Wednesday, 30 September 2015

Water Management

3.1 Ground Water and Watershed management
3.2 Water usage and efficient irrigation systems
3.3 Drinking Water: supply, factors of impurity of water and quality management

Ground Water and Watershed management
Water is a cyclic resources with abundant supplies on the globe. Approximately, 71% of the Earth's surface is covered with it, but the fresh water constitutes only about 3% of the total water. In fact, a very small proportion of fresh water is effectively available for human use. 
India accounts for about 2.45% of world's surface area, 4% of world's water resources and about 16% of world's population. The total water available from precipitation in the country in a year about 4000 cubic km. The availability from surface water and replenishable(replenish meaning - to refill; to renew) groundwater is 1869 cubic km. Out of this only 60% can be put to beneficial uses. Thus, the total utilisable water resources in the country is only 1122 cubic km.

Ground Water Resources
The total replenishable groundwater in the country is are about 432 cubic km that the Ganga and Brahamputra basins, have about 46% of the total replenishable groundwater resources. The level of groundwater utilisation is very high in the river basins lying in North-Western region and parts of South India. The groundwater utilisation is very high in the states of Punjab, Haryana, Rajasthan and Tamil Nadu. However, there are states like Chhatisgarh, Odisha, Kerala etc which utilise only a small proportion of their groundwater potentials.

Deterioration of Water Quality
Water Quality refers to purity of water or water without unwanted foreign substances. Water gets polluted by foreign matters such as micro organisms, chemical, industrial and other wastes. Such matters deteriorate the quality of water and render it unfit for human use.
Monitoring of ground water quality is an effort to obtain information on chemical quality through representative sampling in different hydrogeological units. The chemical quality is being monitored by Central Ground Water Board once in a year through a network of about 15000 observation wells located all over the country, in regular monitoring programme.
The natural chemical content of ground water is influenced by depth of the soils and sub-surface geological formations through which ground water remains in contact.  In general, greater part of the country, ground water is of good quality and suitable for drinking, agricultural or industrial purposes. Ground water in shallow aquifers is generally suitable for use for different purposes and is mainly of Calcium Bicarbonate and Mixed type. However, other types of water are also available including Sodium-Chloride water. The quality in deeper aquifers also varies from place to place and is generally found suitable for common uses. There is salinity problem in the coastal tracts and high incidence of Fluoride, Arsenic, Iron &  heavy metals etc in isolated pockets have also been reported. The distributions of various constituents present in ground water in different parts of the country have been discussed in following paragraphs.

The main ground water quality problems in India are as follows.

Salinity:- Salinity in ground water can be of broadly categorised into two types, i.e. Inland Salinity and Coastal salinity

Inland Salinity
Inland salinity in ground water is prevalent mainly in the arid and semi arid regions of Rajasthan, Haryana, Punjab, Gujarat, Uttar Pradesh, Delhi, Andhra Pradesh, Maharashtra, Karnataka and Tamil Nadu. There are several places in Rajasthan and southern Haryana where EC values of ground water is greater than 10000 mS /cm at 25o C making water non-potable. In some areas of Rajasthan and Gujarat, ground water salinity is so high that the well water is directly used for salt manufacturing by solar evaporation.

Inland salinity is also caused due to practice of surface water irrigation without consideration of ground water status. The gradual rise of ground water levels with time has resulted in water logging and heavy evaporation in semi arid regions lead to salinity problem in command areas. 

Coastal Salinity
The Indian subcontinent has a dynamic coastline of about 7500 km length. It stretches from Rann of Kutch in Gujarat to Konkan and Malabar coast to Kanyakumari in the south to northwards along the Coromandal coast to Sunderbans in West Bengal .The western coast is characterized by wide continental shelf and is marked by backwaters and mud flats while the eastern coast has a narrow continental shelf and is characterized by deltaic and estuarine land forms. Ground water in coastal areas occurs under unconfined to confined conditions in a wide range of unconsolidated and consolidated formations.
Normally, saline water bodies owe their origin to entrapped sea water (connate water), sea water ingress, leachates from navigation canals constructed along the coast, leachates from salt pans etc. In general, the following situations are encountered in coastal areas
  • Saline water overlying fresh water aquifer
  • Fresh water overlying saline water
  • Alternating sequence of fresh water and saline water aquifers
In India, salinity problems have been observed in a number of places in most of the coastal states of the country. Problem of salinity ingress has been conspicuously noticed in Minjur area of Tamil Nadu and Mangrol – Chorwad- Porbander belt along the Saurashtra coast. 

85 % of rural population of the country uses ground water for drinking and domestic purposes. High concentration of fluoride in ground water beyond the permissible limit of 1.5 mg/l poses the health problem. 
19 districts of Madhya Pradesh are effected by fluoride contamiation, they are:
Madhya Pradesh 19
Bhind, Chhatarpur, Chhindwara, Datia, Dewas, Dhar, Guna, Gwalior, Harda, Jabalpur, Jhabua, Khargone, Mandsaur, Rajgarh, Satna, Seoni, Shajapur, Sheopur, Sidhi.

