Drainage and Flood Mitigation

Learn to Manage Water Better

• Flooding
• Excessively wet soils
• Soil Problems - erosion, degradation, 

Lesson Structure

There are 7 lessons in this course:

1. SCOPE AND NATURE OF WATER MANAGEMENT
   • When is it a water problem?
   • What Needs to be Waterproofed in the Backyard?
   • Roofs -mould, mildew, structural damage, roof damage, electrical problems
   • Rooftop Gardens, Retaining Walls
   • Pots, spray units, drains, irrigation pipes, Hoses, Watering cans
   • Materials for Waterproofing - concrete, admixtures, membranes, sealers
   • Asphalt
   • Silicone sealant
   • Butyl liners
   • Fibreglass Kits
   • Plumbers tape
   • Welding
   • Bentonite Clay liners
   • Why Drainage is Important
   • Reasons for Drainage
2. WATER MOVEMENT IN SOILS
   • Types of soil particles
   • Soil structure types - prismatic, columnar. platy, crumb, blocky etc.
   • Influences on water movement - gravity, surface tension, water adhesion
   • Water on soil is in two forms
   • Field capacity
   • Infiltration
   • Suction
   • Saturation
   • Soil Moisture
   • Hygroscopic water
   • Lateral movement of water
3. UNDERSTANDING CAPILLARY ACTION
   • Adhesion forces
   • Capillary migration
   • Relative distance
   • Capillary fringe
4. MANAGING WATER AT THE SOURCE
   • Rainfall
   • Rainwater Harvesting
   • Stored Water – Dams, Reservoirs, Tanks
   • Diverting Storm Water
   • The Water Table
   • Leaks
   • Review What You Have Been Learning
5. MANAGING SURFACE DRAINAGE
   • Types of Surface Drainage Systems
   • Surface Drainage
   • Lesson 5 Additional Reading
   • Additional Suggested Tasks
   • Review What You Have Been Learning
6. MANAGING SUB-SURFACE DRAINAGE
   • Improving Soil Drainage
   • First decision: subsurface or surface drainage?
   • Types of Subsurface Drains
   • The Water Outlet
   • Gradients
   • Layout of Drains
   • Laying an Agricultural (Agi) Drain
   • Distance Between Drainage Pipes
   • Depth of Drains
   • Maintenance
   • Subsurface Drainage
   • Additional Reading
   • Review What You Have Been Learning
7. STORM DRAINAGE
   • Storm Runoff
   • Inlets
   • Manholes
   • Swales
   • Storm Water Management
   • Intensity of Rainfall
   • Stormwater Runoff Estimations
   • Selecting the Size (Diameter) of Pipes
   • Selecting the Size and Shape of Ditches and Swales
   • Set Tasks
   • Review What You Have Been Learning
   • Final Assessment