Watershed management and development

watershed management and development ppt for final year engineering civil students.

1. VisvesvarAyA Technological University BANGALORE INSTITUTE OF TECHNOLOGY DEPARTMENT OF CIVIL ENGINEERING “WATERSHED MANAGEMENT AND DEVELOPMENT” Presented by, Guided by, Chethan K S Mr. G.C. Ranganath IBI14CV034 Associate Professor Dept of Civil Engg

2. CONTENTS Introduction. Watershed management . Principles of watershed management. Factors affecting the watershed management. Watershed management practices. Types of watershed management approach for the watershed development and its perspectives. Need for watershed management and development in karnataka. Watershed management and development programme in karnataka. Case study in karnataka . Conclusion. Reference.

3. INTRODUCTION A watershed is simply the geographic area through which water flows across the land and drains into a common body of water, whether stream, river, lake, or ocean. The watershed boundary will more or less follow the highest ridgeline around the stream channels and meet the lowest point on the land where water flows out of the watershed the mouth of the water way.

4. IMPORTANCE OF WATERSHED Watersheds are important because the surface water features and storm water runoff within a watershed ultimately drain to other bodies of water. It is essential to consider these downstream impacts when developing and implementing water quality protection and restoration actions. According to the Environmental protection agency, more than $450 billion in foods, fibre, manufactured goods and tourism depends on clean, healthy watersheds. Healthy watersheds are also important for the very sustenance of human life.

5. WATERSHED MANAGEMENT Watershed management is defined as the process of formulating and carrying out course of action involving manipulation of natural, agricultural and human resources of a watershed to provide resources that are desired by and are suitable to the watershed community. The watershed management and exploitation should not have any adverse effects on soil and water resources. It is an integrated and multidisciplinary approach.

6. PRINCIPLES OF WATERSHED MANAGEMENT Protecting fertile top layer soil. Minimizing setting up of tanks, reservoir and lower fertile land. In situ conservation of rainwater. Construction of check dams for increasing ground water recharge. Water harvesting for supplemental irrigation. Utilizing the land based on its capability .

7. FACTORS AFFECTING WATERSHED MANAGEMENT a)Watershed characters 1)size and shape 2)topography 3)soils b)climatic characteristic 1)precipitation 2) amount and intensity of rainfall c)Watershed operation d)Land use pattern 1)vegetative cover 2)density e)Water resource and their capabilities f)Geological factors

8. WATERSHED MANAGEMENT PRACTICES To moderate the floods peaks at down stream areas. To increase infiltration of rain water. To enhance the ground water recharge, wherever applicable. To manage and utilize the runoff water for useful purpose. To check soil erosion and to reduce the effect on watershed yield. To protect, conserve and improve the land of watershed for more efficient and sustained production. To improve and increase the production of timbers, fodders and wild life resource. To protect and enhance the water resource originating in the watershed.

9. TYPES OF WATERSHED MANAGEMENT Contour bunding. Graded bunding or channel terraces. Bench terracing. Grassed waterways. Strip cropping. Sub soiling .

10. APPROACH FOR WATERSHED MANAGEMENT & DEVELOPMENT People’s participation is the key to watershed development programmes. While the main development activities have to be carried out by the watershed community itself, the overall facilitation, coordination and supervision of the whole programme will be responsibility of a PROJECT IMPLEMENTATION AGENCY (PIA). The whole setup for the watershed management follows a hierarchical approach.

11. STEPS FOR PREPARATION OF WATERSHED DEVELOPMENT PLAN Preparation of watershed development plan includes two main steps: 1. Identification of watershed problems and setting up of objectives and priorities based on various surveys of watershed. 2. Formulation of proposed development and management plan.

12. PERSPECTIVES OF WATERSHED DEVELOPMENT HYDROLOGICAL ASPECTS. ENVIRONMENTAL ASPECTS. SOCIO-ECONOMIC ASPECTS. FINANCIAL ASPECTS.