Arsenic as a contaminant is significant in terms of its toxic nature with exceedingly diverse manifestations of poisoning. Drinking water is the major pathway for ingestion of arsenic in human system. As per BIS 2012 (IS 10500:2012), the acceptable limit of Arsenic is 0.01 mg/l and the permissible limit in absence of alternate source is 0.05 mg/l.Elevated concentrations of arsenic in ground water are reported from various parts of India but particularly  affecting the large parts of the Ganga- Brahmaputra Plains.

High concentration of Iron (>1.0 mg/l) in ground water has been observed in more than 1.1 lakh habitations in the country. Ground water contaminated by iron has been reported from the states of Andhra Pradesh, Assam, Bihar, Chhattisgarh, Goa, Gujarat, Haryana, J&K, Jharkhand, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Manipur, Meghalaya, Orissa, Punjab, Rajasthan, Tamil Nadu, Tripura, Uttar Pradesh, West Bengal & UT of Andaman & Nicobar. 

Nitrate is a very common constituent in the ground water, especially in shallow aquifers. The source is mainly from anthropogenic activities. High concentration of Nitrate in water beyond the permissible limit of 45 mg/l causes health problems. High Nitrate concentration in ground water in India has been found in almost all hydrogeological formations. 

Water Conservation and Management 
Since there is a declining availability of fresh water and increasing demand, the need has arisen to conserve and efficiently manage this precious life giving resources for sustainable development. Given that water availability from sea/ocean, due to high cost of desalinisation, is considered negligible, India has to take quick steps and make effective policies and laws and adopt effective measures for its conservation. Besides developing water saving technologies and methods, attempts are also to be made to prevent the pollution. There is need to encourage the watershed development, rainwater harvesting, water recycling and reuse and conjunctive use of water for sustaining water in the long-run.

Watershed Management
Watershed management basically refers to efficient management and conservation of surface and groundwater resources. It involves prevention of runoff and storage and recharge of groundwater through various methods like percolation tanks, recharge wells, etc. However, in broad sense watershed management includes conservation, regeneration and judicious use of all resources - nature( like land, water, plants and animals) and human within watershed. Watershed management aims at bringing about balance between natural resources on the one hand and society on the other. The success of watershed development largely depends uupon community participation.

The Center and State Government have initiated many watershed development and management programmes in the country. Some of these are being development by non-governmental organisations also. Haryali is a watershed development project sponsored by the Central Government which aims at enabling the rural population to conserve water for drinking, irrigation, fisheries and afforestation. The main objectives are: Objectives Harvesting every drop of rainwater for purposes of irrigation, plantations including horticulture and floriculture, pasture development, fisheries etc. to create sustainable sources of income for the village community as well as for drinking water supplies. The project is executed by Gram Panchayats with people's participation. Neeru-Meeru (Water and you) programme in Andhra Pradesh and Arary Pani Sansad(in Alwar, Rajasthan) have taken up constructions of various water harvesting structures such as percolation tanks, dug out ponds(johad), check dams, etc through people's participation. Tamil Nadu has made water harvesting structures in the house compulsory. No building can be constructed without making structure for water harvesting. 

Integrated Watershed Management Programme(2009-10) 
Integrated Watershed Management Programme (IWMP) is a modified programme of erstwhile Drought Prone Areas Programme (DPAP), Desert Development Programme (DDP) and Integrated Wastelands Development Programme (IWDP) of the Department of Land Resources. This consolidation is for optimum use of resources, sustainable outcomes and integrated planning. The scheme was launched during 2009-10. The programme is being implemented as per Common Guidelines for Watershed Development Projects 2008. The main objectives of the IWMP are to restore the ecological balance by harnessing, conserving and developing degraded natural resources such as soil, vegetative cover and water. The outcomes are prevention of soil erosion, regeneration of natural vegetation, rain water harvesting and recharging of the ground water table. This enables multi-cropping and the introduction of diverse agro-based activities, which help to provide sustainable livelihoods to the people residing in the watershed area.

Water harvesting structures for dry hilly areas

Water harvesting is a prominent and technically feasible technology in arid hilly areas. It helps in runoff harvesting and ground water recharging. Water harvesting structures such as community tanks, inter-terrace runoff harvesting, hill spring outflow harvesting and rooftop harvesting structures. Runoff utilisation is increasingly becoming a common practice in dryland conservation agriculture.
There are other approaches which can be adopted for conservations of dryland ecosystems are: Sustainable farming practices, Integrated watershed approach and role of agroforestry in soil and water conservation in dryland ecosystems.

MP Special

Hariyali Mahotsav

Jal Abhishek Campaign

Rajiv Gandhi Mission for Watershed Management

Bhagirath Krishak Abhiyan

Water usage and efficient irrigation systems

Water usage

Efficient irrigation systems
Kurukshetra Magazine(July, 2014; New Irrigation Technologies)
Efficient use of water resource is basic to survival of the ever increasing population of a country, this is especially very crucial for India, where we are having less than 5% of the world's water resources and more than 18% world's population.