INITIAL ENVIRONMENT EXAMINATION - Thiruvananthapuram · IEE Report Storm Water Drainage Thiruvananthapuram February 2012 iv LIST OF TABLES Table 1 Environmental Compliance Requirements

INITIAL ENVIRONMENT EXAMINATION OF

STORM WATER DRAINAGE THIRUVANANTHAPURAM MUNICIPAL CORPORATION

February 2012

THIRUVANANTHAPURAM

IEE Report Storm Water Drainage Thiruvananthapuram

February 2012

i

TABLE OF CONTENTS

1. Introduction 1

1.1 Preamble 1

1.2 Project Background 1

1.3 Regulatory Provisions 1

1.4 Level of Environmental Examination 4

2. Project Details

5

2.1 Sector Background 5

2.2 Storm Water Drainage System 5

2.3 Key Issues 5

2.4 Drains Affecting Thampanoor and East Fort 6

2.4.1 Pazhavangadi thodu 7

2.4.2 Ulloor thodu 8

2.4.3 Pattom thodu 8

2.4.4 Kannammoola thodu 8

2.4.5 Thekkenakkara canal 9

2.5 Other Natural Drains 9

2.5.1 Tettiyar thodu 9

2.5.2 Pangappara thodu 9

2.5.3 Kaimanam-Azhamkulam thodu 9

2.5.4 Amathara thodu 10

2.5.5 Koori thodu 10

2.5.6 Vattakkayal thodu 10

2.6 Additional Drains 10

2.7 Parvathy Puthanar 10

2.8 Edayar Island 10


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2.9 Lanka island 11

2.10 Project Definition and Concept 11

2.11 Urban Storm Drainage 11

2.12 Need for Design Criteria 12

2.13 Improvements to Pazhavangadi Thodu 12

2.13.1 Silt pits 13

2.13.2 Fencing 14

3. Thiruvananthapuram

14

3.1 Geography and Climate 14

3.2 Demography 14

3.3 Tourism 14

3.4 Physical Characteristics 15

3.5 Land Use Pattern 15

4. Environmental Setting

16

4.1 Air Environment 16

4.2 Noise Environment 17

4.3 Topography and Soil 18

4.4 Geology 18

4.5 Climate 18

4.6 Water Environment 18

4.6.1 Surface water 18

4.6.2 Ground water 19

19

4.7 Ecological Resources 19

4.8 Socio – Economic 19

4.9 Cultural Heritage 19

5. Screening of Potential Environmental Impacts and Mitigation Measures

20

5.1 Loss of Household, Business Premises or Livelihood 21

5.2 Existence of Residences Adjacent to the Sub-project Site 21


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5.3 Ground Water Contamination Due to High Water Table 21

5.4 Existence of Surface Water Source 21

5.5 Loss of Amenity to Neighbours 21

5.6 Silt Runoff from Construction Site 21

5.7 Social Conflict 22

5.8 Noise, Dust or Hazardous Materials 22

5.9 Contamination of Land and Water 22

5.10 Indiscriminate Disposal of Spoil/Silt 22

5.11 Exposure of Workers to Contaminated Site 22

5.12 Forecasting Environmental Impact and Mitigation 23

6. Institutional Requirements and Environmental Monitoring Plan

27

6.1 Environmental Monitoring Plan 28

6.2 Period of Implementation 30

6.3 Benefits of the Project 30

7. Community Consultation and Information Disclosure

30

8. Findings and Recommendations

31

9. Conclusions

31


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LIST OF TABLES

Table 1 Environmental Compliance Requirements of the Subproject 3

Table 2 Land Use Pattern of Thiruvananthapuram Municipal Corporation (2001) 15

Table 3 Ambient Air Quality at Stations near the Project Site 16

Table 4 Noise level at Sub-Project 17

Table 5

Water Quality at Moonattumukku 18

Table 6 Well Water Quality at Pappanamcode

19

Table 7 Potential Impacts and Mitigation Measures

23

Table 8 Environmental Monitoring Plan

28

LIST OF ANNEXURE

Annexure 1 Rapid Environmental Assessment (REA) Checklist

32


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ABBREVIATIONS & ACRONYMS

ADB ‐ Asian Development Bank

Ac ‐Acre

BOD ‐ Biochemical Oxygen Demand

CPCB ‐ Central Pollution Control Board

oC ‐ Degree Centigrade

DG ‐ Diesel Generator

DPR ‐ Detailed Project Report

DSC ‐ Design and Supervision Consultant

EIA ‐ Environmental Impact Assessment

EMP ‐ Environment Management Plan

GoK ‐ Government of Kerala

Ha ‐ Hactare

IEE ‐ Initial Environmental Examination

IPP ‐ Investment Program Preparation

km ‐ Kilometer

KSUDP ‐ Kerala Sustainable Urban Development Project

KSPCB ‐ Kerala State Pollution Control Board

KWA ‐ Kerala Water Authority

LPCD ‐ Litres per capita per day

LSGD ‐ Local Self Government Department

LSGDU ‐ Local Self Government Department (Urban)

m ‐ metre

m2 ‐ Square metre

m3 ‐ cubic meter


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m3 / hr ‐ cubic meter per hours

max. ‐ Maximum

MC ‐ Municipal Corporation

mld/ MLD ‐ Million Litres per Day

mm ‐ Millimeter

MoEF ‐ Ministry of Environment and Forest

NA ‐ Not Applicable

NH ‐ National Highway

O&M ‐ Operation and Maintenance

OM ‐ Operations Manual

PIU ‐ Project Implementation Unit

PMU ‐ Project Management Unit

PPTA ‐ Project Preparation Technical Assistance

Rs. ‐ Rupees

SIEE ‐ Summary Initial Environmental Examination

Sq.km ‐ Square kilometer

SPM ‐ Suspended Particulate Matter

STP ‐ Sewage Treatment Plant

SWD ‐Storm Water Drainage

TS Canal ‐ Travancore Shornur Canal

TA ‐ Technical Assistance

TSS ‐ Total Suspended Solids

TMC ‐ Thiruvananthapuram Municipal Corporation

US ‐ United States of America


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EXEUTIVE SUMMARY

1. The Government of Kerala (GoK) is implementing the Kerala Sustainable Urban Development Project (KSUDP) under the assistance of Asian Development Bank. The goal of the programme is to improve the level, quality and sustainability of basic urban services in selected Urban Local Bodies (ULBs), contributing to improved quality of life among the urban poor. KSUDP will be implemented over a period of five years beginning in 2006, and will be funded by a loan via the Multitranche Financing Facility (MFF) of the Asian Development Bank (ADB).

2. KSUDP Investment Program implementation activities will be monitored by through a separate Investment Program Management Unit (PMU). The ultimate implementation responsibility lies with ULBs in coordination with various other Departments of GoK.

3. ADB requires the consideration of environmental issues in all aspects of the Bank’s operations, and the requirements for Environmental Assessment are described in ADB’s SPS (2009). This states that ADB requires environmental assessment of all project loans, program loans, sector loans, sector development program loans, loans involving financial intermediaries, and private sector loans.

4. This Initial Environmental Examination (IEE) has been prepared for the Storm Water Drainage of Thiruvananthapuram Municipal Corporation, specifically for the improvements to Pazhavangadi thodu and other storm water drains/canals.

5. An Environmental Management Plan (EMP) is proposed as part of this report which includes (i) mitigation measures for significant environmental impacts during implementation (ii) environmental monitoring program, and the responsible entities for mitigation monitoring, and reporting (iii) public consultation and information disclosure and grievance redress mechanism.

6. Under the Storm Water Drainage programme, detailed study of the flooding of low lying areas and storm water network in the Thiruvananthapuram Municipal Corporation was carried out. This IEE covers the entire improvements proposed for the up gradation of storm water drainage.

7. The subproject locations are all the storm water drains including nallahs and manmade canals. A few stretches of the storm water network is situated in areas in having saline water intrusion. There are no protected areas and there is no mangroves in or near the subproject sites. Trees, vegetation (mostly shrubs and grasses), and animals are those commonly found in urban areas.

8. Some minor negative impacts were identified in relation to construction activities connected with improvement to the storm water drains. A number of impacts and their significance have already been reduced by amending the design thus no impacts were identified as being due to the project design or location. Mitigation measures have been developed to reduce all negative impacts to acceptable levels.

9. During the construction phase, impacts mainly arise from the need to dispose of quantities of silt and sediment removal and disposal and from the disturbance to residence,


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businesses and noise. These are common impacts of construction in urban areas, and there are well developed methods for their mitigation.

10. The proposed subproject intends to provide comprehensive and lasting solution to the flooding problems in the Thiruvananthapuram Municipal Corporation, particularly in the Thampanoor and Pazhavangadi areas. By this subproject the negative environmental impact developed due to unscientific use of natural sources is being corrected and minimized. The proposed system will enhance the carrying capacity of the storm water drainage system of the city and there by improve the utilities of the common people. The storm water drainage in the TMC is concerned with the accumulation of storm water runoff resulting in flooding. So it is required to convey the storm water as quickly as possible to the outfall. Due to urbanization the impervious area in the drainage basin has increased considerably. The Kerala situation doesn’t permit the traditional engineering approach of storm water management through on site or offsite detention storage or infiltration. There is a good network of storm, water drainage system for Thiruvananthapuram Municipal Corporation. Most of these drains become ineffective due to unscientific disposal of municipal solid waste, sewage and sullage from nearby residential building and commercial establishments.

11. The main activities proposed are desilting and side protection of all the thodus and canals in the city. Studies indicated that additional canals are required in the entire Thiruvananthapuram Municipal Corporation area, to completely avoid flooding of low lying areas particularly Thampanoor and East Fort areas.

12. There were limited opportunities to provide environmental enhancements, but certain measures were included. For example it is proposed that the project will employ workers who live in the vicinity of construction sites to provide them with a short-term economic gain.

13. Mitigation will be assured by a program of environmental monitoring conducted during construction to ensure that all measures in the EMP are implemented and to determine whether the environment is protected as intended. This will include observations on-site and off-site, document checks, and interviews with workers and beneficiaries, and any requirements for remedial action will be reported

14. The stakeholders were involved in developing the IEE through face-to-face discussions on site and public meeting held at the proposed sites, after which views expressed were incorporated into the IEE and in the planning and development of the project. A grievance redress mechanism involving a Grievance Redress Committee at TMC level has been proposed under the project.

15. Therefore the subproject is unlikely to cause significant adverse impacts. The potential adverse impacts that are associated with design, construction, and operation can be mitigated to standard levels without difficulty through proper engineering design and by the incorporation or application of recommended mitigation measures and procedures. Based on the findings of the IEE, the classification of the Project as Category “B” is confirmed. It is concluded that the proposed sub‐project should proceed, with appropriate mitigation measures and monitoring programs identified in the IEE.

