2
3 Subsurface drainage systems (culverts) - - - - - - - - - - - - - - - 8
24 Alignment of Drainage System - - - - - - - - - - -
25 Description and Function of Road Drainage System - - - - - - - - - - - - 9
251 Description of Road Drainage Systems - - - - - - - - - - - - 9
252 Functions of Road Drainage Systems - - - - - - - - - - - - 10
26 Failures of Road Drainage System - - - - - - - - - - - - - - - - Effects
27 Effects of Poor Drainage on Roads - - - - - - - - - - - - - - - - poor
28 By poor drainage effects of water on road - - - - - - - - - - - - - - 11
29 Culverts - - - - - - - - - - - - - - - - - - - - - - - - 11
210 Components of a road and pavement drainage system - - - - - - - - - - 13
2101 Ditches - - - - - - - - - - - - - - - - - - - - Erosion
2102 Erosion Control in Ditches - - - - - - - - - - - - - - - 14
211 Necessities to Construct Drainage System - - - - - - - - - - - - - 14
212 The Criteria for Roadside Channels - - - - - - - - - - - - - - - 15
213 Design Flood for Road Drainage System - - - - - - - - - - - - - 15
214 Flow Velocity in Road Drainage System - - - - - - - - - - - - - - 15
CHAPTER THREE: - - - - - - - - - - - - - - - - - - 16 METHODOLOGY - - - - - - - - - - - - - - - - - - - 16 31 Research Methodologies - - - - - - - - - - - - - - - - - - - 16
32 Selection of the Study Area - - - - - - - - - - - - - - - - - - period
33 Study period - - - - - - - - - - - - - - - - - - - - - 18
34 Research design - - - - - - - - - - - - - - - - - - - - - 18
35 Study population - - - - - - - - - - - - - - - - - - - - - 18
36 Sample size and sampling procedures - - - - - - - - - - - - - - - 18
37 Study variables - - - - - - - - - - - - - - - - - - - - - collection
38 Data collection process - - - - - - - - - - - - - - - - - - - 20
39 Data processing and analysis - - - - - - - - - - - - - - - - - - 21 310 Ethical considerations - - - - - - - - - - - - - - - - - - - 21
311 Data quality assurance - - - - - - - - - - - - - - - - - - - 21
312 Limitations of the study - - - - - - - - - - - - - - - - - - - 22
313 Hydrological Analysis - - - - - - - - - - - - - - - - - - - 22
314 Hydrological Equations for Determining Peak Flood - - - - - - - - - - Method
3141 Rational Method - - - - - - - - - - - - - - - - - - 23
31411 Runoff Coefficient - - - - - - - - - - - - - - - 25
31412 Rainfall Intensity - - - - - - - - - - - - - - - - 26
31413 Time of Concentration - - - - - - - - - - - - - - 26
31414 Catchment Area - - - - - - - - - - - - - - - - 27
3142 The SCS method - - - - - - - - - - - - - - - - - - 28
31421 Catchment Area - - - - - - - - - - - - - - Rainfall-Runoff
31422 Rainfall-Runoff Equation - - - - - - - - - - - - - - 28
31423 Time of Concentration - - - - - - - - - - - - - - Curve
31424 Runoff and Curve Numbers - - - - - - - - - - - - - 32
31425 Hydrological Soil Groups - - - - - - - - - - - - - 34
315 Investigations of Design and Construction Practices on the study area - - - - - 34 3151 Design and Construction Practice at Station 18+160 - - - - - - - - 35 3152 Design and Construction Practice at Station 24+200 - - - - - - - - 36 3153 Design and Construction Practice at Station 42+120 - - - - - - - - 37 CHAPTER FOUR - - - - - - - - - - - - - - - - - - - 39 RESULT AND DISCUSSION - - - - - - - - - - - - - - - 39 41 Results from questionnaires analysis - - - - - - - - - - - - - - - - 39
411 Causes and effects of poor drainage system on asphalt road that response from the Engineers - - - - - - - - - - - - - - - - - - - - 39
4111 Causes of poor drainage on the flexible pavement road - - - - -
4112 The effects of poor drainage system on the road - - - - - - - 40 4113 Appropriateness of the drainage system - - - - - - - - - 42
4114 State of the drainage services - - - - - - - - - - - -
412 Causes and effects of poor drainage system on asphalt road that response from road users - - - - - - - - - - - - - - - - - - - - - 43
4121 Level of road users‟ satisfaction of the drainage system - - - - - 44 413 Causes and effects of poor drainage system on asphalt road that response from the residents - - - - - - - - - - - - - - - - - - - - 45
42 Results from observation and photography - - - - - - - - - - - - - - 46
421 Causes and effects of poor drainage system on asphalt road Surface due to poor drainage that collected from the field with the photography - - - - - - - 47
43 Results from Hydrological Analysis - - - - - - - - - - - - - - - Watershed
431 Descriptions of Watershed Area - - - - - - - - - - - - - - 51
432 Computation of Catchment Parameters - - - - - - - - - - - 52 4321 Catchment Parameters at Station 18+160 Drainage system - - - - 5at
4322 Catchment Parameters at Station 24+200 Drainage System - - - - 58
4323 Catchment Parameters for Design and Check at Station 42+120 - - - 58
44 Peak Discharge Computation - - - - - - - - - - - - - - - - - - 59
441 Peak Discharge at Station 18+160 Drainage System - - - - - - - - 59 CHAPTER FIVE - - - - - - - - - - - - - - - - - - - 62 CONCLUSION AND RECOMMENDATION - - - - - - - - - - 62 51 Conclusion - - - - - - - - - - - - - - - - - - - - - - - 62
52 Recommendation - - - - - - - - - - - - - - - - - - - - - 63 REFERENCES - - - - - - - - - - - - - - - - - - - - - - 64 APPENDEX - - - - - - - - - - - - - - - - - - - - - - - 67
APPENDIX A: Time of Flow, Unit Peak Discharge, Velocity of flow and SCS CN Charts 67 APPENDEX B: Roughness and Runoff Coefficient Values and Parameters for the Design of Drainage Structures - - - - - - - - - - - - - - - - - - - - - - 74 APPENDIX C: Questionnaire Type - - - - - - - - - - - - - - - - 82