E4353 V5 Strategic Cities Development Project (SCDP) Environmental Screening Report for Drainage Improvement in Galle City PHASE 01: Rehabilitation Works of Moragoda Canal Draft Final Report January 2014 Uni-Consultancy Services University of Moratuwa 1 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 10 6. Public Consultation 21 7. Environmental Effects and Mitigation Measures 7a. Screening for Potential Environmental Impacts 22 7b. Environmental Management Plan 31 8. Conclusion and Screening Decision 42 9. Details of Persons Responsible for the Environmental Screening 49 Annexes 1. Location maps 2. Terrain and Drainage map 3. Soil map and geological map 4. LS and Photos 2 Strategic Cities Development Project (SCDP) Environmental Screening Report 1. Project Identification Project title Strategic Cities Development Project (SCDP) Drainage Improvement in Galle City : Rehabilitation Works of MoragodaEla Project Sri Lanka Land Reclamation and Development Corporation (SLLRDC) Proponent 2. Project Location Location Galle, Southern Province. Location of the project is depicted in Appendix 1(a & b). Definition of The project area is along the Moragoda Ela from the Kanaduwatta Bridge (0+000 Project Area km) to the sea outfall (4+259 km). (The The objective drainage basin of MoragodaEla is one of the main storm water geographical drainage canals discharging storm water directly into the sea from the Galle extent of the Basin. project & areas affected during Under the proposed project, the interventions in Moragoda Ela starts from construction) Kahaduwatta Junction where Kitulampitiya road and the G.K. Sam AppuhamyMawatha crosses. Total canal length is 4.259 km. Width of the canal varies from 11.0 m to 25.0 m. The project area is illustrated in Annexure 1 (a, b, &c). Adjacent land See “Other features� in Section 5.2 and features 3 3. Project Justification Need for the project The Galle Municipal Area Drainage System comprises of a network of large open canals, smaller tributary canals and a few low-lying marshes functioning as natural retention basins. The system functions to serve the drainage needs of the Galle area and reduces (What problem is the incidence of flooding and thereby improves the health and sanitation project going to solve) conditions of the urban community, particularly of the urban poor who inhabit low-lying regions. The drainage system could be broadly divided into three major canals with three outfalls directly discharging in to the sea. The location of the main canals and the details of the sub canals are provided in Annexure 2 (a & b). 1. MoragodaEla (Length – 4.259 km) 2. KepuEla ( Length – 3.230 km) 3. ModaEla (Length – 3.321 km) The drainage area is relatively a flat area and drainage flows are reduced due to tidal effect of sea outlets. Further the drainage flows are obstructed at structure locations (mainly bridges) constructed across the drainage flow paths and inadequate width of canals and vegetation growth at canal banks. In consideration of the frequent flooding in the Galle Municipal area covered under the 3 main canals, it is proposed to implement a drainage improvement plan in two phases. Phase I: Drainage improvement of MoragodaEla including bank protection and reconstruction of crossing structures Phase II: Drainage Improvements of KepuEla, ModaEla and all the other smaller tributary canals with cross drains. The present major flood damages within the Galle Municipal Council limits (other than localized flood damages in few other isolated areas) are observed in the following areas. (Refer Inundation Areas within Galle MC Limits in Annexure 2a). i. Milladuwa Area ii. Near Alapalawa Area iii. Osanagoda Area iv. Near China Garden v. Kahaduwatta Junction 4 vi. Beligaha Junction vii. Julgaha Junction From above areas, Milladuwa Area located in the MoragodaEla is frequently inundated and the causes of flooding are due to insufficient capacities of drainage canals, insufficient opening of channel crossing structures and water level rise of the MoragodaEla. The development of drainage improvements in the MoragodaEla basin will progress not only in the lowlands but also in the entire basin. The urbanization of the basin will cause increase of flood runoff and the flood runoff increase will result in increase of the flood damage in the lower areas. The proposed Moragoda Ela basin storm water drainage improvement plan will be formulated taking into account the conditions of the entire basin including future development scenario of the basin. It is essential that the storm water drainage project should precede the basin development so as to minimize serious storm water drainage problems. Hence, the implementation of the proposed storm water drainage project will assure the sustainable development of the basin leading to increase the living standard of mainly low income community living in the frequent inundation areas. The proposed Project will bring positive impacts to the environment and will contribute to poverty reduction through improvement of the living conditions of the people affected and benefited by the Project as they are mostly classified into the low-income group. The needs of the proposed Project could be justified based on the above consideration. Purpose of the project The purpose of the project is to derive the following benefits and the beneficiaries are listed below: (what is going to be Benefits achieved by carrying out the project)  Enhancement of flood control.  Increased land values in adjacent areas.  Improved health conditions and reduction in health expenditure.  Reduction in annual and recurrent operation and maintenance 5 cost to the central government for canal clean-up  Increased use of the canal system for recreational purposes and waterfront development. Beneficiaries  People residing close to the canal and with the combined effect, the entire Galle Metropolitan area.  The Government and the agencies managing the storm water drainage. Alternatives considered No any other alternative is considered for the project as it is envisaged that there are no any other technically feasible and (different ways to meet the economically viable engineering interventions that could be project need and achieve accommodated in place of the proposed option. the project purpose) 6 4. Project Description Proposed start date The tender documents are expected to be ready by the end of 2014. Awarding of the tender will take place Before the end of this year. Proposed completion It will take minimum 12 – 15 months to finish the project from the date date of opening bid documents. Estimated total cost Estimate: Present land The canal is managed by the Provincial Irrigation Department (PID), ownership therefore the canal reservations and canal access roads, once restored/implemented, will be owned by the PID. Land on either side of the canal bank is mostly privately owned. Description of the The main objective of the proposed project is to rehabilitate the existing project MoragodaEla/Canal with required canal cross sections or dimensions to minimize storm water flood damage for a 10 year design return period of (with supporting floods with a 2 year return period tidal conditions at the sea outfall. material such as The proposed interventions under the drainage improvement project are; maps, drawings etc attached as 1. MoragodaEla bank protection from Kahaduwatta Junction (Ch. required) 0+000 km) to the outfall (4+259 km) using gabion walls (hard) and earthen vegetated embankments (soft) at selected locations. 2. Canal widening and realignment of bridges identified to constrain the canal flow, causing flow heading up and embankment overtopping 3. Reinstatement of storm water drainage connections (hume pipes) to Moragoda Canal through gabion walls and introduction of catch pits wherever required. 4. Reinstatement of maintenance road (3.0 m wide) and construction of road side drain and cross drainage to the canal. 5. Temporary shifting and relocating of utility posts (electricity and telecom), if required. 