Project: Kerala State Urban Development Project Document: IEE Report Storm Water Drainage Thiruvananthapuram February 2012

Consulting Engineering Services (I) Pvt. Ltd. Page 1 of 34

1. Introduction

1.1 Preamble

ADB extends loans and provides technical assistance to its developing member countries for a broad range of development projects and programmes. It also promotes and facilities investment of public and private capital for economic and social development. An ADB mission made a fact-finding visit to Kerala State from 26th February to 3rd March 2003 for Technical Assistance to prepare the Kerala Sustainable Urban Development Project.

1.2 Project Background

The Project Management Unit (PMU) of Kerala Sustainable Urban Development Project (KSUDP) was created for implementation of the said project under Local Self Government Department (LSGD). Project Implementation Units (PIU) based in the project cities have also been provided with necessary consulting services under the loan to strengthen their project management and implementation capability including engineering design and construction supervision.

The main focus and thrust areas of the project are:

• Improvement and augmentation of water supply system

• Sewerage and sanitation

• Storm water drainage

• Roads and transportation

• Solid waste management

• Community infrastructure development

1.3 Regulatory Provisions

The environmental assessment and review process for any sub-project included under KSUDP should address the requirements of Government of India's (Gol) environmental legislations. In 1986, the Environment (Protection) Act was promulgated as an umbrella legislation that supplements existing environmental regulations. Under this Act a framework for environmental clearance was introduced in 1994, requiring that Environmental Impact Assessments (EIAs) be conducted for new development projects with a cost of Rs.1,000 million (approximately US $ 22.22million) or more and capacity expansion/augmentation with cost of Rs.500 million (approximately US $ 11.11million). This notification is now superseded by the notification dated 14th September, 2006 and provides a detailed and comprehensive framework for environmental clearance, requiring that environmental impact



assessments be conducted for new development projects. Projects are now required to pass through a process of screening, scoping and classification either as category A or category B, depending on severity of impacts and nature of projects, with stipulated thresholds for various types of projects for categorization. As for municipal infrastructure projects are concerned, only common municipal wastewater management facility and common effluent treatment plants require prior environmental clearance under this notification.

Any component of urban infrastructure project having potential to generate sewage or trade effluent will come under the purview of the Water (Prevention and Control of Pollution) Act, 1974. The sub-project "Thiruvananthapuram Storm Water Drainage Project” falls under the ambit of environmental regulations of the country and mandatory requirement of obtaining clearances as per various statutes. The revamping of storm water drains as proposed here under requires activities to stop disposal of solid waste and discharge of sewage and sullage into the storm water drains, nallahs and thodus. This necessitates the requirement of new sewage lines as well as sullage lines. In the case of laying of new sewer lines attracts the provisions of the Water act. Hence consent as required under section 25/26 of the Water (Prevention and Control of Pollution) Act 1974 has to be obtained for establishment and operation of the sewer lines. Such projects have to obtain consent to establish under section 25 of the Water Act from Kerala State Pollution Control Board before starting implementation and consent to operate before commissioning. The Water Act also requires the occupier of such sub-projects to take measures for abating possible pollution due to making the discharges from the sewer lines. It clearly indicates that these sewer lines are to be connected to scientific sewage treatment plants. The sewage treatment plant also required to comply with the provisions of the Water Act. The sub-projects having potential to emit air pollutants into the atmosphere have to obtain consent to establish under section 21 of the Air (Prevention and Control of Pollution) Act, 1981 from Kerala State Pollution Control Board before starting implementation and consent to operate before commissioning the project. Hot mix plants, wet mix plants, stone crushers, diesel generators etc is proposed to be establish as part of the sub-project implementation, the operation of which will fall under the purview of the Air Act. The contractor is required to obtain consent to establish these plants and equipments before installing and is required to obtain consent to operate before starting construction at the site from the KSPCB. The occupier of the project/facility has the responsibility to adopt necessary air pollution control measures for abating air pollution during construction stage.

The ADB guidelines stipulate addressing environmental concerns, if any, of a proposed activity in the initial stages of investment program preparation. For this, the ADB Guidelines categorizes the proposed components into varies categories (A, B, C or FI) to determine the level of environmental assessment required to address the potential impacts. Level of environmental assessment required for each category of Investment Program as per ADB's environmental assessment guidelines, 2003 is presented below



Category A Subproject components with potential for significant adverse environmental impacts. An environmental impact assessment (EIA) is required to address significant impacts;

Category B Subproject components judged to have some adverse environmental impacts, but of lesser degree and/or significant than those for category A projects. An initial environmental examination (lEE) is required to determine whether significant environmental impacts warranting an EIA are likely. If an EIA is not needed, the lEE is regarded as the final environmental assessment report. A subproject is categorized as category B sensitive, if that subproject has environmentally sensitive components. The projects that are near to environmentally sensitive areas, or that involve deforestation, loss of biodiversity, involuntary resettlement, processing, handling or disposal of hazardous substances or activities that may be of concern of wide group of external stakeholders are categorized as B sensitive;

Category C Components of subprojects unlikely to have adverse environmental impacts. No EIA or lEE is required, although environmental implications are still reviewed; and Category Fl Projects are classified as Category FI if they involve a credit line through a financial intermediary or an equity investment in a financial intermediary. The financial intermediary must apply an environmental management system. Unless all subprojects will results in insignificant environmental impacts. The environmental compliance requirements of the sub-project are detailed in table 1

Table 1: Environmental Compliance Requirements of the Subproject

Components of Subproject

Environmental Acts/Regulation Compliance Requirement

Laying of storm water drain

1. The Water (Prevention and Control of Pollution) Act, 1974, as amended from time to time 2. The Air (Prevention and Control of Pollution) Act 1981, as amended from time to time

3. The Municipal Solid Waste (Management and Handling) Rules 2000

1. Consent to establish from KSPCB before starting implementation

2. Consent to operate from KSPCB before commissioning

1. Consent to establish from KSPCB for putting up diesel generators before establishing

2. Consent to operate from KSPCB diesel generators before operating

1. Authorization from KSPCB for the identified site for the disposal of silt and sludge removed from thodus/canals before starting implementation and management of the same as per conditions.



Components of Subproject

Environmental Acts/Regulation Compliance Requirement

During implementation of the storm water drainage project

1. The Water (Prevention and Control of Pollution) Act, 1974, as amended from time

to time 2. The Air (Prevention and

Control of Pollution) Act 1981, as amended from time to time

The contractor is required to obtain consent for making discharge of the sewage from construction camps, if any, from KSPCB before starting the construction camps.

1. Consent to establish hotmix plants, diesel generators etc by the contractor from the KSPCB before starting implementation.

2. Consent to operate hotmix plants, diesel generators etc by the contractor from the KSPCB before starting construction.

3. Valid consent to operate the stone crusher and M- sand units issued from the KSPCB to the crusher owner

Removal of trees from the site

The Kerala Preservation of Trees Act, 1986

Sanction for cutting trees from authorized officer

All components The Environment Policy and Operations Manual (OM) 2003. Environmental Considerations in ADB Operation

Categorization of sub-project components into A, B or C and developing required level of environmental assessment for each component

1.4 Level of Environmental Examination Though the sub-project aims to improve the environmental quality of the city, certain activities involved during various phases of the project may have potential to cause certain negative environmental impacts. These impacts may arise during implementation and operation phase and may also arise after end of operation period. The initial environmental examination (lEE) is conducted for the sub-project to identify these negative impacts of the subproject based on the scale and magnitude of activities coupled with the environmental setting of the project location and to develop appropriate environmental management plan (EMP) to be incorporated in the design and implementation to ensure that the sub-project is unlikely to cause any negative impacts. The lEE was based on secondary sources of information plus field reconnaissance surveys. The data collected through, environmental and geotechnical study of the storm water network were also used for preparation of the report.



2. Project Details

The proposal is for improvements to Pazhavangadi thodu diversion works, Thampanoor area and Thekkanakkara canal. The expected beneficial population in the project area is 1070980 in 2036.

There are large number of sewage discharges and sullage discharges into the storm water drains in the city area. While implementing improvements to thodus and drains all such sewage and sullage discharges will be stopped and alternate arrangement for sewerage lines are to be provided. It has to be ensured that these waste water is reaching the STP being constructed at Valiyathura. The unscientific disposal of municipal solid waste into the storm water drainage system will be prevented and the entire municipal solid waste is proposed to be incorporated with the existing municipal solid waste management system in Thiruvananthapuram Municipal Corporation.

2.1 Sector Background

A detailed project report for upgrading the storm water drainage of the Thiruvananthapuram Municipal Corporation was submitted incorporating projects under KSUDP (ADB assisted) and projects under JNNURM in September, 2008 and got sanction for the project from CPHEEO, New Delhi.

2.2 Storm Water Drainage System

The drainage network of the city consists of two rivers, a few canals (thodus), their feeders and lakes. The rivers are Karamana and Killiyar which flow through the city area. There are a number of drains and sub drains in the city area namely Pazhavangadi, Ulloor, Pattom, Kannanmoola (Amayizhanjan), Thekkenekara and Kariyil thodus and natural drains namely Tettiyar, Pangappara, Kaimanam-Azhamkulam, Amathara, Koori and Vattakkayal thodus. Other important drains contributing to storm water drainage to the TMC are Choozhampala, Anathanthodu, Edanada, Arayalloor ela and Thiruvallom-Pallathukadavu thodu.

Water conservation is another important area that needs immediate attention. In spite of abundant water resources, the city is facing water scarcity. Hence conservation of water is needed to restore the water for future needs. The developing areas surrounding the city are witnessing large scale construction activities resulting in unscientific filling of low lying areas leading to blockage of natural drains and reduction in ground water recharge.