13. NEED FOR WATERSHED DEVELOPMENT IN KARNATAKA Karnataka is the driest state in India after Rajasthan. Large state of the area are subjected to droughts. Around ¾ of all farmland is rain fed and there is still little scope to expand irrigation. F arm productivity is low since water is available only 3 to 4 months within a year. Groundwater tables are falling and most wells run dry in the long summer months . F orest has been cut down to make way for agriculture. This caused rapid soil erosion. U se of more fertilizer and pesticides reduced soil fertility.

14. WATERSHED DEVELOPMENT PROGRAMMES IN KARNATAKA National watershed development programme for rain fed areas(NWDPRA) River valley project Drought prone areas development programme Integrated watershed development programme(IWDP) Western ghat development programme(WGDP) World bank assisted sujala watershed project Karnataka watershed development project(KWDP)

15. CONTOUR BUNDING • Contour bunding consists of constructing narrow-based trapezoidal earthen embankment at intervals along the contour to impound run off water behind them so that all the stored water is absorbed gradually into the soil profile for crop use. • A series of such bunds divide the area into strips and act as barrier to the flow of water.

16. GRADED BUNDING These are constructed where the excess water is to be removed safely to avoid water stagnation. In these water flows in graded channel constructed on the upstream side of the bunds at non erosive velocities and is led to safe outlets .

17. BENCH-TERRACING • It is practiced on steep hill slopes ranging from 16-33%. • Bench terracing which involves converting the original ground into level step like fields constructed by half cutting and half filling, helps in considerably reducing the degree of slope

18. GRASSED WATERWAYS • These are associated with channel terraces for safe disposal of concentrated run-off, thereby protecting the land against rills and gullies. • A waterway is constructed according to a proper design and a vegetative cover is established to protect the channel against erosion because of concentrated flow.

19. STRIP CROPPING Strip cropping consists of a series of alternate strips of various types of crops laid out so that all tillage and crop management practices are performed across the slope or on the contours. Strips of erosion –permitting crops are always separated by strips of close growing or erosion resisting crops .

20. SUB-SOILING • This method consists of breaking with a subsoil the hard and impermeable subsoil to conserve more rain-water by improving physical conditions of the soil.

21. Case study MASTHIHALLA WATERSHED An attempt has been made to assess the long term impact of watershed development programme in mastihalla watershed of Bellary district, the mean annual rainfall (24 year’s average) is 817mm,so watershed was especially selected to conserve rainwater, to control erosion in arable lands and to increase crop productivity Implemented under National watershed Development programme for rain fed areas (NWDPRA) during 1997-98 to 2001-02 with 90% central government fund The Evaluation was conducted covering three results a)production or economic benefits, b)social impacts/employment generation, c)environmental impacts ,

22. CHITRADURGA WATERSHED Watershed development programme was implemented in molkalmuru taluk of chitradurga under KARNATAKA WATERSHED DEVELOPMENT AGENCY. In karnataka chitradurga district is selected for following reason 1)this is semi arid and backward districts with 460.797 ha of area requiring watershed management. 2)mean rainfall in the district was 565mm during 1901-1990 period. Some of micro plans for land treatment are generated as a result 21% of land owned by the KAWAD farmers was irrigated. Increasing in average productivity of kharif crop groundnut from 2.34quintals/ha to 6.95quintals/ha

23. CONCLUSION Watershed is an essential in day to day life, a vast range of activities of every day life depends upon adequate supplies of water for example agriculture and industry, power production, inland transportation, sanitation and so on. Therefore to provide all these activities construction of watershed and manage is essential. The management of watershed provides a means to achieve sustainable land and water management. Save water save earth.

24. References Agriculture census, Department of Agriculture & Cooperation, Ministry of Agriculture,2011,New Delhi. Iyengar ,Sudarshan ,Mid Term Evaluation Report, Karnataka Watershed Development Project,2001,bangalore:KAWAD Mishra A.K,Singh A.K,Das S.N and Singh (2005), ‘Development of an Integrated Watershed Management Plan’ Pandey C.M, and JagatVeerSingh (2007),’Watershed development under river valley projects’