The proposed Baddegedara reservoir project could be justified due to following reasons

Transcription

1 CHAPTER CONCLUSIONS The proposed Baddegedara reservoir project could be justified due to following reasons Salinity survey of existing wells pointed out high salinity in the coastal area of the project. Water quality deterioration due to faecal contamination in densely populated areas like bazaars of Imaduwa and Dikkumbura. I Inadequate quantity in coastal aquifer is not enough even for existing water supply areas. [j Salt water intrusion in existing tube wells is more likely due to over extraction of ground water. Possible improvement to the aquifer could be expected due to alternative water supply for major consumers who are presently using ground waters. The study shows that the project has the following positive impacts. Employment generation. Improvement of health and sanitation. Improvement of living standards. Prevention of deterioration of ground water quality. Prevention of lowering of ground water level. At the same time this has the following negative impacts. Resettlement of 8 families who are living with in the reservoir area. 78

2 Deterioration of surface water quality. U Reduction in surface water quantity downstream of the dam [ Effects on downstream water users. Some environmental parameters like effects on aquatic fauna and flora, and terrestrial fauna and flora would have to be studied further.

3 LIST OF REFERENCES 1. Canter Larry W., Environmental Impact Assessment. MC Graw- Hill, USA. " 2. Canter Larry W and Hill Loren G., 1979, Handbook of Variables For Environmental Impact Assessment, Ann Arbor Science Publishers, 230, Collingwood, Michigan. 3. Committee on Environmental Effects of the United States, Environmental Effects of Large Dams, American Society of Civil Engineers, New York. 4. Dept of Environment, 1994, Environmental Assessment, Construction Industry Research and Information Association, Westminister, London 5. Dorsch Consult and Engineering Consultants, 1996, Feasibility Studies for Water Supply and Sewerage for Koggala EPZ, Volume 1 and Munn R. E , Environmental Impact Assessment, John Wiley and Sons, Toronto, Canada. 7. Teams Ltd and R.D.C. Ltd, 1993, Final Environmental Assessment Report on Kukule Ganga Hydropower Project. 8. World Bank, 1991, Environmental Assessment Sourcebook, Technical Paper no 140, Washington D.C. 9. Central Environmental Authority and Euroconsult, 1994, Wetland site Report for Mioya river basin, Wetland Conservation Project. 10. Central Environmental Authority and Euroconsult, 1994, Wetland site Report for Walauwawatta Waturana Swamp Forest 80

4 APPENDIX - ANNEXES

5 WATER DEMAND PROJECTIONS (m3/d) AREA Z0NE1 TALPE / HABARADUWA KOGGALA EPZ KOGGALA COASTAL BELT AIR FORCE SUB TOTAL ZONE 2 AHANGAMA ZONE 3 DIKKUMBURA ZONE 4 IMADUWA TOTAL QUANTITY

6 Rainfall Data of Hiyare Reservoir Representative of Baddegedara Reservoir Catchment Annex 02 Precipitation in milli meters YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTAL NA NA NA NA NA NA NA NA NA NA NA NA NA NA MEAN Rainfall Data of Hiyare Reservoir Representative of Baddegedara Reservoir Catchment Precipitation in milli meters

7 ANNEX 3 TOLERANCE LIMITS FOR INLAND SURFACE WATERS FOR USE AS RAW WATER FOR PUBLIC WATER SUPPLY SRI LANKA STANDARD 722 : 1985 Determinant Tolerance limit 1. Colifirm organisms (monthly average, most probable number (MPN) per 100 ml Not more than 5000, with less than 5 percent of the samples with value 20,000 and less than 20 percent of the samples with value ph range at ambient temperature 6.0 to Chloride (as CI) mg/1, max 1, Nitrate (as N) mg/1, max Fluoride (as F) mg/1 max Phenolic compounds (as phenolic OH) mg/1, max Oils and grease mg/1, max Pesticide residue As per WHO/FAO requirements 9. Arsenic (as As) mg/1, max Cyanide (as CN)mg/l,max Lead (as Pb), mg/1, max Mercury (total as Hg) mg/1, max Selenium (as Se) mg/1, max Chromium (as Cr) mg/1, max Dissolved oxygen (DO), mg/1, max Biochemical oxygen demand (BOD) mg/1, max. 17. Radio active material: a. Alpha emitters us/ml, max b. Beta emitters us/ml, max 5 io

8 ANNEX 4 Specification for Potable Water SLS 614 (1983) PART 1 PHYSICAL AND CHEMICAL REQUIREMENTS Characteristic Maximum Desirable Maximum Permissible Level Level ph units units Colour 5 units 30 units Odour Unobjectionable Unobjectionable Taste Unobjectionable Unobjectionable Turbidity 2-JTU 8-JTU Elect. Conductivity 750 us/cm 3500 us/cm Chloride (CI) 200 mg/l 1200 mg/l Chlorine-Free resid (CI) mg/l Alkalinity (as CaCoj) 200 mg/l 400 mg/l Ammonia -Free mg/l Ammonia - Albuminoid mg/l Nitrate (as N) - 10 mg/l Nitrite (as N) mg/l Fluoride (as F) 0.6 mg/l 1.5 mg/l Phosphates - Total (P0 4 ) mg/l Total solids 500 mg/l 2000 mg/l Hardness Total (as CaCoj) 250 mg/l 600 mg/l Iron - Total (as Fe) 0.3 mg/l 1.0 mg/l Sulphate 200 mg/l 400 mg/l Calcium 100 mg/l 240 mg/l Magnesium * 30 to 150* 150 mg/l Copper mg/l Manganese 0.05 mg/l 0.5 mg/l Zinc mg/l Aluminium mg/l Arsenic mg/l Cadmium mg/l Cyanide mg/l Lead mg/l Mercury mg/l Selenium mg/l Chromium mg/l Anionic Detergents (as MBAS-LAS) 0.2 mg/l 1.0 mg/l Phenolic Compounds (as Phenolic OH) mg/l mg/l Oil & Grease mg/l Pesticide Residue (Refer to WHO&FAO requirements) Chem. Oxygen Demand (COD) 10 mg/l 85

9 APPENDIX - B PHOTOGRAPHS

10 J BADDEGEDARA STREAM UPSTREAM OF PROPOSED DAM SITE K7

11 SCRUB JUNGLK IN THE RESERVOIR AREA 88

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13 TEA PI ANT A IK )N IN Till'. SETTLEMENT 90

14 UPSTREAM PADDY FIELD WITH TEA PLANTATION