2.3 Overall Study of Pazhavangadi Thodu

The Pazhavangadi thodu (stream) is the smallest but most problematic and southernmost tributary of Kannanmoola/Amazyzhanjan thodu. The entire watershed up to Kannanmoola is bounded roughly between 76o 55’ 30” E and 76o 57’50” E Longitudes and 8o 29’5” N and 8o

30’40” N latitudes, covering an area of about 703 ha. It is relatively shallow with a flat gradient, and as it traverses trough one of the busiest areas of the city, in the vicinity of the



KSRTC bus stand and the central railway station in the Thampanoor area, it has become a notorious receiving stream for debris, other solid waste, silt from construction sites, as also domestic/commercial wastewater. The roadside storm water drains in the area that outfall into the thodu often backs up and floods the Thampanoor, Mele Pazhavangadi and East fort areas, and disturbs the busy pedestrian and vehicular traffic. The thodu occasionally overflows its banks as it comes out of the culvert in the Mele Pazhavangadi area in front of the Ganapathy temple. It is unfortunate that the indiscriminate human abuse of this thodu has turned it into the main cause of flooding in these and other areas, rather than being a boon to relieve the excessive runoff resulting from the ever-counting urbanization. Peak flow estimate were made for the Pazhavangadi thodu at five salient locations, one at the start near KWA water works, second at Bakery Junction, third at Hosing Board Jn, fourth at Thampanoor and fifth at it confluence with Aamayizhanjan/Kannammoola thodu, about 0.5 km downstream of Pattom-ulloor thodu confluence. The drainage areas were delineated using the available contour maps and information collected in the field. The cabinet sub-committee of Government of Kerala and the Thiruvananthapuram Municipal Corporation had already decided that hydrologic analysis of all such channels will be based on the 50 year return period flood through the CPHEEO had suggested the 2 year design flood. Since peak flows in all such channels are determined only merely as ‘estimates’ the relatively simple and universally accepted Rational formula was used in this analysis, using the IDF curves developed for the city and choosing parameters judiciously. The contributing area to Thampanoor is found to be 2.91 sq km , or 291 ha.The stream length up to Thampanoor railway culvert is 2.8 km, in which distance the elevation falls from about 63m MSL at Observatory hills (IMD/KWA Offices) to 22.7 m (bed) at the beginning of the stream, 12.3 at Bakery Jn 8.75 at Housing Board Jn and to 5.8 m in the channel bed at Thampanoor, giving an average slope of 17.7m/km (0,057).the stream transverses through Bacjkery jn. and Chengalchoola in a southerly direction. It may be noted that the flow from backwash at the water treatment plant of KWA, which enters the starting point of Pazhavangadi thodu, is negligible (2% of 72mls=0.017m3/s),at 1.7% of 2 – year and 0.8% of 50-year peak runoff.Tthe quality is also not too bad since the raw water reaches the plant after storage in two dams and a pre-treatment settling tank at the source, and the chemicals are only small concentrations of slum and lime. 2.4 Key Issues



The condition of existing water bodies as natural drainage for storm water is deteriorating. Dumping of solid waste from slaughter houses, markets, hotels, etc., and discharge of untreated sewage directly into the water bodies lead to contamination of water. Unscientific and indiscriminate methods of sand mining have resulted in erosion of river banks.

• Due to reduced cross sectional area of rivers, flash floods have become common during downpour

• Recurrent floods as a result of insufficient drainage are the perpetual problems faced by Thiruvananthapuram Municipal Corporation during the past several years. Thampanoor and East Fort areas are the worst affected with extensive water-logging during rainy season

• Measures to prevent water logging is tried from time to time to ease the graveness of the situation. An abrupt rain of high intensity may lead to water logging of low laying areas disrupting the city life considerably. A permanent solution to the problem is to be evolved.

• The reclamation of low lying areas for development activities is the main reason for water-logging. Most of the flood moderation zones in the city have been converted into concrete buildings and apartments resulting in excessive runoff.

• Improper maintenance of the existing drains coupled with excessive runoff is the root cause of flooding of low lying areas. In-depth study of the present status of the drains, their carrying capacity, anticipated flood discharge and the probable routing/re-routing may be devised and implemented for restoring/enhancing the status of drainage network in the city to solve the issue to a significant extent.

• Reduction in carrying capacity of the existing Pazhavangadi thodu is due to heavy silt deposition, inadequate cross section at few stretches, disposal of solid wastes into the thodu, growth of vegetation in the thodu apart from encroachments.

• Most of the affected areas are low lying • Inadequate cross-section in culverts obstruct normal flow in the canals/drains. • Poor condition of some of the existing culverts resulting in overflow and flooding of

adjoining areas • The drains are more prone to disposal of solid wastes and growth of vegetation resulting

in reduction/stagnation of normal flow • Lack of awareness and public responsibility regarding disposal of wastes • Lack of coordination in maintenance of the existing canals and storm water drains by the

responsible agencies and • Misuse of storm water drains and canals or the disposal of solid waste and discharge of

sewage and sullage.

2.5 Drains Affecting Thampanoor and East Fort



Flooding occurs frequently in Thampanoor and East fort areas during rainy season. The Pazhavangadi thodu (Nallah/natural drain), starting from observatory hills and nearby areas, carries the surface water and backwash from the water treatment plant and passes through Thampanoor, crosses under the railway lines and reaches East Fort area. Detailed analysis of the drainage pattern of the catchments of this drain reveals that the carrying capacity of the thodu at Thampanoor is insufficient to carry the runoff from its catchments along with the runoff of the area adjacent to the railway station and bus stand. Particularly due to the indiscriminate disposal of large quantities of silt and debris which are cleared only infrequently. The water during down-pour in the area adjacent to the railway station and bus stand is not drained quickly into the thodu as the carrying capacity of the leading drains including the drain around Ponnara Sreedhar Park is totally blocked in some places and not having sufficient cross section elsewhere. Storm water stagnates for a period of time causing flooding in the Thampanoor area. So also the cross-sectional area of the culvert beneath the railway yard is getting reduced year after year due to accumulation of debris and silt. Moreover, portions of the old culvert structure is said to be still trapped inside the newly constructed culvert, blocking the already reduced vent-way.

The drains leading to Pazhavangadi thodu from the area adjacent to the railway station and bus stand should be redesigned and reconstructed to carry the storm water and drain off the area to the thodu without stagnation. It is to be ensured that the culverts under the railway line as well as the canal portion below the railway tracks are to be frequently cleared off silt and debris. The capacity of the drain downstream of Ganapathy temple upto Thakaraparambu is observed to be sufficient to carry the flood discharge of the upstream catchments only. So the storm water collected in Putharikandam maidanam and adjacent areas were directed to the drain leading to Thekkenakara thodu through the drain under the commercial buildings. All the leading drains in the area are either choked or defunct resulting in the storm water finding its way to Pazhavangadi thodu, which does not have adequate carrying capacity for this additional flow. Moreover, the water collected in the built up areas like Padmanagar colony also finds its way to the Pazhavangadi thodu. The network of drains in the East Fort city bus stand area is to be restored and revamped so that major share of the storm water is directed to Thekkenakara thodu. The thodu downstream of Ganapathy temple is to be widened to accommodate any additional runoff. The culverts and cross drainage works are also to be remodeled to carry the additional discharge. Chain link fencing on both sides of the thodu to prevent dumping of debris and the solid wastes into the thodu can also be thought of for the entire length.

Other important drains carrying storm water in the city are Amayizhanjan thodu, Kannamoola thodu, Ulloor thodu, Pattom thodu, Kariyil thodu, Choozhampala thodu, Anathanthodu thodu, Edanada thodu, Arayalloor thodu, Ela thodu, Thiruvallom thodu, Pallathukadavu thodu, Azhankal thodu, and Koori thodus. Due to steady increase in population, the need for housing complexes and colonies have also increased. The overall development activities intruded with the drainage system and necessitated new storm water drains have become the imperative need of the day. Additional storm water drains in an average of about 1km per ward may suffice the proper drainage in all the 100 wards of the Thiruvananthapuram Municipal Corporation.



2.5.1 Pazhavangadi thodu

Pazhavangadi thodu starts from observatory hills and KWA water treatment plant area and merges with Amayizhanjan thodu near Kannamoola and has a length of about 5.4km. It is the main discharge canal of Thiruvananthapuram Municipal Corporation and traverses through the important areas of the city such as Thampanoor, Pazhavangadi, Thakaraparambu, Vanchiyoor and Pattoor. The width of the thodu varies from 3 to 6m. Many road side drains make discharge into this thodu. The road culverts of insufficient cross section were noticed to be the main hindrance for the free flow of water through the thodu. These culverts were re-constructed many times to ensure flow of water without any stagnation. The re-construction of the culverts and desilting of the thodu has decreased the incidence of flooding to a certain extent. But periodic desilting of the thodu is not yet to be essential as the disposal of soloid material into the thodu continued unabated.

2.5.2 Ulloor thodu

Ulloor thodu originates from pothencodu area and enters the TMC area at Edavakode and passes through the northern part of the city such as Mannanthala, Ulloor, Chalakuzhy and Murinjapalam and reaches Kannamoola where it joins with the Amayizhanjan thodu. From Edavakode to Kannanmoola the Uloor thodu has a length of about 8km and a width of 10 to 15m. Dhobis in the city used to wash cloths in this thodu. Some portion of thodu is noticed to be highly contaminated and the flow is stagnant in several reaches. Several natural drains join with this thodu bringing silt and debris to Kannamoola thodu. Due to solid wastes disposal and silt deposit inside the thodu the cross sectional area reduces leading to over flow of the thodu during rainy season resulting in flooding in the low lying areas on both sides of the thodu. Further it is observed that sewage and sullage from the houses on the banks of thodu are directly diverted into this canal making the water contaminated.

Several housing colonies, houses, commercial establishments and slums are located on the banks of Ulloor thodu. Whenever flash flood occurs, the thodu overflows and cause havoc to the residents. The Kannanmoola thodu join with Amayizhanjan thodu at Kannanmoola. Restoration of Ulloor thodu is necessary particularly to the stretch passing through the Thiruvananthapuram Municipal Corporation area.

2.5.3 Pattom thodu

Pattom thodu is a natural drain with an average width of 1 to 3m and length of about 6.5km. It starts from the upper reaches of Kudappanakunnu, on the eastern part of the city. Pattom thodu finally discharges into Amayizhanjan thodu at Kannanmmola. It is understood that in early days Pattom thodu has a major role in controlling flood in the city area. However now Pattom thodu is fully silted up resulting in overflow and flooding of nearby areas of the city. It is observed that there are few fully silted areas in the thodu. There is encroachment on the silted area of the canal, which in turn, reduces the carrying capacity of the canal. Pattom thodu is to be urgently desilted and adequate side protection has to be given to prevent further encroachment and to maintain its carrying capacity.



2.5.4 Kannammoola thodu

Kannanmoola thodu also called Aamayizhanjan thodu starts at about 0.7km upstream of Kannanmoola bridge. Before joining Akkulam lake Ulloor todu and Pattom thodu joins with Kannanmoola thodu. The Kannanmoola thodu has a width of 20 to 30m and a length of about 5.7km. The Pazhavangadi thodu joins at about 0.25km below the Ulloor and Pattom thodu confluence. As in the case of other canals in the city, Kannanmoola thodu is also in a very poor condition with low carrying capacity as a result of deposition of silt and debris, vegetation, poor maintenance, bank erosion and low velocity. Unless the condition is scientifically improved, possibility of flooding in this area cannot be controlled.

2.5.5 Thekkenakkara canal

The Thekkenakkara canal is one of the main flood water canals which starts from Karimadom colony southeast of East fort and passes through the most populous areas like East fort, Padmanabhaswamy temple, Sreevaraham, Muttathara, NH bye-pass, and ends in Parvathy Puthanar near Puthenpalam. The entire stretch of the thodu is now choked with silt and debris. About half of the length of the thodu is covered with slab, and desilting is very tedious in this stretch. Thekkenakkara canal has a width of 3m and length of 2.5km. Several small drains join with this canal in various portions, and in many places these canals are to be reconstructed.

