Test page

Sourcing the Rain

Design landscape to welcome the rain

Bioswale: Vegetation captures runoff from paths at UC Berkeley.On any house lot, there are three potential sources for harvesting the rain. The easiest to capture is the rain that falls on the yard. Shape the surface of the soil to slow down runoff, raise paths and patios, and sink all planting areas to capture the flow. Choose plants -- primarily low-water-use natives -- that can absorb and hold that water in their root systems. This means that rainwater doesn't run off into the street, where it would be swept away with motor oil to be further polluted in the sewer system or discharged directly into a local waterway.

Harvest runoff- curbcuts and bioswales

The second source of rainwater is the street. Streets run a little like rivers:  Roads are typically graded so that water flows to the curb and then runs down the gutter to storm drains. In some cities like San Francisco and Portland, the storm drains are connected to the sewer treatment plant, and heavy rains cause the sewer plant to overflow raw and partially treated sewer into the bay or river. Other cities connect storm drains to underground creeks, and the polluted water runs straight into the bay or nearby river. By cutting curbs and digging sunken basins street water enters the basin and infiltrates the soil, rather than erosively running over it. These vegetated basins or "bioswales" grow native plants, clean water, protect creeks, and green cities.

Sidewalk swale: Sidewalk bioswale-Portland, ORBasin after curb cut: Storm water runoff flows into basin.Cutting the curb.: A concrete saw rented for the day cuts the curb.

Store the rain- cisterns and rainbarrels

The third source of rainwater is the roof. Even in areas with low rainfall there is an enormous potential for harvesting rainwater.

For example, the roof a 1,000 square foot house can collect around 600 gallons per ONE inch of rain! In an "average" year with 12 inches of rain in Los Angeles, that small roof could collect 7,200 gallons. A larger house with 2000 square feet, could collect 14,400, now that's a big tank for a back yard! A raincatchment system that collects rainwater to be used for outdoor irrigation is straight forward. Roof water gathers in the gutters and runs to a pipe. The dirtiest first rain of the year cleans the roof and is directed away from the tank in a "first flush system". The cleaner water goes through a screen to remove leaves, and then funnels into the top of the covered tank. The tank is dark, to prevent algea from growing, and screened, to prevent mosquitoes from entering. Near the bottom a hose attachment allows for irrigation.

Rainbarrels are a popular way to begin rainwater harvesting, especially in urban areas; they are low cost, and can be installed along houses, under decks, or in other unused spaces.

There is a huge range of options for cisterns, from plastic, to ferrocement, to metal, to fiberglass.

(images, different cistern examples)

Indoor use

Rainwater can also be used indoors for non-potable uses. These systems more efficiently utilize the rainwater as it's used all winter long when there is no need for outdoor irrigation. They are more complicated to install, and thus much more expensive.

Photos
http://www.camden-family.com/gallery/water_tank

waterharvesting resources

http://www.harvestingrainwater.com/rainwater-harvesting-inforesources/
Links
www.waterharvestonline.com