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Rain Barrel Workshops and Resources

A 55-gallon barrel painted with flowers and mountains sits on a stand and is connected to the rain gutter of a home.

2025 Rain Barrel Workshops

In-person workshops

Interested community members can still register for all workshops as observers.  Please note that due to the size of the existing waitlists for each workshop, you will not be able to receive a free rain barrel – the remaining space is for observers who can attend to listen, learn, receive handouts, and ask questions at the workshop. Registering does not confirm an observer spot in the workshop – you will receive a confirmation email within a week of registering. English Registration Form.

Join us virtually

Due to the high demand for these workshops, we have scheduled a webinar for Wednesday, May 14, 6-8pm. Register for our Rain Barrel Webinar.

Interest form – Join us later!

You can also fill out the Rain Barrel Interest Form to receive updates about future rain barrel workshop opportunities.

For questions about the 2025 Rain Barrel Workshops, email Cristina Ramirez at [email protected].

ADA statement: Boulder County wants to ensure that everyone has equal access to our programs, activities, and services. To request an Americans with Disability Act (ADA) accommodation, please email [email protected], or call 303-441-1386. Submit your request as early as possible, and no later than two business days before the event.

Language access statement: If you need help in another language, please email [email protected] or call 303-441-1531. Contact us as early as possible, and no later than three business days before the event.

In-Person Workshops

Lafayette Workshop *FULL*

  • Date: Thursday, April 3
  • Time: 5:30-7:30pm
  • Where: Lafayette Public Library, 775 Baseline Rd, Lafayette, CO 80026, in Meeting Room

Longmont Workshop – *FULL*

  • When: Saturday, April 5
  • Time: 10am-12pm
  • Where: Longmont Senior Center, 910 Longs Peak Ave, Longmont, CO 80501 in Classroom D-E

Louisville Workshop *Observers only – waitlists for rain barrels are full*

  • When: Saturday, May 10
  • Time: 2-4pm
  • Where: Louisville Recreation and Senior Center, 900 Via Appia Way, Louisville, CO 80027 in the Crown Room

Boulder Workshop *Observers only – waitlists for rain barrels are full*

  • When: Monday, May 12
  • Time: 6-8pm
  • Where: Boulder County Recycling Center, 1901 63rd St, Boulder, CO 80301, in the Education Room

Interest Form

Can’t attend a rain barrel workshop right, now but interested in attending one in the future? Please fill out the Rain Barrel Interest Form to help inform future rain barrel workshops and rebate opportunities.

Frequently Asked Questions (FAQ)

How do rain barrels conserve water?

Rain barrels conserve water by collecting rainwater that would otherwise run off your roof and into storm drains, allowing you to store and reuse this captured water to irrigate your lawn and garden, essentially providing a free source of water that reduces your use of and reliance on municipal water supply.

To actually conserve water and reduce your overall municipal water use, it is important that you adjust your current irrigation schedule and replace it with water from your rain barrel:

  • Adjust your irrigation schedule: reduce the amount of water (length of cycle or number of cycles), or remove a day from your watering schedule, and replace with rain barrel water.
  • Use your water rain barrel to water a NEW garden, tree, or other planting instead of adding an additional drip line or sprinkler.

How do rain barrels protect water quality?

Collecting rainwater keeps it from becoming stormwater runoff that can pick up pollutants as it flows to the nearest storm drain and instead puts this precious resource to good use. Stormwater pollution occurs when runoff collects trash, pet waste, chemicals, and other pollutants as it flows through our community. Stormwater ends up directly in local waterways – it is never cleaned or treated.

Is collecting rainwater legal in Colorado?

Collecting rainwater is legal in Colorado. Rainwater harvesting was legalized in Colorado in 2016 with some restrictions: the water can be used for outdoor use only, and single-family residences or multi-family residences (4 or fewer units) can only install 2 barrels with a combined maximum storage of 110 gallons.

I live in a community with a homeowners association, can I install a rain barrel?

Homeowners associations (HOAs) cannot prevent you from getting a rain barrel, but they may have aesthetic or location requirements. Talk to your HOA about what approval processes or aesthetic guidelines you might need to follow.

