Need for barrage at the entrance of the Tambrabarani River Estuary

1. NEED FOR BARRAGE
AT THE ENTRANCE OF
THE TAMBRABARANI
ESTUARY

2. LAYOUT OF THENGAPATTANAM FISHING HARBOUR

3. Enayam
Chinnathurai
Puthenthurai
Ramanthurai
Mullurthurai
Eraiyumanthurai
Poothurai
Thoothur
Ezhuthesam
Chinnathurai Eravi Puthenthurai
Vallavilai
Marthandamthurai
Neerodi.

4. Satellite Map showing Tambrabarani
River Mouth on 3rd may 2007

5. Fishing Crafts:
Total population = 52,105
Fishermen population = 28500
Fishermen likely to be benefitted
Direct Beneficiaries = 17401
Indirect beneficiaries =5400
Fishing Crafts and
Fishermen to be benefitted

6. FISHING CRAFTS
BENEFITTED:
Motorised Fishing Vessels =676 Nos
Fibre Vallams = 1432Nos
Fibre Catamarans = 70 Nos
Designed accommodation 750
MFVs
300 nos of 12-13m and
450 nos of 15-16m

7. • Fishing Harbour under construction at
Thengapattanam is located at the estuary of river
Tambraparani
• At river mouth, sand deposit is formed to about (+)
1.00m and above, which forms natural backwater.
• Water is always stagnating for about 4m depth in the
tail reach of the river.
• Width of river mouth at Thengapattanam is 750 m.
• Some reaches in lower and upper lower plains, river
width is only around 100m , which causes
submergence of patta lands during flood season.
EXISTING CONDITION OF
RIVER

8. • Ground level on estuary =RL +2.00 m to +2.4 m
• Bed levels in the estuary =2.0m to -3.5m
• The average rise of the spring tide =+.18m to
+.79m w.r.t chartered datum(MSL=+.49m CD)
• The average rise of neat tides = +.43 to +.55m .
Estuary Details

9. SALT WATER INTRUSION PROBLEM
• If there is no barrage at the place where
tambraparani joins estuary, the problem of
influx of saline water during the high tide
will affect the underground water quality of
the nearby villages and severely affect the
livelihood of people.
• The sea water entering estuary is diluted by
the fresh water flowing from river.

10. • If there is no barrage across tambraparani
river where it meets estuary there will be
severe siltation which will reduce depth
of water at estuary.
• Because of this siltation problem the
entry of trawlers and other fishing
vessels into the fishing harbour will be
affected.
SILTATION PROBLEM

11. Tambrabarani River Estuary and the river
mouth on Erayumanthurai side

12. • Maximum flood 4000 cumecs (141000 cusecs) observed
in NH 47 Bridge @ L.S 14.76 Km upstream river mouth
on 13-11-1992.This is mainly due to overflow from four
dams which are
• Petchiparai dam
• Perunchani dam
• Chittar I dam
• Chittar II dam
Observed Maximum
Flood(in 25 years duration)

13. SI. No R.F. Station Year 1992
Nov.14
Year 2010 Dec 8
1 Petchiparai 220 mm 168 mm
2 Chittar I Not Available 194
3 Chittar II 97 136
4 Kuzhithurai 124 240
5 Thiruvattar 145 110
6 Adayamadai 177 235
7 Perunchani 200 204
Maximum Daily Rain Fall (in mm)
Causing Maximum Flood Damages in
Tambraparani Basin Area

14. • 1.Petchiparai dam – 27000 cusecs
• 2.Perunchani dam - 15000 cusecs
• 3.Chittar I dam - 2000 cusecs
• 4.Chittar II dam - --
• Total over Flow from Dams - 44000 cusecs
• 5.Kuzhithurai Sub-Path(River Mid Reach) – 78000
cusecs(8.12.2010)
• 6.River Mouth at Thengapattanam (Harbour Site) – 100000 cusecs
approximately(8.12.2010)
Maximum Flood Discharge in
Tambraparani Basin (on 7.12.2010 Night)

15. Tambrabarani River Estuary where AVM canal joins
and Erayumanthurai Boat jetty.

16. Location L.S from River
Mouth
Flood Level Area Submerged
Vaikalloor 1.71 KM upstream +3.80M 2KM stretch in
plain
terrain(Right
Flank)
Parthibapuram
Bridge
5.8 KM upstream +6.00M 1KM stretch in
plain terrain(Left
Flank)
Kuzhithurai Sub-
path
14.76 KM
upstream
+7.50M 200M on either
side of river
Submergence details(As
on 8-12-2010)

17. • If there is no barrage across tambraparani river where
it meets estuary there will be severe siltation which
will reduce depth of water at estuary.
• Because of this siltation problem the entry of trawlers
and other fishing vessels into the fishing harbour will
be affected.
• Also if there is no barrage at the place where
tambraparani joins estuary, the problem of influx of
saline water during the high tide will affect the
underground water quality of the nearby villages and
severely affect the livelihood of people.
Necessity for providing
Barrage

18. • To avoid salt water intrusion in to the Tambrabarani
river beyond estuary , a 140 m long barrage at the
location where river meets the estuary , with its top
level at +1.00m w.r.t Chart Datum must be constructed
before connecting sea with river by removing the
temporary approach to Main breakwater at the river
mouth.
• The Location of the 140m long proposed barrage with
top level of +1.00m w.r.t CD is as below,
• At the western end – on Erayumanthurai side -UTM
737978.38m E and 912819.50mN.
• At the eastern side – UTM 738093.84m E and
912768.75m N.
Solution to Avoid Salt
Intrusion

19. Location of Proposed Barrage

20. Photo showing the entrance of Tambrabarani River
Estuary where a Barrage is proposed. -24Apr14