1. The document describes various irrigation systems used in Tamil Nadu, including surface irrigation systems like canals, tanks, and reservoirs, as well as groundwater irrigation systems like open wells and tube wells. 2. Surface irrigation systems divert water from rivers and streams or store water upstream in reservoirs/tanks, then distribute it through canal networks. Groundwater systems extract underground water using various well types. 3. Tamil Nadu has a large number of irrigation sources including thousands of tanks and wells, as well as several major canal and reservoir projects that irrigate large areas and are important for agriculture.

2. IRRIGATION SYSTEMS????
• SURFACE IRRIGATION SYSTEMS
• Diversion systems
• River systems
• Reservoir or tank system
• Canal system
• GROUNDWATER IRRIGATION SYSTEMS
• Openwells or dug wells
• Tubewells or borewells

3. WHAT AN IRRIGATION SYSTEM CONSISTS OF??
• The irrigation system consists of a main intake structure or
main pumping station,a conveyance system ,a distribution
system, a field application system, and a drainage system
• The main intake structure or main pumping station directs water
from the source of supply such as a reservoir or a river into the
irrigation system.
• The distribution system assures the transport of water through
field ditches to the irrigated fields.
• The field application system assures the transport of water
within the fields.
• The drainage system removes the excess water from the fields

4. 4

5. TAMIL NADU STATE
 Total Geographical Area : 13.01 M Ha. (4.0% of India)
 Water Resources : 4.49 M.Ha.m (3.0% of India)
 Population as on 2001 : 62.11 M (6.4% of India)
 Districts : 29
 Taluks : 206
 Blocks (Revenue) : 385
 Villages : 17,273
 River Basins : 17

6. WATER POTENTIAL
SURFACE WATER 853.0 TMC
GROUND WATER 733.4 TMC
TOTAL 1586.4 TMC
SURFACE WATER UTILIZED 95%
EXPLOITATION OF GROUND 78%
WATER

7. Source-wise Net Area Irrigated in Tamil Nadu
7
Year Net Area Irrigated (Lakhs Ha.)
Tanks Canals Wells Others Total
1960s 9.36 8.82 5.98 0.46 24.62
1970s 8.98 8.84 7.75 0.35 25.92
1980s 5.90 8.89 10.67 0.24 25.70
1990s 5.31 7.69 10.58 0.14 23.72
1997-98 6.76 8.38 14.12 0.19 29.45
1998-99 6.90 8.34 14.77 0.18 30.19
1999-2000 6.33 8.67 14.54 0.18 29.72
2000-2001 5.89 8.33 14.49 0.16 28.87

8. Sources No.
1. SURFACE IRRIGATION SYSTEMS
2. CANALS a) Govt.
2393
b) Private 2
2. RESERVOIRS 71
3. TANKS
a) Ayacut above 40 ha. 7933
b) Ayacut below 40 ha. 32386
Total 40319
4. GROUNDWATER SYSTEMS
WELLS
A) Tube Wells & Others
a) Govt. 1181
b) Private 286123
Total 287304
B) OPEN WELLS
a) Govt. 670
b) Private 1620721
Total 1621391
TOTAL NO. OF WELLS (A+B) 1908695

9. SURFACE IRRIGATION SYSTEMS
• In surface irrigation systems ,water is either
diverted from the rivers and streams when
they are flowing (diversion works) for
irrigating the standing crops or stored
upstream side by constructing barrier
across the flow (reservoirs /tanks)for future
use.

10. 1.DIVERSION SYSTEMS
• The purpose of diversion work is mainly to raise the water level
and divert the river or stream flow into canals to irrigate the
standing crops of the anacut.
• Small dams are used to raise the river water level to feed an off -
taking canal and or some other conveyance system.
• A diversion dam is called a weir or barrage.
• In earlier days emphasis was on diverting river and stream flows
during rainy season .Such schemes were largely developed in
indo-gangetic plains due to snow melt from the himalayas
• Later emphasis was given on construction of storage tanks as in
south india.

11. RESERVOIR OR TANK SYSTEM
• Tank irrigation is a storage irrigation scheme,which utilises the water stored
on upsream side of earthern dam called the bund.These earthern bund
reservoirs are known as tanks,especially in south india.
• A large sized tank is termed as a reservoir.
• Reservois are generally dams made of any material (mansonry dam
,concrete dam,earth dam etc) whereas tanks are formed by earthern dams
only.These earthern bunds are called as tank bunds.
• Most of the existing tanks have a depth of 4.5m while a few are as deep as 7
to 9 m.and a few exceptional cases exceed 11m in depth.When the depth of
tank exceeds 12m the tank is generally referred as a reservoir.
• Tank bunds are usually provided with sluices or outlets for discharging water
from the tank for irrigation.In dam reservoir projects tanks are provided with
the surplus escape arrangements for spilling away the excess surplus water
that may enter the tank to avoid over topping of the bund