A portion of the storm water of Pazhavangadi thodu is proposed to be diverted to this canal at East Fort, and flooding in East Fort area can be avoided to a considerable extend. The proposal is to construct a connecting canal. The canal beds and sides appear to have been constructed with rock planks with brick arch. Manholes are provided for proper maintenance of the canal.

2.6 Other Natural Drains

Tettiyar and Pangappara thodu are natural drains which, if restored, may help drain out water from the marshy and waterlogged areas at Kazhakootam near Technopark and the college of engineering, Kulathoor.

2.6.1 Tettiyar thodu

The Thettiyar thodu is running in the premises of Technopark, Kazhakuttam and is being silted up. Protection of Tettiyar thodu will prevent flooding and water logging in the surroundings of the Technopark area.

2.6.2 Pangappara thodu

The Pangappara thodu runs in the proximity of Karyavattom university campus and college of engineering campus, Kulathoor. Major portion of the thodu is not in a stable condition to sustain the seasonal rainwater flow. Protection of this thodu is a potential solution of the total flooding problems in the area and may help prevent water-logging.



2.6.3 Kaimanam-Azhamkulam thodu

The Kaimanam-Azhamkulam natural drain starts from Kaimanam and runs parallel to Karamana river and finally discharges into Karamana river. The drain has to be desilted and side protection works are required for a stretch of about 1km.

2.6.4 Amathara thodu

Amathara todu runs through Nalanda junction, Charachira and leads to Plamoodu via Kanaka nagar in the city. The drain is observed to be blocked and ineffective at several places and needs urgent repairs.

2.6.5 Koori thodu

Koori thodu, once used for navigation is one of the drains reach in Parvathy Puthanar. It is observed that, now the entire length of Koori thodu is blocked. The koori thodu is to be opened with adequate maintenance work which is essential for controlling the water-logging in Chakka area.

2.6.6 Vattakkayal thodu

Vattakkayal thodu discharges into Parvathy Puthanar. The canal starts from a big pond at Chacka and is having a length of 500m.

2.7 Additional Drains

Several natural drains in TMC are observed to be chocked, defunct and even encroached upon. In some cases it is difficult to trace the path of original drains mainly due to encroachment. As the influence areas of these drains could not find way to drain off water either creating a water stagnant condition or flooding. For such redundant drains some suitable alternative drains are to be constructed or the original path is to be located and restored. Other important drains contributing storm water to the city canals are Choozhampala, Anathanthodu, Edanada, Arayalloor Ela and Thiruvallom Pallathukadavu thodus. Apart from this, the road side drains carrying storm water also form part of the drainage system in the city, the improvement of which has been included under the sector on traffic and transportation.

2.8 Parvathy Puthanar

The major man-made drain in the city is Parvathy Puthanar (Travancore Shoranur canal or T S canal) with Edayar at south end and Aakkulam lake at the north. 36 small drains from the city area discharge into this canal. Parvathy Puthanar runs parallel to the sea shore through the coastal belt of Thiruvananthapuram city. Some of the reaches of the canal are badly damaged and so need to be protected. Certain reaches of T S canal identified for improvement include Moonnattumukku to Vazhavila, Thekkanekara feeder canal, Kariyal thodu and Panathura to Kovalam. Although desilting of the canal has been arranged under other projects, side protection and strengthening are to be taken up.



2.9 Edayar Island

Karamana and Killi rivers meet upstream of Edayar near Thiruvallam, after which the river bifurcates and passes around Edayar before joining the Lakshadeep sea on the west. The river outlet at Poonthura (Poonthura Pozhi/sandbar) is adjacent to this island and hence the back flow of water at the Pozhi causes damage to the island, constantly eroding the banks. Suitable retaining structures are to be constructed to protect the island. The discharge route of the two rivers into the sea is passing through this area causing very much turbulent to the water body. Moreover this island is fit to be developed as a tourist centre.

2.10 Lanka Island

Lanka island is situated near the famous Sree Parasurama swamy temple. The banks of the island are prone to severe erosion, and needs urgent stabilization. Smooth flow of flood water is also obstructed due to the bank erosion.

2.11 Project Definition and Concept

The proposed subproject intends for ensuring a comprehensive and lasting solution to the flooding problems in Thampanoor and Pazhavangadi areas. The works involved can be divided into the following three categories:

A. Improvements to Pazhavangadi thodu

B. Improvements to drains and canals in Thampanoor area

C. Improvements to Thekkanakkara canal

Alternatives for solving the flooding problems

Following alternatives are considered under improvements of Pazhavangadi thodu to eliminate flooding problems in Thampanoor and Pazhavangadi areas.

Alternative – 1: Widening of Pazhavangadi thodu, wherever necessary and providing adequate improvements for road and railway culverts.

Alternative – 2: Diverting some of the storm water from Pazhavangadi thodu at few locations

2.12 Urban Storm Drainage

In an urban situation, storm water drainage is concerned with the accumulation of runoff resulting from rainfall, which needs to be conveyed to an appropriate outfall as quickly as possible, without causing inconvenience to pedestrian and vehicular traffic, and damage to property. Urbanization is always accompanied by increased impervious areas in the drainage basin, resulting in increased peaks and volumes of runoff. The traditional engineering



approach is to dispose the runoff quickly, but in the past three or four decades, storm water management through onsite or offsite detention storage/infiltration, etc, is being practiced in most countries. However, in the Kerala situation in general, such techniques may not be practical due to high cost of land, unless strategic land allocation for such measures were to form a part of the land use master plan itself.

In the present subproject therefore, it is suggested to adopt a strategy to convey the runoff as quickly and efficiently as possible from and along the roads and along the natural water courses. However, also as a strategy, wherever and whenever feasible, natural or created storages, either transitory or long-term, above ground or in the soil, or infiltrated into the groundwater system, would be adopted or encouraged, with the idea of reducing the adverse impact of urbanization, through reduction of peaks and volumes of runoff, which incidentally reduces the size and cost of downstream drainage systems.

2.13 Need for Design Criteria

At present, storm drains are designed, repaired and built on an ad-hoc basis and not based on a comprehensive analysis that lead to an effective drainage network. This has often created immense problems of inadequate carrying capacities in the downstream reaches, culverts, bridge openings, and at outfalls.

It is therefore necessary to adopt a proper scientific set of guidelines and criteria for the development of a comprehensive storm drainage network. Such design criteria should be founded on sound scientific background and engineering principles. All modern urban infrastructure systems such as water supply, sewerage, storm drainage and roads are planned designed and built on such acceptable design criteria and standards. The criterion pertains mainly to three aspects:

• Hydrologic Analysis

• Hydraulic Analysis

• Structural Aspects

2.14 Improvements to Pazhavangadi Thodu

Studied two alternatives to eliminate flooding in Thampanoor and Pazhavangadi areas and the alternative 1 were selected.

In this alternative studied the adequacy of existing section of Pazhavangadi thodu from KWA outlet to Kannanmoola confluence point. It is evident that even after desilting and lowering drain bed level to a possible extent, the thodu has inadequate cross sections at various stretches. In all these stretches widening of thodu is suggested, involving evictions and acquisitions. Apart from this there are road and railway culverts with inadequate sizes, which need to be either widened or additional culvert of the required size parallel to the existing need to be constructed.



Site investigations, survey and design of Pazhavangadi thodu clearly showed the type of improvements required and the extent of flood mitigation and other benefits to be accrued. The proposed works in Pazhavangadi thodu are listed below:

1. In general removing the silt and debris accumulated over a period of several years, in a systematic manner for the entire stretch of the thodu and minor repairs to existing RR masonry wall. The depth of proposed desilting/deeping will depend partly on the depth of accumulated silt but mostly on the criteria of providing different specific bed slopes in different reaches. Desilting alone is found to bring down the water level by about one meter. It is to be ensured that these slopes are strictly maintained, especially since all the downstream structures are designed on the basis.

Also the construction of RCC partition structure at confluence point of Pazhavangdi thodu and Pattom thodu to avoid back flow of storm runoff from Pattom thodu and causing heading up of water in Pazhavangadi thodu at Kannanmoola.

2. Construction of additional pipe culvert across the railway track at Thampanoor railway station (1700mm x 3 no.s) to avoid backflow of storm runoff from thodu to adjoining low lying areas, opposite to railway station. Size of culvert is calculated considering 2 year return period. Work will be taken up by the railways.

3. Laying of MS pipe by trenchless technology (pipe jacking) method at following locations so as to by-pass the excess flows:

i. 1 no. of 1800mm dia MS pipe (60m) near Ganapathi temple

ii. 1 no. of 1900mm dia MS pipe (15m) parallel to the existing Uppilammoodu railway culvert

iii. 3 no.s of 1600mm dia MS pipe (3 x10m) near Patoor road culvert at Pattoor Pettah road.

4. Widening of Pazhavangadi thodu is required as per the design of Pazhavangadi thodu with 2 year return period.

2.14.1 Silt pits

In order to catch the silt and debris entering the thodu and for easy removal, it is proposed to provide nine numbers of slit pits. The dimensions of the slit pits are 3m wide at top, 2m wide at bottom, and 1m deep PCC paved. These silt pits are provided immediately upstream of:

i. Bakery junction

ii. Housing board-model school road

iii. Proposed open RCC drain near KSRTC bus stand

iv. Thampanoor railway culvert

v. Mele Pazhavangadi slab

vi. Uppilammoodu



vii. Uppilammoodu railway culvert

viii. Vanchiyoor box culvert and

ix. Pattoor road culvert

2.14.2 Fencing

In order to avoid solid waste dumping into the drains it is proposed to provide fencing at the stretches where it is more prone to dumping of solid waste. These stretches are as under:

a) Thampanoor bus stand area

b) Putharikandam area

c) Pazhavangadi to Thakaraparambu

Alternative 2 :

In order to avoid land acquisition issues, as it is very difficult in acquiring in the prime areas

of the city along Pazhavangadi thodu, DSC1 has analyzed various options of diverting part of

the storm runoff from Pazhavangadi thodu. Options include diverting to bypass the

inadequate stretched of the todu and rejoining the same thodu on downstream of these critical

bottle necks. Other option is to divert the flow from the Pazhavangadi drainage system into

another drainage (catchment) system. This option would directly reduce the quantum of

storm throughout the length of the thodu on downstream side of the diversion point. In this

alternative diversion of runoff has been considered as under,

i. First Diversion is in between existing Railway culvert and the road culvert near Indian

coffee house at Thampanoor. A 2.3mx2.0 m pre-cast box drain is prosposed to be laid to

Vanchiyoor along the road running parallel to railway line on north side via over bridge

junction and rejoining Pazhavangadi thodu just after railway crossing at Uppilammodu

diverting 9 m3/s) This is at CH.8514 m(with reference to CH.11214m at KWA outlet at

Vellyambalam)

ii. Second Diversion is from U/S side of road culvert on Powerhouse road, near Southern

exit gate of Railway Station to Killiyar river along power house road (Diverting 10 m3/s).

