Design of Water Resources Systems

Contents

Chapter 1. Water resources engineering 1

Introduction, 1

Water resources management, 2

An engineered water cycle, 4

The engineering design process, 5

Chapter 2. Applied hydrology 10

Introduction, 10

Rainfall, 12

Measurement of runoff, 15

Velocity-area method, 15

Hydraulic structures, 17

Floods and droughts, 19

Floods, 19

Droughts, 21

Rainfall and runoff, 24

Catchment, 24

Hyetographs and hydrographs, 25

Modelling, 26

Groundwater, 31

Catchment yield, 33

Surface sources, 33

Sub-surface sources, 34

Chapter 3. Development of water resources 37

Introduction, 37

Design of water resources systems

Planning considerations, 39

Estimating future water demand, 39

Design period, 40

Water quantity requirements, 41

Types of water supply scheme, 44

Run-of-the-river scheme, 44

Impoundment scheme, 45

Groundwater scheme, 47

Intakes, 47

River intakes, 47

Reservoir intakes, 48

Reservoirs, 49

Dams, 54

Types of dams, 54

Design considerations, 54

The design flood, 56

Spillway design, 60

Groundwater, 67

Wells, 67

Groundwater quality, 71

Chapter 4. Water treatment 74

Introduction, 74

Water dispersed species, 74

Water quality parameters, 76

Physical parameters, 76

Chemical parameters, 78

Biological parameters, 81

Water quality standards, 82

Background, 82

Raw water quality, 82

Drinking water quality, 83

Conventional water treatment processes, 84

Coagulation and flocculation, 86

Coagulation reactions, 86

Jar tests, 87

Floc growth and separation, 89

Sedimentation, 91

Sedimentation tanks, 91

Sedimentation theory, 93

Filtration, 99

Slow sand filtration, 99

Rapid sand filtration, 100

Hydraulics of filtration, 101

Water disinfection, 108

Background, 108

Kinetics and chemistry, 109

Chlorination practice, 110

Chemical stability, 111

Chapter 5. Water distribution 115

Introduction, 115

Pipelines, 116

Categories, 116

Design criteria, 117

Materials, 117

Laying, 118

Testing, 119

Joints, 120

Valves, 120

Pipe hydraulics, 121

Friction losses, 121

Fitting losses, 123

Pump-rising main systems, 125

General description, 125

Pumps, 128

Pressure limits in pipelines, 133

Distribution reservoirs and water towers, 135

Chapter 6. Sewerage systems 143

Introduction, 143

Sewer systems, 143

Combined and separate sewers, 143

Design considerations, 145

Wastewater flows, 146

Presentation of sewer data, 148

Storm sewer design, 149

Background, 149

Rainfall, 150

Catchment and sewer network characteristics, 151

Design computation, 153

Foul sewer design, 161

Pumping stations, 166

Storm overflows, 169

Chapter 7. Wastewater treatment 175

Introduction, 175

Wastewater characterisation, 176

Physical parameters, 176

Chemical parameters, 179

Wastewater composition, 183

Concentration and flow, 183

Wastewater sources, 185

Population equivalent, 185

Wastewater standards, 186

Treatment processes, 188

Primary treatment, 191

Screening, 191

Grit removal, 192

Primary sedimentation, 193

Secondary treatment, 194

Background, 194

Activated sludge, 195

Biofilter, 199

Sludge processing and disposal, 205

Effluent disposal, 207

References 209

Index 213