drainage and its types

1. TOPIC:DRAINAGE CONSIDERATIONS
SUBMITTED BY: Prisi Ksh
MSc. Agronomy

2. DRAINAGE
 Drainage refers to artificial removal of excess water
from the soil surface and from the soil profile.
 Drainage aims at maintenance of soil moisture within
the range of required for optimum growth.
 In humid areas, drainage is needed for the removal of
excess rainwater.

3. OBJECTIVES OF DRAINAGE
• To control waterlogging, ponding and salinity.
• Removal of excess water from the soil.
• Arrangement for good aeration in the soil.
• To control the loss of plant nutrients.
• To enhance the activity of soil organisms.
• To improve the soil structure.
• To control soil erosion.
• To develop favourable conditions for the growth of plant roots.
• To lower the water level below the root zone.

4. DRAINAGE SYSTEM AND TYPES OF
DRAINAGE SYSTEM
 It is a system by which water is drained on or in
the soil to enhance production.
 ITS TYPES:
1. SURFACE DRAINAGE
2. SUBSURFACE DRAINAGE
3. BIO DRAINAGE

5. SURFACE DRAINAGE
 It can be defined as the removal
of excess water from the soil
surface, it is also known as open
drain system.
 Generally carried out by shaping
the land so as to direct and
dispose of overland flow.

6. TYPES OF SURFACE DRAINAGE
 There are four types of drainage systems
used in flat areas where slope is less
than 2 per cent:
1. RANDOM SYSTEM: Used where small
scattered depressions to be drained.
Drains are designed to connect one
depression to another, and water is
conveyed to an outlet.
2. PARALLEL SYSTEM: It’s the most
effective surface drainage system,
suits well in both rainfed and irrigated
areas. Individual fields are graded for
discharge into field drains. The field
drain discharge into field laterals
bordering the field.

7. 3. BEDDING SYSTEM: Adopted when the
slope of land does not exceed 0.5 % and
in slowly permeable soils. Parallel beds
are developed by shaping and
smoothening the surface, water is
drained from the beds into furrows
created in same location yearly by
ploughing.
4.INTERCEPTION SYSTEM: Adopted in
area where slope is exceeding 2%. It
consist of a series of shallow open drains
across the slope to intercept and remove
surface runoff. It is also known as cross
slope ditch system.

8. SUBSURFACE DRAINAGE
 It refers to the natural outflow or the
artificial disposal of excess water within
the soil or subsoil.
 It prevents the water table to rise, it is
also known as groundwater drainage.
 Subsurface drainage lowers the water
table to provide better environment in
the root zone.
 Water moves to outlets under the
influence of gravity.

9. TYPES OF SUBSURFACE DRAINAGE
1. PIPE OR TILE DRAINAGE: Continuous line of pipes or tiles laid at specific
spacing, depth and grade remove excess water from the soil profile. Pipes
should be placed at 60 to 70cm below the soil surface.
2. MOLE DRAINAGE: Mole drains are cylindrical channels formed at a desired
depth in the soil profile. Water entering throughout the mole drains is guided
to the outlet.
 Random or natural system is used for draining isolated patches and when
entire area does not need drainage.
 Herringbone system: is used in areas where a main line or submain could be
laid in low area and laterals are drawn from both sides.
 Parallel pattern system: similar to herringbone system except that laterals
enter the main only from one side.

11. BIO-DRAINAGE
 Bio drainage may be defined as “pumping of excess soil water by deep-
rooted plants using their bio-energy.“
 The bio drainage system consists of fast-growing tree species, which absorb
water from the capillary fringe located above the ground water table.
 The absorbed water is translocated to different parts of plants and more
than 98% of the absorbed water is transpired into the atmosphere mainly
through the stomata.
 This combined process of absorption, translocation and transpiration of
excess ground water into the atmosphere by the deep-rooted vegetation
conceptualizes bio drainage.

12.  Fast growing Eucalyptus species known
for luxurious water consumption under
excess soil moisture condition are
suitable for bio-drainage.
 Other suitable species for bio-drainage
may be Casuarina glauca, Terminalia
arjuna, Pongamia pinnata and Syzygium
cuminii. etc.

13. THANK YOU