6. Removal of debris and nuisance weeds (Salvinia and water hyacinth) obstructing water flow from the waterway area and maintenance dredging of the canal bed in selected locations mainly to remove solid waste/silt obstructing water flow (no 7 dredging causing lowering of the channel bed will be carried out). The bank protection measures (soft and hard) are proposed based on the designs developed following the detailed model analyses and alternative comparisons, as elaborated in the Conceptual Design Report by the Sri Lanka Land Reclamation and Development Corporation (SLLRDC). The present ESR has been carried out based on the interventions proposed and inundation assessments carried out in accordance with the findings and recommendations of the said report. The scenarios analyzed are: a. Moragoda Ela as it is (existing condition) for 5 year return period peak discharge b. Moragoda Ela as it is (existing condition) for 10 year return period peak discharge c. Moragoda Ela as it is (existing condition) for 5 year return period peak discharge under 2025 land use scenario d. Moragoda Ela as it is (existing condition) for 10 year return period under 2025 land use scenario e. Moragoda Ela with proposed interventions for 5 year return period peak discharge f. Moragoda Ela with proposed interventions for 10 year return period peak discharge g. Moragoda Ela with proposed interventions for 5 year return period peak discharge under 2025 land use scenario h. Moragoda Ela with proposed interventions for 10 year return period peak discharge under 2025 land use scenario It is noted that existing channel condition with present land use scenario can withstand 5-year and 10-year return period peak discharges without causing embankment overtopping and subsequent inundation (Annexure 4 a, b & c). However, under the 2025 land use scenario, the canal conditions will be satisfactory for the 5-year return period peak discharge but overtopping is observed at 10-year peak discharge level at several sections (Ch. 3+200, 3+268, 3+373 & 3+877 km; Annexure 4 d). The scenario analyses incorporating proposed interventions including debris removal and maintenance dredging (no channel deepening), embankment stabilization and flow guidance with gabions, and bridge re- 8 alignment at selected locations show that the interventions have increased the flow conveyance capacity of the canal and no over topping or inundation occurs for both 5- and 10-year return period peak discharges excepting for the future land use scenarios where a few locations are vulnerable.; Annexures 4 e to h). It has been further ensured that the bridge re-alignment will not cause additional flooding in upstream areas for storms with 10 year return period. The canal water surface profile, bed elevation (no dredging), elevations of the existing/proposed embankment elevations are depicted in Annexure 4 (a-h). The detailed drawings of the project area and proposed interventions are given in Annexure 5. And Project A Project Management Unit (PMU) will be established under the Management Team Ministry of Defense and Urban Development (MoDUD) to implement the proposed development activities in Galle under the Strategic Cities Development Project (SCDP) together with Project Partner Agencies (PPA). The PPA for this project will be the PID which will be responsible for implementing the proposed interventions. The consultant for design and supervision is the Sri Lanka Land Reclamation and Development Co- operation (SLLRDC) Contact Persons: Mr. JanakaKurukulasuriya, Additional Secretary, Ministry of Defense and Urban Development Mrs. GangadariRanawaka, Assistant Director (Urban Development), Additional Secretary, Ministry of Defense and Urban Development Tel.: 011 2866445 E-mail: gangaajith@yahoo.com Eng. C. B. Amarasinghe Designation : Deputy General Manager (Research & Designs) Sri Lanka Land Reclamation & Development Corporation No. 03, Sri JayawardenapuraMawatha Welikada, Rajagiriya Tel : +94 11 2867532 9 Nature of consultation and input received Meetings and consultation with project engineers and design engineers at SLLRDC’s Head Office in Rajagiriya; Additional meetings with Provincial Irrigation Department and site visits were conducted. Hydrological design details, and other relevant information were gathered. 10 5.0 Description of the existing environment 5.1 Physical features – Ecosystem components Topograph The topography of Sri Lanka is marked by great diversity caused by long years of faulting and erosion of the landscape. y and The central mountainous region with the highest elevations covered by virgin forests and grasslands rises up to about terrain 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 markedpeneplains featuring the coastal belt, the plains, and the central highlands. The Galle 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 Galle district situated in this coastal peneplain ranges to a maximum elevation of 150 m from sea coast. The terrain in Galle area 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 12-hectare (30-acre) Mahamodara Lake situated in the downstream part of KepuEla. The ground profile of the MoragodaEla basin area is generally flat with ground level varying approximately between 1.5 m AMSL & 10.0 m AMSL, except for the isolated ridges and fragmentary blocks of hilltops located in the borderline,rising intermittently to the heights of 15.0~30.0 m AMSL. The canal bed elevation varies from +0.5 m AMSL in the upstream (0+000 km) to -2.0 m AMSL at sea outfall (4+259 km), thus the canal slope is also very minimal (~0.03%), causing stagnating flows with very low flow velocity. Soil (type The geology of Galle is representative of the geology of the South-western coast of Sri Lanka and has existed for much and of the Quaternary era. The coastline is characterized by estuarineformations, however, a few kilometers upstream in the quality) inland valleys, there is a high-level gravel formation consisting of quartz pebbles embedded in a matrix of laterite 11 separated with pebble-free layers of laterite. The floodplains along the rivers consist mainly of alluvial deposits. A vast area (over 90%) of Sri Lanka is underlain by metamorphic crystalline rocks of Precambrian age, which includes the project area and covers a variety of Gneisses. The geology of Galle is representative of the geology of the south- 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 Galle region produced by the Geological Survey and Mines Bureau. The typical rock types of this basement include Garnet sillimanite schist and gneiss, Quartz peldspar granulite, Charnockitic gneisses, Pyriclaciteand Charnockitic biotitic gneisses of undifferentiated Highland Series. According to Survey Department soil maps (Annexure 3a & b) the main soil types in the project area are as follows. • Red Yellow Podzolic soils with weel developed laterite and their drainage • Alluvial soils of variable texture and drainage: flat terrain • Regosols on beach sands: flat terrain It is presumed that these site-specific features are the most important ones as the environmental impact is considered. Surface Sources water (sources, The most prominent source of surface water in the vicinity is the MoragodaElaand surface water drainage canal network distance that are connected with the main canal: from the Distance from the site: Project area includes the canal and the outfall. site, local uses and Local uses: The canal plays an important role in conveying surface drainage and flood waters. Although the local people quality) do not derive other benefits than diverting their surface drainage into these canals, the intrinsic function is vital and 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 canal, and due to the appalling level of water pollution, no other local uses can be derived from the water body. Quality 12 COD, BOD, turbidity and total suspended solid content are very high in the water. Dissolved oxygen, and pH are within the normal range. Phosphate concentrations are relatively high which indicate nutrient enrichment due to disposal of domestic and industrial wastewater into the canal over time. According to a previous study conducted by several researchers attached to University of Ruhuna, the temperature along the canal was within a range of 25.9-29.60C.Temperature does not vary significantly along the stream. The pH values were within 6.5-8.3 along the canal and it did not show a significant variation with the type of surrounding area. Alkalinity level was within 90-365 mg/L. Sulphate levels of MoragodaEla varied between 160-970mg/L. The high sulphate concentration at the upstream of Moragoda Ela may be due to the discharge of detergent-laden sanitary water directly into the stream by the surrounding residential areas. Dissolved oxygen concentration varied from 8.55 mg/L to 3.49 mg/L. The COD and BOD5 values were around 14.8 mg/L for BOD5 and 127.5 mg/L, respectively. Therefore the degree of pollution of this canal can be considered to be high when compared with other natural streams. Mean values of faecal and total coliforms were around 47 colonies/100mL and 23,471 colonies/100mL, respectively. 