1. Metro Colombo Urban Development Project

Public Disclosure Authorized

Environmental Screening Report for Construction of bank protection walls of Beira Lake and Rehabilitation of McCallum lock gates

Final Report

December 2011

Uni‐Consultancy Services University of Moratuwa Public Disclosure Authorized

Table of Contents

1. Project Identification 3

2. Project Location 3

3. Project Justification 5

4. Project Description 7

5. Description of the Existing Environment 11

6. Public Consultation 19

7. Environmental Effects and Mitigation Measures

7a. Screening for Potential Environmental Impacts 21

7b. Environmental Management Plan 29

8. Conclusion and Screening Decision 43

9. Screening Decision Recommendation 52

10. EMP implementation responsibilities and costs 53

11. Details of Persons Responsible for the Environmental Screening 55

Annexes

1. Photographs of some of the important locations along project roads

URBAN UPGRADING WORK

Metro Colombo Urban Development Project

Environmental Screening Report

1. Project Identification

Project title 1. Construction of bank protection walls of the Beira Lake and 2. Rehabilitation of McCallum lock gates

Project Urban Development Authority Proponent

2. Project Location

Location Location of the project is shown in the Figure 1.

Definition of The project area is along some stretches of the Beira Lake banks as shown in Project Area Figure 1 and the McCallum Lock Gates located next to the Convention Centre (DR Wijewardena Mawatha). (The geographical The bank protection wall to be constructed commences from the end of Fire extent of the Department premises of the Air Force and continues up to Hyde Park Corner, the project & areas other portion of the proposed protection wall commences from Northern Bank of affected during the West Lake and continues up to Western Bank of the West Lake. Total length construction) of the proposed walls is 2.5 Km.

Adjacent land See “Other features” in Section 5.2 and features

Fig 1: Location map showing the areas where protections walls will be constructed.

The location of the McCallum Lock Gate is shown in green

3. Project Justification

Need for the project Beira Lake is the only water body located within the city of Colombo with an extent of 65 hectares. It was originally created by the Portuguese as a defensive measure and later used as means of water transport system and recreational purposes during the Dutch (What problem is the and the British periods. With the decline of its importance as a project going to solve) transport route, this Lake was neglected and the surrounding area was converted into many other uses. Considering the importance of rehabilitation of the lake as a public property, a master plan was prepared in 1996 by the UDA with the help of the German Government. The linear park development is also included in the Beira Lake Development Master Plan which will be undertaken subsequently under the MCUDP. .

Being the only water body in the city of Colombo the Lake has much potential but its usage by the public at present is rather limited due mainly to non-availability of access to the lake and poor maintenance. The lake has been used only as a back yard property of the buildings located by the Beira Lake banks. Therefore, the UDA has decided to implement the proposed project to unlock its vast potential for recreation and water front development comprising of two stages. Stage I of the project has been selected considering the following:

1. Protecting the lake banks from collapse and erosion

2. Minimizing lake pollution

3. Increasing cultural/historic attractions of the lake

The proposed project which includes only bank wall protection and rehabilitation of historic McCallum gates will pave the way for the next stage of lake development (that is the linear park and nodal parks) which will (a) increase recreation and thereby improve public health and (b) create a conducive environment to attract future investors and thereby making a positive contribution to the city economy.

Purpose of the project The lake acts as a predominant landmark which relates the historical, social and physical evolution of the city and as such the (what is going to be purpose of the project is to facilitate its preservation, enhancement

5 achieved by carrying out the and public use. As stated before the proposed interventions project) (considered in this report) are a part of a larger Beira Lake Development plan and will facilitate the implementation of Linear parks and Nodal parks in the subsequent stage by strengthening and supporting the lake banks. In addition, the bank protection walls will help minimize incoming pollution by unauthorized sewer and waste water discharges by the communities living near by as well as in upstream areas which has caused considerable pollution in the lake.

Alternatives considered No other alternative is considered as the proposed project is envisaged to be needed and timely. (different ways to meet the project need and achieve the project purpose)

4. Project Description

Proposed start date The tender documents for the project are expected to be ready by15/02/2012. Construction period is estimated to be 30 months for bank protection and 12 months for McCallum gate restoration.

Proposed completion It will take minimum 32 months to finish the project from the date of date opening bid documents.

Estimated total cost See Table 1.

Present land Sri Lanka Ports Authority ownership

Description of the Package I - Construction of Bank Protection Wall project Package II - Rehabilitation of McCallum Lock Gates

(with supporting Package I material such as maps, drawings etc Construction of Bank Protection wall attached as required)

Fig. 2. Cross section of the bank protection wall

The Bank Protection wall (See Fig. 2) commences from the end of the Air Force Fire Department premises and continues up to Hyde Park Corner, the other portion of the protection wall commences from Northern Bank of the West Lake and continues up to Western Bank of the West Lake. Total length is 2.5 km.

Package II

Rehabilitation of McCallum Lock Gate

McCallum Lock Gate which has historical value will be rehabilitated. These gates are located in between Colombo Fort and the East Beira Lake. The area will be landscaped and opened up for public use.

Project Management Agency: The agency responsible for design and supervision is the UDA. Team However the design of wall has been sub contracted to SLLRDC as they are experienced in this type of work while the design and construction of McCallum Gates are to be done by SLPA. With regard to environmental safeguards, day to day compliance will be monitored by the Environmental Officer at the UDA (appointed to MCUDP unit within UDA) while overall supervision support will be provided by the Environmental Specialist at the PMU.

Contact person:

Mrs. Priyani , Development Officer, UDA

Nature of the consultation and input received:

Meeting and consultation at design office and site were done. Design drawings, master plans and other relevant information were too gathered.

Table 1. COST ESTIMATE FOR BEIRA LAKE RESTORATION PROJECT

McCALLUM LOCK GATE AND BANK PROTECTION

Item Description Unit Qty. Rate Amount

(Rs.) (Rs.)

