Summary Environmental Impact Assessment

SUMMARY ENVIRONMENTAL IMPACT ASSESSMENT KLANG RIVER FLOOD MITIGATION AND ENVIRONMENTAL MANAGEMENT PROJECT IN MALAYSIA March 1995 KLANG RIVER FLOOD MITIGATION AND ENVIRONMENTAL MANAGEMENT PROJECT, MALAYSIA SUMMARY ENVIRONMENTAL IMPACT ASSESSMENT A. INTRODUCTION 1. The Klang River Flood Mitigation and Environmental Management Project has been proposed by the Drainage and Irrigation Department (DID) of the Ministry of Agriculture, Malaysia to integrate three ongoing flood mitigation and environmental management projects to expedite protection. The three ongoing projects are: (i) The Federal Territory Drainage Project; (ii) The Klang River Valley Flood Mitigation Project (following a Japan International Cooperation Agency (JICA) study); and (iii) The Ten Year Program on Cleaning Up the Klang River (TYPCRKR). 2. The proposed project includes priority drainage works and environmental management in the Federal Territory and the surrounding Klang River catchment area in the state of Selangor. 3. The project was classified a Category A project by the Asian Development Bank and requires an environmental impact assessment (EIA). The objectives of the EIA study were to: (i) assess the immediate and long-term overall environmental impacts during implementation of the project and upon its completion; (ii) propose preventive and/or remedial measures to avoid or minimize adverse impacts induced by the project; and (iii) recommend a monitoring program for the project. 4. The EIA study involved a review of the technical reports about the project and detailed site assessments. The EIA was submitted to the Department of Environment (DOE) for review, although an EIA would normally not be required by the Malaysian Government under its current environmental legislation which uses a list of types and sizes of projects to determine the need for an EIA. Nevertheless, the DOE appreciated the Bank’s action in initiating the EIA and approved it subject to the condition that all mitigation and control measures outlined in the EIA need to be fully implemented. B. DESCRIPTION OF THE PROJECT 5. The study area is the Klang River basin on the west coast of Peninsular Malaysia. The river basin fully encompasses the Federal Territory and parts of Gombak, Petaling, Klang, and Hulu Langat districts in the state of Selangor. 6. The focus of the study has been on the Klang River, from its head waters to the estuary, and the main tributaries of the Batu, Gombak, Jinjang, Keroh, Bunus, Ampang, Kerayong, Kuyoh, Penchala, and Damansara rivers. The local drainage network associated with these rivers has been reviewed in broad terms only. 7. The Klang River basin comprises all of the Federal Territory, which includes Kuala Lumpur, the major urban area in Malaysia that is part of the conurbation that comprises the other highly developed, urbanized, and industrialized areas of Petaling Jaya, Shah Alam, Klang, and Port Klang. Recently, the rate of development and growth in this region has accelerated. 8. Periodic flooding has always been a significant constraint to optimal land use and quality of life in the Klang Valley. Approximately 14 per cent of the Klang Valley administrative area (234,347 ha) is flood prone. On average, there are three floods a year, which usually cover approximately 32,800 ha. About 500,000 people live in the flood prone area. Of these, 38 per cent (190,000 are squatters. The main flood area is below central Kuala Lumpur and adjacent to the Klang River. 9. The flood mitigation measures implemented so far have included enlarging the river channel to a vegetated trapezoidal cross section and constructing canals with concrete revetments and berms to increase channel flood conveyance capacity and reduce the need for wide river reserves. The major sections of most of the rivers upstream of the Federal Highway Bridge are concrete lined and further works are being constructed. Sheet piling or concrete blocks have also been used. These measures are expected to improve the hydraulic efficiency of the channel and to reduce scour and maintenance. 10. The accumulated silt in the channel has significantly reduced its flood conveyance capacity. To maintain the required channel, the sediment needs to be excavated. The accumulation of solid waste also impedes channel flow and has been addressed by installing floating trash booms. 11. Two of the recommendations in the JICA study were to the Gombak diversion channel and with the Batu retention pond. These are currently under construction. The JICA report also recommended that the Puchong drop be removed. 12. The proejct includes structural works on the main Klang River System, on the major tributaries, and on the lesser tributary channels in the Klang River catchment. These structural works are to be complemented by nonstructural measures, for the beautification of the river and its environs. 