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 only been used for bathing at present. This is due to two reasons: site, local availability of ample water supplies by NWS&DB and ground water being polluted. uses and Distance from the site quality) The ground water table is very shallow and is about 0.4-0.5 m on average close to the Canal, and can be at a level from almost at surface up to 1.5-3.0 m. Local uses Only a handful of households use shallow wells to abstract water. Even those who have shallow wells do not use water 13 for daily consumption; they use the wells only occasionally for bathing, washing of clothes and watering the garden. Quality There are no data available for quality of ground water. However, it can be assumed that dissolved solid levels including salinity to be high as the project area is located very close to the coastal belt. The ground water can get contaminated due to dilapidated state of sewer connections and leakages. Flooding The midstream catchment area has suffered from frequent flooding up to around two to three times per year (Annexure 1c and 2a). Even though the canal stretch in the proposed project area appear to have adequate drainage capacity to withstand 5- and 10-year return period design peak discharges, the drainage flows are seemingly obstructed due to inadequate width of canals and vegetation growth at canal banks. Some of the structures (mainly bridges) constructed across the drainage flow paths act asobstacles, causing downstream backwater effect leading to embankment overtopping and subsequent inundation in the low-lying floodplain.. The terrain is either flat in most areas or consists of mild slopes, therefore flow velocities are very low, causing flow stagnation in the downstream. After heavy storm events and especially due to temporary blockage of existing storm water drainage system, the water movement concentrates in the low-lying areas causing temporary ponding or minor flooding in the adjacent localities, as has occurred in the recent past. Tidal effects (on main drainage lines and sea outfall) The tidal effects should be considered in determining design levels for the downstream drainage structures including sea outfall. Due consideration should be given to maximum tidal variations and maximum wave heights when establishing drainage line and sea outfall design capacities. Tidal Levels and Periods The tide around Sri Lankan coast is mixed semi-diurnal type with two high waters and two low waters occurring approximately every 24 hours. First high water is almost twice high than the second high water. Amplitude of the tide in 14 the west coast sea where the proposed project is located ranges from 35 cm at neap tide to 75 cm at spring tide. Wave Heights, Periods, Dominant Directions and other Ancillary Offshore and Near shore Wave Parameters Directional wave measurements near the project area are not available. However the wave conditions in the area have been established by a wave transformation study. According to Directional Wave Climate Study of Southwest Coast of Sri Lanka, dominant wave characteristics of the project area can be summarized as follows. Wave Frequency Wave frequency has not been measured but seasonal variations need to be taken care of. Such data are given below. Waves, tides and ocean current regimes Much of the swell that affects Sri Lanka originates in the South Indian Ocean under the influence of westerly depressions and storms. This moves northwards and is felt most along the coasts of the Southern half of the island. Most large waves have a southerly component, but they rarely reach a height of over two meters. The highest waves are during the SW monsoon season, but the effective fetch is only about 800 km between the Maldives Island chain and Sri Lanka. During the SE monsoon, the northerly winds blow over short stretches of water from the North, and even when blowing across the bay of Bengal, are not steady enough to generate large waves. The period between tides is approximately 12 hours and is thus semidiurnal. 15 16 Air quality Heavy vehicle movements along major roads located nearby and other bye-roads in the project area lead to high levels (any of air pollutant emissions, such as dust including particulate matter, smoke including CO, CO2, NOx, SOx etc. Such air pollution pollution episodes can aggravate during peak hours when traffic movements are impeded. Fugitive dust particles could issues) escape into the atmosphere during construction activities and during transportation and subsequent storage and handling. Emanation of foul odors from the canal, especially during dry weather when water levels are low, could take place from rotting solid wastes thrown in the water and sewage discharges. Noise level Existing ambient noise and vibration levels in the area correspond tohighly urban and light industrial, businesses, hotel and and restaurants. There is also heavy traffic noise fromHirimbura Road and Galle-Matara Road, a road which carries vibration heavy traffic during peak hours as well as during the night time. Intermittent high levels of noise and vibration levels are (Any observed due to train operations, which is also one of the busiest railway sections of the country. All these urban anticipated activities contribute to high noise levels in the project area. issues) 17 5.2 Ecological features – Eco-system components Vegetation Aquatic vegetation such as Salvinia and water hyacinth are predominant in the canal particularly in the areas where salinity is very low. (trees, ground cover, aquatic vegetation) Presence of wetlands In the upstream areas of the canals there exist wetlands in the form of low lying marshes which are usually inundated absorbing the flash floods. Fish and fish No fish have been observed during the field visit, however there have been no threatened or endemic species habitats recorded in this canal. Birds (waterfowl, Common water fowl birds inhabit the wetland areas associated with the upstream canal. migratory birds, others) Presence of special No such areas are found. habitat areas (special designations & identified sensitive zones) Other features Residential/Sensitive No sensitive areas are found in the vicinity except the dwelling units and commercial buildings where the canal Areas goes through town centres. The canal banks in most places are built. (Eg, Hospitals, Schools) 18 Traditional No such activities are found in the vicinity. economic and cultural activities Archeological No such artifacts are reordered in the vicinity. resources 19 6. Public Consultation Public consulted Consultation Date Details/Issues raised method No separate public consultations were done as the Social Safeguard Study has extensively covered this area. 20 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 Yes Moderate – Positive impact Project involve actions which will cause physical changes in the locality Most of the interventions are carried out along the canal and its banks, hence no physical changes in topography and landform is anticipated. Strengthening of the canal banks with gabion structures and streamlined earthen embankments, realignment of bridges and reinstatement of a maintenance road will bring positive impacts to the canal and its immediate surroundings 2 Will the Project involve use, storage, Yes Low transport, handling or production of substances or materials which could be Transport of material and construction activities, harmful to human health or the environment including excavation, demolition of existing or raise concerns about actual or perceived structure and material piles will emit dust and risks to human health? fugitive 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. 21 3 Will the Project produce solid wastes during Yes Moderrate to high construction or operation? During construction: Removal of debris and nuisance weeds obstructing water flow from the waterway area and removal of silt and solid waste from maintenance dredging of the canal bed in selected locations will produce sizeable amounts of solid waste. There will be general spoilage (construction debris) produced during the widening of the canal, gabion construction and realignment of bridges. Maintenance dredging and and construction of gabions along the canal banks are expected to generate some amount of bottom sediments mixed with general debris and embankment soil, respectively, which will need to be disposed off properly, so as not to pollute the environment. Therefore, the sediment quality at the site (the proposed stretch of the canal) needs to be established prior to preparing the canal banks for gabion placing in order to determine the disposal method. During operations There will be material dredged along the canal, 22 solid waste collected along canal banks etc which need regular collection and disposal appropriately. In addition, debris and sediments, floating matter , nuisance weeds such as Salvinia and other solid waste carried by surface drainage can get collected along the canal that needs proper disposal methods. Regular cleaning of side drains and road will too generate such material. Culverts will also generate spoil material. 