McCallum Lock Gate 1 Preliminaries Item 6,000,000.00

2 Site preparation Item 200,000.00

3 Paving m2 3,800.0 4,000.00 15,200,000.00

4 Landscaping and Greenery m2 1,500.0 1,500.00 2,250,000.00

5 Planting Trees and tree troughs Nos Nos. 18.0 35,000.00 630,000.00

6 New Structures m2 214.0 10,000.00 2,140,000.00

7 Furniture S-6 Nos. 30.0 5,000.00 150,000.00

- S4 Nos. 10.0 15,000.00 150,000.00

8 Illumination - Lamps Nos. 60.0 80,000.00 4,800,000.00

9 Railing m 625.0 6,000.00 3,750,000.00

10 Access to the site - Staircases and ramp Pro. Sum 2,000,000.00

11 Demolition of Buildings Pro. Sum 500,000.00

12 Restoration of Old Buildings Pro. Sum 550,000.00

13 Drainage Pro. Sum 1,000,000.00

14 Sanitary Pro. Sum 6,000,000.00

15 Under Passes m 60.0 40,000.00 2,400,000.00

16 Foot Bridge m 75.0 200,000.00 15,000,000.00 Lock Gate Restoration (Engineering Work 17 Approx) Pro. Sum 10,000,000.00

TOTAL 72,720,000.00

Allow for 10% Contingencies 7,272,000.00

Project Cost 79,992,000.00

Allow for 7% Price Escalation 5,599,440.00

GRAND TOTAL 85,591,440.00

Bank Protection - 2.5 Km Construction of Gabions and Rubble Retaining Wall 400,000,000.00 Drainage and wall illumination (Conduting only) Pro. Sum 89,000,000.00

GRAND TOTAL 489,000,000.00

Note 1. Foot Bridge (15 Rs.Mn.) And Under pass (2.4 Rs.Mn) were taken out from the package of “Foot Bridges” and Nodal Parks” 2. Added amount for price escalations(5.6 Rs.Mn) and contingencies(7.2 Rs.Mn)

5. Description of the existing environment 5.1 Physical features – Ecosystem components

Topography and terrain The topography of Sri Lanka is marked by great diversity caused by long years of faulting and erosion of the landscape. The central mountainous region with the highest elevations covered by virgin forests and grasslands rises up to about 2,500 m above mean sea level. The surrounding plains, which rise to about 50 to 100 m above sea level, are largely used for agriculture and homesteads, but still have virgin scrubland where the population distribution is lower. This general topography of the country can be divided into three distinct geographical areas or well marked peneplains featuring the coastal belt, the plains, and the central highlands.

The Colombo district which incorporates the project area falls into the so called lowest peneplain of Sri Lanka (after P.G. Cooray – Geology of Sri Lanka, 1984). The elevation variation of Colombo district situated in this coastal peneplain ranges to a maximum elevation of 150 m from sea coast. The terrain in Colombo largely consists of gently undulating plains and low-lying flatlands with a high density of drainage paths formulating a geography consisting of a mix of land and water. The city has many canals and the 65-hectare (160-acre) Beira Lake situated in the heart of the city is one of the most distinctive landmarks of Colombo. The project sites for the proposed Beira Lake restoration, embankment protection and Linear Park under Stage I are situated about 0.5 km south to the Colombo commercial hub (Colombo Fort). Rehabilitation of the Beira sea outfall and McCallum Lock Gates of the Colombo city drainage system located at St.Sebastian South Canal and Beira Lake are also considered under Stage I, however, this outfall has no drain function under normal circumstances due to the high crest level of the Beira Lock (i.e.+1.8 m MSL).

The extent of the area covered under the proposed project is located within a mere 1.8 km from the coastal line and the elevation varies from 2.5 m above mean sea level (MSL) up to a maximum of 12 m MSL only. The general topography of the project area largely consists of flat or very mildly sloping (<1.2 %) low-lying terrain with slopes in seaward direction while the contour lines are aligned approximately parallel to the shoreline.

Soil (type The geology of Colombo is representative of the geology of the western coast of Sri Lanka and has existed for much of and quality) the Quaternary era. Bore holes drilled in central Colombo City show that this area once formed an estuary of the Kelani River and the Kalu Ganga River, the two main rivers that drain into the sea on the western coast. A few kilometers upstream in the inland valleys, there is a high-level gravel formation consisting of quartz pebbles embedded in a matrix of laterite separated with pebble-free layers of laterites. The floodplains along the rivers consist mainly of alluvial deposits. The floodplains of Kelani River also provide thick alluvial profiles for unconfined aquifers, in addition to the productive overburden along tributary banks.

Vast area (over 90%) of Sri Lanka is underlain by metamorphic crystalline rocks of Precambrian age, which includes the project area, which cover a variety of Gneisses. The geology of Colombo is representative of the geology of the western coast of Sri Lanka and has existed for much of the Quaternary era. This is shown in the 1:10,000 and 1:50,000 geological maps of Colombo region produced by the Geological Survey and Mines Bureau. The typical rock types of this basement include Biotite gneiss, Hornblende Biotite gneiss, Charnockites, Charnockitic gneisses, Quartzite and undifferentiated Meta sediments. The floodplains along Kelani River and the Kalu Ganga rivers consist mainly of alluvial deposits. The floodplains of Kelani River also provide thick alluvial profiles for unconfined aquifers, in addition to the productive overburden along tributary banks.

According to Survey Department soil maps (Fig. 3) the main soil types in the project area are as follows. • Red Yellow Podzolic soils with soft or hard laterite and undulating terrain • Bog and Half bog soils: flat terrain • Alluvial soils of variable texture and drainage: flat terrain • Regosols on recent beach sands: flat terrain

Field surveys have indicated that the local geology in the proposed project area is characterized by alluvium and organic clays with depth to bedrock > 20 m while the soil types include peat and peaty clay. It is presumed that these site- specific features are the most important ones as the environmental impact is considered.

Fig. 3. Soil Maps of the Study Area (Source: Greentech, 2011)

Surface Sources water (sources, The most prominent source of surface water in the vicinity is the Beira Lake and surface water drainage canal network. distance Distance from the site: Project area is the banks of the Lake. from the

13 site, local Local uses: The lake plays an important role in conveying surface drainage and flood waters. Although the local people uses and do not derive other benefits than diverting their surface drainage into these canals, the intrinsic function is vital and quality) most important in draining the flood waters of the area. There are numerous illegal discharge points of grey water from residences, commercial establishments and warehouses located adjoining the lake, and due to the high level of water pollution, no other local uses can be derived from the water body.

Quality

Water quality of the Beira Lake is given in Table 2.

Table 2. Water quality fluctuations of Beira lake

Parameter Water Quality (during 1997-2009) pH 5.6 – 7.3 Conductivity (dS/m) 0.17-3.3 Turbidity (NTU) 2-7 Ammonia (mg/l) 0.8-4.2 Nitrates (mg/l) 0.3-3.1 Phosphates (mg/l) 0.4-3.4 DO (mg/l) 1.2-4.5 BOD (mg/l) 10-38 COD (mg/l) 23-75 Reference :Greentech.(2011).