This is at CH.8304m(w.r.t CH 11214 m at KWA outlet at Vellyambalam)



The third diversion which is from in front of Ganapathi temple to Thekkanakkara canal,

proposed in the earlier DPR has been removed as that flow of 2 cu.m/sec has been taken

count in the second diversion itself.

The quantity of diversion has been arrived at by carrying out various iterations so that there is

no need of widening of the thodu till the confluence point at Kannanmoola except after

Uppilamoodu Rauilway culvert.with these above dicversions the adequacy of exisiting

section of Pazhavangadi thodu from KWA outlet to Kannanmoola confluence point has been

checked with considering only desilting to the desired level. As the runoff from

Pazhavangadi thodu is diverted to differnect drainage zones, adequancy of receiving canal

namely Killiyar river has been checked and found to be adequate, considering return period 2

years. Details of Killiyar river with adequacy check are as under.

Kiliyar River

The Killiyar river originates from Nedumangad area. The river has a width of 20 to 25m

with bed slope of 1: 750 to 1: 1000 up to the city limit and thereafter maintaining a bed slope

of 1:2000 to 1:3000, before it merges with the Karamana river at Pallathukadavu. The

reaches in Maruthankuzhy, Pangode, Vivekananda Nagar, Jagathy, Iranimuttom and

OPallathukadavu are the important reaches inside the city. The river needs protection as it

passes through highly residential area. Major portion of the river reaches inside the city

have already been taken for stabilization. The left over areas need to be attended to.

The basin area of Killiyar river is approximately 80 sq.km(8000ha) and bounded between 8o

27’15” and 8o 39’45” N latitudes and 76o 57’15” and 77o 01’ 45” E longitudes. The upper

and lower portion of the basin are relatively under developed, while the reaches along the

eastern parts of the city are urbanized which can be expected to continue in the future, even

in aerial coverage of extent. Peak flows for the 2 year and 50 year return periods were

estimated using gauge data for the 16 year measured annual maximum instantaneous river

discharge series at Maruthankuzhy (74.25 sq.km)as well as by applying rational formula.

Analysis involved the use of Gumbel’s Extream Value (EV-1) probability distribution to fit

the data, and then to find the flood peak for the desired frequency, which in the present case,

is the 50 year return period.



3. Thiruvananthapuram

Thiruvananthapuram, is the capital of the Indian state of Kerala. It is located on the west coast of India near the extreme south of the mainland.

Thiruvananthapuram is located at 8.5o N 76.9o E on the west coast. The city covers an area of about 214.86 square kilometers. The average elevation above sea level is 4.9m and the maximum is about 80m. The city has a tropical climate. The mean maximum temperature is 34oC and the mean minimum temperature is 21oC. The humidity is high and rises to above 90% during the monsoon season. The city gets a moderate (compared to the State average of 3000mm) rainfall of around 1700mm per year.

3.1 Geography and Climate

Thiruvananthapuram is built on hills by the sea shore on the west coast. The Geological Survey of India has identified Thiruvananthapuram Municipal Corporation as a moderately earthquake-prone urban centre and categorized the city in the seismic III zone.

Thiruvananthapuram Municipal Corporation lies on the shores of Karamana and Killi rivers. Thiruvallam and Veli backwaters are part of the Thiruvananthapuram Municipal Corporation.

3.2 Demography

Thiruvananthapuram Municipal Corporation was established on 30th October 1940. In October 2010, the area of the Thiruvananthapuram Municipal Corporation was increased consequent to the merging up of Sreekariyam, Vattiyoorkkavu, Kudappanakkunnu, Vizhinjam and Kazhakkuttam panchayats with the Thiruvananthapuram Municipal Corporation. The Thiruvananthapuram Municipal Corporation has now an area of 214.86km2 and a population of 9, 57,730.

3.3 Tourism

Tourism has contributed heavily to the economy of Thiruvananthapuram Municipal Corporation. Foreign tourists generally use Thiruvananthapuram as a hub to explore the highly promoted tourism industry of the state of Kerala. Thiruvananthapuram functions as a transit point for domestic and foreign tourists. There are a large number of tourist destinations and tourist visiting Thiruvananthapuram are attracted more towards leisure tourism including beaches, ecotourism and historical monuments.

3.4 Physical Characteristics

The Thiruvananthapuram Municipal Corporation area consists of a number of rivers and canals, both natural and man-made. Karamana and Killi are the major rivers passing through the city. Both the rivers run from north-east to south-west skirting the city before meeting the Lakshadeep sea. At the confluence with the sea there is an island and water lagoons. The major storm water drainage collection basins in the city region are Veli and Aakulam lakes in the north as well as Edayar and Vellayani lakes in the south. The T S canal



(Thiruvananthapuram-Shornur canal) also called Parvathy Puthanar runs along the north-south direction connecting the Edayar and Aakulam lakes and continues to flow towards the north.

Geologically the city is characterized by sandy soil along the west coast and red laterite soil in the eastern regions. Granite deposits exist in some part of the city especially at Peroorkada and Thirumala.

3.5 Land Use Pattern

The land use of Thiruvananthapuram Municipal Corporation has changed considerably in the recent past due to urbanization. Various physical, social, political and economical factors have played their decisive roles in forming the city’s land use pattern. The table 2 provides land use pattern in the Thiruvananthapuram Municipal Corporation.

Table 2: Land use pattern of Thiruvananthapuram Municipal Corporation (2001) Land Use Area (sq.km) Distribution (%)

Residential area 54.5 38.4

Commercial area 5.3 3.7

Industrial area 6.9 4.8

Public & semi public 12.2 8.6

Transportation area 9.3 6.5

Agriculture 43.3 30.5

Water course 3.1 2.3

Parks & open spaces 7.3 5.1

Source: Development Plan for Thiruvananthapuram, 2001.

The total area of the Thiruvananthapuram Municipal Corporation is 214.86sq.km. The land use of the newly added areas is mainly agricultural and residential with comparatively low density settlements in fringe areas. Major use of urban land is classified under residential areas which includes not only the area occupied by the houses, but also the coconut plantations around the houses.

4. Environmental Setting

During the PPTA stage of the project, sub project activities were tentatively assessed and presented in the report. Subsequently storm water drainage surveys and geo-technical studies at the site were carried out. The layout and detailed design of the sub-project were finalized. The environmental assessment of the sub-project is done as per ADB's Environmental Assessment Guidelines and the Environmental Assessment and Review Framework (EARF) approved for the project to ensure that the sub-project is complying with the existing



environmental regulations of the country and will not have any adverse impact on the environment.

The main purpose of the KSUDP is to improve urban environmental conditions. As such there are many environmental benefits to the proposed improvements to the storm water drains, thodus and canals to Thiruvananthapuram Municipal Corporation. This section focuses on the identification of potential adverse environmental impacts short and long term. It takes the subproject components with identified consequences and considers them in the context of receiving environment.

4.1 Air Environment

The sub-project site comprises almost the entire Thiruvananthapuram Municipal Corporation. The storm water drains, thodus and canals are passing through thickly populated and commercial areas of the city. The Kerala State Pollution Control Board is maintaining ambient air quality stations at Veli (industrial), which is about 3km from Thekkanakkara canal, SMV school, over bridge (sensitive) which is about 750m from Thampanoor area, murinjapalam (sensitive) which is about 1km from Ulloor thodu, Pettah (residential and others) about 2km from Kannanmoola and 1km from T S canal as per CPCB norms. Ambient air qualities in these stations are very much comparable with the ambient air quality in the project area. Relevant details on ambient air quality for these stations are shown in table 3

Table 3: Ambient Air Quality at stations near the Project Site Parameter Standard

µg /m3 Observed value , µg /m3

Range Annual average Veli (category: industrial ) Sulphurdioxide (SO2) 120 max. 5 - 40 15.79

Oxides of Nitrogen (NOx)` 120 max. 8 - 35.4 18.43

Respirable Particulate Matter 150 max. 30 - 129 63.7

Suspendable Particulate Matter (SPM) 500 max. 37 - 144 84.33

SMV school, Overbridge (category: sensitive)

Sulphurdioxide (SO2) 30 max. 4.32 -10.4 6.74

Oxides of Nitrogen (NOx)` 30 max. 10 -54.2 27.19

Respirable Particulate Matter 75 max. 26 -604 56.2

Suspendable Particulate Matter (SPM) 100 max. 32 -683 64.54



Parameter Standard µg /m3

Observed value , µg /m3 Range Annual average

Murinjapalam (category: sensitive)


Oxides of Nitrogen (NOx)` 30 max. 9.9 - 170.4 25.87


Suspendable Particulate Matter (SPM) 100 max. 37 - 87 59.05

Pettah (category: residential and others)


Oxides of Nitrogen (NOx)` 80 max. 10 – 43.3 25.37


Suspendable Particulate Matter (SPM) 200 max. 38 -110 57.4

Source: Water and Air Quality Directory 2010, KSPCB, Thiruvananthapuram

4.2 Noise Environment

The sub-project site is mainly in residential and commercial areas. Sound levels were monitored as part of field investigation. The monitoring results are presented in the table 4. Table 4: Noise level at Sub-Project Site

Location Observed Value, dBA(Leq) Standard 55.0 North side West side South side East side

48.8 47.0

58.0 55.6

Source: Field Study

4.3 Topography and Soil

Topographically, the sub-project site forms almost a plain land with slight slope towards west. The area forms part of Karamana river and killi river basins. The site is covered with sandy soil. The soil is highly porous and well drained.

4.4 Geology

The soil at the project sites consisting of sandy soil and sand is loose to medium dense at all levels.

4.5 Climate



Thiruvananthapuram Municipal Corporation region has hot humid climate and relative humidity varies from 75 percent in January to 96 percent in June and July. The annual variation of temperature ranges between 27°C and 32°C. The region experiences two major seasons, namely the dry season and the wet season. The wet season is associated with the months in which Southwest and Northeast monsoons occur. This wet season is spread over a period of six months from June to November. The average annual rainfall is 1700mm. December, January and February are the coldest months while March, April and May are the hottest.

4.6 Water Environment 4.6.1 Surface water

The project is for the improvement of storm water drains, canals and thodus. The entire storm water network was studied in detail and this is the project area. The Kerala State Pollution Control Board is having a water quality monitoring station at Moonattumukku. The Moonattumukku station is located near the point where Parvathy Puthanar confluence with Karamna river. The major canals in the Thiruvananthapuram city such as Ullor thodu and Amayizhanhjan thodu empty into this river. The water quality monitoring results are summarized and presented in table 5. The water quality at Moonattumukku as well as canals and thodus in the proposed site are very much comparable.