4 Will the Project release pollutants or any Yes Low hazardous, toxic or noxious substances to air? Only fugitive particles emitted during construction stage is of concern, but the significance is low. 5 Will the Project cause noise and vibration or Yes Low release of light, heat energy or electromagnetic radiation? The project activities will cause noise and vibration during demolition of the bridges, temporary structures along the canal (not houses), excavation of trenches, 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 canal bankbed at the base of the gabions will 23 surface waters, groundwater or coastal need to be excavated to build a consistent base layer wasters? for the structure. In addition, canal bed maintenance will generate solid waste mixed with bed sediments. Such excavated material should be disposed of safely. Stock piling of excavated matter mixed with soft sediments, soil, debris and other material may release pollutants back into surface waters, groundwater or coastal waters. If the excavated material would contain sediments contaminated with heavy metals, it would have to be appropriately handled and disposed in order to avoid any potential environmental and health risks to the residents and downstream marine ecosystems. Pollution within the canal is mainly caused by sewage disposal, as such, occurrence of heavy metals at concentrations that will affect aquatic biota or people living in the area is not expected. However, sediment sample analysis at selected locations will need to be done. 7 Will the project cause localized flooding Low and poor drainage during construction Annexures 4 a to 4 c indicate that the present canal Is the project area located in a flooding sections are adequate to withstand 5- and 10-year location? design return period peak discharges under existing land use conditions. However, some low-lying embankment sections will be subject to overtopping and undergo flooding under 10-year design return 24 period peak flow discharge and future (2025) land use conditions, presumably due to partial blockage to the flow at some bridge locations with improperly aligned cross drainage openings and restricted flow condition due to construction of piers obstructing through flow. The proposed interventions after being implemented can provide additional conveyance capacity, thus, alleviating risk of flooding at 5- & 10-year design return period peak flow conditions even under future land use scenario. However, raised finish levels, stock piling of construction debris and other materials may cause temporary blockage to existing flow paths and disturbance to drainage patterns during the period of construction causing giving rise to flow stagnation and localized flooding effects. Ensuring of proper construction practices like provision of improved drainage network, maintaining naturally stable slopes, vegetation replanting/turfing, etc. will improve drainage conditions, reducing flow stagnation risk during the construction phase and in the aftermath of project completion. 25 Further, the interventions are implemented to provide a maximum of 10-year flood protection against bank overtopping, thus, any severe/extreme storm event can lead to flooding and inundation in the low-lying areas within the project area. Therefore, the designs should be cross checked for at least a 25-year design return period flood event and consequences should be identified and addressed to minimize damages. 8 Will there be any risks and vulnerabilities to Yes Low public safety due to physical hazards during Safety issue in terms of injuries caused by construction or operation of the Project? construction material, machinery and falling into excavated trenches by neighbors and commuters could take place. 9 Are there any transport routes on or around Yes Low the location which are susceptible to congestion or which cause environmental The access roads are wide enough to allow for problems, which could be affected by the construction equipment and machinery to be moved project? and hence impacts on residents and commuters near the canal from restricted access should be looked into. The residents will be temporarily impacted by access restriction during construction works. Where the bridges are located, traffic on the main road will be impacted when construction commences. However, there are many connecting roads so that impact would be mitigated. 26 10 Are there any routes or facilities on or Yes Low to moderate around the location which are used by the Realignment of bridges, provision of culverts and public for access to recreation or other road side drains will cause disruptions to road users, facilities, which could be affected by the both vehicular traffic and pedestrians. Traffic on project? these main roads may worsen during construction. Some roads used as access for residential areas may be temporary affected but not completely cut off. 11 Are there any areas or features of high No Since project mainly deals with work along canals, landscape or scenic value on or around the no impact is anticipated. location which could be affected by the project? 12 Are there any other areas on or around the Yes Low location which are important or sensitive for At the upstream the canal is connected to some low reasons of their ecology e.g. wetlands, lying marshes and at the downstream with the watercourses or other water bodies, the coastal area. The wetlands are not expected to be coastal zone, mountains, forests which could impacted from the project in anyway and is be affected by the project? important for detention of flood waters. Similarly, impacts to coastal areas are also not significant. 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 27 resting, migration, which could be affected fauna or flora were found. by the project? 14 Is the project located in a previously No No such green-field is encountered. undeveloped area where there will be loss of green-field land 15 Will the project cause the removal of trees Yes Low in the locality? It has been decided that mature large trees on the canal banks will be preserved and incorporated into the canal bank design during construction of the gabion walls. Removal of some vegetation would be unavoidable though. Where soft embankments are constructed (which is more in length than gabions) trees will not be removed. However in the case of maintenance road construction there will be a possibility of a few trees being removed which needs to be monitored but they seem to be common trees with no or low economic values. 16 Are there any areas or features of historic or No There are no historic or culturally important areas cultural importance on or around the or features around the project location. location which could be affected by the project? 17 Are there existing land uses on or around Yes Moderate the location e.g. homes, gardens, other private property, industry, commerce, Where land is acquired for maintenance road, home 28 recreation, public open space, community gardens of those living bordering the canal will be facilities, agriculture, forestry, tourism, affected. mining or quarrying which could be affected by the project? 18 Are there any areas on or around the Yes Moderate location which are densely populated or built-up, which could be affected by the The project area is densely populated with generally project? narrow roads. The project will create moderate impacts in terms of road congestion, inconvenience and restricted access as the construction activities of the project would involve canal width correction and realignment of the bridges. Reinstatement of drainage canals and maintenance road along the canal will also lead to disruptions causes to road users, especially vehicle users. Transportation of building materials and construction equipment, and storage of material will also cause inconveniences to road users, and the neighbourhood. 