COD, BOD, turbidity and total suspended solid content are high in the water. Dissolved oxygen is low which indicates organic pollution. Phosphate concentrations are relatively high which indicate nutrient enrichment due to disposal of domestic and industrial wastewater into the lake over time.

Ground Sources water (sources, According to the Land Use Division of the Irrigation Department, the project area falls within the local or discontinuous distance moderate to low aquifer in fractured rock. Only available source of ground water in the project site is shallow wells. from the However, ground water as a source of water is not been used. site, local Distance from the site uses and quality) The ground water table is very shallow and is about 0.4 - 0.5 m on average close to the Lake, and can be at a level from almost at surface up to 1.5 - 3.0 m.

Local uses

No uses were observed.

Quality

There are no data available for quality of ground water.

Flooding Beira Lake is artificially kept at +1.8 m MSL by means of pumps installed at Beira Lock that are operated by the Sri Lanka Ports Authority mainly to prevent buildings constructed on wooden piles along the lake from collapsing. As a consequence, Beira Lake’s flood discharge function is only operational at water levels exceeding +1.8 m MSL.

However, the road segments and area considered for the development of linear parks and foot walks covered under the proposed Stage I of the project are all supposed to have adequate drainage systems in place at present. The terrain is either flat in most areas or consists of mild slopes, therefore, no historical records of past flooding are available for any of the road segments under consideration and additional measures for flood management are not envisaged.

Air quality The lake is located in the heart of the city and as such many busy urban streets circle the project area. Heavy vehicle (any movements along these nearby roads lead to high levels of air pollutant emissions, such as dust including particulate pollution matter, smoke including CO, CO2, NOx, SOx etc. Such air pollution episodes can aggravate during peak hours when issues) traffic movements are impeded. Fugitive dust particles could escape into the atmosphere during construction activities and during transportation and subsequent storage and handling.

Noise level Existing ambient noise and vibration levels in the area correspond to highly urban and light industrial, businesses, hotel and and restaurants. There is also heavy traffic noise from nearby roads which carries heavy traffic during peak hours as vibration well as during the night time. Intermittent high levels of noise and vibration levels are observed due to train operations (Any in some locations. All these urban activities contribute to high noise levels in the project area. anticipated issues)

5.2 Ecological features – Eco-system components

Vegetation Construction of Bank Protection Wall

(trees, ground cover, At present, most of the lake bank is covered with several uses such as commercial establishments, human aquatic vegetation) settlements, institutions, religious places etc. Therefore, it is hard to see vegetation or ground cover. Only in some part of the lake bank which has been interrupted by human interventions, vegetation and tree cover could be found. However, during the field visit following tree species were observed: Mangifera indica (Amba), Cocos nucifera (Pol), Terminalia catappa (Kottan), Gliricidia sepium (Weta Mara), Leucaena leucocephala (Ipil Ipil), Azadirachta indica (Kohomba), Filicium decipiens (Pehimbiya), Plumeria obtuse (Araliya), Musa x paradisiaca (Kesel), Carica papaya (papol), Ficus religiosa (Bo), Hibiscus rosasinensis (Wada), Delonix regia (Mai mara), Calotropis gigantiea (Wara), Lantana camara (Gandapana)etc. These provide ecological niche to many bird species. However, these are common trees and do not have a special conservation status.

Rehabilitation of McCallum Lock Gates

McCallum Lock Gate and its surrounding consists of common vegetation types such as Terminalia catappa (Kottan), Plumeria obtuse (Araliya), Tabernaemontana divaricata (Watu Sudda), Filicium decipiens (Pehimbiya), Cocos nucifera (Pol), Musa x paradisiaca (Kesel), Spondias dulcis (Amberella), Psidium guajava (Pera), Areca catechu (Puwak) etc. However, there is no ground cover as most of the area built-up and hence no ecological sensitivity was found.

Presence of wetlands The lake itself is a wetland and supports different types of birds and other water loving animals such as Monitor Lizards.

Fish and fish Fish sampling was not carried out due to limited time. However, historical data fish population to be habitats dominated by Tilapia sp.

Birds (waterfowl, Baira lake is an attractive place for birds and other wetland species such as Saxicoloides fulicata (Indian migratory birds, Robin), Copsychus saularis (Oriental Magpie Robin), Acridotheres tristis (Common Mayna), Streptopelia others) chinensis (Spotted Dove), Pelecanus philippensis (Spot Billed Pelicon), Ardeola grayii (Indian Pond Heron), Haliaspur indus (Brahmani kite), Halcyon smyrnnsis (Laya Sudu Pilihuduwa), Bubulcus ibis (Cattle egret), Colubma livia (Domestic pigeon), Hirundo rustica (Common Swallow), Amaurornis thoenicurus (White breasted water hen).

Presence of special The Beira lake itself represents special designations for many birds, animals and aquatic flora and fauna. habitat areas (special However, the lake is considered polluted and it has no conservation status. designations & identified sensitive zones)

Other Features

Residential/Sensitive The project area is surrounded by mixed land uses residential, commercial public and private sector offices. St. Areas Joseph College located on T.B. Jaya Mawatha is one of the leading private schools in Colombo. No hospitals (Eg, Hospitals, or any other similar sensitive land uses are located within or adjacent to the project area. Schools)

Traditional No significant traditional economic or cultural activities are located within the project area. economic and cultural activities

Archeological There are several buildings of Archeological / Historical value (particularly belong to colonial architectural resources heritage) located around the project area. St. Joseph’s College, Several "Stores" and "Office" buildings on T.B. Jayah Mawatha and D.R. Wijewardhane Mawatha are some of them.

The three lock gates (McCallum gates)are of high Archeological value. They were installed during the British colonial era, for navigation of Crafts between the lake and the Colombo port for transportation of goods related to export and import industry. These lock gates are in dilapidated conditions due to lack of maintenance and disuse for a long period. The proposed restoration of the lock gates will need to replace these lock gates and accessories with new items. It is proposed that these lock gates and accessories after proper erosion control treatment be used as artifacts along the linear park.

6. Public Consultation

Public consulted Consultation Date Details/Issues raised method

Mr. M.M. Yusuf Informal 22nd "If a Gabion wall is constructed, there is a need for a linear park similar to the west discussion December lake near Gangaramaya so that the community can spend thier free time. People in Near Hyde park 2011 this community do not have similar open space nearby. Construction activities will corner not have any negative impact as it is something people have been waiting for a long period."

Mr. Informal 22nd "Construction of the Gabion wall has been a long due project. UDA started B.A.Rathnayake Discussion December dredging the lake sometimes back and suddenly stopped. However, they had a 2011 good plan of creating a lake drive along the lake starting from the Hyde Park to A managerial D.R.Wijewardhane Mawatha. If the gabion wall is constructed, this road must be level officer in a created. Then one can get the full value to the community and business people" private company nearby, interviewed opposite the Fire Brigade.

