Best examples of 3 examples of building a rainwater storage tank (plus more real-world ideas)

3 headline examples of building a rainwater storage tank

Let’s start with three clear, real-world builds. These are the backbone examples of 3 examples of building a rainwater storage tank you can adapt to your own home.

Example 1: The classic 55-gallon backyard barrel

Picture a small suburban house with a simple asphalt shingle roof and one downspout that always gushes during storms. The homeowner wants a basic example of a rainwater storage tank that doesn’t require plumbing permits or contractors.

Here’s how this first example of a tank usually comes together in practice:

• A food-grade 55-gallon plastic drum sits on a sturdy stand made from concrete blocks or a wood frame. Raising the barrel 18–24 inches off the ground makes it easier to fit a watering can under the spigot and improves gravity flow.
• A downspout diverter kit sends water from the gutter into the barrel when it rains and back into the downspout when the barrel is full. Many off-the-shelf diverters include a built-in overflow path.
• A simple hose bib (spigot) is installed near the bottom of the barrel, with a short garden hose attached.
• The top opening is covered with fine mesh to block mosquitoes, leaves, and debris.

This is one of the best examples of 3 examples of building a rainwater storage tank for beginners because it’s:

• Cheap: Often under $150 in parts if you can find a used food-grade barrel.
• Fast: Many people complete the whole build in a weekend.
• Flexible: You can add a second barrel later and connect it with a short length of hose.

A realistic scenario: A gardener in Austin, Texas, hooks up two 55-gallon barrels to a 200-square-foot roof section. A one-inch rain on that roof can produce over 100 gallons of water. The barrels fill, and she uses the stored water to hand-water raised beds for a week or two. This very simple build shows up again and again in real examples of rainwater harvesting because it’s accessible to renters and homeowners alike.

Example 2: A 300–500 gallon slimline tank along a side yard

Now imagine a narrow side yard between two houses, where there isn’t space for a big round tank but the homeowner wants a more serious supply for garden irrigation. This is a great example of stepping up from barrels to a purpose-built rainwater storage tank.

In this example of a mid-sized system:

• A tall, slimline polyethylene tank (often 300–500 gallons) is tucked against the wall along the side yard, on a compacted gravel or concrete pad.
• Two or three downspouts from the main roof are combined into a single inlet to the tank.
• A first-flush diverter is added: a short vertical pipe that captures the first few gallons of dirty roof runoff (dust, pollen, bird droppings), then automatically closes so cleaner water goes into the tank.
• The tank has a screened inlet, an overflow outlet piped away from the foundation, and a bottom outlet plumbed to a hose bib or irrigation manifold.

This is one of the best examples of 3 examples of building a rainwater storage tank for people who are serious about gardening or want to reduce outdoor water use in drought-prone areas. A homeowner in Southern California, for instance, might use a 400-gallon tank to drip-irrigate fruit trees during the dry season. With a modest 1,000-square-foot roof, a single 1-inch storm can produce over 600 gallons of water, so the tank refills quickly when it does rain.

You’ll see examples of similar systems featured in many municipal water conservation programs, because they strike a balance between capacity and footprint. Cities like Tucson and Austin actively encourage this kind of setup through rebates and guidelines.

Example 3: A 2,500+ gallon underground cistern for toilet flushing and irrigation

For the third of our core examples of 3 examples of building a rainwater storage tank, let’s jump to a more ambitious build: an underground cistern that can supply non-potable indoor uses.

Think of a new home in a rural area with limited well capacity, or a homeowner in a city with high water rates who’s planning a major landscaping project. They decide to install a buried concrete or fiberglass cistern of 2,500–5,000 gallons.

Here’s what this example of a larger system usually involves:

• An excavation near the house, sized to fit the tank plus space for bedding and backfill.
• A precast concrete or reinforced plastic cistern with access risers and a lockable lid.
• Piping from multiple downspouts to a central pre-filter, then into the cistern.
• An overflow outlet tied into a storm drain or daylighted away from the foundation.
• A submersible pump inside the cistern, connected to a pressure tank and a dedicated non-potable plumbing line.
• Indoor fixtures like toilets, a laundry cold-water line, or hose bibs plumbed to this rainwater line, with proper backflow protection and compliance with local codes.

This is one of the clearest real examples of a building-scale rainwater system that moves beyond gardening. It costs more and usually requires permits and professional help, but the payoff can be big. In some regions, homeowners cut their municipal water use by 30–50% when toilets and landscaping are supplied by rainwater.

If you want to dig into the safety and regulatory side of using non-potable water indoors, the U.S. Environmental Protection Agency has guidance on water reuse and rainwater systems here: https://www.epa.gov/waterreuse.

More real examples of building a rainwater storage tank in everyday life

The three builds above are the backbone, but you asked for examples of 3 examples of building a rainwater storage tank, and in practice people get creative. Here are more real-world scenarios that round out the picture.

Small-space example: Balcony or patio tote system

Apartment dwellers often feel left out of rainwater harvesting, but there are clever examples of small systems.

