| |
Increase
permeability of driveways,
patios, walkways, and parking areas |
Direct
rainfall from rooftops
to landscaped areas |
 |
Wheel
tracks, also known as “Hollywood driveways,” can be used
in place of full-width asphalt or concrete driveways.
|
Local examples: 725 Homer Avenue and 735 Homer Avenue*,
Palo Alto. |
|
 |
If
your yard has clay soils, direct rooftop runoff to a rain
garden,
a landscaped area built with highly absorbent soil and set in a shallow
depression where runoff collects. A rain garden can also be used to
absorb runoff from paved surfaces and reduce ponding in yards with poor
drainage. |
Local examples:
735 Homer Avenue*, Palo Alto (rain garden absorbs downspout runoff) and
Menlo Park Parking Plaza #5* (biofilter absorbs parking lot runoff). |
|
 |
Pervious
concrete
contains air pockets that let rain trickle through to the soil
below. Use a layer of crushed rock beneath the concrete to
increase the amount of water that can be stored while it slowly
percolates.
|
Local examples:
Menlo Park Parking Plaza #5* (southeast of Santa Cruz Avenue between
Crane and Evelyn Streets), and 367 Addison Street, Palo Alto (driveway
of the historic Hewlett-Packard garage). |
|
 |
Roof
runoff can also be captured in a rain barrel
and used later for irrigation. Because of West Nile virus concerns, ask
your county vector control office about standing water regulations and
recommendations before installing a rain barrel or cistern. |
| Photos,
parts list & techniques from our workshop! |
|
 |
With
sufficient spaces between blocks, unit pavers
allow rainwater to pass through to the ground below. Open spaces can be
planted or filled with gravel. A layer of crushed rock under the pavers
is recommended for clay soils. |
Local example:
735 Homer Avenue*, Palo Alto |
|
 |
If
the runoff from your roof is piped directly to the storm drain,
consider disconnecting your
downspouts
from the storm drain. Instead, direct water to landscaped areas where
it can soak into the soil. Use downspout extensions and splash blocks
to keep water away from the building foundation. |
|
|
| |
Resources
Low Impact Development Center
www.lid-stormwater.net • Excellent
design information for a variety of runoff reduction techniques.
www.lowimpactdevelopment.org •
Homepage of the organization.
Center for Watershed Protection
www.cwp.org
• Thorough research and resources about many watershed issues.
www.stormwatercenter.net • The
“Stormwater Manager’s Resource Center” part of the website, with useful
fact sheets.
Environmental Protection Agency
www.epa.gov/owow/nps/lid • This
page on low-impact development contains fact sheets, study results, and
a good resources list.
Treepeople
www.treepeople.org
• The About Us section contains information on several completed
demonstration projects that retain, absorb, and reuse runoff. For the
residential project, select “T.R.E.E.S. Project”; for the school
project, select “Open Charter Project.”
www.sunvalleywatershed.org •
Treepeople is currently working on designs for a whole district of
the San Fernando Valley.
Puget Sound Action Team
www.psat.wa.gov/Programs/LID.htm •
Description of low-impact development principles, and lists of storm
water studies and resources.
Bay Area Stormwater Management Agencies
Association
www.basmaa.org
• Includes “Start at the Source,” a useful guide for anyone considering
a runoff reduction project. Look under “List of all documents” in the
Meeting Documents & Technical Reports section. |
|
296 KB)