Mr. S. de Silva Informal 22nd "Never knew such interesting lock gates were located here. If they are re-instated it Discussion December would be a big attraction. If Gabion walls are constructed please create a linear A Pedestrian, 2011 park around the lake similar to Gangaramaya lake. It would be a great service for interviewed near people who walk up and down – from the Fort Railway Station to nearby the lock gate offices.(including himself) There will not be any impact to pedestrians during construction"

M. Imitiasz Informal 22nd "If the UDA project is done it will benefit them as they can improve their business (Vendor who sells Discussion December activities. There are many people in this community who sells similar items and "Prawn Wadai" at 2011 food to the visitors at Galle Face Green. If this project is done they can do their Galle Face Green) business around Beria Lake also"

Interviewed near " Project will have no adverse impact on us, hope they will get alternate houses in the Scout Head nearby locations" Quarters behind the Dept. of Inland Revenue.

M. Mustafa "Construction of the Gabion wall is a good project, but what is most wanted is to clean the water as children in the community often fall in sick due to the polluted (A person from Informal 22nd water. This project will bring a lot of benefits to the community. If they are moved the underserved Discussion December out they need to be provided with good alternate housing." settlement) 2011 interviewed near Elephant House.

7. Environmental Effects and Mitigation Measures

7a. Screening for Potential Environmental Impacts

Screening question Yes No Significance of the effect Remarks

(Low, moderate, high)

1 Will construction and operation of the No Project involve actions which will cause physical changes in the locality

2 Will the Project involve use, storage, Yes Low transport, handling or production of substances or materials which could be Transport of material, stock piling, construction harmful to human health or the environment activities, including bank excavation, demolition of or raise concerns about actual or perceived existing structure will emit dust and fugitive risks to human health? particles which may pose a health hazard to vulnerable persons on temporary basis. The winds will be the triggering factor for such impacts though it is sporadic in nature. However in the case of disposal of material excavated from the lake bottom in order to place gabion walls , the project should conduct a sediment quality testing and dispose according to its recommendations.

3 Will the Project produce solid wastes during Yes Moderate construction or operation?

During construction:

There will be general spoilage (construction debris) produced during the wall construction.

In addition, constructing gabions will generate a moderate quantity of excavated material which will need to be disposed. The sediment quality at the site needs to be established prior to canal bank/bottom excavations in order to determine the disposal method.

During operations:

There will be excavated material from the lake bottom along the banks, which need regular collection and disposal appropriately. In addition, debris and sediments, floating matter and other solid waste carried by surface drainage can get collected along the banks that needs proper disposal.

4 Will the Project release pollutants or any No No pollutants are expected from the project. hazardous, toxic or noxious substances to air?

5 Will the Project cause noise and vibration or Yes Low release of light, heat energy or The project activities will cause noise and vibration

electromagnetic radiation? during demolition of structures along the banks, excavation, driving sheet piles, compaction, and during transport of material etc. These impacts are temporary in nature and cause only inconvenience to the neighboring people only.

6 Will the Project lead to risks of Yes Low contamination of land or water from releases of pollutants onto the ground or into The surface soil and the topmost layers of subsoil in the proposed site areas are either peat or peaty clay. surface waters, groundwater or coastal Typically, clayey soils with their smaller grain sizes wasters? are less resistant to erosion and washout. Therefore, once loosened due to excavation and harrowing or heaped and left uncovered, these soil layers will pose threat to the environment by causing washout of fine material degrading surface and groundwater quality in the downstream and coastal waters, silting downstream catch pits and canals, degrading soil stability and risking slope and bank failures.

On the other hand, proper construction practices like soil compaction and stabilization, turfing, maintaining naturally stable slopes, re- vegetation/turfing and proper disposal of excavated material and debris at designated isolated dumps, etc. will improve soil stability, reducing erosion risk, siltation and pollution due to leachate effects thus improving surface lake and groundwater

quality during the construction phase and in the aftermath of project completion.

7 Will the project cause localized flooding Temporarily blockage of existing drainage paths and poor drainage during construction and flow diversions for the rehabilitation of lock gates during construction activities and formation of Is the project area located in a flooding new embankments without proper cross drainage location? facilities will lead to localized flood effects and poor drainage within and around adjacent localities of the project area.

However, the proposed project site is located in an area where adequate drainage systems and other associated facilities are properly in place at present, so the risk of flooding is relatively insignificant.

Moreover, ensuring the adoption of proper design guidelines and construction practices like provision of storm water drainage paths through the gabion walls, provision of alternative drainage network during the construction period, will reduce the flood risk during construction phase and in the aftermath of project completion.

8 Will there be any risks and vulnerabilities to Yes Low public safety due to physical hazards during Most of the shoreline to be protected is not construction or operation of the Project? accessible to the general public at present. However, where public access is possible safety issues in terms of injuries caused by piles of

construction material, machinery etc to public and commuters cannot be ruled out.

9 Are there any transport routes on or around No N/A the location which are susceptible to congestion or which cause environmental problems, which could be affected by the project?

10 Are there any routes or facilities on or No N/A around the location which are used by the public for access to recreation or other facilities, which could be affected by the project?

11 Are there any areas or features of high No N/A landscape or scenic value on or around the location which could be affected by the (The project will be supplementary to enhance the project? scenic value of the lake and the water front areas.

12 Are there any other areas on or around the Yes Low location which are important or sensitive for reasons of their ecology e.g. wetlands, The lake which is a wetland has been subjected high watercourses or other water bodies, the human interference over the years and as a result is coastal zone, mountains, forests which could polluted. The areas around the lake too are highly be affected by the project? modified as an urban environment and supports limited floral and faunal species.

Construction of Bank Protection Wall will be

carried out using manpower. No heavy machinery will be used. Therefore, the impact on existing lake ecology will be minimal.

13 Are there any areas on or around the No No such areas are found. location which are used by protected, important or sensitive species of fauna or Since the area has already been interfered by human flora e.g. for breeding, nesting, foraging, activities, neither important nor sensitive species of resting, migration, which could be affected fauna or flora were found. by the project? Construction of Bank Protection Wall will be carried out by using manpower. No heavy machinery will be used. Therefore, there will not be any major environmental impact by the construction on the lake ecology.

14 Is the project located in a previously No N/A undeveloped area where there will be loss of green-field land There was no such a green field encountered during the field visit.

15 Will the project cause the removal of trees No N/A in the locality? The project will do landscaping only and some additional trees will be introduced.

