need of shore protection works to safeguard the approach tothengapattanam fishing harbour

NEED OF SHORE PROTECTION WORKS TO SAFEGUARD THE APPROACH ROAD TO BE

CONSTRUCTED ON THE EASTERN SIDE

Satelite Map showing the Thengapattanam Coast on 1st december 2005 .

Location of site:The fishery harbor at Thengapattanam village (Lat 805’ 19”N

and Long. 770 33’ 20” E) is situated at a distance of 42km from Nagercoil.

It is also at a distance of 11 km from Marthandam town and all weather motorable road joining the National Highway connecting Trivandrum and Kanyakumari connects the site .

The proposed location is on the estuary of the tambraparaniriver draining into the Arabian sea on the west coast of TamilNadu.

Satelite Maps showing the Thengapattanam Coast at 2002,2005 and 2007 before Construction of Fishing Harbour

Tidal ValuesMHWS +0.79 m

MHWN +0.55 m

MLWN +0.43 m

MLWS +0.18 m

MSL +0.49 m

Wave characteristics for the Shoreline evolution

MonthDeep water

Wave direction w.r.t North (θo)

Wave height (m)

Wave period (sec), T

Wave direction from shore normal

(θ) in d=6m

January 3600 1.5 5 -66.68

February 3400 1.0 5 66.14

March 1800 1.0 5 -38.73

April 2700 1.0 5 -38.73

May 2700 1.0 5 48.21

June 2700 2.0 5 43.23

July 2700 2.0 6 43.23

August 2700 2.0 6 43.23

September 2700 2.0 5 43.23

October 2700 1.0 5 43.23

November 1800 1.5 5 -35.08

December 1800 1.0 5 -35.08

Shoreline Evaluation

19.11.13

9.1.14

1.5.14

19.11.13 9.1.14

1.5.14

19.11.13

9.1.14

1.5.14

Thengapattanam Coast before Construction of Fishing Harbour on 1st june 2007

APPROACH ROAD• The Chief Engineer, Fishing Harbour Projects Circle ,

Chennai has informed that 1.75.7 ha . of land has been acquired in S.No :445/1 of Painkulam Village .

• Further ,land has been acquired and alloted for creating approach road to Thengapattinam Fishing Harbour in Survey No : 464/1 ,466/1 ,3,467/2B , 9 , 10 ,12, 13 and 468/16B ,17,18D,19 and 20

Approach to Leeward Breakwater before high wind waves

EXPENDITURE DETAIL An approach of 350m length has been formed with the expenditure of 110 lakhs as below

SI No

Details of Work

As per the Estimate As per Execution

Qty Rate Amount Qty Rate Amount1 Earth

Work3500 23.7 82950 3500 27 94500.00

2 Core Layer

14800 312.6 4626480 14752.25 370 5458332.50

3 Secondary Layer

13600 378.25 4917250 12999.12 420 5459630.00

9626680 11012462

Approach to Leeward breakwater before sea erosion

DAMAGE TO APPROACH ROAD• In the original estimate 1150 mt .length has been proposed for

approach road . • The proposed approach road has been damaged due to sea erosion

and sea water has occupied . • There is a need for selection of alternative site for the approach

road to Thengapattinam Fishing Harbour.• The approach has been damaged due to high wind waves on 11.08.2010 to 19.08.2010 25.02.2011 20.06.2012 to 30.06.2012 02.09.2012 to 03.09.2012

Approach to Leeward breakwater under erosion due to high wind waves

News paper report – about damage caused by high windwaves

News paper report – about damage caused by high windwaves

ALTERNATIVE SITE• During the site inspection on 25.03.2013 at

Thengapattinam Fishing Harbour by the Chief Engineer , Fishing Harbour Projects Circle , Chennai, alternative site has been identified for creating approach road to Thengapattinam Fishing Harbour.

• The details of alternative site are furnished below .Vilvankodu Taluk , Amsi Junction - Parakani Road : S.No

:444/2,3 and 445/2,222mt . length and 10mt . breadthThengapattinam – Enayamputhurai Road : S.No :467/2A ,9A

and 468/4A,4B,14A,16A,360 mt.length and 10 mt. breadth.

Approach to Leeward breakwater after washed away by the sea erosion

SHORE PROTECTION • Due to long shore drift accompanied by the

cross shore sediment movement, coastal protection measures have to be suitably proposed.

• From the coastal side, it is proposed to construct one L-shaped and one T-shaped groin of 50m length on the eastern side of the eastern breakwater.

Photo showing high wind waves on Eastern side of Leeward Breakwater -15 April 2014

LOCATION PROPOSED FOR SHORE PROTECTION

• The Location of the one L-shaped and one T-shaped groin of 50m length on the eastern side of the eastern breakwater with +5m height is proposed as below.

• At the Eastern end – from existing RMS wall on Mullurthurai side one L-shaped- groin of 50m length -UTM 739171.78mE and 911169.87mN.

• At the Centre of 350m shore one T-shaped groin of 50m length– UTM 739040.69m E and 911276.73m N.

Eastern side of Leeward breakwater on 22nd April 2014

Proposed coastal protection by groin field