Rhythm

of the Rain

 

RAINWATER

HARVESTING

GARDEN


Presented By

MiraCosta College

Department of Horticulture

San Diego County Fair 

Summer 2009

WHY HARVEST RAINWATER?

 

San Diego is experiencing its third year of drought. This summer will undoubtedly bring more water rationing and shortages. Global warming, over development, and environmental court decisions have reduced water supplies available to our community. Even in our wettest years, San Diego relies on imported water to support the many water-needy plants common in our lush landscapes.          

 

Rain water is an invaluable source of water that reduces our demands on imported water supplies, especially for those who have wells.  The growth of the urban development and the increase of impermeable surfaces (parking lots, sidewalks, roofs, roads, etc.) have decreased the amount of rain water that is able to infiltrate into our aquifers and have increased the amount of urban runoff that pollutes our water ways. Urban landscapes can be designed to clean and harvest rainwater as opposed to allowing it to run off, overwhelming storm drains, and polluting our oceans. 

 

This garden is designed to demonstrate how San Diego’s homeowners can integrate rainwater harvesting concepts into their landscapes. Our design includes drought tolerant plants, permeable paving, a green roof to reduce runoff and provide thermal insulation to the structure, a bioswale planted with water cleaning grasses, and a rain barrel to collect rain water for irrigation in an attractive, aesthetically pleasing way. Time has come for San Diegans to be proactive in dealing with our water situation.



Please consider adding rainwater harvesting elements to your yard!

 

 

THE BENEFITS OF IRRIGATING WITH RAINWATER:

·         It is free! Irrigating with harvested rain water can significantly reduce your water bills, especially if you retrofit your landscape to feature a rain barrel or cistern and low water plants.

 

·         It reduces alkalinity in the soil! Many soils in San Diego are alkaline and suffer from low micro-nutrient availability. Irrigating with rainwater over many years can help acidify soil naturally and improve micro-nutrient availability.

 

·         It is salt-free! Another benefit of using rainwater to irrigate plants is that it does not contain the dissolved minerals and salts that normally occur in our tap water. These minerals and salts are detrimental to plant growth and build up in soil over time. Irrigating with rainwater helps clean these salts out of the soil and improve plant growth, especially for potted plants and houseplants with limited rooting area.




Helpful Web Resources:

Rainwater Harvesting Online Community: http://www.harvesth2o.com/


Brad Lancaster's Rainwater Harvesting Page:http://www.harvestingrainwater.com/


Rainwater Harvesting

Reference Books:

Sustainable Landscape Construction, a Guide to Green Building Outdoors, 2nd Ed. by Kim Sorvig.

 

Rainwater Harvesting for Drylands and Beyond, Vols 1-3 by Brad Landcaster

 

Rain Gardens: Managing Water Sustainably in the Garden and Designed Landscape by Nigel Dunnett and Andy Clayton

 

Rainwater Collection for the Mechanically Challenged by Suzy Banks, Richard Heinichen, and Trea Arenz.