16 Are there any areas or features of historic or No McCallum lock gates have historical value and the cultural importance on or around the project will restore the gates which at present are in location which could be affected by the a very dilapidated state. In addition, there are project? several historic and culturally important areas

located around the lake but they will not be affected by the project.

17 Are there existing land uses on or around No The land use around the project area is mixed – the location e.g. homes, gardens, other residential, commercial, institutional etc. however private property, industry, commerce, they will not be affected by the project. The project recreation, public open space, community would be supplementary. facilities, agriculture, forestry, tourism, mining or quarrying which could be affected by the project?

18 Are there any areas on or around the No The area around the project is densely populated location which are densely populated or with (i) the working population who occupy built-up, which could be affected by the public/private office buildings during the day time project? and (ii) underserved settlements located in four places along the lake shoreline. However the project will not have an adverse impact on them as it is limited to construction of bank protection wall.

19 Are there any areas on or around the No St. Josephs school (A leading private school in location which are occupied by sensitive Colombo) is located adjacent to the lake. However land uses e.g. hospitals, schools, places of the project will have no negative impact on it. It worship, community facilities, which could gets access from the main road and all the school be affected by the project activities are limited to the school premises.

20 Are there any areas on or around the No N/A location which contain important, high quality or scarce resources e.g. groundwater, surface waters, forestry, agriculture,

fisheries, tourism, minerals, which could be affected by the project?

21 Are there any areas on or around the No The most polluted site in the project area is the location which are already subject to Beira Lake itself. According to the UDA plan, the pollution or environmental damage e.g. lake would be conserved and that this project will where existing legal environmental create positive benefits. standards are exceeded, which could be affected by the project?

7b. Environmental Management Plan

Key project Potential Environmental Effects Mitigation Measures activities

Rehabilitation of McCallum Lock Gates

Site preparation Physical: Physical: including provision of access roads, No significant impact N/A material storage yards Social: Social:

No Impact N/A

Ecological: Ecological:

N/A N/A

Removal of parts of Physical: Physical: the McCallum lock gates Beira Lake is artificially kept at +1.8 m Temporary structures are needed on either side of the MSL by means of pumps installed at lock gates under repair work to maintain adequate

Beira Lock to prevent buildings water surface elevation in the Lake while providing dry Removal of constructed on wooden piles along the working condition for the intended canal rehabilitation demolition waste lake from collapsing. Therefore, any

and other debris at changes to the water level of the Beira and lock gate repair works. the McCallum Lock lake can have an adverse effect on the Gate Premises stability of foundations.

Site littering and eventually washout to The demolition waste and other solid wastes should be the lake waters recycled or reused if possible. Otherwise waste should be collected on site in a designated area within the premises and disposed to a CMC solid waste collecting point for final disposal.

Social: Social:

No Impact N/A

Ecological: Ecological:

No impact N/A

Fixing of the gates No impact N/A and other peripheral components

Refurbishment of No impact N/A old buildings

Creating accesses to No impact N/A the site (Staircases and ramp)

Under pass and foot bridge

New structures for Physical: Physical: sanitary facilities and surface drainage Existing drainage paths may be blocked Adequate temporary drainage facilities should be during construction of new or provided during construction period not to hinder replacement of structures, causing existing surface and drainage water flows, and localized flooding effects. alternative pathways should be arranged where necessary. Existing drainage paths may be blocked after resurfacing and new formations Additional drains, gullies should be provided when with elevated finishing levels. necessary to address drainage issues arising due to altered flow paths. Existing drainage facilities should Increased flows due to altered land use be checked against altered micro-land use within the types with less permeable paving site and subsequent changed flow regimes. surfaces Use of high permeable paving materials, vegetative cover and turfing to increase surface infiltration is highly recommended to reduce induced high surface runoff flows. Social: Social: N/A No Impact

Ecological: Ecological:

No Impact N/A

Paving and Fixing of No adverse impact N/A railings

Providing street furniture

Illumination

Landscaping and Positive impact N/A Greenery

Planting Trees

Bank Protection Walls along Beira Lake

Site preparation Physical: Physical: including provision of access roads, Site preparation and work at material N/A material storage storage yards will be carried out mainly yards by using manpower. No heavy machinery will be used. Therefore, there

will be no significant environmental impact by site preparation activities

Social: Social:

Inconvenience to the community in the Make provisions for not to disturb their pathways and underserved settlement area children play areas. Keep the community adequately informed by way of fixing sign boards at appropriate locations and by announcing/communicating the construction program. Ecological: Ecological: No impact N/A

Excavation of canal Physical: Physical: banks and bottom where the gabions Excavation for embankment construction Sediment quality in identified locations of the lake will be constructed, and attaining required design depths in periphery should be established to understand the risk dewatering and the Lake before placing the gabions may of contamination involved and to determine the disposal of generate debris, soil and bottom suitable disposal method for the excavated sediments excavated sediments which may pose a risk of (i) and waste. If contamination is established according to spoil/sediments fine material washout, causing accepted reference criteria, the following mitigation obstruction to existing drainage paths measures are proposed to be implemented.

,(ii) hinder site mobility when not stored properly and also (iii) pose environmental and health risks if lake ( (a) explore the possibility of using the two existing bottom sediments are contaminated and (and only) small semi engineered landfills in Sri Lanka is not disposed of in a planned manner. at Mawanella and Nuwara Eliya. Since the anticipated volume of excavated bottom sediments in this case would be small, the project would be able to negotiate with the Central Environmental Authority and the

relevant Pradheshiya Sabhas for using their facility or (c) dispose to Holcim industrial incinerator as alternative fuel.

As the bottom sediment is watery drying will be necessary prior to transport to the disposal site, which will prevent leachate from leaking out during material handling and transportation. Drying can be done at the banks of the canal where the leachate will flow back to the canal.

Social:

Take extra precautions in such area and make provisions to construct the embankment without causing damage to houses Keep the community adequately informed of the construction program by way of fixing sign boards at appropriate locations and through direct communication.

Ecological:

Since this is temporary in nature no special mitigation Social: is necessary

During lake bank/bottom excavations it is possible that some houses in the

nearby underserved settlements will get affected if they are located on delicate soils.

Ecological:

Smothering of benthic fauna

Removal of Physical: Physical: demolition waste and other Construction debris collected along the Construction debris should be collected at designated construction debris shoreline can lead to site littering and points along the lake shoreline (where there is space), along the banks of eventually get washed into the lake collected on a regular basis and disposed to a CMC the lake solid waste collection point for final disposal.

