Taking steps during development

1
LOW IMPACT DEVELOPMENT

• Taking steps during development
• design to minimize changes to the
• hydrologic cycle (runoff and
• infiltration after a storm)

2
PERMEABLE PAVEMENT

• Allows water to infiltrate through the
  construction material back into the ground

NCSU BAE
3
GREEN ROOFS

• Help to lessen the effects of urbanization on
  water quality by filtering, absorbing, or
  detaining rainfall

NCSU BAE
4
BIORETENTION(RAIN GARDENS)

• Provides a storage area, away from buildings and
  roadways, where stormwater collects and filters
  into the soil

NCSU BAE
NCSU BAE
5
STORES ROOFTOP RUNOFF
CISTERNS AND RAIN BARRELS
6
STORMWATER WETLANDS

• TREAT STORMWATER RUNOFF BY SLOWING STORMWATER
  WHICH TRAPS POLLUTANTS

7
OPEN SPACE

• PARKS
• RECREATIONAL FIELDS
• LAND COVER THAT ALLOWS STORMWATER TO SOAK INTO
  THE GROUND

8
LEVEL SPREADERS

• Take channelized flow and spread it out into
  sheet flow

9
NARROW STREETS

• Reduce the amount of impervious surfaces, thereby
  reducing flooding and pollution from stormwater
  runoff

10
NO CURB AND GUTTER

• Avoiding the standard curb and gutter road design
  allows water to flow off the road and not
  accumulate in any one spot

Puget Sound Water Quality Action Team
11
SMALLER DRIVEWAYS

• Minimizing house setbacks from streets and
  narrowing driveways reduces impervious surfaces

12
FILTER STRIP

• Can be designed as landscape features within
  parking lots or other areas to collect flow from
  large impervious surfaces

13
GRASS SWALES

• Function as alternatives to curb and gutter
  systems

Uses grass or other vegetation to reduce runoff
velocity and allow filtration, while high volume
flows are channeled away safely
14
DISCONNECTED IMPERVIOUS AREAS

• Areas without any direct connection to a drainage
  system or other impervious surface, thus
  increasing the opportunity for infiltration