- per 1000 litres Bulk supply Rs. 12/- per 1000 litres
Consumer Behavior on Water Use
The residents of Gangtok city are highly dependent on the quality and quantity of water supplied by the Public Health Engineering Department (PHED) or the natural springs. Natural springs are one of the essential sources of water for the residents of the city. About 85% of the respondents were dependent on the water supplied by PHED and about 11% met their demand from natural springs. The consumer satisfaction survey was conducted to know their view regarding water supply in the city from May to September and October to April season. The majority of the respondents are least satisfied during the monsoon months, which can be attributed to the frequent damage to the supply network. About 77% of respondents are moderately satisfied during October to April. It was observed during the field survey that about 96% of the respondents are connected with proper water supply pipeline. It was also noted that households with proper pipeline connections were also dependent on the springs as a means to conserve water in their houses.
The respondents of the city received water in varied duration. Out of 144 households surveyed, 23 households received water for only 40 minutes to one hour, 65 household received water for 2-3 hours and 58 households for 3-4 hours per day depending on the socio-economic conditions of the residents. The period of water supply is not satisfactory
for those who receive water for less than one hour. The water supply duration shows an inverse relationship with the location and the high density populated wards. Water utilization for domestic purposes includes cleaning and cooking in the household. Table 5 gives an idea about water requirement per person per day (litres).
Table 5 Water requirement per person per day (litres) Parameters Consumption (Ipcd) Cooking 5 Washing utensils 10 Drinking 5 Washing cloths 20 Bathing purpose 55 Lawns 10 Flushing latrines 30 Total 135 Source: Agor, 2009
The residents of the city faced seasonal water scarcity due to pipeline damaged during the rainy season. Apart from that, about 23% of respondents reported that they are facing water shortage during the winter season and 29% during the summer season. About 53% of low-income group respondents spend Rs.80-130/- per month on water charges, followed by 41% middle income group and 6% high-income group.
Various optimization measures have been undertaken by local residents. About 98% of the respondents practice water management. Majority of the households practice rooftop water harvesting to conserve the water. Other measures include avoiding overflow and checking leakages, using ball cock in the water tanks, using a ferrule valve in the tank pipe, using a bucket while bathing, using sprinkler instead of watering plants directly with a hose. Leakage caused due to faulty taps and toilet flushes are the primary cause of water scarcity in a household. Introducing and involving gender dimensions and participants of lower income group in mainstream policy and programmes can help the decisions makers in incorporating the most affected population to formulate an effective solution.
Physio-chemical and Bacteriological Properties
The results of physio-chemical and bacteriological analyses are presented in Table 6. The pH of the water tested in 15 sampling stations at Gangtok city showed that the pH is within the permissible limit of 6.8 to 8.5 in the majority of the stations. The highest value of turbidity ranged from 8.8 to 8.9, but the turbidity levels showed considerable reductions after the treatment of water at Selep WTP i.e. 5.6 to 5.7. Sulphate occurs naturally in numerous minerals including barite, epsomite, and gypsum. These dissolved minerals contribute to many drinking water problems. Selep water tank has the highest amount of sulphate per litre with 3.8 mg/l in the pre-monsoon and 0.7mg/l in the monsoon season. Nitrate is higher in Ratey Chu in both the seasons and ranged from 4.4mg/l in pre-monsoon to 0.45mg/l in monsoon season. The temperature of the water during pre and monsoon season was constant and varied between 17-15[degrees]C in all the sampling stations. No significant change was observed in raw water quality on a day-to-day basis. A similar observation was reported by Khadse et al. (2011).
The bacteriological parameters i.e., total coliform and fecal coliform of sampled water were analyzed and presented in Table 6 (given in Annexure-1). Total coliform is used as a general indicator of potential contamination with pathogenic organisms. However, many coliform bacteria live in the soil and these organisms may be the source of those that appear in surface water. Table 5 indicates a high level of contamination of total coliform and fecal coliform at Ratey Chu. The presence of fecal conforms in the tanks after passing through the treatment process also calls for immediate attention as it poses a looming threat to the health of the consumers.
