water resource engineering-I

1. WATER SHED MANAGEMENT
( p
(Special emphasis on soil
p
and water conservation)
WRE-I
UNIT- VIII
Prof S S JAHAGIRDAR
BE (CIVIL) ME(ENV ) PhD(persuing)
(CIVIL), ME(ENV.),PhD(persuing)
NK Orchid college of Engg. and Tech. , Solapur

2. Watershed:
• Definition:
“Watershed can be defined as a unit
“ h d b d fi d i
of area covers all the land which
contributes runoff to a common
point or outlet and surrounded by a
ridge line”.
Deterioration of watershed takes place due
to faulty and bad management through
the activity of man and hi animals.
h i i f d his i l

3. Causes of watershed Deterioration:
These activities are:
• Faulty agriculture, f
l i l forestry and pasture
d
(Grass land) management leading to
g g
degradation of land.
• Unscientific mining and quarrying
quarrying.
• Faulty road alignment and construction.
• I d t i li ti
Industrialization
• Forest Fires
• Apathy (less interest) of the people.

4. Results of watershed
Deterioration
D t i ti :
• Less production from agriculture, forests,
grass lands etc.
• Erosion increases and decreases biomass
production
• Rapid siltation of reservoirs, lakes
reservoirs
and river beds.
•LLess storage of water and l
f d lowering of
i f
water table.
• Poverty as a result of less food production.

5. WATERSHED DEVELOPMENT
Possible range of treatment
measures
• Contour bunding
• Contour trenching
• Contour stone walls
• Bench terraces
• Land levelling
• Summer ploughing

6. • Agro forestry with suitable species
• Vegetative barriers
• Ch k dams (Temporary and
Check d (T d
Permanent)
• Retaining walls
• Farm ponds and Percolation
ponds
• Renovation of existing water
bodies and inlet channels

7. COMPONENTS OF WATERSHED
DEVELOPMENT:
• • Human Resource Development (
p (Community
y
Development)
• Soil and Land Management
• Water M
W Management
• Crop Management
• Afforestation
• Pasture/Fodder Development
• Livestock Management
•R lE
Rural Energy MManagement
• Farm and non-farm value addition activities
• All these components are interdependent and
interactive.

8. DEVELOPED WATERSHED

9. Methods for hill slopes
p
• CONTOUR TRENCHES AND
STONE WALLS
• BENCH TERRACING

10. CONTOUR TRENCHES AND STONE
WALLS

13. •Suitable erosion control in
S it bl i t li
hills
•Adopted for hill slopes
>20% %
•Continuous or interrupted

15. BENCH TERRACING

17. • It helps to bring sloping land into
different level strips to enable
cultivation.
lti ti
• It consists of construction of step
like fields along contours by half
cutting and half filling.
g g
• Original slope is converted into
level fields The vertical and
fields.
horizontal intervals are decided
based l d slope.
b d land l

18. Methods for agric lt ral land
agricultural
• Check dam
• Percolation pond
• Micro catchments
• Contour bund
• Broad beds and furrows
• Gully l
G ll plugs
• Tree plantation
• Summer ploughing
S l hi
• Agro forestry
• Vegetative barriers
• Farm ponds

19. Check dam

21. • A low weir normally constructed across the
y
gullies
• Constructed on small streams and long
gullies formed by erosive activity of flood
water
• It cuts the velocity and reduces erosive
activity
• The stored water improves soil moisture of
the adjoining area and allows percolation
to recharge the aquifers
h h if
• Height depends on the bank height, varies
from a 1 m t 3 m and l
f to d length varies from
th i f
less than 3m to 10m

22. Percolation pond

23. • To improve the ground water
recharge.
• Shallow depression created at lower
portions in a natural or diverted
stream course
• Located in soils of permeable nature
p
• Adaptable where 20-30 ground
water wells for irrigation exist with
in the zone of influence about 800 X
900 m

24. Micro catchments

26. • To conserve insitu moisture and
reduce soil loss
• Circular basin of one meter dia
for level lands depending upon
infiltration and rainfall
• Ditches of size 5m x 5m with
trees planted centre
• Saucer basins / semi circular
bunds with 2m diameter to a
height of 15-20cm across the
slope

27. Broad b d and furrows
B d beds d f

28. • To control erosion and to
conserve soil moisture in the
soil during rainy days
• The broad bed and furrow
system is laid within the field
boundaries.
• Conserves soil moisture in dry
land.
• Controls soil erosion
erosion.
• Acts as a drainage channel
during heavy rainy days.
d i h i d

29. Contour bund

32. • To intercept the runoff flowing
p g
down the slope by an
embankment.
embankment
• It helps to control runoff
velocity.
• It can be adopted in light and
medium textured soils.
• It can be laid up to 6% slopes.
• It helps to retain moisture in the
field.

33. Gully plugs
yp g

34. • Gully plug is one of the simple method of
soil and water conservation. It plays an
important role in soil and water
conservation.
• G lli are f
Gullies formed d to erosion of top
d due i f
soil by the flow of rain water. In course of
time, a gully assumes a big shape and
erosion goes on increasing. To prevent
erosion, barriers or plugs of different
types of material are put across the gully
gully,
at certain intervals.

35. Tree plantation
• Instead of uneconomical agriculture,
g ,
farmers can grow grass in this hilly
area and can use that as a fodder for
cattle.
• Farmers can go for dairy development
if good quantity and quality of grass is
available.

36. •For soil and water conservation
this activity will help. Plantation
on common l d will satisfy b i
land ill ti f basic
need of fuel wood.
•Cheapest method for soil and
water conservation

37. Summer ploughing
p g g

38. •Main objective of field
preparation is to control weeds
•Facilitate easy sowing and to
establish good seed soil contact
•For easy absorption of moisture
y p
•To provide sufficient aeration
•To i
improve water holding
h ldi
capacity

39. Agro forestry
g y
• Agroforestry is an integrated
approach of using th i t
h f i the interactive ti
benefits from combining trees and
shrubs with crops and/or li t k
h b ith d/ livestock.
• It combines agricultural and forestry
technologies to create more di
h l i diverse,
productive, profitable, healthy and
sustainable l d
i bl land-use systems.

41. Vegetative barriers
g

43. •Vegetative barriers are also an
g
effective inter-terrace land
treatment in place of earthen
barriers.

44. Farm ponds
p

45. • Rain water is harvested and stored
• Used for storing water for longer duration
duration.
• Covered with polythene sheet to prevent
evaporation.
evaporation

46. Roof top rainwater harvesting
p g
• To recharge the wells (open and
tube wells) particularly
abandoned wells by a runoff
y
collection system.
• Direct on-use of collected water
on use
if storage facility is available.

47. RECHARGE TUBE WELL
• To directly feed depleted
aquifers to fresh water from
g
ground surface so that the
recharge is fast without any
evaporation loss
• Depth of recharge tube well
depends on the present depth of
bore wells in the area