Rain Barrels and Water Harvesting

Rain Barrels can be placed under roof downspouts to collect rainwater that runs off your roof. The collected water can be used for any number of things around your house. Its a great way we can do something for the environment by conserving water, protecting local waterways and the Chesapeake Bay; while saving money at the same time.

Page updated on Nov 5, 2020 at 1:52 PM

Jesse's Rain Barrel

 New! Watch a presentation by the Northern Virginia Soil and Water Conservation District here.

Why Rain Barrels?

Provide your plants with water they will love!
Unlike treated water, which is "softened" with dissolved minerals, rain water is naturally soft. The water stored in your rain barrel is great for washing your car and watering indoor or outdoor plants.  It also doesn’t contain chlorine or fluoride.

Save money and water!
Instead of water from the tap or faucet, you can use the water you've saved to keep your home landscape happy and growing. You'll also reduce your water bill!

Protect the Chesapeake Bay! 
Water stored in your rain barrel is water that won't rush off into our streams. Instead, as you use the stored rain water around the home and garden, it will absorb slowly into the ground, replenishing groundwater supplies. By decreasing the volume of storm runoff, rain barrels also help moderate stream erosion and the resulting pollution that is impairing the Chesapeake Bay.

Build Your Own Rain Barrel Workshops

The City of Alexandria is dedicated to protecting and enhancing the natural environment.  One of the ways we do this is by providing outreach and education to citizens for practical solutions like installing rain barrels at home.  The City provides "Build Your Own Rain Barrel Workshops" as part of the Northern Virginia Rain Barrel Program Partners.  
The barrels we use are thick, sturdy, plastic barrels that were once used for pickling.  The Partners purchase the barrels and have "cleaning events" with volunteer groups to wash the barrels.  So while there may be some scuffs here and there on the barrels, its because they are being re-purposed and kept out of the landfill.  Another plus for the environment!  Please visit  Northern Virginia Rain Barrel Registration  or sign up for  "Environmental News" eNews  to get details on the next rain barrel workshop.  

Want to make one at home?   Check out this podcast and find out how to make and install one yourself! 

Rain Barrel FAQs

What do the rain barrels look like and where do you get them?
The rain barrels offered in the Rain Barrel Partners workshops are made from plastic barrels that used to hold pickles, olives, peppers, or onions. During the workshops, the barrels are re-purposed into rain barrels.  New and other re-purposed barrels can be found at locations in the area.

How large are the rain barrels?
The rain barrels from the workshops hold approximately 50 gallons. They are approximately 23 inches wide. The height ranges from 41.25 inches to 43.75 inches tall.

Will I get mosquitoes in my rain barrel?
The rain barrels are capped with a fiberglass screen that allows water in, but keeps mosquitoes from getting into the barrel to lay their eggs. However, if you are concerned about mosquitoes breeding in your rain barrel, you can add a whole or a half of a Mosquito Dunk to the water in your barrel to kill mosquito larvae. Mosquito Dunks can be purchased at most garden supply stores.

Is the water in the rain barrel safe to use in my vegetable garden?
There are differing opinions on this subject. Rain barrels that collect water from copper roofs or from roofs that have been treated with CCA (chromated copper arsenate) to prevent moss or algae growth should not be used on edible plants. If you have treated your roof with chemicals or installed zinc strips to prevent moss or algae growth, you should also not use the water in your rain barrel on your vegetable garden. Other considerations include the potential for air pollution in your area. Water flowing from your roof can contain deposited air pollutants. However, this water may end up in your vegetable garden anyway. No matter what you decide, make sure to wash all your garden produce thoroughly before you eat it!


Things to Consider

There are two main drivers to look at first when considering rain barrels.

The first thing you want to consider is whether or not your roof downspouts are connected to the storm drain system.  Currently, City ordinance does not allow for disconnection of the downspouts if they were connected as part of the development.  If, however, the downspouts are not connected (meaning they discharge onsite as part of overland flow), then they may be good candidates for rain barrels.

The rain barrels can be placed under the downspout by first cutting the downspout.  Keep the bottom "elbow" and reconnect it to the cut end.  The new end should discharge into the top of the barrel and fill up during a rain event.  If the barrel gets full, it should overflow through a hose connected at the top.  The overflow should be situated so that water is directed away from the building foundation.  Or a diverter can be placed on the downspout so that when the barrel is filled, the water is then diverted back into the downspout and discharges at the "normal" location.

It is also important to remember to empty rain barrels after a storm event so that they are ready to receive the rain from the next event.  Either way, it's good to empty the barrel about every week (5-7 days).  There are a couple approaches to emptying rain barrels. The rain barrel has a spigot (aka hose bib) attached to the bottom.  A soaker hose can be attached to this and the spigot opened to allow slow infiltration into landscape areas for a less hands-on approach.  You can also leave the spigot closed and fill a watering can.  Installation height above ground level will determine the water pressure at the spigot (and hose).  A pump (either hand or electrical - possibly solar) can be installed to increase the pressure and allow you to use the hose in a more traditional manner.


Here are some resources to assist you install and maintain your rain barrel - whether you went to a Build Your Own Rain Barrel workshop or bought one from a retailer.  The links are provided not as an exhaustive list or a show of preference, but just to help you get going with other accessories, finding installation help, or to paint your rain barrel.

Rain Barrel Installation Brochure
Rain Barrel Accessories and Maintenance