Social: Social:

No Impact N/A

Ecological: Ecological:

No impact N/A

Material transport Physical: Physical: and storage Emission of dust and noise due to All construction materials (sand, gravel, aggregates,

stockpiling and transport cement, soil,) should be stored with proper cover; frequent watering of the site and stock piles susceptible

to releasing dust and fine particles

Stock piling of soil, debris and other Material storage sites should be identified for each material may block surface drainage working section of the lake and erosion control paths causing localized water stagnation practices should be implemented, as necessary, during and potentially contaminate surface construction to limit turbidity and silt transport off site. runoff and increase turbidity in the lake during construction. Rainy season should be avoided as practical as possible. If any case rainy period is unavoidable, it is necessary to make sure to have temporary drainage so as to drain off the rain water.

Proper storage of material and handling of construction material is essential. Material recycling and proper scheduling of ordering and disposal should be promoted to avoid unnecessarily maintaining material/debris stockpiles for extended periods. Social: Social: Material carrying vehicles could create a danger particularly to children of the Work along the underserved settlements should be underserved settlements who play on the carefully planned out with the community and the pathways. drivers of vehicles bringing material made duly aware of the risks and the need to exercise extra precaution.

The community should be kept adequately informed by way of fixing sign boards at appropriate locations and through direct communication.

Ecological: Ecological:

No impact N/A

Excavation for the Physical: Physical: gabion wall, and coffer damming The construction of gabion walls along Vertical and near vertical soil embankments and the canal embankment for bank excavation faces in saturated, sandy/peaty soils in the

strengthening and stabilization would area should always be protected by shoring or require substantial excavation close to installation of sheet piles/coffer damming. Dewatering the existing earth embankments. Such should be provided where necessary to lower water deep excavations in saturated week soil table and pore pressure development within subsurface would result in collapsible vertical soil soil structure. faces and increased susceptibility to erosion and liquefaction leading to bank Minimum driving power should be used where the failures. installations are located close to sensitive/load bearing structures to avoid differential settlements, cracks and Coffer damming is required to contain other undesirable deformations in soil subsurface and divert movement of lake water, to structure. prevent slope failures at soil embankments/ near vertical excavation Deploying of material supply barges/trailers of faces and to provide a reasonably dry adequate capacity, barge mounted unloading cranes, construction area for the laying of screed barge-mounted excavators, etc. is recommended to concrete base (if required by design) and provide accessibility to those restricted areas and to interlocking rubble work arrangement maintain speedy construction. during gabion wall construction.

Excessive vibration during hydraulic driving of sheet piles for coffer damming may weaken adjacent soil layers while it may also affect nearby foundations and other load bearing structures.

Limited accessibility from landside due to strategic installations, high security zones, etc.

Social: Social:

During excavations near underserved Take extra precautions in such area and make settlements it is likely that some houses provisions to construct the embankment without will be affected if they are located on causing damage to houses Keep the community delicate soils. adequately informed of the construction program by way of fixing sign boards at appropriate locations and Ecological: through direct communication. No impact Ecological:

N/A

Construction of Physical: Physical: rubble walls and gabions along the Due to existence of high percent of silt Dry condition construction using coffer damming, banks and peat in bottom layers and saturated suitably designed base/foundation, compacted granular

soil structure, load carrying capacity of bed or screed concrete with adequate shear resistant the bed soil may be relatively weak. angle is recommended for all rubble walls and gabions to avoid differential settlements and weakening of interlocking feature.

Limited accessibility from landside due Deploying of material supply barges/trailers of to strategic installations, high security adequate capacity, barge mounted unloading cranes, zones, etc. barge-mounted excavators, etc. is recommended to provide accessibility to those restricted areas and to maintain speedy construction.

Social: Social:

Disturbance to the community living in Section by section construction will be encouraged. underserved settlements. Ecological: Ecological: N/A No impact

Reinstatement of Physical: Physical: storm water drainage connections (hume Erosion of soil adjacent to structure Strom water connections across the gabion walls pipes) to Beira Lake leading to loosening of bank support will should be provided using hume pipes or box culverts of through gabion walls lead to weakening of the interlocking of adequate size according to pre-determined design rubble used causing immature failure of storm events and return periods.

gabion structure before its intended design life. Blockage due to Catch pits should be provided at suitable spacing to accumulation of fines due to cross remove excessive fines through settlement. Catch pits

drainage flows will lead to pore pressure should be regularly cleaned and maintained in proper build-up behind the gabion structure, order. Fines removed should be properly disposed to leading to unbalanced pressure forces, avoid them joining flow paths again. making the structure susceptible to failure by toppling.

Social: Social:

No impact N/A

Ecological: Ecological:

No impact N/A

Backfilling of banks Physical: Physical: behind the gabions, turfing and Selection of below-grade fill materials Proper backfill materials should be selected after replanting of trees would not attain required soil strengths carrying our required field/laboratory tests and after compaction and will lead to optimum compaction conditions should be maintained

differential settlements in banks causing and compaction should be carried out in payers with the pavement layers to develop minimum thickness to attain maximum possible soil differential settlements and fail. strengths after compaction of bank back fill layers.

Social: Social:

No impact N/A

Ecological: No impact Ecological: N/A

Fixing of railing No impact N/A along the wall and Illumination

Landscaping and No impact N/A Greenery

Planting Trees

8. Conclusion and Screening Decision

Summary of environmental effects: Assuming that all mitigation measures are implemented as proposed, the following effects can be predicted

Key project activities Potential Environmental Effects Significance of the environmental effect with mitigation in place

NS- Effect not significant, or can be rendered insignificant with mitigation SP - Significant positive effect SN - Significant negative effect U - Outcome unknown or cannot be predicted, even with mitigation NA – Not applicable

Rehabilitation of McCallum Lock Gates

Site preparation including Physical: provision of access roads, material storage yards No significant impact NS

Social:

No Impact NA

Ecological:

N/A NA

Removal of parts of the Physical: McCallum Lock Gate Beira Lake is artificially kept at +1.8 m MSL NS

by means of pumps installed at Beira Lock to Removal of demolition waste prevent buildings constructed on wooden piles and other debris at the along the lake from collapsing. McCallum Lock Gate premises Therefore, any changes to the water level of the Beira lake can have a adverse effect on the NS stability of foundations.

Site littering and eventually washout to the lake waters NA

Social: NA

No Impact

Ecological:

No impact

Fixing of the gates and other No impact NA peripheral components

Refurbishment of old buildings No impact NA

Creating accesses to the site No impact NA (Staircases and ramp)

Under pass and foot bridge

New structures for sanitary Physical: facilities and surface drainage Existing drainage paths may be blocked during NS construction new or replacement structures, causing localized flooding effects.

