GOVERNMENT OF TAMIL NADU WATER RESOURCES ORGANISATION PUBLIC WORKS DEPARTMENT ENVIRONMENT IMPACT ASSESSMENT STUDY FOR CONSTRUCTION OF GROYNE AT VEMBAR IN VILATHIKULAM TALUK, THOOTHUKUDI DISTRICT WAPCOS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING) Flat No: 2C, II nd floor, Jai Durga Apartment, 38/2, First Avenue, Ashok Nagar, Chennai-600 083. Tel.: 24710477 / Tel Fax: 044-24714424 E-mail: [email protected] June 2014 Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District CONTENTS SL.NO DESCRIPTION PAGE NO. EXECUTIVE SUMMARY CHAPTER-1 INTRODUCTION 1.1 GENERAL 1 1.2 PROJECT DESCRIPTION 1 1.3 NEED FOR THE STUDY 2 1.4 OBJECTIVES OF THE EIA STUDY 4 1.5 OUTLINE OF THE REPORT 4 CHAPTER-2 ENVIRONMENTAL BASELINE STATUS 2.1 GENERAL 6 2.2 METEOROLOGY 7 2.3 BASIN AND SUB-BASIN 8 2.4 GEOMORPHOLOGY AND SOIL TYPES 8 2.5 PHYSICAL OCEANOGRAPHY 9 2.6 AMBIENT AIR QUALITY 10 2.7 NOISE ENVIRONMENT 14 2.8 LANDUSE PATTERN 15 2.9 MARINE ECOLOGY 19 2.10 SOCIO-ECONOMIC ASPECTS 57 CHAPTER 3 IMPACTS AND MITIGATION MEASURES 3.1 GENERAL 67 3.2 IMPACT ON PHYSICAL ENVIRONMENT 67 3.3 IMPACT ON BIOLOGICAL ENVIRONMENT 69 3.4 CONSTRUCTION OF TEMPORARY ROAD AND 71 MOVEMENT OF VEHICLES 3.5 IMPACTS ON SOCIO-ECONOMIC ENVIRONMENT 73 CHAPTER-4 ENVIRONMENTAL MONITORING PROGRAMME 4.1 THE NEED 74 4.2 AREAS OF CONCERN 74 4.3 MARINE WATER & SEDIMENT QUALITY 74 4.4 MONITORING PROGRAM 75 CHAPTER – 5 CONCLUSIONS 77 ANNEXURE I National Ambient Air quality Standards (NAAQS) ANNEXURE II Ambient noise standards WAPCOS Centre for Environment Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District TABLES Table 2.1 Average Meteorological Conditions in the Project Area District Table-2.2 Details of ambient air quality monitoring stations Table -2.3 Ambient air quality monitoring results at DSF Lodge Table – 2.4 Ambient air quality monitoring results Near RC St.Thomas Church Table – 2.5 Ambient air quality monitoring results Near CSI St.Thomas Church Table – 2.6 Ambient air quality monitoring results Near Antoniyur Temple Table – 2.7 Ambient air quality status-PM2.5 (Unit: µg/m3) Table – 2.8 Ambient air quality status – PM10 (Unit: µg/m3) Table – 2.9 Ambient air quality status – SO2 (Unit:µg/m3) Table – 2.10 Ambient air quality status – NO2 (Unit : µg/m3) Table – 2.11 Equivalent noise levels in the study area (Unit: dB(A)) Table – 2.12 Land use/Land Cover of the Study area Table – 2.13 Sampling locations and its geographical coordinates Table – 2.14 Physico - Chemical Properties of Water Table – 2.15 Nutrients in Water Table – 2.16 pH, Soil Texture, Total organic Carbon of Sediment Table – 2.17 Chlorophyll a, Phaeo pigments and Total Biomass recorded in Vembar coastal waters Table – 2.18 Bacterial population recorded in water sample at Vembar coastal waters Table – 2.19 Bacterial populations recorded in sediment sample at Vembar coastal waters Table – 2.20 Phytoplankton Table – 2.21 Zooplankton Table – 2.22 Macrobenthos Table – 2.23 Meiobenthos WAPCOS Centre for Environment Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District Table – 2.24 Demographic profile in the study area villages Table – 2.25 Distribution of literate and illiterate population in the study area villages Table – 2.26 Occupational profile in the study area villages Table – 2.27 Access to educational facility in the study area Table – 2.28 Access to medical facility in the study area Table – 2.29 Access to water in the study area villages Table – 2.30 Access to post, telegraph and telephone facilities in the study area villages Table – 2.31 Access to Transport facilities in the study area villages Table – 3.1 Fuel combustion during construction phase WAPCOS Centre for Environment Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District FIGURES Fig.1.1 Proposed location for Groyne with HTL and LTL Fig.1.2 Google image of the study area Fig.2.1 Satellite imagery of the study Area Fig.2.2 Classified image of the study Area Fig.2.3 Map showing the sampling stations WAPCOS Centre for Environment Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District EXECUTIVE SUMMARY 1. INTRODUCTION The coast along the state of Tamil Nadu is very dynamic in nature due to occurrence of various development activities along the coast, which leads to sea erosion along the coast. Vembar, with geographical coordinates 9°4′34.67″ N and 78°21′29.44″ E is located in Vilathikulam Taluk of Thoothukudi District in Southern Tamilnadu. This area is a sandy beach prone to littoral drift, there has been sever accretion in the mouth of the River Vembar which was being used to anchor the boats of the local fisherfolks that hinders the free movement of fishing boats. To facilitate the smooth movement of