California LID

Low Impact Development Greens Facilities to Reduce Risk and Water Contamination
Managing water the natural way is pretty effective -- and low impact development is always a cost saver in the long run!

California water conservation in watersheds
Low Impact Development Reduces Stormwater and Urban Runoff
Historically, America's community motto for stormwater management has been "conveyance" -- moving water away from the site where it falls as quickly as possible. Traditional stormwater management tools include street gutters and curbs, pipes, and canals to remove water from the developed areas by reshaping creeks and rivers and lining them with concrete. And detention ponds, some with water quality filtration devices, regulate discharge to reduce peak flow impacts on receiving waters. For the most part, these practices reduce flood impacts, but do not completely address water quality, and aquatic and riparian habitat degradation issues.

Low Impact Development Reduces Cost with Source Control and Infiltration
In contrast with these long-practiced, expensive approaches, the guiding principle of low impact development approaches is not conveyance; it is "source control and infiltration". LID techniques maximize the area available for absorbing water into prepared soil through infiltration so that runoff volume and pollutant concentrations are reduced. Low impact development is achieved through a variety of site design and engineered infiltration techniques.
Benefits of Low Impact Development that Save Money and Environment
Some of the benefits of low impact development include:

* Groundwater recharge through infiltration of surface water
* Filtration of surface water with natural soils
* Protection of lakes, streams and the ocean from urban and agri runoff
* Meet Clean Water Act requirements for reduced pollutant levels and volume of runoff
* Reduce frequency and severity of floods
* Preserve stream and upland habitats
* Preserve regional trees and native vegetation
* Reduce sediment erosion in streams and lakes
* Increase aesthetics and recreational open space
* Increase land value and prevent degradation
* Increase public/private collaborative partnerships.

California Rain Garden Plants
Information on plants compatible for use in a California rain garden is posted at: Brooklyn BBotanic Gardens. Here's a list of California related plants for Rain Gardens.
California Wildflowers, Ferns, Grasses, and Sedges:

* Aquilegia formosa, Columbine
* Aralia californica, Elk clover
* Aristolochia californica, Pipevine
* Darmera peltata, Umbrella plant
* Delphinium glaucum, Tower delphinium
* Dicentra formosa, Pacific bleeding heart
* Epipactis gigantea, Stream orchid
* Lilium pardalinum, Leopard lily
* Mimulus cardinalis, Scarlet Monkeyflower
* Mimulus primuloides, Primrose monkeyflower
* Rudbeckia californica, Coneflower
* Polypodium californicum, California polypody
* Carex nudata, California black-flowering sedge
* Juncus patens, California gray rush

California Trees and Shrubs:

* Calycanthus occidentalis, Western spicebush
* Corylus cornuta var. californica, Hazelnut
* Myrica californica, Wax myrtle
* hysocarpus capitatus, Ninebark
* Populus fremontii, Freemont cottonwood
* Salix lucida ssp. lasiandra, Yellow tree willow
* Ribes sanguineum, Red-flowering currant
* Rubus spectabilis, Salmonberry
* Vaccinium ovatum, California huckleberry
* Washingtonia filifera, California fan palm

Desert Southwest Wildflowers and Grasses:

* Baileya multiradiata, Desert marigold
* Gaillardia spp., Blanketflowers
* Machaeranthera bigelovii, Purple aster
* Mirabilis multiflora, Giant four o'clock
* Penstemon spp., especially P. ambiguus, P. fendleri var. venusta, and P. superbus, Penstemons
* Salvia greggii, Cherry sage
* Zinnia grandiflora, Desert zinnia
* Aristida purpurea, Purple three-awn

Desert Southwest Trees and Shrubs:

* Acacia gregii, Catclaw acacia
* Celtis reticulata, Desert hackberry
* Cercidium microphyllum, Foothill palo verde
* Ephedra trifurca, Comatilla
* Justicia californica, Chuparosa
* Lycium fremontii, Wolfberry
* Olneya tesota, Ironwood
* Prosopis velutina, Velvet mesquite
* Yucca baccata, Banana yucca

Retrofit a Parking Lot to Increase Permeability.
Over sixty-five percent of impervious areas are associated with "habitat for cars". Using porous pavement in parking lots is a simple way to provide infiltration and reduce runoff.

Adding bioretention cells to landscaped areas and disconnecting downspouts can reduce peak runoff without losing parking space. Re-design of parking and driving space can reduce runoff without decreasing the amount of parking spots -- and reduced peak runoff and pollution protects and helps restore our streams, rivers, lakes and the ocean...the ultimate catche basin for all our urban runoff stormwater and pollutants.
Retrofit Streets to Reduce Runoff..and Increase Shade
Building vegetated swales, bioretention cells, and narrower streets without curbs promote effective drainage and filtration systems that use natural filtration by soil to keep pollutants, fertilizers, and other chemicals out of our precious fresh ground water system.

The basic components of a bioretention cell, or rain garden, are water flow from impervious areas; a filter strip that allows infiltration; a detention and filtration zone to hold rapid runoff, amended soil for hardy, native vegetation, and a buried under-drain discharge pipe for excess water.

These beautifully disguised water systems provide natural water storage, filtration and watershed flow of rains.

Local watershed systems not only are natural storage for our fresh water supplies, but they are the nurseries for local wildlife such as fish, frogs, dragonflies, and even mammals. After all, what life doesn't need fresh, potable water for drinking and bathing?
Replace lawns with rain gardens.
Rain gardens are small bioretention cells landscaped with plants, trees, and grasses. They are a particularly good way for small lot owners to enhance their landscaping while protecting water quality. By planting easy-care native wildflowers, hardy perennials and grasses, attractive gardens can be landscaped that have added environmental benefits.

More information on rain gardens is available at: Rain Gardens.

You can find more information about bioretention cells and stormwater management using rain gardens,etc. at the following resources:

* Low Impact Development Center www.lowimpactdevelopment.org
* U.S. Environmental Protection Agency www.epa.gov/owow
* Stormwater Manager’s Resource Center www.stormwatercenter.net
* National NEMO Network www.nemonet.uconn.edu
* LID Urban Design Tools www.lid-stormwater.net
* National Association of Home Builders www.toolbase.org/
* California Stormwater Quality Association www.cabmphandbooks.com"

There are challenges with low impact development, such as cost and maintenance, but the economic benefits offset these with environmental integrity: reduced cost of stormwater infrastructure, reduced utility fees, increased land value and decreased spending on some other environmental conservation programs. The natural way is pretty good -- and low impact is always a cost saver in the long run!

Publication Date: 10/10/2007