12. AMARAVATHI DAM BHAVANISAGAR
PERIYAR VAIGAI

13. KRISHNAGIRI MANIMUTHAR
METTUR SATHANUR

14. PAPANASAM
ALIYAR

15. CANAL SYSTEMS
• Surface water stored in major and medium irrigation projects or diverted
directly is distributed directly for irrigation through the canal irrigation network
to reach the fields to be irrigated.
• The canal networks consists of canals,distributaries,watercourses and field
channels,which are termed according to their capacity and orientation with
respect to the head works.
• MAIN CANAL:It takes its supply directly from the reservoir or the river and
its capacity varies fron 280 to 425 cubic meter per sec in india.
• BRANCH CANALS:These canals take off from main canal and convey water
to different major parts of irrigated areas.Branch canals generally carry a
discharge from 4 to 8.5 cubic meter per sec.
• MAJOR DISTRIBUTORIES:They take off from branch canals and sometimes
from main canals and supply water to distributories or outlets.They generally
carry discharge between 0.75 and 5.5 cubic meter per sec.

16. • MINOR DISTRIBUTARIES:These are smaller channels
taking their supply from major distributories and supplying
water to outlets.The carrying capacity is less than 750 l per
second.
• CANAL OUTLETS:They are provided in irrigation canal
system at appropriate points.The size depends on irrigated
area.Discharge of outlet varies with level of water in the
channel.
• WATERCOURSE:It is any channel which is supplied with
water from canal but which is not maintained at the cost of
government.They pass through common land and are
maintained by farmers.
• FIELDCHANNELS:They carry water to individual fields
from the watercourse.

17. Canal irrigation is popular in deltaic and coastal areas accounting for 29
per cent of the net cropped area.
1. Kaveri Delta Canals-The Kaveri delta has the oldest and the longest
(6,400 km) irrigation canal system in the state. These canals taken off
from the Grand Anicut (built in 1889) irrigates about 5.15 lakh hectares of
land in Thanjavur and Tiruchchirappalli districts.
2. Mettur Canal System-these canals taken out from the Kaveri River
(Mettur dam) provide irrigation to 1.8 lakh hectares of land in Salem and
Coimbatore districts.
3. Lower Bhawani Project Canals-Bhawani Sagar reservoir has been
constructed over the Bhawani River to irrigate 78.917 hectares of land in
Coimbatore district.
.

18. 4. Periyar Project Canals-a barrage has been built across the Periyar River
and its water is transported to the Suruliyar River (tributary of the Vaigai
River) through a 1737 m tunnel. This water is distributed through 432 km
long canals to irrigate about 40,000 hectares of land in Madurai, and
Ramanathapuram districts.
5. Katalai Canal-the Katalai High Level Canal irrigates 8,300 hectares of
land in Thanjavur and Tiruchchirappalli districts.
6. Manimuthar Project Canals-The Manimuthar is a tributary of the
Tamraparni river over which an earthen dam has been constructed. Canals
taken out from this dam irrigate 41,694 hectares of land in Tirunelveli
district.
7. Parambikulam-Aliyar Project Canals-this is a joint venture of Tamil Nadu
and Kerala states under which 244 km long canals have been constructed
to utilise the water from eight rivers to irrigate 97.13 thousand hectares of
agricultural land

19. KALINGARAYAN CANAL BUCKINGHAM CANAL
KAVERI-VAIGAI CANAL LOWER BHAWANI CANAL

20. GROUNDWATER IRRIGATION SYSTEMS
• Ground water is the underground water that occurs in the
standard zone of variable thickness and depth below the earths
surface.About 46 % of the total irrigated area in india gets its
irrigation water from this source.
• Groundwater is utilised through wells using various lifting
devices such as those using animal,manual,wind.diesel or
electric power.
• Use of open wells is the traditional method of tapping
groundwater .
• Use of tube wells is however a subsequent development.

21. OPEN WELLS OR DUG WELLS
• Dugout wells up to water bearing
strata are called openwells or
dugout wells..
• They have comparitively bigger
diameter with low discharges of
the order of 1 to 5 l per sec.
• The diameter of open wells
generally varies from 2 to 9 m
and they are generally less than
20 m in depth.

22. TUBE OR BORE WELLS
• Tube wells are sunk by inserting pipes below ground surface
through water bearing and non-water bearing strata.
• DEEP BORE WELLS:Are as deep as 70 to 300 m and tap more
than one aquifer.Such wells may yield as high as 200 to 220 l
per sec.Average yield however is of the order of 40 to 45 l per
sec.The diameter of the hole is 0.6 m upto 60 m depth and then
0.56 m below 60m.
• SHALLOW TUBE WELLS:Having 20 to 70 m depth may yield
as high as 15 to 20 l per sec if located at proper place.Such
wells can irrigate around 6 hectares.

24. • Depending on the entry of water through a cavity or screen
tube wells are classified into two categories.
• CAVITY TYPE TUBE WELL:draws water from the well and not
from the sides .It essentially consists of a pipe bored through
the soil and resting on the bottom of a strong clay layer.A cavity
is formed at the bottom and water from the aquifer enters the
well pipe through the cavity.
• SCREEN TYPE TUBE WELLS: can easily tap a number of
aquifers unlike a cavity well.These are of two types:
1. Strainer tube wells
2. Slottedpipe gravel packed tube wells