The International Committee of the National Geographic Channel defines watershed on the basis of the criterion that the effect of overland flow rather than the effect of channel flow is a dominating factor affecting the peak runoff. On larger watersheds, the effect of channel flow or the basin storage effect becomes very pronounced so that such sensitivities are greatly suppressed.
Planning and development of watersheds calls for rigorous understanding about the occurrence and movement of water in the surface and sub-surface systems along with soil and nutrient losses in a watershed as the need arises for a proper watershed management of that area .In a country like India where a lot of running water goes on waste it becomes very important to apply the technology of watershed management to solve its annual problems of droughts and floods.
The main objectives of watershed management program are:
1.To generate data on hydro-meteorological, soil, nutrients and process related parameters at watershed level in different agro-ecological zones of the country through instrumentation.
2. To carry out modeling studies on watershed hydrology.
3. To develop SDSS for land and water management at the watershed scale.
4. To assess the impact of on-site and off-site management structures for soil and water conservation.
Outputs expected out of these programs are:
(1) Integrated database for water sector at small watershed level for different Agro-climatic regions.
(2) Spatial Decision Support Systems (SDSS) for watershed management
(3) Scientific indices for impact assessment of watershed management programs.
(4) User manual for using the database and SDSSs
In India, demand for water exceeds supply. Conflicts are increasing over shared water resources between agriculture, industry, and urban domestic use as well as between state governments. Sustainable water management is thus crucial for economic development and people’s livelihoods in India.
Various projects are going on in India on watershed management programs. For example The Confederation of Indian Industries (CII) and the World Economic Forum are the lead partners combining their existing networks and convening power to benefit sustainable development in India. USAID India and UNDP have also committed to building the Indian Business Alliance on Water (IBAW).
IBAW serves as a non-biased multi-sectoral platform for developing projects and exchanging good practices to enhance sustainable water and watershed management in India. Its objective is to improve water availability and quality to businesses, communities and the environment by providing a neutral platform to help multistakeholders to foster dialogue, raise a level of awareness, explore, and capture opportunities for coorperation in the water sector.
Watershed management basically involves harmonizing the use of soil and water resources between upstream and downstream areas within a watershed toward the objectives of natural resource conservation, increased agricultural productivity, and a better standard of living for its inhabitants. Identifying and addressing the significant externalities associated with a watershed is critical for these objectives to be achieved in a sustainable manner.
The Bank of Netherlands Partnership Program (BNWPP) in India basically aims at this. Even though in India watershed development has largely evolved into generic rural development programs. Despite the broader movement towards more decentralized and devolved management of natural resources, the sustainability and equity of public investments in watersheds have been increasingly called into question. The challenge of identifying and further developing institutional innovations which have succeeded in overcoming the problems posed by watershed externalities is an immediate concern is something which the Bank of Netherlands Partnership Program is exploring.
Landscape and climate changes as well economic developments in watersheds stimulate a corresponding cascade of dynamic adjustments in both water quantity and quality at locations further downstream. Sophisticated hydrologic simulation models and GIS have become the standard means for assessing the impacts on water resources systems in India.
For the last three decades the US-inspired International Crops Research Institute for Semi-Arid Tropics (ICRISAT), in Hyderabad, one among the “international links” scattered along the length and breadth of the disadvantaged nations of the world, India included, has received massive funding from the Consultative Group for International Agriculture Research (CGIAR).
In the 1980s and 1990s agricultural scientists and planners aimed to promote rain-fed agriculture through watershed development. A watershed is an area from which all water drains to a common point, making it an interesting unit for managing water and soil resources to enhance agricultural production through water conservation.
It is an eye-opening fact that by the late 1990s, annual expenditure on watershed development in India approached almost an equivalent of $500 million (Rs 2,500 crore), yet very little concrete information is available on the success or failure of the different project approaches.
A lot more needs to be done even though the government of India and the various states Governments together with the international organizations are doing a lot to make this concept a success in India yet a lot more needs to be done so far the success story of watershed management in India has been a mixed bag.