3. What is watershed?
• A topographically delineated area draining into a• A topographically delineated area draining into a
single channel (Brooks, 1985)
• The boundary of watershed is the divide
separating one drainage basin from anotherseparating one drainage basin from another.
• Comprise of a catchment area (recharge zone)• Comprise of a catchment area (recharge zone),
a command area (transition zone) and a delta
area (discharge zone)area (discharge zone).
• Shape of water shed may be Fan shaped or Fen
shapedshaped
4. watershed Types
• Watershed is classified on the basis of size• Watershed is classified on the basis of size,
shape, drainage and land use pattern etc.
Sl. No Watershed type Area (ha.)
1 Macro‐watershed >50 0001 Macro watershed >50,000
2 Sub‐watershed 10,000‐50,000
3 Mili‐watershed 1,000‐10,000
4 Micro‐watershed 100‐1,0004 Micro watershed 100 1,000
5 Mini‐watershed 1‐100
• For easy management generally 500 ha is taken
as a watershed unit
5. Characteristics of watershed
1. Physiography- i. Size
ii. Shapeii. Shape
iii. Land slope
iv. Drainage Density & Patterniv. Drainage Density & Pattern
2. Edaphic condition
3. Vegetative Cover3. Vegetative Cover
4. Land Use
5. Rain fall5. Rain fall
6. Socioeconomic factor
6. Causes of watershed Deterioration
A F lt A i lt C lti ti SlA. Faulty Agriculture‐ Cultivation on Slope,
Along Nalla, erosion promoting crops,
B D t i ti f G l dB. Deterioration of Grass land
C. Forest Fire
D. Shifting Cultivation
9. watershed management
Watershed management implies the wise
use of soil and water resources within a givenuse of soil and water resources within a given
geographical area so as to enable sustainable
d ti d i i i fl dproduction and minimize floods.
It emphasizes on activities like changed land
use practices, vegetative cover, structural andp , g ,
nonstructural actions to be taken towards
attaining specific objectives of management.g p j g
10. Objective of watershed management
• Increase in infiltration into soil
• Control damaging excess runoffControl damaging excess runoff
• Manage and utilize runoff for useful purposesManage and utilize runoff for useful purposes
• Promote the economic development of thep
village community
• Encourage restoration of ecological balance
I th i i diti f th• Improve the socio-economic condition of the
resource poor and disadvantaged sections of
t h d itwatershed community
11. Principles of watershed management
Utili i l d di t it bilit• Utilizing land according to its capability
• Putting adequate vegetal cover on the soil during
irainy season
• Conserving as much as rain water as possible at
th l h It f llthe place where It falls
• Draining out excess water with safe velocity and
di ti it t t d f f tdiverting it to storage ponds for future use
• Maximizing productivity per unit area per unit time
d it tand per unit water
• Safe utilization of marginal lands through
lt t l d talternate land use system
• Improving and stabilizing annual income of people
I f t t d l t f th• Infrastructure development of the area
12. Watershed in Management India
1980 1990 1994 2003 2008Ti li
Interventions
(objectives)
Soil
Conservation
Water
Conservation
Productivity
Enhancement
Increased
income for rural
1980s 1990s 1994 2003 2008Time line
(objectives) Conservation Conservation Enhancement
community
Strategy Compartmental
Holistic system
approach
Livelihood
Approach
Holistic
development of
rural economypp pp rural economy
Approach Top down and
Contractual
Participatory
Mode
Sustainability
No ownership
by farmer
Inequitable
benefits
Transparent
and vigilant
community
Community
ownership
Transparency Less
Transparency
Tangible
benefits will
distributed
Policy Shifts Departmental/
special projects
Ch. HanumanthaRao
recommended
guide lines
…….. Haryali
Guide lines
Common
Guide lines
13. Components of Watershed Management
A. Entry Point Activity (EPA)‐ First formal project intervention which
is undertaken to build the rapport
with the community
B. Land and Water Conservation Practices
C. Crop Diversification and Intensification
D Integrated Pest and N trient ManagementD. Integrated Pest and Nutrient Management
E. Use of Multiple Resources-
Dairy, Goatry, Piggery, Poultry, honey bee rearingDairy, Goatry, Piggery, Poultry, honey bee rearing
and other livelihood activities.
F. Capacity Building
14. Soil and water conservation measures
A. Mechanical/Engineering measures of SWC
1. Erosion control measures‐
Bunding, Trenching, Terracing,
Vegetative Barriers Grass waterwaysVegetative Barriers, Grass waterways
2. Water harvesting structures‐
F P d L E th D MI T kFarm Pond, Low Earthen Dams, MI Tanks,
WHS, Percolation Tanks
3. Drainage line treatment measures‐
Check dam, Gully control structures, , y ,
Spill ways, Grass out lets
15. Soil and water conservation measures
B. Biological measures of SWC
1 A i ti C t f i1. Agronomic practices‐ Contour farming,
Strip cropping, Cover cropping, Mulching,
Crop rotation and mixed cropping, Tillage
2 A l i l h d2. Agrostological methods‐
Cultivation of grasses, Retiring of land
3. Agroforestryg y
16. 1. Bunding
Objective-Objective
• Increase time of concentration Infiltration
• converting long slope to short ones
• Divert run off
• easy agronomic practices
Graded Bunds Contour Bunding
Medium to high rain fall areas Low rainfall areas (600 mm orMedium to high rain fall areas
(600 mm and above)
Low rainfall areas (600 mm or
less)
Heavy textured soils Light textured soils
17.