What else can I do to prevent stormwater pollution?

Stormwater pollution can start at home. There are many easy ways residents can take action to prevent stormwater pollution. They center around only allowing rain or clean water to enter the road and flow into nearby storm drains. See KICP’s Resources for Residents webpage for more ideas and information.

  • Clean up pet waste
  • Use commercial car washes
  • Monitor your vehicle for leaks
  • Compost or mulch yard waste and leaves, keep it out of streets
  • Minimize pesticide use
  • Minimize fertilizer use: do a soil test, leave grass clippings, use compost or compost tea

What else can I do to prevent water runoff from my property?

As we have replaced permeable natural environments like forests and grasslands with the impermeable surfaces of houses, driveways, and roads, a lot of the water that used to soak directly into the ground now “runs off,” becoming runoff that enters the nearest storm drain or waterway. Learn more on the KICP’s Slow the Flow webpage.

Some projects and practices to prevent water runoff from your property and encourage it to go straight into the ground include:

  • Prioritizing vegetated landscaping and mulch and using permeable landscaping materials (materials with “breaks” in them instead of one long flat piece of concrete) like gravel and pavers.
  • Disconnecting downspouts by directing water from downspouts to vegetated areas.
A 55-gallon barrel coated in gray paint being prepared to be turned into a rain barrel for collecting rainwater.

Rain Barrel Installation Guide

Thank you to the Colorado Stormwater Center for compiling the original rain barrel installation guide that the information on this webpage is based on.

Colorado Rain Barrel Regulations

In 2016, Rainwater Harvesting was legalized for the very first time, but there are some restrictions:

  • Single-family residences and multi-family residences (4 or fewer units) can only install 2 barrels with a combined maximum storage of 110 gallons.
  • The water may only be used for outdoor purposes: watering lawns, plants or gardens. Users should evaluate the water before using it for other outdoor purposes such as car washing, livestock watering, etc.
  • Never use rainwater for drinking water, cooking, or other indoor household purposes. Rainwater is untreated and may contain contaminants that could harm you or your pets if ingested.
  • Containers must have a sealable lid to prevent mosquito breeding.

Learn more from the Colorado Division of Water Resources Rainwater, Storm Water & Graywater.

Getting Started

Before purchasing and installing your rain barrel, there are several considerations to keep in mind:

  • Rain barrels come in many different sizes. Maximize the amount of water you can store by planning for two 55-gallon barrels.
  • Check with your landlord or Home Owner’s Association (HOA) before you purchase your rain barrel as they may have aesthetic and/or location requirements. HOAs legally CANNOT prevent you from installing rain barrels.
  • Consider spigot placement and have a plan for overflow water. If your barrel has an overflow valve, direct it away from your house or flood-prone areas. Overflow water can be directed toward your lawn or garden.
  • Rain barrels need winterization just like a sprinkler system. Make a barrel storage plan for winter.

This installation guide walks you through how to build and install a rain barrel using a 55-gallon plastic barrel and diverter kit.

 

Supplies

Make sure you have all the necessary supplies before installation!

1. Rain barrel with sealable lid or cap

2. Diverter kit including:

  • Diverter
  • Fill hose
  • Fill hose seal
  • Threaded rubber spigot seal
  • Winterization cap
  • Hole saw kit
  • 2 stainless steel screws
  • Plastic full port spigot

3. Other tools and supplies

  • Drill
  • Gloves
  • Eye Protection
  • Level
  • Tape Measure
  • Pencil
  • Wrench

4. Decorating (if you are painting or decorating your barrel)

  • Sander and sand paper (100 weight)
  • Primer (plastic paint primer)
  • Exterior house paint and/or acrylic paint
  • Paint sealer (if using acrylic paint)

Where to Buy

These are locations we are aware of where you can buy, rent, or borrow these supplies in the Boulder County area. Prices listed are from Spring 2025.