19 Are there any areas on or around the Yes Low location which are occupied by sensitive land uses e.g. hospitals, schools, places of Project activities will take place mainly along the worship, community facilities, which could canal. At places where the canal crosses main roads be affected by the project (bridge locations) normal road activity will be disturbed. Some of these roads lead to sensitive 29 places such as schools and hospitals. 20 Are there any areas on or around the No The canal is the only water resource that exist location which contain important, high (being close to the sea the water quality in this quality or scarce resources e.g. groundwater, stretch would make it moiré brackish) in the surface waters, forestry, agriculture, immediate project area. However, water in the canal fisheries, tourism, minerals, which could be is polluted due to a high concentration of affected by the project? urbanization with poor waste disposal practices. No significant additional impacts are expected due to proposed project components and intended construction activities. 21 Are there any areas on or around the Yes Low location which are already subject to pollution or environmental damage e.g. Moragoda Ela and connected canals are highly or where existing legal environmental moderately polluted depending on the seasonal standards are exceeded, which could be effects. However, the addition from the project affected by the project? seems to be very marginal or perhaps negligible. 30 7. Environmental Management Plan Key project activities Potential Environmental Mitigation Measures Effects Site preparation including  Emission of dust  Minimize use of heavy machinery in site clearance work, provision of access roads,  Generation of noise preparation of temporary access roads, storage sheds and material storage yards  Disturbance to pedestrian storage areas. movements and children who  Select bare lands along the canal trace for storage of material play on the road and equipment should be strongly considered to avoid haphazard storage along the construction sites. Provision of proper site drainage, fencing and covering of material Should be ensured.  Sprinkling water in an appropriate manner to reduce dust.  Avoid using heavy machinery for transport of construction material along narrow access road along the banks of the canal  Avoid cutting of trees unless they obstruct construction of designed- structures. Express approval of Project Manager to be obtained before cutting and removal of any tree exceeding 300 mm girth. Temporary shifting &  Community will lose the  Interact and communicate with relevant Govt. Agencies, relocating of utility posts services for a short period Local Govt. Authorities and Employer to arrange for (electricity & telecom).  Disturbance to pedestrian relocation as early as possible and with minimum disturbance movement on the access road to public. and children playing on the  To erect barriers/ draw barricade tape to ensure security of road public during removal/ relocation of utility posts. 31 Key project activities Potential Environmental Mitigation Measures Effects Canal bank/bottom  Excavation of canal banks  Silt and sediment quality in the canal should be established to excavation,, dewatering and and bottom will generate a understand the potential risk of contamination by heavy disposal of bottom sediments mixed spoilage consisting of metals (and the leachability) and to determine the most soil from the banks, solid suitable disposal method for the excavated debris and waste and sediments from canal bed sediments. If contamination is established according to  Stockpiling of such excavated accepted reference criteria, the following mitigation measures material may block surface are proposed to be implemented. (Note: Sri Lanka does not drainage paths causing have regulatory standards for sediment quality. Under localized flooding during MCUDP it was decided to use the ANZECC interim construction period. standards for sediment quality)  If not properly stored and (a) given the small volume of excavated matter (mixed with adequately covered washout of fine material may sediments, and solid waste) that will be generated from contribute to further this stretch of the canal the project should explore the deterioration of surface water possibility of finding a site for landfilling with adequate quality in the canal, inland protection. Since the anticipated volume of excavated reservoirs and sea outfalls, matter in this case would be small, the project should be and may increase risk of able to obtain the necessary clearances from the Central slope failures, siltation and Environmental Authority and the relevant Pradheshiya blockage of structures.  If not properly disposed the Sabhas to use their facilities or (b) dispose to an existing excavated material will landfill site elsewhere in the country, or (c) stockpile it at pollute water sources at the Mahamodara SW dumping site of the Galle Municipal location where it is disposed Council with an agreement that the waste will be  Dewatering which may need transported to the Regional Engineered Landfill (17 miles to be carried out during from Galle City) which is planned to be commissioned in construction activities, may 2015. 32 Key project activities Potential Environmental Mitigation Measures Effects cause slope instability,  Selection of the suitable option will depend on the level of transport of fines and surface contamination and the possibility of contaminant ponding of water if proper leachability. If level of contamination warrants excavated material to be transported to any special dumping site further drainage is not provided. than 10 km radial distance, Contractor will make necessary Further water quality of public arrangements for same, in a safe and acceptable manner well in the canal bank, used specified by the Project Manager. Actual cost of such work by community, may change. and contractors overhead cost for same shall be paid under a Provisional Sum allocated for this.  If contamination is ruled out, the excavated matter along with other construction debris will be disposed to the SW dumping site operated by the local authority which is located within 10 Km radius from the canal site.  Wet excavated material / construction debris that can generate leachate when transported out of the site, shall be allowed to dry before transporting out to dumping sites.  Contractor must ensure that excavated material/ construction debris stacked within the site, will not prevent surface- drainage of the area causing inconveniences to public. Adequate measures shall be taken by contractor to avoid ponding of rain water runoff on the access road and canal bank reservation.  If the sediment analysis confirms the canal to contain contaminated sediments, the contractor should be instructed to carry out excavation in such a way that bottom sediments/debris is isolated (to the extent possible) from the 33 Key project activities Potential Environmental Mitigation Measures Effects rest of soil/spoilage, so that quantities needing special disposal would be minimal. Also, separating excavated soil from the bank from the rest of the debris should be pursued if the soil is considered suitable as a backfill for the gabions.  Contaminated sediments/soil should be transported only after drying to prevent leakage of water during transport. It will also be necessary to cover the material fully to prevent any particles from being air borne. Any accidental leakages will be immediately attended to by the contractor and the area should be cleaned up before the public can be exposed to any hazards.  Contractor must ensure that excavated material/ construction debris stacked within the site, will not prevent surface- drainage of the area causing inconveniences to public. Adequate measures shall be taken by contractor to avoid ponding of rain water runoff on the access road and canal bank reservation.  If dewatering is carried out, proper surface drainage should be provided to safely remove pumped water back to natural drainage avoiding any on-site ponding effects  Construction activities should be planned during the periods of low water table to avoid excessive dewatering requirements and save costs while reducing risks of slope failures, increased erosion, etc.  Suitably arranged barge may be used where access through existing roads is not available. 