Table 5: Water Quality at Moonattumukku (Class E as per CPCB Classification) Sl.no Characteristics Unit Observed Value Mean value Standard

1 pH 6.2-7.6 7.0 6 - 8.5 2 Conductivity µ mhos/cm 550-4500 1787 2250 3 Dissolved oxygen mgll 0-1.6 0.57 4 Biochemical

Oxygen Demand mgll 8.6-20.4 8.6

5 Nitrate (N) mgll 0.98-2.4 1.49 6 Amoniacal Nitrogen mgll 1.5-5.76 3.94 7 Total coliform no/100ml 2200-38000 17500 5000 8 Fecal colifirm no/100ml 900-22000 8541

Source: Water and Air Quality directory 2010, KSPCB, Thiruvananthapuram 4.6.2 Ground water

Ground water in the sub-project area occurs under confined and semi confined conditions. The course and porous and layers of sandy soil form aquifer system. The main recharge to groundwater takes place from precipitation. There are number of open wells exists in the houses of project premises. These open wells are mainly used for domestic purposes. The directional flow of ground water is mainly from west to east. Ground water quality is also studied by Kerala State Pollution Control board. The one well water monitoring station is located at Papanamcode near Kaimanam Azhamkulam road. The details of ground water monitoring at the station is given in table 6.



Table 6: Well Water Quality at Pappanamcode Sl.no Characteristics Unit Observed Value Mean value Standard

1 pH 5.1 - 5.4 5.2 6.5 - 8.5 2 Conductivity µ mhos/cm 49 - 420 235 3 Biochemical

Oxygen Demand mgll 0.3 - 0.4 0.35 2

4 Nitrate (N) mgll 1.9 - 2.1 2 5 Total coliform no/100ml 26 - 110 68 50 6 Fecal colifirm no/100ml 2 - 11 7

Source: Water and Air Quality Directory 2010, KSPCB, Thiruvananthapuram 4.7 Ecological Resources

The sites for the improvement of Pazhavangadi thodu diversion works, Thampanoor area and Thekkanakkara canal are part of storm water network in the city. All these canals and thodus are joining with T.S canal, an artificial canal, national waterway No.3 or Karamana river.

No forest or wild life sanctuaries are situated within 40km from the sub-project site. The site is a plain ground with small bushes only. Coconut trees are very common around the project area.

4.8 Socio – Economic

Thiruvananthapuram Municipal Corporation is the state capital and biggest urban area in the state, so houses many state and central government offices, government and private organizations and companies. The TMC is also an educational hub with world renowned institution and research centers. The major population of the TMC forms the middle class families and upper middle class families. The influx of people from other southern states and northern states is more for the past 10 – 20 years.

4.9 Cultural Heritage

There is no enrochment to cultural heritage and other protected structures adjacent to the sub-project area. On both sides of the storm water drains, thodus and canals there are residential houses. In-between these houses there are religious centers such as temples, mosques and churches. The world renowned temples, Sree Padmanabha Swami temple and Pazhavangadi Ganapathi temple are situated in the East fort area. The improvement of the canals and storm water drains proposed may not adversely affect the people visiting the temples.

5. Screening of Potential Environmental Impacts and Mitigation

The main purpose of the sub-project "Thiruvananthapuram Storm Water Drainage” project under KSUDP is to improve the urban environmental conditions of Thiruvananthapuram Municipal Corporation area. As such there are many environmental benefits to be gained from the proposed sub-project. Though the subproject improves the environmental quality of the city, there will be some adverse environmental impacts during its implementation and



operation stages. This section, proposes to focus on the identification of potential adverse environmental impacts both short term and long term. Mitigation measures are proposed to minimize the adverse environmental impacts identified. Recommendations for environmental quality monitoring to be conducted during the design, implementation and operation of subproject with agencies responsible for the monitoring are also drawn up.

The screening for environmental impacts is done in all the four phases of the project; viz. planning, design, construction and operation and maintenance.

• Location Impacts. Impacts associated with the planning are mainly due to site selection. Location impacts include on site biophysical array and encroachment/impact either directly or indirectly on adjacent environments. It also includes the impacts on the people who will lose their homes or livelihood due to the development of the proposed site,

• Design Impacts. Impacts arising from the design of the project, including the technology used, scale of operation/throughput, waste production, discharge specification, pollution sources and ancillary services,

• Construction Impacts. Impacts associated with the site cleaning, earth works, physical construction related materials movements and works, machinery, vehicles and workers. It also includes the erosion, dust, noise, traffic congestion and waste production associated with the construction activities, and

• O&M Impacts. Impacts arising from the operation and maintenance of the infrastructure facilities provided under the project. These include the impacts arising from the management of operational waste streams and occupational health and safety issues of the workers involved.

Based on the field visits of sub-project site and review of sub-project activities during design, construction and operation phase, following issues have been identified.

5.1 Loss of Household, Business Premises or Livelihood

The sub-project has been designed taking into consideration buildings such as households, business premises etc. No households, residents and business premises are affected and hence no need of rehabilitation and payment of compensation. The site is part of the land fully owned by the Government of Kerala.

5.2 Existence of Residences Adjacent to the Sub-project Site There are residences on all sides of the storm water drains/canals of the sub-project site. There is weld mesh protection to canals from disposal of municipal solid waste. There are pucca roads near to the canals or crossing the canals at many places. The improvement to the canals during construction stage may cause nuisance and health problems of these residences. The layouts have been finalized giving maximum clearance to the residences adjacent to the site. Greenbelt development on both sides of canals and roads, where ever land available have been proposed to form a physical separation and visual screen to the development.



5.3 Ground Water Contamination Due to High Water Table

The ground water table at these sites is noticed to be between 1.5m to 10.5m below ground level during the field study conducted. Adopting proper design criteria ground water contamination can be avoided.

5.4 Existence of Surface Water Source

The subproject is for the improvement of storm water and canal network in the city so there are chances of canals/thodus are affected due to storm water runoff. The canal water and thodu water quality is likely to be affected due to storm water during rainy season. The sub-project design includes diversion of storm water from other areas by providing diversion drains/channel. However, it is ensured that sewage or sullage discharges from residential buildings and commercial establishments to the storm water drains or canals leading to contamination of waters has to be avoided during constructions stages.

5.5 Loss of Amenity to Neighbours

The improvements proposed to the storm water drains and canals may have no adverse impact on the aesthetics as it is proposed to dispose the silt removed from the drains and canals to re designated locations with all safe guard measures. It is proposed to develop a greenbelt whereever adequate vacant land is available to form a physical separation and visual screen to the development to maintain aesthetics. It is proposed to notify 25m on both sides of the drains and canals as buffer zone or no development zone. For the improvements proposed no trees in the site will have to be cut/removed. To minimize the impact, the design has been finalized ensuring preservation of as many trees as possible for shading the development and green belt around the periphery.

5.6 Silt Runoff from Construction Site

Silt and/or loose soil may be carried by storm runoff causing pollution of the nearby water body. To reduce this impact, site preparation will be limited to the project site without disturbance to adjoining vegetation and natural resources. Protection will be given to unstable soil surface from high velocity runoff with interception drains and stabilization. Proper siting of stock piles and protection of construction materials will be ensured at site through contract agreement.

5.7 Social Conflict Contractor may bring his own labours for construction activities which may affect the interest of the local workers. A condition to engage local labours as far as possible will be included in the contract to protect the interest of the local workers.



5.8 Noise, Dust or Hazardous Materials

The operation of generators, mixing plants, earth movers and the construction activities may cause dust emission and sound pollution. It will be ensured that the plants and equipments employed in the construction will comply with environmental standards. Regular wetting of stock piles of sand and gravel will be ensured. Dust curtain will be provided to the construction site.

5.9 Contamination of Land and Water

There is possibility of contamination land and water bodies due to improper disposal of wastes by works in the construction camps as well as at the work site. The workers engaged in construction activities may be provided with labour quarters/ settlement. The indiscriminate disposal of waste by workers may contaminate the surrounding area of workers camp shed. The contractor will be insisted by incorporating a condition in contract to provide proper sanitation facilities at labour quarters/settlement as well as solid waste management facilities. The workers shall be given adequate awareness on proper sanitation and solid waste management.

5.10 Indiscriminate Disposal of Spoil/Silt

The silt/spoil generated during construction may cause contamination of the surrounding area. Proper and scientific methods has to be taken for the handling and management of silt/spoil. Proper stock piling of silt/spoil at site, examination of the reuse opportunities for silt/ spoil, identification of sites for disposal of silt/ spoil, and proper covering of the disposal site on completion of work, protection against spreading of dust during transportation, and adequate maintenance of the transportation vehicles will be ensured by specific condition in the work contract.

5.11 Exposure of Workers to Contaminated Site

There is chance of workers exposed to contaminated site and hazardous work environment during the construction. Necessary provisions for providing appropriate protective gears such as gumboots, gloves, and masks etc. training/awareness to workers regarding the potential dangers and health effects and need for the use of protective gears will be made in the contract document.

5.12 Forecasting Environmental Impact and Mitigation

The main purpose of KSUDP is to improve urban environmental conditions. As such, there are many environmental benefits to the proposed sub project. This section, however, focuses on the identification of potential adverse environmental impacts short and long term. It takes the sub project components with identified environmental consequences and considers them in



the context of the receiving environment.

Water quality both surface and groundwater in adjacent water bodies will be critical site consideration for subproject, which result in the desilting of storm water drains and canals and proper management of desilted material and its disposal.

Ambient air quality is important in judging impact potential for construction activities. Data for both particulate (SPM and RSPM) and gaseous pollutants (So2, NOx and NH3) is presented in the IEEs. Mitigation measures are proposed with recommended monitoring actions to be conducted during implementation to minimize any adverse environmental impacts. The mitigation measures will form the basis for an environmental monitoring plan during the implementation stages of the KSUDP project.

Each components of the sub-project is subjected to thorough assessment and the impacts and mitigation measures identified were summarized and presented in table 7.

Table 7. Potential Impacts and Mitigation Measures No Impacts Magnitude of

impact Mitigation Measures Responsibility

1. Loss of on-site ecology or natural feature

Permanent/low Control of site layout to avoid or minimize loss of natural features. New and additional trees are planted wherever loss occurs. It is proposed to develop a greenbelt where ever land is available on both sides of storm water drain.

PIU, PMU

2. Water quality in the wells and ponds in the vicinity may be affected during desilting of storms and canals.

Permanent/low Make sure that only the accumulated sludge or mud will be removed from the storm water drains or canals. It will be ensured that the present sewage/sullage discharge into storm water drains or canals will be adequately connected to existing sewer lines.

PIU, PMU

3. Loss of amenity (aesthetics, property values) to neighbors

Permanent/low Provision of development of a buffer zone on both sides of

PIU, PMU



No Impacts Magnitude of impact

Mitigation Measures Responsibility

the storm water drains or canals with greenbelt development and landscaping to provide physical separation and a visual screen for the development.