1. Rain barrel with sealable lid or cap

  • Colorado Rain Catcher (local)
    • DIY Up-Cycled Rain Barrel & Kit Bundle – $92
    • Up-Cycled 55 Gallon Rain Barrel – $50.00
  • Container Reclaimer (local – Arvada)
    • Open Top Poly Barrel, Food Grade 55-Gal – $45
  • Blue Barrel (nationwide)
    • Relies on local barrel vendors

2. Diverter kit

3. Other tools and supplies

  • Borrow from a family member, friend, or neighbor
  • Post in a neighborhood group or online community group
  • Resource Central for affordable used tools
  • Check Home Depot or Lowe’s for tool rental options
  • Longmont residents can use the City of Longmont Library of Things

4. Decorating

Choosing a Rain Barrel

When choosing a rain barrel, there are some features you need to have, and some that you want to avoid or be cautious of.

Features to look for:

  • Removable, sealable/screw cap lid: Makes the barrel easier to clean and ensures pests cannot enter the enclosed barrel.
  • Spigot located 1-3” from bottom: You will not be able to reach any water below the spigot.
  • Thick plastic: A metal barrel would need to be painted with a plastic paint coating to prevent rust.
  • Divertor/overflow mechanism: Diverters will keep leaves and debris out of the barrel. Water needs to be able to safely overflow from the barrel when it is full – it should not back up into the gutter or spill too close to the house foundation.
  • Food-safe barrel: Beware buying barrels second hand from places like Craigslist and Facebook Marketplace that may have stored dangerous or unknown materials.

Features to avoid:

  • Open top/screen (will allow critters, bugs, mosquitos, and sunlight to enter the barrel – sunlight will encourage algae growth)
  • High spigots (cannot access water at bottom)
  • Metal (needs paint to avoid rusting)
  • Barrel of unknown origin
An installed rain barrel with several landscaping pavers set on top of it to weigh it down.

Rain Barrel Safety

Keep safety in mind at each step of the installation process and understand what precautions to take long-term to keep kids, pets, and property safe once your rain barrel is installed. Full rain barrels weigh nearly 500 pounds!

  • Supervise children and pets: Children must always be supervised around rain barrels – no one should climb, tip, or play with the rain barrel. Watch pets who may try to tip or climb the rain barrel.
  • Build a good base: An unstable rain barrel or one that can be tipped over can hurt people or surrounding property, or spill water too close to the foundation of the house. A flat, well-built, secure base ensures that your rain barrel stays upright.
  • Secure the rain barrel long-term: You may also need to secure your rain barrel to its base if it is an exposed area, or if you are storing it outdoors during the winter. Windy conditions can tip over empty or light, causing damage to the downspout it is attached to, the surrounding property, and the barrel itself.
    • Tip: Use straps, bricks, cinder blocks, or landscaping rock to weigh down your barrel if needed

Choose a Location

Consider the following when selecting a location for your rain barrel:

  • Locate the downspouts around your house. Pick a location based on the ease of making a level base and its proximity to where you need the water.
  • The area must be flat, at least 2 ft. x 2 ft., and within 3 feet of a downspout.
    • A 55-gallon barrel has a diameter of about 2 feet – you may need more space depending on your base and how you will access the spigot.
    • Installing less than 3 feet from the downspout is preferable to prevent the connection hose from drooping.

Create a Base

The base for the rain barrel raises the barrel off the ground to create water pressure and improve access to the spigot. It must be strong and sturdy to support the barrel, which can weigh up to 500 pounds when full.

Important reminder: Decide on your base BEFORE installation – the height of your base will determine where you drill into your downspout.

  • The base should give your barrel enough height to fit a hose, bucket, watering can, etc., under the spigot.
    • Tip: Purchase a short hose to use at the spigot of your rain barrel. This gives flexibility to fill various sizes of watering cans and buckets.
  • Purchase a commercially available rain barrel stand or construct a simple base with wood, cinder blocks, bricks, or extra patio pavers.
    • Tip: If you don’t like the look of cinder blocks or landscaping pavers, or need to follow aesthetic guidelines, get a piece of wood to install in front and around your base.