18.
19. TRENCHING
Objectives:Objectives:
• To cut down the velocity of over land flow.
• To store rain water for the benefit of plantsTo store rain water for the benefit of plants.
Made in nonagricultural areas having Silvi-Pasture, Silvi-
Horticulture or Agro Horticulture programmes at a spacingHorticulture or Agro-Horticulture programmes at a spacing
of 10-30 m.
Staggered contour trenches Continuous contour trenche
Runoff harvesting in continuous contour trench
20. TERRACING
Terraces are usually constructed for cultivatingTerraces are usually constructed for cultivating
sloppy areas by converting the land into series of plat
forms one above the other These measures areforms one above the other. These measures are
popular in hilly areas.
21. FARM POND
Farm ponds are bodies of water; made either byFarm ponds are bodies of water; made either by
constructing an embankment across a water course or
by excavating a pit or the combination of bothby excavating a pit or the combination of both.
22. MINOR IRRIGATION TANKS
Earthen dams designed on the basis ofEarthen dams, designed on the basis of
engineering principles, are constructed across the
streams for creating water reservoirs for providing one orstreams for creating water reservoirs for providing one or
two irrigations to crops at critical periods.
23. WATER HARVESTING STRUCTURES
Water harvesting structures are similar toWater harvesting structures are similar to
minor irrigation tanks except that they generally
d t h t i l t d th ido not have extensive canal system and their
command area is limited to field laying close to
the Bundhi at the downstream.
24. PERCOLATION TANKS
Percolation tanks are structures constructedPercolation tanks are structures constructed
across the nalas for checking velocity of runoff,
i i t l ti d i i ilincreasing water percolation and improving soil
moisture regime. In facts both terms are synonymous
although used alternatively in different places.
25. CHECK DAMS
A Check dam is a small temporary orA Check dam is a small, temporary or
permanent dam constructed across a drainage
h l t l th d f t t d fl fchannel to lower the speed of concentrated flows for
a certain design range of storm events.
A Check dam can be built from wood logs, stone, pea gravel-
filled sandbags or bricks and cement.
26. BRUSH WOOD CHECK DAMS
Brushwood check dams made of posts andBrushwood check dams made of posts and
brush are placed across the gully . The main objective
f b h d h k d i t h ld fi t i lof brushwood check dams is to hold fine material
carried by flowing water in the gully.
27. LOOSE BOULDER CHECK DAMS
Loose boulder check‐dam is a structure made ofLoose boulder check‐dam is a structure made of
rocks (medium to small) and placed across the gully or
ll t hi h d th l it f ff dsmall stream, which reduces the velocity of runoff and
prevents the deepening and widening of the gully.
28. MASONRY CHECK DAMS
Masonry check dams constructed withMasonry check dams constructed with
cement mortar and non-disintegrating stones are
ll d i t t t l Th igenerally used in torrent control. The main
objective of the dam is to hold fine and coarse
material carried by flowing water in the gully or
torrent.
29. CONTOUR FARMING
Contour cultivation is the practice of tillageContour cultivation is the practice of tillage,
planting and other farming operations performed on
th t f th fi ld l Thi th d ior near the contour of the field slope. This method is
most effective on slopes ranging between two to ten
percent.
30. STRIP CROPPING
In strip cropping crops are planted in regular or
irregular strips. The long slope is divided into a series
of cultivated slopes in which different crops arep p
grown. Strip creation across slopes helps in reducing
the erosive capacity of runoff that flows down a longthe erosive capacity of runoff that flows down a long
slope
31. COVER CROPS AND MULCHING
Cover crops:Cover crops:
Cover crops are those which are sown or planted in thick
stands primarily for the purpose protecting soil fromstands primarily for the purpose protecting soil from
erosion enriching it with organic matter.
Mulch:
Mulch is a material placed on the soil surface top
maintain moisture, reduce weed growth, mitigate soil
erosion and improve soil conditions. Mulching can helpp g p
to improve crop yield and optimise water use . It is
expensive and labour intensive. Materials for mulchingp g
can be organic (straw, shredded bark, wood chips
etc.) or inorganic (plastic sheeting, volcanic rock etc.).) g (p g, )
32. CROP ROTATION
Crop rotation can greatly affect the amount of soil
lost from erosion by water. In areas that are highlyy g y
susceptible to erosion, farm management practices
such as zero and reduced tillage can be supplementedg pp
with specific 'crop rotation' methods to reduce raindrop
impact, sediment detachment, sediment transport,p , , p ,
surface runoff, and soil loss.
33. TILLAGE AND FIELD PREPARATION METHODS
Conservation tillage is field operations aimed at
preserving soil aggregates, organic matter and surface
residue from previous crops.
• Ridges and furrowsg
• Broad-bed and Furrow System
• Conservation Furrow System (Dead furrow)
Broad‐bed and Furrow System
BBF formation with Tropicultor. Groundnut crop on BBF.
34. AGROSTOLOGICAL MEASURES:
A grass‐legume association is ideal for soil
conservation. Legumes build up soil fertility by fixing
atmospheric Nitrogen in root nodules. Grasses have several
uses in soil conservation.