Table 6- Water quality of treatment plant at Gangtok City, Sikkim Annexure-1 Treatment pH Turbidity Sulphate plants Pre- Monsoon Pre- Monsoon Pre- Monsoon monsoon monsoon monsoon Rateychu 8.4 8.2 8.8 8.9 1.6 0.2 Selep 7.5 7.7 5.6 5.7 3.8 0.7 WTP Enchey 7.3 7.3 5.1 5.4 2.4 0.3 Tank Enchey 7.4 7.4 5.0 5.1 - - Distribution Tank Tibet Road 7.0 7.2 2.4 2.9 2.9 0.6 Tank Tibet Road 7.1 7.3 3.2 3.8 - - Control Room Branch of 7.3 7.0 3.7 3.5 - - High Court,1/2" mainline Branch of 7.1 7.1 4.3 4.8 - - High Court, 3&4" mainline from Enchey GICI Tank 6.9 7.5 3.6 3.7 - - Deorali 7.2 7.2 3.8 3.5 2.2 0.1 Tank Press 8.1 8.0 5.3 5.5 - - Tank Housing 7.7 7.0 4.8 4.3 3.4 0.4 Tank Housing 7.3 7.3 5.1 5.7 - - colony Tap Water Tadong 7.1 7.1 3.1 4.6 - - Govt. College Development 7.6 7.2 3.9 4.9 - - Area Tank Treatment Nitrate Temp [degrees]C Conductivity plants Pre- Monsoon (us/cm) monsoon Pre- Monsoon Pre- Monsoon monsoon monsoon Rateychu 4.4 0.45 16.0 2.4 3.5 3.5 Selep 2.7 0.39 16.5 12.9 3.8 3.0 WTP Enchey 2.9 0.42 16.9 12.7 3.1 2.9 Tank Enchey - - 16.4 12.6 2.9 3.5 Distribution Tank Tibet Road 2.4 0.41 17.0 12.3 4.0 3.7 Tank Tibet Road - - 17.1 12.6 3.7 3.2 Control Room Branch of - - 16.8 13.0 3.0 3.1 High Court,1/2" mainline Branch of - - 16.3 12.8 2.4 4.0 High Court, 3&4" mainline from Enchey GICI Tank - - 17.3 12.3 2.5 3.8 Deorali 3.1 0.37 16.8 13.1 2.8 3.4 Tank Press - - 16.9 13.2 3.2 3.5 Tank Housing 2.7 0.67 17.2 12.8 4.0 4.2 Tank Housing - - 16.8 12.6 3.5 2.8 colony Tap Water Tadong - - 15.9 12.7 2.6 2.3 Govt. College Development - - 16.8 13.2 3.6 3.0 Area Tank Treatment Total Coli Form Faecal Coli plants (less 10, CFU) Form Pre- Monsoon Pre- Monsoon monsoon monsoon Rateychu 19 21 4 4 Selep 14 14 3 3 WTP Enchey 9 8 1 1 Tank Enchey 8 13 3 2 Distribution Tank Tibet Road 6 10 1 1 Tank Tibet Road 11 11 2 2 Control Room Branch of 7 7 1 1 High Court,1/2" mainline Branch of 8 8 2 2 High Court, 3&4" mainline from Enchey GICI Tank 6 5 1 1 Deorali 8 6 3 2 Tank Press 14 12 3 3 Tank Housing 11 10 2 2 Tank Housing 5 5 1 1 colony Tap Water Tadong 3 3 1 1 Govt. College Development 7 7 2 2 Area Tank Source: Rai, 2016
The study revealed that the water supplied through the distribution network was not up to the BIS water quality standard for physio-chemical and bacterial quality. The awareness about drinking water quality is highest among high-income group and educated people and least among illiterate people. The monitoring of water quality from time to time will lead to safety and better health of the community. The proper maintenance of the distribution network system, awareness about the hygienic and sanitary conditions, and adequate storage of water will help in maintaining water quality. Necessary measures need to be undertaken at places where fecal contamination was present, to avoid any adverse impact on human health. Introducing and involving gender dimensions and participants of the lower income group in policy and programmes can help the decisions makers in incorporating the most affected population to formulate an effective solution.
We are thankful to the Head, Department of Geography, Delhi School of Economics, University of Delhi for providing facilities.
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|Author:||Rai, S.C.; Rai, Smriti|
|Publication:||Political Economy Journal of India|
|Date:||Jan 1, 2019|
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