fishing vessels, Public Works Department of Government of Tamil Nadu is proposing to construct the Training wall/Groyne at coastal stretch in Vembar 2. NEED OF THE PROJECT The coast of Tamilnadu, dominated by sandy beaches is dynamic in nature. The manmade activities have accelerated the erosion and accretion along the coastline. Vembar located in the Vilathikulam Taluk of Thoothukudi District of Southern Tamilnadu. Reduction in rainfall has lead to closure of the mouth of the River Vembar which has resulted in the deposition of sediments in the mouth, thereby rendering the estuarine area to remain closed. Vembar, being a fishing hamlet had been using the estuarine area as a safe place to anchor the boats and carry out fishing activities in the sea side. Due to accretion of sediment in the mouth, the fishermen are now forced to anchor their boats in the open seas, which is prone to damage and risks due to high waves and strong winds. Hence it is proposed to construct a Groyne on either side of the River Vembar to keep the mouth open in all seasons. WAPCOS Centre for Environment Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District 3. ENVIRONMENTAL IMPACTS During the construction phase there is a possibility of decrease in the benthic faunal assemblages. This will stabilize over a period of time and hence the impact due to construction will be short term. The placement of rock to construct a terminal Groyne would result in a temporary and footprint specific loss of the existing benthic community. The placement of rock may also result in the permanent loss of intertidal and nearshore subtidal habitat; however, this loss may be negligible when compared to the total amount of intertidal habitat within the project area. The loss of these habitats would be replaced by rocky, hardbottom material that would add diversity to the bottom habitat thus providing a new habitat type that can be utilized by certain groups of invertebrates, juvenile/larval fish, and birds. The addition of rocky habitat within a sandy intertidal area is not necessarily a positive benefit, rather a habitat trade-off. Localized fish abundance and distribution patterns have been significantly associated with the presence of rock Groyne, with greater fish captures and higher species richness at areas nearest Groyne. The presence of rock Groyne may increase the sampling efficiency near these structures, resulting in more abundant and species-rich catches. Alternatively, Groyne habitat may provide a foraging site and shelter for fishes in the surf zone, and is associated with higher fish abundances and species richness than in other surf zone communities. The same sand by-passing action would also affect the by-pass of estuarine dependant larval forms. 4. SHORELINE MONITORING PROGRAM The monitoring program shall encompass the following surveys Shoreline profile of the coastal tract of the proposed project prior to construction of the Groyne Periodic bathymetry profile of the entire stretch for atleast 2km north and south of the proposed Groyne prior to construction of Groyne to form a baseline data WAPCOS Centre for Environment Public Works Department EIA Studies for Construction of Groyne at Vembar in Vilathikulam Taluk, Thoothukudi District Shoreline and bathymetry Surveys during construction as a part of monitoring surveys Shoreline Monitoring Surveys after completion of the Groyne for a minimum of 10 years with close intervals of once in 4 months for the first 2 years and once in 6 months in the next 3 years and one time a year for the next 5 years. Bathymetric survey with single or multi-beam echo sounders once in a year for 5 years Morphology of emerged and submerged beaches; 5 CONCLUSION The conclusions of the study are as follows: The marine water quality and ecology in and around the proposed area for the construction of the groyne is that of any normal coastal environment during the study period with no rare, endangered, threatened marine species were recorded during marine survey. Regular monitoring of the health of the associated river mouth and its ecosystem of the project area along with the details of sediment erosion and deposition regimes by visual observations and periodic surveys is also recommended. A single line sea bed level survey along the proposed training wall alignment as proposed need to be carried out prior to the commencement of the work in order to assess the length of the training wall and the depth along the alignment for the proposed length. During the construction phase If any substantial change in the beach profile is observed a detailed study is recommended and to halt any further construction of the groins.