4. Loss of household, residence, business premises or livelihood

Permanent/low By the implementation of the project no residential building is proposed to be removed and there is no loss of business or livelihood anticipated.

PIU/TMC/ PMU

5. Encroachment into cultural, heritage and other protected structures adjacent to the sub project, site.

Temporary/low Layout has been finalized giving maximum clearance from the boundaries. Visual curtains with green belt will be provided on both sides of the storm water drains or canals to improve aesthetics.

PIU/TMC/ PMU

6. Existence of residences adjacent to the sub-project site

Permanent/low Layout has been finalized giving maximum clearance to the adjacent residences. Greenbelt on both sides of storm water drains or canals proposed to form a physical separation and visual screen to the development

PIU/TMC/ PMU

7. Existence of surface water and quality of canal may be affected due to storm over run.

Temporary/low The construction activities will be limited to non rainy days and minimize the slit runoff in the storm water drains or canals

PIU/TMC/ PMU

8. Trees existing in the site may be cut/removed for the development.

Permanent/low Design finalized ensuring preservation of as many trees as possible. Double the number of trees will be planted as compensatory afforestation.

PIU/TMC/ PMU





Provision will be made in the project cost for compensatory afforestation and maintaining them for 3 years.

Design



9. Inadequate methods for the handling of sludge removed from storm water drains or canals leading to environmental pollution

Temporary/low Design to include appropriate sludge management and disposal. A sludge management plan will be prepared which includes provisions for on-site handling, maximized re-use of sludge, analysis of the quality of sludge for heavy metals, locations for the disposal of the sludge will be finalized and management measures taken.

PIU, PMU

Construction



10. Silt runoff from construction operations causing soil erosion and damage to water quality

Temporary/low Implement construction site management through provisions in contracts to cover: site preparation, which minimizes causing any disturbance to adjoining vegetation and natural soil surfaces from high velocity runoff (interception drains and temporary stabilization),

Contractor (responsible under contract for all sub-contractors) and PIU (monitoring)





siting of construction material stockpiles and access routes to avoid any disturbance to adjoining vegetation and natural areas; disposal of construction waste to pre - determined locations on a case-by-case basis; recycled use or landfill disposal should be sought.

11. Road blocking and/or increased traffic during construction and laying/rehabilitation of sewerage carriers

Temporary/low Implement construction site management to cover to cover traffic management and nuisance minimization


12. Noise and dust from construction activities

Temporary/low Plant and equipment employed in the construction will comply with environmental standards. Implement construction site management (through provisions in contracts) to cover dust and noise management (including water spraying and scheduling of activities). Dust curtain will be provided to the construction site.


13. Social conflict between workers from other area and local workers

Temporary/low Include a condition in the contractor to engage local labour, wherever appropriate.

PIU/PMU

14. Contamination of land and water due to improper disposal of waste by workers

Temporary/low Proper sanitation facilities will be provided to the labour quarters/settlement and at worksite

Contractor/PIU

15. Exposure of workers to contaminated site during construction.

Temporary/low Provision of appropriate protective gears (Gumboots, gloves, masks etc.);

Contractor/PIU





training to workers regarding the potential dangers and health effects and need for the use of protective gears

16. Dust from unloading. Temporary/low Dust from unloading operation inside the disposal site may generate dust emission. The vehicle moving areas at the work site will be sprayed with water.

TMC/LSGD

Operation and Maintenance

No. Impacts Magnitude of impact


17. Sewer trench cave in hazards

Temporary/low Quality assurance of work to ensure appropriate materials and site finishing/ drainage

Thiruvananthapuram Municipal Corporation /KWA

6. Institutional Requirements and Environmental Monitoring Plan The executing agency for KSUDP sub-projects is the Local Self Government Department (LSGD) and appointed Project Management Unit (PMU) for this purpose. The implementing agency for the sub-project will be the Thiruvananthapuram Municipal Corporation. A Project Implementation Unit (PIU) will be established in the Thiruvananthapuram Municipal Corporation to oversee the implementation of all components under KSUDP in the Thiruvananthapuram Municipal Corporation area. The Thiruvananthapuram Municipal Corporation will be assisted by a Design and Supervision Consultant. Operation and management of the assets will be vested in the Thiruvananthapuram Municipal Corporation.

An environmental specialist will be appointed to assist in the planning, design, implementation and monitoring of KSUDP city components. During the planning and detailed design stages of the project, the Thiruvananthapuram Municipal Corporation and PIU will be responsible for incorporating the mitigation measures and monitoring plan in the contract document.

During project implementation the environmental specialist will (i) review the lEE documents (ii) inspect and ensure compliance with the mitigation measures proposed in the IEEs and EMPs for all components of KSUDP and (iii) provide necessary training.



During the construction phase, the Project Implementation Unit of the Thiruvananthapuram Municipal Corporation will monitor the performance of the contractor who will be contracted to carry out all construction works in a manner that mitigates adverse environmental impacts during the construction phase. Mitigation measures of a planning, functional, institutional and procedural character will have been included in the tender documents and in the supplementary activity plans. The PIU, with the support of the Project Management Unit (PMU), will be responsible for monitoring and enforcement of the mitigation measures during construction and operation phases. During the operational phase, the Thiruvananthapuram Municipal Corporation will be responsible for monitoring the performance of the infrastructure components. 6.1 Environmental Monitoring Plan

Major environmental issues identified are the air pollution, enhanced noise level, ground water contamination and surface water contamination during the construction and operational phase of the subproject. The ambient air, noise level, ground water and surface water quality monitoring data available are presented in this report as background environmental quality data. An environmental monitoring plan is prepared for the sub-project. The monitoring plan presents the recommended environmental monitoring activities. The plan also identified the agencies / institutions that are responsible for monitoring. table 8 provides a summary of recommended environmental monitoring plan based on responses to potential adverse impacts identified.

Table 8. Environmental Monitoring Plan Project stage

Type of monitoring

Location Parameters to be monitored

Frequency Responsibility Preliminary costing

C

onst

ruct

ion

Ambient air quality

Construction site and the vicinity

Suspended Particulate Matter (SPM) Sulphur dioxide Methane Ammonia and Carbon monoxide

Once in three months

Contractor Rs.5,000 per test

Noise 1m outside the boundary

Sound level Leq., (day time and night time)


Contractor Rs. 1,000 per test

Ground water quality

Project site pH Suspended solids BOD Oil & Grease Nitrates and Coliforms


Contractor Rs.2,000/-per sample



Project stage

Type of monitoring

Location Parameters to be monitored

Frequency Responsibility Preliminary costing

Surface water quality

Storm water drain/ canal where the work is in progress

pH Suspended solids BOD Oil & Grease Nitrates and Coliforms

Once in a six months

Contractor Rs.2,000/-per sample

Aft

er C

ompl

etio

n of

the

proj

ect

Ambient air quality

At the bank of major Storm water drain/canal

Suspended Particulate Matter (SPM), Sulphur dioxide, Methane Ammonia and Carbon monoxide

Once in six months

TMC Rs. 5000 per test per site.

Noise 1 m outside the boundary

Sound level Leq (day time and night time)

Once in six month

TMC Rs.1,000 per test

Ground water quality

At the bank of Storm water drain/canal

pH, Suspended solids BOD Oil & Grease Nitrates and Coliforms

Once in a month

TMC Rs.2,000/-per sample

Surface water quality

Storm water drain/ canal where the work is in progress

pH, Suspended solids BOD Oil & Grease Nitrates and Coliforms

Once in a month

TMC Rs.2,000/-per sample

Con

stru

ctio

n an

d O

pera

tion

Tree plantation and maintenance of greenbelt

On both sides of the Storm water drain/canal and all available vacant areas

Tree plantation starts once the improvement of works are completed and ensure constant surveillance of the trees C

onst

ant s

urve

illan

ce

TMC Part of O& M Cost.

6.2 Period of Implementation

Period of implementation of the sub-project is 40 months from the date of award of contract. The estimate cost for construction of the 107 MLD capacity STP based on extended aerator



technology and its O&M charges for 5 years is Rs. 80 crores.

6.3 Benefits of the Project

The sub-project will improve the environmental quality of the Thiruvananthapuram Municipal Corporation area. When the proposed improvements of the storm water network system is fully completed, the flash flooding of the low lying areas of municipal corporation areas will be fully addressed. The residents of the city suffering from various insanitary environmental conditions due to flooding of low lying areas will be safeguarded. Pollution of water bodies like T.S canal and all the river lets and thodus due to disposal of untreated wastewater will be mitigated to a larger extent on completion of the sub project. Overall cleanliness and sanitary environment of the city will improve which will reflect in the socio-economic growth of the city. 7. Community Consultation and Information Disclosure

During the project scoping exercise considerable dialogue had with the Thiruvananthapuram Municipal Corporation Mayor, councilors and the staff. Focused public consultations were undertaken during the site visits in the sub-project area. The details of the sub-project and the mitigation measures proposed were explained to them. The details of the projects and the environmental mitigation measures proposed were detailed to the councilors and officials of Thiruvananthapuram Municipal Corporation during discussions at various stages of detailed project report preparation. Further public consultations were held with people residing nearby the storm water drains/canals, the project site. Community priorities were examined through a baseline socio-economic survey in the Thiruvananthapuram Municipal Corporation area. The percentage sample house hold survey included matters on municipal service delivery priorities for improvement. The public in general welcomed the sub-project provided that the sub-project will not cause any nuisance to their normal living.

8. Findings and Recommendations

The sub-project as described above was found on the basis of environmental assessment during the project formulation stage to be environmentally acceptable and able to proceed to the implementation phase. Certain environmental issues noticed during the environmental assessment were listed out and an environment management plan to address these issues were also drawn up and presented in table 5. The main environmental issues noticed during the environmental assessment are the impact due to handling of desludge materials. Proper management system will be developed to handle the sludge. In order to meet the statutory requirements, the following measures will be taken.

• The construction materials will be purchased from agencies/ manufacturers having valid clearances from statutory authorities

• Equipments/plants/generators used in the construction activities will comply with the environmental standards prescribed by agencies like KSPCB, CPCB and MoEF



• Consent to establish from KSPCB will be obtained before awarding contract for construction

• Sanction from the State Government will be obtained for cutting trees which are prohibited by the Kerala Preservation of Trees Act, 1986

The mitigation measures proposed in the management plan has been incorporated in project design and most of the mitigation costs are incidental to the construction costs. The environment management plan and environmental monitoring plan will form part of the contractual arrangements with construction contractor, or directly implemented by the PIU as facility operator, as required work practices. 9. Conclusions

Proposed sub-project "Thiruvananthapuram Storm water Drainage” will greatly improve the overall environmental quality of the Thiruvananthapuram Municipal Corporation area. The sub-project is considered not to have significant environmental impacts and classification B is considered appropriate.

