Rain Water

Why Rain Barrel in San Diego?

Sunny San Diego is not a location that pops into someone’s mind when they think of rain and definitely not a location that is thought to be ideal for rainwater harvesting. But San Diego is exactly the kind of place that needs to do rainwater harvesting. Before the benefits of rain harvesting are discussed, it is best to clarify what rainwater harvesting is.

What is the key idea behind harvesting rain?

A household or businesses collects rainwater for future use.

Rainwater capture is achieved by placing a barrel (usually 55 gallons) below a downspout. The downspout is the part of the rain gutter system that runs up and down a building’s exterior walls. Please see the pictures below for rain barrel system examples.

San Diego is an arid climate, so what is the rain harvest potential of the area?

This table depicts the rain harvest potential for the San Diego area under the following four assumptions:

1.     Barrels can hold up to 55 gallons of water

2.     Overflow from the barrels cannot be harvested

3.     The average annual rainfall in San Diego is 10.77 inches

4.     There is at least 0.3 inches of rain for 17 different rain events

What benefits would San Diegans gain through rainwater harvesting?

There are three main benefits that rainwater harvesting provides:

1.     Resource Conservation

2.     Pollution Prevention

3.     Free Water for Gardens

1. Resource Conservation

Rainwater harvesting will help San Diego conserve water, reducing stress on this precious resource. The strain on our water supply is a serious issue. Consider that in June of 2009, the City of San Diego issued a Stage 2 Water Alert and began mandating water use restrictions. Harvesting rainwater is one of many tools that San Diegans can utilize to help safeguard our water resources. For further water conservation tips, please see the City of San Diego’s water conservation tips website at: http://www.sandiego.gov/water/conservation/tips.shtml

By conserving water, San Diego also indirectly reduces energy consumption. San Diego gets the majority of its water from the Colorado River and San Joaquin Valley. To transport this water to San Diego, pumps powered by electricity are needed. When San Diegans reduce their water consumption they also help California conserve energy by decreasing the amount of water pumped from these two principle sources.

2. Pollution Prevention

Capturing rainwater reduces the amount of runoff entering storm drains and nearby water bodies. Runoff contains pollutants such as pesticides, fertilizers, litter, and heavy metals. The runoff can directly enter water bodies or be carried through the stormwater conveyance system to outlets in nearby rivers, lakes, and ocean areas. Decreasing runoff helps keep San Diego beaches and aquatic systems clean.

3. Free Water for Gardens

Rainwater is great for gardens and it is free! Water from rain harvesting lacks chlorine, fluoride, and dissolved solids, providing terrific water for landscapes. Additionally, this water is free and may reduce monthly water bills, saving money.

Sources:

http://www.sdcwa.org/manage/sources-rainfall.phtml

http://www.wrh.noaa.gov/sgx/climate/san-san.htm

http://www.lakesuperiorstreams.org/stormwater/toolkit/rainbarrels.html

http://www.sandiego.gov/water/conservation/tips.shtml

http://howtomakearainwaterbarrel.com/wp-content/uploads/2009/03/make-a-rain-water-barrel-250×300.jpg

http://www.sandiego.gov/water/conservation/#reduce

http://www.sandiego.gov/water/conservation/rainwater.shtml

http://www.sandiego.gov/water/conservation/rainwater.shtml#advantage

http://www.sandiego.gov/water/conservation/

http://www.signonsandiego.com/news/2010/apr/11/water-runoff-fixes-could-be-costly/

http://www.signonsandiego.com/news/2010/jan/27/rain-their-parade-please/

http://www.water-ed.org/watersources/community.asp?rid=10&cid=663