Rainwater Harvesting in the Wake of Climate Change: a Case Study from Shimla City, Himachal Pradesh
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Universal Journal of Environmental Research and Technology All Rights Reserved Euresian Publication © 2012 eISSN 2249 0256 Available Online at: www.environmentaljournal.org Volume 2, Issue 4: 336-346 Open Access Research Article Rainwater harvesting in the Wake of Climate Change: A Case Study from Shimla city, Himachal Pradesh Tanu Singh 1* and L.S. Kandari 2 1Integrated Research and Action for Development (IRADe), New Delhi-110017 2School of Natural Resource Management and Environmental Sciences, College of Agricultural and Environmental Sciences, P. Box #337, Haramaya University, Dire Dawa, Ethiopia Corresponding author: [email protected] Abstract: Shimla city depends mainly on surface water, available in the form of springs, streams and piped rivulets to fulfill its water demand. With rapid development of the city along with the ever increasing tourist inflow, there is a change in the trend of urbanization, which is highly water intensive. Earlier, the water supply system was meant to support a small population, but the population has now increased many folds. The city faces water shortage in every summer leading to huge demand and supply gap. The sources of water are located quite far from the city and mainly tapped from five main sources namely, Dhalli catchment area, Cherot Nallah, Chair Nallah, Nauti Khad (Gumma) and Ashwani Khad. In the face of changing climate, rainwater harvesting (RWH) could be seen as a promising solution to deal with the urban water demand. However, in Shimla city, roof top harvesting is the best way to collect rainwater and then storing it into the reservoirs (either overhead or underground) for further use. From the present study it has been observed that, the city is suitable for rainwater harvesting as it has the required potential for it and receives a good amount of rainfall during rainy season (from June-September), which constitutes almost 70% of the total rainfall in the region. Therefore, RWH can be a viable option to preserve water for the scarce period in the city. It is also necessary now, to educate people and make them aware about the potential and benefits of rainwater harvesting in times of acute scarcity. Keywords: Climate change; Rainwater harvesting; Shimla 1.0 Introduction: parks, open fields, roads etc.) and storm water The Fourth Assessment Report of the drains (drains along the roadside). Rain water can Intergovernmental Panel on Climate Change (IPCC, be stored in two ways, ie., i) it can either be stored 2007) points out that freshwater availability in Asia in the containers above the ground or ii) below the is projected to decrease due to effects of climate ground or it can be charged into the soil as change. In order to meet our future water needs, recharged groundwater. we have to work not only towards climate change mitigation strategies but also towards adaptation India has a long tradition of rainwater harvesting. strategies such as water resource management Different techniques of rainwater harvesting were and conservation of our natural resources. The earlier developed and practiced in various parts of reasons for the water scarcity are attributed to the country based on the geographical and changing climate due to global warming and the meteorological conditions of the region. Significant additional burden of non-climatic factors such as benefits of rainwater harvesting prevail in urban population growth and rapid urbanization. Over areas as water demand has already exceeded dependence on secondary sources of water has supply in most of the cities in India like Delhi, made us forget that rain is the ultimate source that Mumbai, Bangalore, Chennai, etc. Rainwater feeds all these secondary sources and harvesting potential of a site is determined mainly consequently remained oblivious of its importance by the rainfall and the catchment area (CSE, 2010). Following collection, rainwater can be characteristics. The need and the design for stored for direct use or can be recharged into the rainwater harvesting are also influenced by the groundwater. In urban areas, rainwater can be number of rainy days. The fewer the annual rainy captured from various surfaces ie., rooftops of the days or longer the dry period, the more the need building, paved and unpaved area (i.e, landscapes, for rain water collection in a region. For rainwater 336 Singh and Kandari Universal Journal of Environmental Research and Technology harvesting, the catchment area of water resources population, comprising of tourists and visitors and also play an important role. The catchment area a permanent population of nearly 0.2 million characteristics determine the storage conditions. people (Joshi, 2008). The city population has All calculations relating to the performance of grown tremendously in recent years thereby rainwater catchment systems involve the use of putting lot of pressure on the existing