Rainwater Harvesting Video
TWDB Rain Water Harvesting Manual.jpg

Safety First!

Safety is always a must when working with power tools. So, we strongly recommend you wear a pair of safety glasses or some sort of eye protection during this project.


Where to find an empty barrel:

  • Dave the Barrel Man (www.davethebarrelman.net); 811 Roosevelt, San Antonio, Tx 78210; Phone: 210-534-5416

  • Tank Depot- (all size barrels); 2620 SE Loop 410, San Antonio, TX 782223 Phone: 210-648-3866

  • Tanks A Lot - 7403 West Loop 1604, San Antonio, TX 78249; Phone: 210-393-2225

  • Son Beverage Co.; 6896 Fairgrounds Pkwy, San Antonio, TX 78229; Phone: 210-733-7761

  • Barrels by Joel - Phone: 210-717-6850

  • Home Depot/Lowes - small barrels

  • Many on-line resources - Watch out for shipping costs!​​

Tools needed:

  • drill - 3/8 to 1/2 hp

  • Paddle (spade) bit, 15/16" and 2 3/8" hole saw

  • Set of hole saws or a jigsaw to make a 6" hole in the top

Materials needed:                                                                

  • A ¾” brass faucet (hose bibb)

  • 2” male PVC connectors & electrical Nut

  • Tube of silicone (bathtub)

  • Barrel​

Step 1 - Drill a hole in the top of the barrel for rainwater to flow into.

Mark a spot in the top of the barrel. It doesn’t have to be the middle. Use a 6” hole saw to cut it out. Or using the bottom of a one-gallon plastic pot, mark a circle around the bottom of the pot.  Drill a ¼” hole on one side of the circle and saw the circle out.  Saw to the outside line you drew with the plastic pot.

Step 2 - Drill the overflow hole.

Using the pot as a depth gauge, mark and drill the overflow hole just beneath the depth of the pot. Use the 2 3/8” hole saw.  

Step 3 - Drill a hole for the hose bibb. 

About 3 inches up from the bottom of the barrel, drill a 15/16” hole for the 3/4” hose bibb. 

Step 4 - Install the hose bibb. 

Put a little silicone around the threads on the hose bibb, push down and screw it in.  It will be sealed when you finish. Be sure to point the hose bibb to the side for better access. About 3 inches up from the bottom of the barrel, drill a 15/16” hole for the 3/4” hose bibb. 

Step 5 - Install the overflow. 

Insert the 2” adapter with the male threads through the hole. Thread the 2” electrical nut on adapter inside of the barrel.

Step 6 - Screening out debris.

Place mosquito screen in bottom of pot & add rocks (about 2-3 inches deep) and place it in the top of the barrel.  This is the filter to keep out the large stuff off the roof. 

Step 7 - Connect your rain barrel to the downspout.

Place your rain barrel in a location where it will capture rain running off of the roof. Or, you can attach a diversion to your existing downspout that will direct water into the barrel.

Other Considerations

  • Level your barrel!!

  • Elevating barrels provides room for watering cans and increases gravity flow

  • If linking barrels together, place an overflow pipe on last barrel

  • Pond Pumps and transfer pumps can be used to increase flow

  • Consider placement of faucet if you live in a windy area

  • If you have children, strongly advised to anchor the barrel to your home

Connecting two or more barrels together is easy!

1.If you want to hook two or more barrels together, use the overflow hole as the hookup between the barrels.​

2.Use a piece of 2” PVC pipe with a male-threaded connector glued to the end and screw it into the female fitting on the inside of the first barrel.  Do the same thing on the other end of the pipe and on the next barrel until all the barrels are hooked up.

3.If you do the same setup on the bottom of all the barrels, the water will empty out of all the  barrels at the same time.  PLUS, you only need one hose bibb in one barrel.