34 Key project activities Potential Environmental Mitigation Measures Effects Removal of temporary  Emission of dust  All large mature trees on canal banks shall be preserved. structures, debris, demolition  Generation of noise Anything to the contrary will require to be approved by the waste, trees and other solid  Disturbances to local Engineer of the PID and Environmental officer of the PMU. waste along the banks traffic,residents and other On the maintenance road, a tree inventory will be carried out road-users during storage of to document and monitor those large trees that will need to be material and debris. removed.  Loss of habitat  Demolition to be carried out with minimum use of heavy machinery and sprinkling water in an appropriate manner to reduce dust during demolition activities.  Transporting out debris/construction waste to be carried out with minimal use of heavy transport vehicles and taking due care to avoid unwanted damages to existing structures.  Until transported out to arranged disposal sites, debris and waste from demolition shall be held stockpiled in a place with minimal interference with local drainage paths and obstruction to traffic, local residents and pedestrians. These stockpiles should be suitably covered to minimize wash out back to the canal. Excavation for the gabion  The construction of gabion  Proper dewatering plan must be made and stability of coffer wall construction and coffer walls along the canal dams during rainy period must be ensured. Excavated damming embankment for bank material must be carefully managed as highlighted earlier due strengthening and stabilization to the potential risks involved. would require substantial  Driving sheet piles to coffer dam the construction site might excavation close to the existing cause issues for weakly built structures nearby, hence, it is 35 Key project activities Potential Environmental Mitigation Measures Effects earth embankments. Such deep best to build earthen coffer dams. On completion of work, excavations in saturated weak soil material of the coffer dam should be completely removed soil could result in collapsible to restore conveyance. 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 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. The excavations in saturated soil may lead to failure if collapsible soil faces and excavated material will pose health and environmental risks if not properly handled and disposed.  Excessive vibration during hydraulic driving of sheet piles 36 Key project activities Potential Environmental Mitigation Measures Effects for coffer damming may weaken adjacent soil layers while it may also affect nearby foundations and other structures. Material transport and storage  Emission of dust due to  The construction materials intended for temporary storage transport of construction should be properly stockpiled in most appropriate areas in the material site to avoid disturbance to site mobility, traffic and stored  Disturbance to pedestrian away from drainage paths and suitably covered to avoid movement and the children washout. As stated earlier, bare lands should be identified playing on the road for this purpose (see above)  Dust emissions should be controlled by wet spraying of construction sites and roads which are used for transportation of construction materials. Tarpaulin covers shall be provided for vehicles used to transport material to avoid emission of dust. If considered necessary, dust barriers should be erected to protect nearby houses.  Adequate safety measures should be adopted in transporting and handling construction material to avoid any harm/accident to people using the road. Construction of flow  Deep excavations may cause  Adequate safeguards should be taken against slope failures guidance walls made of slope failures and result in and /or damages to existing structures by way of shoring gabions damages to existing /lateral supports & struts etc before carrying out excavations. structures and trees  Adequate measures should be taken to minimize damages to  Improper alignment of existing structures due to vibration by applying minimum 37 Key project activities Potential Environmental Mitigation Measures Effects Gabion wall and inadequate driving power. Adequate support should be provided to bottom support and/or soil nearby trees when excavation depth exceeds root depth. erosion may affect strength  Proper alignment of rock wall and adequate bottom support and stability of gabion walls. should be maintained by following appropriate design guidelines and correct construction methodologies to ensure precise interlocking of the rubble work. Lined concrete flow guide walls should be used where necessary to control bottom and side erosion when the gabions walls are exposed to through flow.  Contractor shall record tie measurements to mark the layout of centerlines and obtain Project Managers written approval for at site lay-out of each section of gabion wall, before construction is taken up. Reinstatement of storm water  Erosion of soil adjacent to  Storm water connections across the gabion walls should be drainage connections (Hume structures will lead to provided using hume pipes or box culverts of adequate size pipes) to Moragoda Canal loosening of bank support. This according to pre-determined design storm events and return through gabion walls and will weaken the interlocking of periods. introduction of catch pits rubble used causing immature  Catch pits should be provided at suitable spacing to remove wherever required failure of gabion structure excessive fines through settlement. Catch pits should be before its intended design life. regularly cleaned and maintained in proper order. Fines  Blockage of drain pipes due to removed should be properly disposed to avoid them joining accumulation of fines. flow paths again.  Proper slopes, invert levels and adequate opening sizes 38 Key project activities Potential Environmental Mitigation Measures Effects should be maintained to facilitate the entering of cross drainage flows to the canal,  Where through flow is expected, adequate protection should be provided with coir mats/geotextile membranes to curtail washout of fines though gabion structures, weakening surrounding soil layers. Backfilling of banks behind  Use of improper fill material  Backfill materials should be selected after proper analyses of the gabions, turfing and and sub-standard compacting soil characteristics and with approval from Project reinstatement of the behind gabion walls may lead Manager/Engineer. Adequate compaction should be applied to differential settlement maintenance road to attain required soil strengths in banks and embankments. causing gabion walls misalign and fail.  The construction materials intended for temporarily storage should be properly stockpiled in most appropriate areas in the site to avoid disturbance to site mobility, traffic and stored away from drainage paths and suitably covered to avoid washout. Reinstatement of maintenance  Lack of well designed drains  Side drains and toe drains of adequate design sizes should be road (width: 3 m) and along canal access road leads provided alongside of the maintenance roads and proper cross construction of road side to ponding of water on the road drainage structure should be provided where necessary to surface, weakening the road drain and cross drainage to divert accumulated flows to the main drains. paving. the canal.  Disturbance to pedestrian  Ensure community is adequately informed about project movement and children playing activities. Exhibit sign boards in both Sinhala and Tamil on the road. Children will be languages at appropriate locations. Organize the re-statement 39 Key project activities Potential Environmental Mitigation Measures Effects subjected to accidents if activities in such a way so that alternate ways of accessibility construction equipment are not to houses are made sure handled taking extreme care.  Lack of proper health and  Contractor must comply with the provisions in Health and Health and Safety of workers safety standards will put the Safety regulations under the Factory ordinance with regards and the public workers and the public at risk to provisions of health and safety measures and amenities at from accidents and work places. respiratory/auditory health impacts  Ensure appropriate safety equipment, tools and protective clothing are provided to workers and that safe working methods are applied. A safety inspection checklist should be prepared taking into consideration what the workers are supposed to be wearing and monitored during specific construction activities. .  No paint containing lead or lead products will be used. Facemasks shall be supplied to workers who are working in spray painting or scraping lead paint.  