文档介绍：School of Civil Engineering
孙仁娟
2012-05-21
URBAN ROAD DESIGN
Lecture 13- Stormwater drainage
Contents
Background
Components of stormwater drainage
Types of stormwater drainage
Design of stormwater drainage
1. Background- Stormwater flow in a natural environment
1. Background-
A storm drain, storm sewer (.), stormwater drain (Australia and New Zealand) or drainage well system (UK) or simply a drain or drain system is designed to drain excess rain and ground water from paved streets, parking lots, sidewalks, and roofs.
Storm drains vary in design from small residential dry wells to large municipal systems. They are fed by street gutters on most motorways, freeways and other busy roads, as well as towns in areas which experience heavy rainfall, flooding and coastal towns which experience regular storms.
1. Background- History
Archaeological studies have revealed use of rather sophisticated stormwater runoff systems in ancient cultures. For example, in Minoan Crete approximately 4000 years before present, cities such as Phaistos were designed to have storm drains and channels to collect runoff.
1. Background- Environmental impacts
Water quality
The first flush from urban runoff can be extremely dirty. Storm water may e contaminated while running down the road or other impervious surface.
Water running off these impervious surfaces tends to pick up gasoline, motor oil, heavy metals, trash and other pollutants from roadways and parking lots, as well as fertilizers and pesticides from lawns.
Roads and parking lots are major sources of nickel, copper, zinc, cadmium, lead and polycyclic aromatic hydrocarbons (PAHs), which are created bustion byproducts of gasoline and other fossil fuels.
Roof runoff contributes high levels of pounds and zinc. Fertilizer use on residential lawns, parks and golf courses is a significant source of nitrates and phosphorus.
1. Background- Reuse
Reducing stormwater flows
Runoff into storm sewers can be minimized by includi