The Initial Environment Examination report has thoroughly assessed all potential environmental impacts associated with the sub-project. The environmental impacts identified by the study are manageable, and Thiruvananthapuram Municipal Corporation will implement the mitigation measures stated in the Environment Management Plan and Initial Environment Examination reports. Therefore, no further environmental assessment is needed.

It is concluded that the proposed sub-project should proceed to the implementation phase, subject to the mitigation measures and monitoring programs identified in the Initial Environment Examination and the above recommendations.



Annexure - I Rapid Environmental Assessment (REA) Checklist Instructions: (i) The project team completes this checklist to support the environmental classification of a project. It

is to be attached to the environmental categorization form and submitted to the Environment and Safeguards Division (RSES), for endorsement by Director, RSES and for approval by the Chief Compliance Officer.

(ii) This checklist focuses on environmental issues and concerns. To ensure that social dimensions are

adequately considered, refer also to ADB's (a) checklists on involuntary resettlement and Indigenous Peoples; (b) poverty reduction handbook; (c) staff guide to consultation and participation; and (d) gender checklists.

(iii) Answer the questions assuming the “without mitigation” case. The purpose is to identify potential

impacts. Use the “remarks” section to discuss any anticipated mitigation measures.

Country/Project Title: Sector Division:

Screening Questions Yes No Remarks A. Project Siting Is the Project area adjacent to or within any of the following environmentally sensitive areas?

Cultural heritage site

Yes Worship centres adjacent to the site. Greenbelt development all along the thodus of the site. The project is the upgradation of storm water drainage system of TMC

Legally protected Area (core zone or buffer zone)

No The improvement proposed are for water bodies. However there is no declared protected areas.

Wetland Yes The improvement proposed are for water bodies.

Mangrove

No No mangroves are there in the site. As well as exist in the near vicinity.

Estuarine

Yes The thodus are connected to the T.S. canal. Many of the thodus and T.S. canal are having tidal impact

Special area for protecting biodiversity

No Not applicable.

B. Potential Environmental Impacts Will the Project cause…

Impairment of historical/cultural areas; disfiguration of landscape or potential loss/damage to physical cultural resources?

No The project is for the improvement of storm water drain/thodus and there will not be any impairment of historical/ cultural monuments/ areas. There will not be any loss/ damage to such sites.

Thiruvananthapuram Storm Water Drainage



Screening Questions Yes No Remarks Disturbance to precious ecology (e.g. sensitive or

protected areas)?

No There is no protected area near the project site.

Alteration of surface water hydrology of waterways resulting in increased sediment in streams affected by increased soil erosion at construction site?

No The project is for effecting improvements to the storm water drain in the city area, particularly for avoiding flooding in low lying areas of the city. So the project is propose to desludge some of the storm water drains to increase its cross section.

Deterioration of surface water quality due to silt runoff and sanitary wastes from worker-based camps and chemicals used in construction?

Yes Implement construction site management through provisions in the contract. Minimize clearing and disturbance to adjoining vegetation and natural areas. Protection of unstable soil surfaces from high velocity runoff by proper compaction, interception drains and temporary stabilization is proposed. Siting of construction materials stock piles done ensuring no block to access roads. The slit runoff reaching the storm water rains will curtailed during construction stage.

Increased air pollution due to project construction and operation?

Yes There will not be any air pollution during operation. However during construction there is chance of dust emission from construction materials as well as construction activities. Action proposed is to sprinkle water and thereby to avoid dust generation. In case any equipments such as DG set, mixing equipments etc are used. It is to be ensured that the emissions from these are within limits.

Noise and vibration due to project construction or operation?

Yes Adequate measures to minimize noise from construction activities will be made a contractual condition. Noise generating equipments will be enclosed. Noise and vibration due to civil works may occur. Strict conditions will be included in the contract to make corrective measures to minimize noise and vibration. No blasting operation anticipated at the site. Gravel and stones will be brought from crushes and mines situated away from the site.

Involuntary resettlement of people? (physical displacement and/or economic displacement)

No The site is completely owned by Kerala Irrigation Department/Kerala Water Authority/TMC. As part of the project there is no involuntary settlement of people is proposed.

Disproportionate impacts on the poor, women and children, Indigenous Peoples or other vulnerable groups?

No Being a storm water improvement project it will have positive impact on all groups of the community. Some minor impacts that may occur during the construction phase will be same to all groups of community.



Screening Questions Yes No Remarks Poor sanitation and solid waste disposal in construction

camps and work sites, and possible transmission of communicable diseases (such as STI's and HIV/AIDS) from workers to local populations?

Yes Adequate measures for sanitation to workers at site as well as labour camps will be made a contractual condition and this condion will be implemented strictly. Adequate awareness will be given to workers on possible transmission of communicable diseases

Creation of temporary breeding habitats for diseases such as those transmitted by mosquitoes and rodents?

Yes A Site Management Plan as well as an operation manual will be prepared and implemented so as to avoid influx of insects, rodents, etc.

Social conflicts if workers from other regions or countries are hired?

Yes The contractor will be issued with advice to engage local construction workers as far as possible.

Large population influx during project construction and operation that causes increased burden on social infrastructure and services (such as water supply and sanitation systems)?

No Not anticipating population increase during construction of the subproject and hence there may not be any increased burden on existing social infrastructure and services.

Risks and vulnerabilities related to occupational health and safety due to physical, chemical, biological, and radiological hazards during project construction and operation?

Yes An occupation safety manual will be prepared and implemented. The contractor will be asked to take all safety measures during construction stage.

Risks to community health and safety due to the transport, storage, and use and/or disposal of materials such as explosives, fuel and other chemicals during construction and operation?

Yes The storage of fuel for DG sets will be as per the rules of the land. No explosives or chemicals are proposed to use at site. Stone and aggregates for construction activity will be brought from nearby mines and crushes

Community safety risks due to both accidental and natural causes, especially where the structural elements or components of the project are accessible to members of the affected community or where their failure could result in injury to the community throughout project construction, operation and decommissioning?

Yes All construction materials and components thereon will be stored in a protected manner so as to avoid any injury to the members of the community. Action proposed to avoid accidental risks.

Generation of solid waste and/or hazardous waste?

Yes Solid waste anticipated are the construction debris and construction waste apart from MSW generation at labour camps and by workers. Adequate steps will be taken to dispose this material along with the MSW management system of the TMC. The chances of hazardous waste generation namely waste oil generation at construction camps will be properly handled.

Use of chemicals?

No Not Applicable

Generation of wastewater during construction or operation?

No The waste water generation is anticipated only at labour camps



Climate Change and Disaster Risk QuestionsThe following questions are not for environmental categorization. They are included in this checklist to help identify potential climate and disaster risks.

Yes No Remarks

Is the Project area subject to hazards such as earthquakes, floods, landslides, tropical cyclone winds, storm surges, tsunami or volcanic eruptions and climate changes (see Appendix I)?

No The natural hazard history of the area indicates no possibility of natural hazards and action taken to avoid all accidental risks such as earthquake, floods, landslides, etc.

Could changes in precipitation, temperature, salinity, or extreme events over the Project lifespan affect its sustainability or cost?

No No changes in precipitation, temperature or salinity expected due to implementation of the sub project.

Are there any demographic or socio-economic aspects of the Project area that are already vulnerable (e.g. high incidence of marginalized populations, rural-urban migrants, illegal settlements, ethnic minorities, women or children)?

No The area is a part of urban area where people of all socio-economic groups are living.

Could the Project potentially increase the climate or disaster vulnerability of the surrounding area (e.g., increasing traffic or housing in areas that will be more prone to flooding, by encouraging settlement in earthquake zones)?

No There will not be any considerable change in traffic or housing area due to implementation of the project.



Appendix I: Environments, Hazards and Climate Change

Environment Natural Hazards and Climate Change Arid/Semi-arid and desert environments

Low erratic rainfall of up to 500 mm rainfall per annum with periodic droughts and high rainfall variability. Low vegetative cover. Resilient ecosystems & complex pastoral and systems, but medium certainty that 10–20% of drylands degraded; 10-30% projected decrease in water availability in next 40 years; projected increase in drought duration and severity under climate change. Increased mobilization of sand dunes and other soils as vegetation cover declines; likely overall decrease in agricultural productivity, with rain-fed agriculture yield reduced by 30% or more by 2020. Earthquakes and other geophysical hazards may also occur in these environments.

Humid and sub-humid plains, foothills and hill country

More than 500 mm precipitation/yr. Resilient ecosystems & complex human pastoral and cropping systems. 10-30% projected decrease in water availability in next 40 years; projected increase in droughts, heatwaves and floods; increased erosion of loess-mantled landscapes by wind and water; increased gully erosion; landslides likely on steeper slopes. Likely overall decrease in agricultural productivity & compromised food production from variability, with rain-fed agriculture yield reduced by 30% or more by 2020. Increased incidence of forest and agriculture-based insect infestations. Earthquakes and other geophysical hazards may also occur in these environments.

River valleys/ deltas and estuaries and other low-lying coastal areas

River basins, deltas and estuaries in low-lying areas are vulnerable to riverine floods, storm surges associated with tropical cyclones/typhoons and sea level rise; natural (and human-induced) subsidence resulting from sediment compaction and ground water extraction; liquefaction of soft sediments as result of earthquake ground shaking. Tsunami possible/likely on some coasts. Lowland agri-business and subsistence farming in these regions at significant risk.

Small islands

Small islands generally have land areas of less than 10,000km2 in area, though Papua New Guinea and Timor with much larger land areas are commonly included in lists of small island developing states. Low-lying islands are especially vulnerable to storm surge, tsunami and sea-level rise and, frequently, coastal erosion, with coral reefs threatened by ocean warming in some areas. Sea level rise is likely to threaten the limited ground water resources. High islands often experience high rainfall intensities, frequent landslides and tectonic environments in which landslides and earthquakes are not uncommon with (occasional) volcanic eruptions. Small islands may have low adaptive capacity and high adaptation costs relative to GDP.

Mountain ecosystems

Accelerated glacial melting, rockfalls/landslides and glacial lake outburst floods, leading to increased debris flows, river bank erosion and floods and more extensive outwash plains and, possibly, more frequent wind erosion in intermontane valleys. Enhanced snow melt and fluctuating stream flows may produce seasonal floods and droughts. Melting of permafrost in some environments. Faunal and floral species migration. Earthquakes, landslides and other geophysical hazards may also occur in these environments.

Volcanic environments

Recently active volcanoes (erupted in last 10,000 years – see www.volcano.si.edu). Often fertile soils with intensive agriculture and landslides on steep slopes. Subject to earthquakes and volcanic eruptions including pyroclastic flows and mudflows/lahars and/or gas emissions and occasionally widespread ashfall.

Documents

INITIAL ENVIRONMENT EXAMINATION - Thiruvananthapuram · IEE Report Storm Water Drainage Thiruvananthapuram February 2012 iv LIST OF TABLES Table 1 Environmental Compliance Requirements