Existing drainage paths may be blocked after NS resurfacing and new formations with elevated finishing levels.

Increased flows due to altered land use types NS with less permeable paving surfaces

Social: NA No Impact

Ecological: NA No Impact

Paving and Fixing of railings No adverse impacts NA

Providing street furniture

Illumination

Landscaping and Greenery Positive Impact SP

Planting Trees

Bank Protection Walls along Beira Lake

Site preparation including Physical: provision of access roads, material storage yards Site preparation and work at material storage NS yards will be carried out mainly by using

manpower. No heavy machinery will be used. Therefore, there will be no significant environmental impact by site preparation activities

Social:

Inconvenience to the community in the underserved settlement area NS

Ecological:

No impact NA

Excavation of canal banks and Physical: bottom where the gabions will be constructed, dewatering and Excavation for embankment construction and SN disposal of excavated attaining required design depths in the Lake spoil/sediments may generate debris, soil and bottom sediments which may pose a risk of (i) fine material

washout, causing obstruction to existing drainage paths ,(ii) hinder site mobility when not stored properly and also (iii) pose environmental and health risks if lake bottom

sediments are contaminated and is not disposed of in a planned manner.

Social: NS During lake bank/bottom excavations it is

possible that some houses in the nearby underserved settlements will get affected if they are located on delicate soils.

Ecological: NS Smothering of benthic fauna

Removal of demolition waste Physical: and other construction debris NS along the banks of the lake Construction debris collected along the shoreline can lead to site littering and

eventually get washed into the lake

Social: NA No Impact

Ecological: NA No impact

Material transport and storage Physical:

Emission of dust and noise due to stockpiling NS and transport

Stock piling of soil, debris and other material may block surface drainage paths causing NS localized water stagnation and potentially contaminate surface runoff and increase turbidity in the lake during construction.

Social:

Material carrying vehicles could create a danger particularly to children of the underserved NS settlements who play on the pathways.

Ecological: NA No impact

Excavation for the gabion wall, Physical: and coffer damming The construction of gabion walls along the NS

canal embankment for bank strengthening and stabilization would require substantial excavation close to the existing earth embankments. Such deep excavations in saturated week soil would result in collapsible vertical soil faces and increased susceptibility to erosion and liquefaction leading to bank

failures.

Coffer damming is required to contain and divert movement of canal water, to prevent NS slope failures at soil embankments/ near vertical excavation faces and to provide a reasonably dry construction area for the laying of screed concrete base (if required by design) and interlocking rubble work arrangement during gabion wall construction.

Excessive vibration during hydraulic driving of sheet piles for coffer damming may weaken adjacent soil layers while it may also affect nearby foundations and other load bearing structures. NS

Limited accessibility from landside due to NS strategic installations, high security zones, etc.

Social:

During excavations near underserved settlements it is likely that some houses be NS affected if they are located on delicate soils.

Ecological: No impact NA

Construction of rubble walls and Physical: gabions along the banks Due to existence of high percent of silt and peat NS

in bottom layers and saturated soil structure, load carrying capacity of the bed soil may be relatively weak. NS Limited accessibility from landside due to strategic installations, high security zones, etc.

Social:

Disturbance to the community living in NS underserved settlements.

Ecological: NA

No impact

Reinstatement of storm water Physical: drainage connections (hume pipes) to Beira Lake through Erosion of soil adjacent structure leading to NS gabion walls loosening of bank support will lead to weakening of the interlocking of rubble used

causing immature failure of gabion structure before its intended design life. Blockage due to accumulation of fines due to cross drainage flows will lead to pore pressure build-up behind the gabion structure, leading to unbalanced

pressure forces, making the structure susceptible to failure by toppling.

Social:

No impact NA Ecological:

No impact NA

Backfilling of banks behind the Physical: gabions, turfing and replanting of trees Selection of below-grade fill materials would NS not attain required soil strengths after

compaction and will lead to differential settlements in banks causing the pavement layers to develop differential settlements and fail.

Social: NA No impact

Ecological:

No impact NA

Fixing of railing along the wall No impact NA and Illumination

Landscaping and Greenery No impact NA

Planting Trees

9. Screening Decision Recommendation:

Final Majority of the potentially adverse effects can be classified as general recommendation construction related impacts and are mitigatable with good construction planning and management. The public is very supportive of the project and hence does not warrant further environmental assessment. Therefore, a stand- alone Environmental Assessment is not required and, the Environmental Management Plan provided with this report would be sufficient to mitigate the identified impact.

The following specific recommendations given in the EMP are of utmost importance to be implemented.

A sediment quality testing and the quantification of lake bottom sediments thatwill need to be removed along the banks before placing the gabions must be undertaken by the UDA prior to commencement of construction. Depending on the results of the sediment quality testing a proper disposal plan for the volume of sediments excavated must be worked out.

Disposal in the form of thermal destruction or transportation to the semi-engineered landfills in Mawanella or Nuwera Eliya (as the quantity is not expected to be huge) will be encouraged if the excavated sediment material is found to be contaminated. If not the material can be stored in a suitable site and subsequently used for refilling once the construction of gabion wall is done or even disposed to a municipal waste dump to be used as a daily soil cover.

Safe handling of excavated sediments including transport must be impelemnted.

Construction debris management plan must be worked out and implemented.

Heavy vehicles i.e., large trucks, should not be allowed for material transport. Only small vehicles such as tractors, carts will be promoted particularly in the areas of restricted space. In such areas, head transport must be allowed with slightly higher rate.

More roosting trees for birds would be planted in areas where appropriate by the side of the Beira Lake for the attraction of birds. However such trees are discouraged in the walk ways as the birds

dropping becomes an issue for uses of the walk way. In the walk way trees that are not possible to be used for roosting will be recommended.

10. EMP implementation responsibilities and costs

The overall responsibility of ensuring compliance with safeguard requirements for the sub- project lie with the UDA. Specifically, it will be responsible for undertaking sediment quality testing in the proposed section of the lake, estimation of sediment material quantities generated and guiding the contractor on suitable disposal methods. The contractor will be responsible for implementing all other provisions in the EMP that relate mostly to good construction planning, site management and public safety practices.

The additional cost involved in implementing the EMP relate to (a) undertaking sediment quality tests and (2) disposal of excavated material if contamination is established. Environmental monitoring will be carried out largely through compliance monitoring using the checklist provided in the EMF by the Environmental Officer of the UDA and the contractor jointly.