All reasonable precautions must be taken in order to prevent any danger of the workers and the public from accidents by providing. • delineation devices such as cones, lights, tubular markers, orange and white strips and barricades are erected to inform oncoming vehicular traffic and pedestrians in the area about work zones. • signposts and flash lamps in nighttime to warn of all digging and installing work that are not completed 40 Key project activities Potential Environmental Mitigation Measures Effects • dangerous warning signs to inform public of particular dangers and to keepthe public away from such hazards. • swift rehabilitation of trenches progressively once work is completed. • barricades such as humps around excavated areas with proper sign boards especially during heavy rain when work has to be stopped. • The safety inspection checklist must look to see that the delineation devices are used, whether they are appropriately positioned, if they are easily identifiable and whether they are reflective.  Ensure prevention of risks from electrocution by regular inspection and maintainance of all electric power driven machines used on the construction site. They must be kept away from permanent/temporary pedestrian walkways.  Ensure basic emergency aid service is in place in the work zone  Ensure training of basic health and safety is be provided to the work force prior to commencement of construction where emphasis on all the above critical factors are emphasized.  Poor site management practices  Locations for material storage should be identified prior to General site management can lead to numerous adverse commencing work and approved by the Engineer. As the aspects enviornmnetal impacts that can Road and the surrounding area is built storage space will be be easily mitigated, hence this limited. Selection of storage locations should avoid being 41 Key project activities Potential Environmental Mitigation Measures Effects is an important area to be close to sensitive receptors such as schools, hospitals and strongly monitored. places where crowds congregate.  All cement, bitumen (barrels), oil and other chemicals such as paint should be stored and handled on an impervious surface above ground level.  The storage location for these products should be enclosed and not exposed to rain and storm water run off  A temporary ridge should be constructed with suitable material around such places to avoid storm water getting in.  The contractor must avoid overloaded trucks to bring material to construction sites. During transport the material should be covered with Tarpaulin  Construction vehicles, machinery and equipment must be used and stationed only in areas of work and any other area approved by the Engineer.  Entry and exit points for construction vehicles should be defined and instructed by the Engineer  No activity should lead to the destruction of ground cover and vegetation unnecessarily and the contractor must instruct its staff adequately about this  Vehicle/machinery and equipment servicing and maintenance work must be carried out only in designated 42 Key project activities Potential Environmental Mitigation Measures Effects locations and should strictly avoid sensitive areas closer to waterways.  If the contractor intends to set up his own vehicle servicing yard, he should obtain an EPL from the CEA  If there is a spillage of petroleum products from storage tanks and containers, immediate corrective measures should be taken to arrest pollution especially in areas closer to waterways.  Once work is completed, these service yards must be restored back to its initial status and this will be considered as incidental to work.  Noisy construction work such as crushing, concrete mixing and batching should be carried out at least 150m away from closest habitation. If the contractor operates Hot mix/Batching/Crusher plants or if outsourced, the plant operations shall be undertaken in accordance with CEA guidelines/conditions and operated with an Environmental Protection License in order to minimize noise pollution. Implementation Responsibility : Contractor 43 7. Conclusion and Screening Decision : The proposed Moragoda Ela basin storm water drainage improvement plan is formulated taking into account present as well as future conditions of the entire basin. This is essential in order to minimize serious storm water drainage problems that may occur during the design life of the project interventions. Hence, the implementation of the proposed storm water drainage project will help the basin develop sustainably leading to improved living standard, especially of those low income communities who occupy low lying lands. Of the potentially adverse impacts anticipated during project implementation, the most important is the disposal of mixed debris from the canal bed/banks which will contain silt, solid waste and embankment soil generated from maintenance dredging and gabion construction. In order to determine the site of disposal of this debris, it is necessary to establish the quality of sediments with regard to heavy metal contamination and likelihood of contaminants leaching out at the disposal site. Pollution in Moragoda Ela is mainly due to raw sewage disposal and as such it is unlikely to be contaminated with heavy metals and organic compounds. Nevertheless it is important to follow the EMP in handling this issue. If careful disposal is warranted based on sediment test results, the PMU should prepare a sediment disposal plan covering, storing, loading, unloading, disposal and monitoring, Considering the physical characteristics of the area and the proposed interventions, most of the environmental impacts described in the EMP caused by project activities are not expected to have any significant or irreversible impact and are related to dust/noise generation, siltation, safety hazards, traffic congestion and other general impacts which can be mitigated with good construction, site management and public safety practices. The areas affected during rehabilitation work are mainly confined to the canal corridor. The impact on water quality in the canal is negligible given its present state of pollution. The requirement to remove trees will be minimal given that the PID has taken a decision to preserve all large trees in the canal embankments and incorporate them in to the embankment layout. However, not all trees will be saved and it is important to evaluate and document each case of tree removal and follow guidelines of this EMP. Given the above, it is considered that a stand alone EIA is not needed for the proposed project and that the EMP thus prepared is suffice to manage the potentially adverse impacts. It is noted that existing channel condition with present land use scenario can withstand 5-year and 10-year return period peak discharges without causing embankment overtopping and subsequent inundation (Annexure 4 a, b & c). However, under the 2025 land use scenario, the canal conditions will be satisfactory for the 5-year return period peak discharge but overtopping is observed at 10-year peak discharge level at several sections (Ch. 3+200, 3+268, 3+373 & 3+877 km. It is recommended that the design consultants review the model to address this particular aspect to minimize damage. 8. Environmental Monitoring Environmental monitoring will be carried out largely through compliance monitoring using the checklist provided in the EMF by the Environmental Officer of the PMU and the 44 contractor jointly. The Environmental officer of the PMU Galle office will be required to visit the site on a weekly basis and report to the PID and main PMU of the contractors performance on the implementation of the EMP. If disposal of sediments need to be carried out in a cautious manner, a special monitoring plan will need to be prepared to monitor the process from generation to final disposal. 45 10. EMP implementation responsibilities and costs The overall responsibility of ensuring compliance with safeguard requirements for the sub- project lies with the PID. Specifically, it will be responsible for undertaking sediment quality testing in the proposed section of the canal, estimation of excavated 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. As such, the only additional costs envisaged are explained below: Item Cost (Rs) Implementation Responsibility Sediment quality testing – 3 180,000 PID 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 need to test dioxin content in the samples will also be evaluated and if necessary will be included. The testing will be done before the monsoon rain comes Disposal of excavated material The cost of mitigation is hard to Contractor estimate at 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 PID for estimating the mitigation cost once results of the sediment quality test are received. 