Ongoing Care and Maintenance

A rain barrel may collect and accumulate sediment and organic debris throughout its lifespan. Here are a few quick tips for proper rain barrel hygiene:

  • Use collected water within 7 days.
  • Empty, clean, and dry your barrel every year, or more often if possible/necessary.
  • Disconnect if leaving home for an extended time.
  • Downspout filter must be cleared of debris periodically.

Mosquitos

Keep insects, particularly mosquitoes, away from your rainwater harvesting system:

  • Ensure the barrel and all openings are properly covered.
  • Empty the barrel regularly.
  • Keep the top clear of standing/pooled water.
  • Use “Mosquito Dunks” in the barrel and on top if water is pooling there.
  • Use several tablespoons of vegetable oil to create a barrier at the water surface.

Algae Build Up

If not properly maintained, particularly in humid regions, your rain barrel may provide an ideal habitat for algae growth. This layer of algae growth on the interior of the barrel walls can settle at the bottom of the barrel, causing clogs and even harm to your irrigated landscape.  Thinking through the placement of your barrel and proper maintenance can help avoid some of these issues:

  • Place barrels out of direct sunlight.
  • Use opaque barrels or paint your barrel (so the walls shade the inside).
  • Keep gutters clean (nutrients can leach into your barrel from the roof runoff).
  • Clean the barrel regularly and use harvested water frequently.

If you need extra assistance removing stubborn algae, use a diluted (2%) bleach solution. Dispose of this used bleach solution into an indoor sewer drain, not outdoors.

Cleaning Your Barrel

Cleaning your barrel is important for maintaining water quality and preventing algae blooms:

  1. Disconnect the barrel from your house.
  2. Rinse out the barrel with a hose.
  3. Use a long-handled scrubber.
  4. Add mild cleaning products:
    • 16 oz. box of baking soda and 64 fl. oz. distilled white vinegar.
    • Mild dish soap, castile soap, and/or phosphate-free soap.
  5. Turn the barrel on its side and swish vigorously, use a scrubber if possible.
  6. Rinse out the barrel with a hose.

Tip: Barrels with a fully removable lid are easier to clean. If you have the style of barrel with two small holes on top, it is important to stay on top of cleaning and maintenance since build up and algae will be more difficult to reach and scrub out of this style of barrel.

Winterization

Rain barrels are typically used between March and October in temperate climates. In warmer parts of the US, rain barrels can be used year-round. However, freezing temperatures can cause permanent damage to your system, particularly the diverter and spigot. Keep your rain harvesting system in good shape by following these easy winterization steps:

Barrel Storage

  1. Drain your system – let gravity slowly empty the barrel.
  2. Dry the barrel thoroughly.
  3. Remove diverter and overflow hose. The spigot should survive outdoor temperatures.
  4. Store your barrel:
    • Inverted in the garage or basement.
    • Resting upside-down on bricks or concrete blocks if storing outdoors.
    • In its usual location, as long as it is disconnected from the downspout and weighed down/secured to prevent it from falling.

Downspout

This step is critical if you cut your downspout to install your rain barrel! You will need to add a gutter extension to channel the water away from your house.  If your rain barrel uses a diverter such as the flexi-fit-diverter found in the RainRecycle rain barrel kit or the Earthminded DIY rain barrel kit, there is a winter hole cover provided. Simply install it and you are done. If you do not have a winter hole cover, you can order one from the www.rainbarreldepot.com.

Decorating Your Barrel

Rain barrels can be functional and look great! Painting the barrel may help meet aesthetic requirements. Remember to use a ground cover and never rinse paint brushes outside – keep soap and all paint out of out of landscaping and storm drains.

  1. Disconnect your barrel from the downspout (or decorate before installation – do not decorate while it is attached to your house).
  2. Use sandpaper (100 weight) on the outside of the barrel.
  3. Wipe down the barrel and allow it to dry.
  4. Spray or brush on plastic paint primer – paint will not stick without it.
  5. Use exterior house paint or acrylic paint. Create your own design or use cardboard stencils.
  6. Spray with a paint sealer if using acrylic paint.