runoff coefficient to account for losses due to infrastructure of the city. The influx of tourists spillage, leakage, infiltration, catchment surface visiting Shimla increases drastically particularly wetting and evaporation, which will together during summer season leading to increase in water contribute to reducing the amount of runoff. demand. The City requires 42 million litres water in Owing to heavy slope in hills, water harvesting is a a day (MLD) whereas; it receives only 30 MLD of very difficult task. Unlike other urban cities in water (Himvani, 2010) thus facing acute water India, Shimla the capital of Himachal Pradesh shortage each year during summer (Table 1). On largely depends on the surface sources like spring one side, the influx of tourist increases the or streams for its adequate and safe water business of the hotels and on the other side; it demand. In the recent years, the problem of water increases the consumption of water in the city by 3 supply has started increasing rather at a rapid MLD (Susngi, 2010). Hence, there is an urgent pace, with the growth and expansion of city. In need to study the water management framework addition, water supply network constructed of Shimla city to address the problem and around 1875 is being still operated although the implement some counter measures or techniques population has increased many folds (Pubby, that could be used to deal with the present and 1996). future demand of water. Besides, it also requires complete overhauling of the existing water system. In this study, Shimla city had been taken as a case Furthermore, there is high subsidy on water in study to understand how the available water can Shimla city, which is putting extra financial be managed well in hill towns by scaling up some pressure on the water institutions. In this regard, best practices, as that can also reduce the pressure rainwater harvesting (RWH) has come out as a on existing resources. This would serve as an viable management adaptation strategy that the example which could be replicated for other hill water sector in Shimla city could undertake in towns facing similar water shortage situation. order to cope with present and future water Water supply facilities were introduced in Shimla shortage. The present study therefore, more than 130 years ago during the British rule, by encompasses the following. i) To study various pumping water from nearby spring sources. The water sources and further augmentation studies. first systematic system of water supply was ii) To review and assess various existing steps for executed in the year 1875 to feed a small water storage. iii) To review practices adopted by population of 16000 people (Pubby, 1996). With Shimla city water supply and distribution systems. the increase in demand, the supply continued to iv) Need to undertake rainwater harvesting within be augmented several times. The system of earlier municipal limits by people through enforcement. water supply in Shimla city comprised of tapping of spring water, old baoris and stream sources, 2.0 Methodology: treating it and pumping the same to the storage 2.1 Profile of the Study Area: tanks, which was linked with the pipe network and Shimla, the capital city of Himachal Pradesh, being finally carried to the consumer end (Sharma, a hill town with a very pleasant climate, is a 2008a). The authorities or the government bodies primary tourist destination in the northern part of responsible for water supply in Shimla are the India. Every summer, this tourist destination faces Irrigation and Public Health (IPH) department and acute water shortage and the locals are usually the the Municipal Corporation Shimla (MCS). The IPH ones to bear the brunt. Over the years, the is responsible for operation and maintenance of situation has reached a point where the hotels in these systems, while the Shimla Municipal the city have to engage private tankers to tap Corporation receives treated bulk water from IPH spring water (Sharma, 2008b) and pay a hefty and distributes it for commercial and domestic amount to avail their services. connections. The other duties of SMC include, pumping, metering, billing and collection of water 2.2 Geographical Setting: charges of potable water (CDP, 2006). Shimla is situated in the north of India in the State of Himachal Pradesh. The city is located in the mid Shimla is a major tourist destination with the state hills of the Western Himalayas. It is situated in the capital attracting, national and international Shimla district, which is surrounded by Kinnaur tourists and housing more than 50,000 floating 337 Singh and Kandari Universal Journal of Environmental Research and Technology district in the north-east, by Kullu and Mandi districts in the south-west and by the state of districts in the north-west, by Solan and Sirmaur Uttaranchal in the south-east (Figure 1). Figure 1.Map of the Study area 338 Singh and Kandari Universal Journal of Environmental Research and Technology 2.3 Climate and Rainfall: from 1980 to year 2005 (Table 1).