5.13 - Reducing Urban Runoff

Question 1

Environmental Consequences of Urban Runoff

Answer 1

• Decreased infiltration (groundwater recharge)
• Rain washes pollutants into storm drains & into local surface waters:
  Pollutants & effects
• Salt (plant & insect death)
• Sediment (turbidity)
• Fertilizer (eutrophication)
• Pesticides (kill non target species)
• Oil & gasoline (suffocate fish/kill aq. insects)

Question 2

Solution: Permeable Pavement

Answer 2

• Specially designed to allow stormwater to infiltrate & recharge ground water
• Decreases runoff, decreasing pollutants carried into storm drains & into local surface water
• Decreases likelihood of flooding during heavy rainfall

Cons
- More costly than traditional pavement

Question 3

Solution: Rain Garden

Answer 3

• Gardens planted in urban areas, especially surrounding a storm drain
• Decreases runoff by allowing it to soak into garden soil surrounding storm drain
• Decreases likelihood of flooding during heavy rainfall
• Creates hab. for pollinators, sense of place & stores CO2

Question 4

Solution: Public Transit

Answer 4

Negative Effects of Cars:
- More cars on the road = more pollutants on streets to runoff into storm drains & local waters
- motor oil
- tire pieces
- gasoline
- Antifreeze
- More cars = more lanes & parking lots (impervious surfaces) & more stormwater runoff

Solution:
- Public transit decreases urban runoff, pollutants on road, CO2 emissions & even traffic!

Question 5

Solution: Building up not out

Answer 5

• Building vertically decreases impervious surfaces (decreasing urban runoff)
• Can be combined with “green roof” or rooftop gardens to further decrease runoff
• Green roof also sequesters CO2 and filters air pollutants out
  - Plants absorb NO2, PM, & other pollutants into stomata & store in tissue or soil