1. Structural Works 13. The structural works have been broken into four subproject categories: (i) Klang River Channel improvement − A total of 43 kilometers (km) of channel improvement works on the Klang River from the Federal Highway bridge to below the junction with the Damansara River, − Removal of the Puchong drop bridge and weir, and construction of a new bridge, and − Construction of internal drainage, pumping stations, and related structures. (ii) Extension of Klang River Downstream Levees − Levee improvements on the right (6.7 km) and left bank (9.5 km) of the Klang River downstream from the channel improvements. (iii) Construction of 12 Sediment Traps − Sediment trap construction program for Batu River and tributaries, Gombak River, Klang River, Kerayong River and Kuyoh River, Damansara River, and Penchala Rivers. (iv) Improvement of Tributary Rivers and Drainage Areas − Improvements of 23 tributary rivers and drainage lines for about 80 km in the various local authority areas identified and reviewed by DID, Federal Territory; Kuala Lumpur City Hall; Gombak District Council; Hulu Langat, and Petaling, and Shah Alam areas. 2. Nonstructural Works 14. The nonstructural measures include: (i) Integrated Catchment Management − Establishment of a permanent integrated catchment management (ICM) unit within DID and carry out a pilot ICM program to conserve soil and reduce the sediment volumes entering the river system; (ii) Solid Waste Management − Implementation of an effective solid waste management network combined with public education; (iii) Flood Forecasting and Warning System − A flood forecasting and warning system (FFWS) will be established by joint venture between DID and Malaysia Meteorological Services to provide flood warning, better reservoir operation, and less transportation interruption; − The progressive enhancement by landscaping and by fixing the river corridor for recreational and tourism use. (iv) Squatters’ Resettlement − About 1,000 units of houses, shop houses, and workshops situated in the Government’s river reserve lands will be relocated under the project during the construction of the flood mitigation facilities. C. THE EXISTING ENVIRONMENT 1. Physical Characteristics 15. The Klang River, and its major tributaries the Gombak and Batu rivers, originates in the main mountain range and flows in an east-west direction through hilly areas and the coastal plain before entering the Strait of Melaka about 55 km away. The Klang River basin is the most developed and densely populated area in Malaysia. In the past two decades, the use of the land in the basin has changed from agriculture and mining to residential, commercial, and industrial. 16. The Klang River flows continuously, with the streamflow fluctuating similarly to the monthly distribution of rainfall. Floods can occur in any month of the year. Critical duration of floods vary from 1 to 24 hours, most tributary catchments have a critical storm duration of six hours. 17. The increase in socioeconomic activity, urbanization, and industrialization has had an impact on the quality of the river water. The deterioration in the quality in the Klang River is due to the direct discharge into the waterways of sewage, solid waste, and industrial effluent as well as silt from erosion. The Environmental Quality Report (1991) listed the Klang River as among one of the six most polluted rivers in Malaysia. Pollution comes from both point and non-point sources and is compounded by the presence of squatter settlements along the river. 18. Floating debris in the rivers remains a problem despite a general improvement in the solid waste collection service. Trash booms have been erected in strategic locations to screen and remove the floating rubbish. An average of 14 metric tons (t) of solid waste are collected each day from the trash booms. 19. The high suspended solid content of the water needs to be reduced, however, recently there has been some reduction in suspended solid levels in the Klang River. Erosion from development sites has been identified as the main factor contributing to this condition, although in the past plantation and mining activities were the main sources of sediment. Previous erosion studies showed that some 3 million t of soil a year are eroded from the basin or an average loss of 23.4 t per hectare a year with a sediment yield varying between 6.0 and 42.6 per hectare a year. 20. The quality of the landscape is unsightly within the urban areas along most reaches of the Klang River and its tributaries. The river is highly polluted and unattractive as it passes through low quality squatter housing areas. 2. Biological Characteristics 21. The upper reaches of the Batu, Gombak, and Klang rivers are covered by tropical forest and its associated fauna and flora. The foothills, upstream of the city, used to be rubber plantations, however, currently most of them have been cleared for development. Downstream of the city area, the river banks are mostly covered with grasses and native shrubs. Towards to mouth of the river, and particularly downstream of Klang Town, mangrove species predominate. 22 Fauna in the basin is closely related to the flora distribution and is generally not very diverse.

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