What is Rainwater Harvesting?

What is rainwater harvesting?

"Rainwater harvesting is the process of capturing rain and making the most of it as close as possible to where it falls.  By harvesting rainwater on the land within the soil and vegetation, or in cisterns that will later irrigate the land, it is possible to control erosion, reduce flooding, and minimize water pollution.  This practice is enormously beneficial in a world with a finite supply of fresh water that is becoming increasingly polluted.

Although rainwater harvesting has been accomplished by humans in virtually every drought vulnerable region of the world for millennia, our society, until very recently, seemed to have a collective amnesia about the utility, efficiency, and beauty of rainwater harvesting practices." Brad Lancaster, harvestingrainwater.com


You can collect 600 gallons of water from a 1000 sq ft roof in a 1” storm. If we had harvested rainwater off that roof over the course of our 9 inch rainy season in Santa Barbara last year, we could have collected 5400 gallons of water! This can be redirected into our landscapes from our downspouts, via swales (channels) and mulch basins, to slow, spread, and sink the water. Basins, depressions in the soil that are filled or partially filled with mulch, create a focal point for water to percolate into the soil, creating a biologically rich sponge that is a perfect medium for nurturing drought tolerant and other plants. 


Run-on is stormwater that comes from outside your property or runs down the street and through your neighborhood, picking up speed and heading towards the ocean. Capturing run-on in the soil, in yards or parkways, allows it to slow, spread and sink, as well as hydrate drought tolerant and other plants. 

 Santa Barbara, with one rainy season a year, is a perfect place to build systems to make the most of the rain we get.

Sweetwater Collaborative helps people put in water harvesting earthworks, tanks, and raingardens, through community based hands-on workshops, design, consulting, coaching, and public and professional classes and courses, building skills and models in our community.

rainwater tank on the big island of Hawaiirainwater tank in Puna district, on the big island of Hawaii