As such, the only additional costs envisaged are explained below:

Item Cost (Rs) Implementation Responsibility

Sediment quality testing – 3 180,000 UDA samples

For following physical and chemical parameters

Particle size distribution, pH, Sulphate, Chloride, Total Organic Carbon, Fe, Cd, Ni, Zn, Cu, Cr, Al, Pb, Mn, Ca, Mg, Hg, As and leachability test for heavy metals

The testing will be done in early January 2012

Disposal of excavated sediments The cost of mitigation is hard to estimate at Contractor from the lake bottom this stage as the quantities of material, quality of pollutants/substances, detailed methodologies, and sites for disposal etc. are undecided. The consultant will work with the UDA for estimating the mitigation cost once results of the sediment quality test is available.

Screening report completed by Date

Dr. Mahesh Jayaweera, Team Leader

University of Moratuwa

Tel: 0777320590 email: [email protected] Signature

Name/Designation/Contact information

Screening report reviewed by Date

Name/Designation/Contact information Signature Approved by Date

Name/Designation/Contact information Signature

11. Details of Persons Responsible for the Environmental Screening

(1) Dr. Mahesh Jayaweera, PhD, BSc in Civil Eng (Hons.), MIE (SL), CEng. – Team Leader (Overall coordination and planning) Experience: Team Leader/Consultant/Expert for more than 60 EIA and IEE studies during the past 15 years

(2) Professor Mrs. Niranjanie Ratnayake, BSc in Civil Eng (Hons.), MSc, FIE (SL), CEng. – Environmental assessment specialist Experience: Team Leader/Consultant/Expert for more than 40 EIA and IEE studies during the past 20 years

(3) Dr. Jagath Manatunge, PhD, MSc, DIC, BSc in Civil Eng (Hons.), MIE (SL), CEng. – Environmental Engineer (Noise, Water, Wastewater, Vibration, Air) Experience: Team Leader/Consultant/Expert for more than 40 EIA and IEE studies during the past 12 years

(4) Dr. Lalith Rajapakse, PhD, MEng, BSc in Civil Eng (Hons.), MIE (SL), CEng. – Civil Engineer (Hydrology, Geology, other civil engineering aspects) Experience: Consultant/Expert for more than 20 EIA and IEE studies and assignments mainly related to hydrological during the past 6 years

(5) Mr. Hemantha Jayasundara, BA (Hons.), MSc (Town and Country Planning), PG Dip in Urban Development, PD Dip in Environmental Sci. –Urban Planner Experience: More than 20 years as a Consultant/Expert on Urban and Regional Planning, Urban Design, Disaster Management, Environmental Management, Projects Management etc.

(6) Dr. Anusha Kasige, PhD, MSc, BSc in Zoology – Ecologist (Flora, Fauna, Ecosystems) Experience: more than 15 EIA and IEE studies and ecological studies during the past 5 years

References

Cooray, P.G.(1984). An introduction to the geology of Sri Lanka (Ceylon), with a foreword by John Sutton, National Museums of Sri Lanka Publication, Colombo, Sri Lanka.

Greentech (2011). Environmental Assessment Final Report for Metro Colombo Urban Development Project, Vol. 1, Greentech Consultants (Pvt) Ltd., Colombo 5, Sri Lanka.

Annex 1:

Photographs of some of the important locations along project roads

McCallum Lock Gates

0 Fig.A‐ 1 Main canal Lat‐6.93211 Fig.A‐ 2 Near Lake House side Lat‐6.932130 Lon‐79.848400 Lon‐79.848490

0 0 Fig.A‐3 Beira end Lat‐6.93217 Fig.A‐ 4 Main canal Lat‐6.93211 Lon‐79.848480 Lon‐79.848400

Fig.A‐ 5 Second canal Lat‐6.932110 Fig.A‐ 6 Gate operation Lat‐6.932130 Lon‐79.848270 Lon‐79.848180

0 Fig.A‐7 Beira side Lat‐6.932110 Fig.A‐8 Third canal Lat‐6.93221 Lon‐79.848260 Lon‐79.848100

Fig.A‐9 Boat deck Lat‐6.932130 Fig.A‐10 Lat‐6.931860 Lon‐79.848630 Lon ‐79.848400

BEIRA LAKE

0 0 Fig.A‐11 Lat‐6.93180 Lon‐79.84932 Fig.A‐ 12 Lat‐6.931350 Lon‐79.85201 0

0 0 Fig.A‐ 13 Lat‐6.930870 Lon‐79.853280 Fig.A‐14 Lat‐6.92920 Lon‐79.85506

Fig.A‐ 15 Lat‐6.926480 Lon‐79.856400 Fig.A‐16 Johnson Estate Lat‐6.926130 Lon‐79.856670

Fig.A‐17 Norris canal Lat‐6.925540 Fig.A‐18 Sand Island Lat‐6.925010 Lon‐79.857030 Lon‐79.857770

Fig.A‐ 19 Lat‐6.924590 Lon‐79.858380 Fig.A‐20 Lat‐6.923770 Lon‐79.859080

0 Fig.A‐ 21 Phase II Lat‐6.92356 Fig.A‐22 Lat‐6.922760 Lon‐79.859550 0 Lon‐79.85921

0 Fig.A‐23 End point Lat‐6.92256 0 0 0 Fig.A‐24 Lat‐6.92262 Lon‐79.85952 Lon‐79.85966

Fig.A‐25 Entrance to the west Lake Fig.A‐26 Canal to west lake Lat‐6.931230 0 0 0 Lat‐6.93133 Lon‐79.84846 Lon‐79.84738

0 Fig.A‐27 Discharge to canal Lat‐6.93083 Fig.A‐28 IMP work Lat‐6.930670 Lon‐79.846830 Lon‐79.846000

0 0 Fig.A‐ 29 Lat‐6.927040 Lon‐79.847370 Fig.A‐30 Lat‐6.9303 Lon‐79.84577

Fig.A‐31 Lat‐6.926550 Lon‐79.847430 Fig.A‐ 32 walls to be fell down Lat‐6.926240 Lon‐79.847320

0 0 0 Fig.A‐ 33 Lat‐6.92572 Lon‐79.84674 Fig.A‐34 Ending edge Lat‐6.92552 Lon‐79.846650

Fig.A‐ 35 Ending edge Lat‐6.924540 Fig.A‐36 Lat‐6.924830 Lon‐79.846730 Lon‐79.846920

0 0 Fig.A‐ 37 Lat‐6.926740 Lon‐79.847320 Fig.A‐38 Lat‐6.92822 Lon‐79.84684

Fig.A‐ 39 Lat‐6.932070 Lon‐79.848430