46 Screening report completed by Date 29 – 01 - 20014 Dr. Mahesh Jayaweera, Team Leader University of Moratuwa Tel: 0777320590 email: maheshjayaweera@gmail.com Signature Name/Designation/Contact information Screening report reviewed by Date Name/Designation/Contact information Signature Approved by Date Name/Designation/Contact information Signature 47 9. 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) Dr. JagathManatunge, 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 (3) Dr. LalithRajapakse, 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 (4) Mr. HemanthaJayasundara, 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. (5) Ms. Samangi Hewage, M.Phil. (Botany), B.Sc (Hons) in Forestry and Environmental Science – Ecologist (Flora, Fauna, Ecosystems) Experience: more than 10 EIA and IEE studies and ecological studies during the past 3 years 48 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. 49 Annexure 1: Location Maps 50 Annexure 1: Location map a. Project Area (1: 50,000 topographic map of Survey Department, Sri Lanka) 51 b. Project Area (Google Street View Map) 52 c. Project Area (Proposed Drainage Improvements) 53 Annexure 2: Terrain and Drainage Map 54 Annexure 2a: Terrain and Drainage Map with Identified Flood Locations 55 Annexure 2b: Main Canal System in Galle Municipal Council Area (SLLRDC, 2013) 56 LENGTH TO BE DESCRIPTION OF NO NAME START END REHABILITATE THE WORK (Km) 1 Bombe castle Ela Karapitiya Moragoda Ela Concrete 1.625 2 Kanampitiya mohideen watta cross drain Thanipolgaha junction Moragoda Ela Concrete 1.80 3 Dangedara Appaladuwa Cross drain Dangedara Indika Nishantha Mawatha Moragoda Ela Concrete 0.85 4 Dangedara Donald Janze Cross drain Mahinda Patumaga Moragoda Ela Concrete 0.97 5 Heenela Cross drain Samson Rajapakse Mawatha Moragoda Ela Concrete 0.90 Gabion wall with 6 Heenela Samson Rajapakse Mawatha Moragoda Ela 0.58 03 Nrs Bridges 7 Dikela Cross drain Dikela junction Lunuwilawatta Concrete 0.65 8 Thenkallagoda Cross drain Thenkallagoda Lunuwilawatta Concrete 1.20 9 Kovilawatta Cross drain Kongaha road Concrete 0.63 10 Thalapitiya weliwatta Weliwatta Moragoda Ela Concrete 2.45 11 Pump Station Bandaranayake Pedesa Restoration 12 Kepu Ela Mahamodara Lake Concrete 0.99 13 Bope Cross drain Wekunagoda road Kepu Ela Concrete 0.78 14 Batalawtta Ela Piyadigama Sea Gabion 2.50 15 Mahamodara watta Cross drain Mahamodarawatta Mahamodara Lake Concrete 0.45 16 Darmaraja Mawatha Drain Dr. Richerd Pathirana Mw. Kepu Ela Concrete 1.50 17 Maitipe Cross Drain Maitipe Labuduwa Concrete 2.00 18 Hirimbura New Lane Hirimbura Pasal Mawatha Moragoda Ela Concrete 1.20 19 Wekunagoda Cross Drain Wekunagoda road Heenpandala Lake Concrete 0.80 20 Katugoda Cross Drain Katugoda 3rd Lane Sea Concrete 2.00 Annexure 2c: Sub Canal System in Galle Municipal Council Area (SLLRDC, 2013) 57 Annexure 3: Soil map & Geological Map 58 Annexure 3a: Soil map Source: Survey Department, Sri Lanka 59 Annexure 3b: Geological map Source: Survey Department, Sri Lanka 60 Annexure 4: Scenarios Analyzed in the Conceptual Design Report by the Sri Lanka Land Reclamation and Development Corporation (SLLRDC) 61 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4336 4329 [meter] 4254 4245 4236 4227 4218 4180 4209 4200 4190 41604170 0.0 4150 4140 4130 4120 4110 40704080 4100 4090 4060 Annexure 4 a. 4050 4040 4030 4020 4010 3991 4000 39823964 39733955 3947 3939 3932 3925 3868 3877 3859 38493840 3830 3820 3810 3800 3790 3780 3770 3760 3750 3740 3730 3720 3710 3700 3686 3684 3688 3680 3682 3678 3676 3674 3672 3670 3668 3666 3664 3660 3662 3656 3658 3652 3650 3654 3640 3630 3620 500.0 3610 3600 3590 3580 3570 3560 3544 3546 3548 3550 3540 3542 3538 3528 3519 3509 3499 3489 3480 3470 3460345034403430 342034103400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 MoragodaEla as it is (existing condition) for 5 year return period flood 600 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] 62 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4336 4329 [meter] 4254 4245 4236 4227 4218 4180 4209 4200 4190 41604170 0.0 4150 4140 4130 4120 4110 40704080 4100 4090 4060 Annexure 4 b. 4050 4040 4030 4020 4010 3991 4000 39823964 39733955 3947 3939 3932 3925 3868 3877 3859 38493840 3830 3820 3810 3800 3790 3780 3770 3760 3750 3740 3730 3720 3710 3700 3686 3684 3688 3680 3682 3678 3676 3674 3672 3670 3668 3666 3664 3660 3662 3656 3658 3652 3650 3654 3640 3630 3620 500.0 3610 3600 3590 3580 3570 3560 3544 3546 3548 3550 3540 3542 3538 3528 3519 3509 3499 3489 3480 3470 3460345034403430 342034103400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 MoragodaElaas it is (existing condition) for 10 year return period flood 600 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] 63 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4336 4329 [meter] 4254 4245 4236 4227 4218 4180 4209 4200 4190 41604170 0.0 4150 4140 4130 4120 4110 40704080 4100 4090 Annexure 4 c. 4050 4040 4030 40204060 4010 3991 4000 39823964 39733955 3947 3939 3932 3925 3877 3868 3859 38493840 3830 3820 3810 3800 3790 3780 3770 3760 3750 3740 3730 3720 3710 3700 3686 3684 3688 3680 3682 3678 3676 3674 3672 3670 3668 3666 3664 3660 3662 3656 3658 3652 3650 3654 3640 3630 3620 500.0 3610 3600 3590 3580 3570 3560 3544 3546 3548 3550 3540 3542 3538 3528 3519 3509 3499 3489 3480 3470 3460345034403430 342034103400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 600 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] MoragodaElaas it is (existing condition) for 5 year return period flood under 2025 land use scenario 64 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4336 4329 [meter] 4254 4245 4236 4227 4218 4180 4209 4200 4190 41604170 0.0 4150 4140 4130 4120 4110 40704080 4100 4090 4060 Annexure 4 d. 4050 4040 4030 4020 4010 3991 4000 39823964 39733955 3947 3939 3932 3925 3877 3868 3859 38493840 3830 3820 3810 3800 3790 3780 3770 3760 3750 3740 3730 3720 3710 3700 3686 3684 3688 3680 3682 3678 3676 3674 3672 3670 3668 3666 3664 3660 3662 3656 3658 3652 3650 3654 3640 3630 3620 500.0 3610 3600 3590 3580 3570 3560 3544 3546 3548 3550 3540 3542 3538 3528 3519 3509 3499 3489 3480 3470 3460345034403430 342034103400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 600 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] MoragodaElaas it is (existing condition) for 10 year return period under 2025 land use scenario 65 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 4336 4329 [meter] 4254 4200 0.0 4150 4100 Annexure 4 e. 4050 4000 3947 3925 3877 3840 3750 3650 500.0 3610 3550 3538 3499 3460 3400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 600 MoragodaEla with proposed interventions for 5 year return period flood 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] 66 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 4336 4329 [meter] 4254 4200 0.0 4150 4100 Annexure 4 f. 4050 4000 3947 3925 3877 3840 3750 3650 500.0 3610 3550 3538 3499 3460 3400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 600 550 MoragodaEla with proposed interventions for 10 year return period flood 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] 67 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 4336 4329 [meter] 4254 4200 0.0 4150 4100 Annexure 4 g. 4050 4000 3947 3925 3877 3840 3750 3650 500.0 3610 3550 3538 3499 3460 3400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 600 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] MoragodaEla with proposed interventions for 5 year return period flood under 2025 land use scenario 68 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 4336 4329 [meter] 4254 4200 0.0 4150 4100 Annexure 4 h. 4050 4000 3947 3925 3877 3840 3750 3650 500.0 3610 3550 3538 3499 3460 3400 3350 3331 3288 3240 3200 3160 3100 1000.0 3057 2950 2990 2900 2850 2800 2776 2700 2732 2653 2600 1500.0 2550 2505 2450 2400 2384 2364 2359 2300 2250 2213 2182 2157 2107 2000.0 2050 2000 1910 1950 1859 1825 Maximum 1798 1750 1696 1646 1626 1596 MORAGODAELA 4336 - 0 2500.0 1550 1500 1441 1399 1346 1300 1244 1200 1159 1136 1100 3000.0 1054 1000 950 900 850 800 750 700 654 644 3500.0 628 600 550 500 450 400 352 300 250 200 150 4000.0 100 50 16 0 [m] MoragodaEla with proposed interventions for 10 year return period flood under 2025 land use scenario 69 Annexure 5: LS of the Canal Trace (Plan) and Proposed Interventions 70 71 72 73 74 75 76 77 78