One common example of a compact build uses a 30–50 gallon stackable plastic tote or decorative barrel on a balcony:

• A short section of gutter is installed along the balcony railing or roof edge.
• A flexible downspout or chain directs water into the tote.
• The lid is cut to accept water, then covered with mesh to keep mosquitoes out.
• A simple spigot near the bottom lets you fill watering cans for potted plants.

This doesn’t store much, but it’s a realistic example for renters who can’t modify downspouts. It also teaches the same principles as bigger examples: capture, screen, store, and draw.

Rural example: Livestock trough conversion

On small farms, real examples include repurposing old livestock troughs as open-top rainwater tanks.

A farmer might:

• Place a large galvanized or plastic trough under a simple shed roof.
• Add a gutter and downspout to the roof, directing water into the trough.
• Cover most of the surface with a hinged wooden lid or mesh to reduce algae and keep animals out.
• Use a float valve to top off a smaller drinking trough for goats or chickens.

This example of a rainwater storage tank is low-tech, but it’s incredibly common in rural areas and can reduce demand on wells, especially in summer.

Community example: Shared cistern at a garden or school

Community gardens and schools often showcase some of the best examples of rainwater storage tanks because they’re designed to be educational.

A typical setup might include:

• Two or three 1,000-gallon above-ground poly tanks painted with murals.
• A large roof catchment from a shed, classroom, or pavilion.
• Clear signage explaining how many gallons are captured per inch of rain.
• A gravity-fed drip system for garden beds.

These real examples are useful if you’re trying to convince a board, HOA, or school district that rainwater harvesting is practical and safe. They also make it easy to teach kids about water cycles and conservation.

For curriculum ideas and water-education resources, the U.S. Geological Survey has approachable materials here: https://www.usgs.gov/special-topics/water-science-school.

Design lessons from the best examples of 3 examples of building a rainwater storage tank

When you look across all these real examples, a few patterns show up again and again. Use these as a mental checklist while planning your own build.

1. Roof area and climate matter more than tank size

Many people start by obsessing over the tank, but the best examples of 3 examples of building a rainwater storage tank all begin with the roof and rainfall.

Two key questions:

• How much roof area do you have feeding the tank?
• How much rain do you get in an average year, and how is it distributed?

A 500-gallon tank in Seattle may overflow constantly, while the same tank in Phoenix may sit half-empty most of the year. The examples above from Texas and Southern California show how local climate shapes what “enough” storage looks like.

The National Oceanic and Atmospheric Administration (NOAA) offers rainfall normals and maps you can use to plan: https://www.ncei.noaa.gov.

2. Simple filtration beats complicated gadgets

If you scan real-world examples of functioning systems, they nearly all use very simple filtration steps:

• Gutters kept reasonably clean.
• A leaf screen or basket at the inlet.
• A first-flush diverter on larger systems.

That’s it. High-end filters exist, but many of the best examples work for years with just basic screening and regular maintenance. Complicated filters often get ignored and eventually clog.

3. Overflows and foundations are non-negotiable

Two things that go wrong in a lot of DIY attempts:

• Tanks placed directly on soft soil that later settles and leans.
• Overflow water dumped right next to a foundation, causing damp basements or erosion.

Every solid example of a well-built rainwater storage tank includes a flat, compacted base (gravel, pavers, or concrete) and a clear overflow path that sends excess water away from structures.

4. Mosquito control is about screens and lids

In 2024–2025, with more awareness of mosquito-borne diseases in many regions, health departments are very clear: any standing water must be covered or treated.

The most reliable examples include:

• Tight-fitting lids.
• Fine mesh screens on all openings.
• Overflow outlets covered with mesh.

Some regions also recommend or allow mosquito dunks (Bacillus thuringiensis israelensis, or Bti) for non-potable water. Check with your local health department or resources like the Centers for Disease Control and Prevention (CDC) mosquito control guidance: https://www.cdc.gov/mosquitoes.

2024–2025 trends shaping new examples of rainwater storage tanks

Recent years have pushed rainwater harvesting from “nice idea” to practical strategy in many places.

Here’s what’s showing up in newer examples of 3 examples of building a rainwater storage tank:

• Smart monitoring: Wi‑Fi tank-level sensors that send alerts to your phone when tanks are full or nearly empty. These show up more often in larger cistern examples.
• Fire resilience: In the Western U.S., some rural homeowners are adding 2,500+ gallon tanks specifically for wildfire defense, with fire department connections.
• Code-friendly systems: More cities and states are publishing clear guidelines, which means newer examples of permitted systems are easier to copy without guesswork.
• Hybrid graywater + rainwater setups: Some advanced examples include both laundry graywater and roof runoff feeding landscape irrigation.

If you’re planning a build in 2024 or 2025, it’s worth checking your city or state environmental agency site for updated guidance and possible rebates.

FAQ: common questions about examples of building a rainwater storage tank

What are some simple examples of rainwater storage tanks I can build in a weekend?

Realistic weekend examples include a single 55-gallon barrel on a stand with a downspout diverter, or a pair of barrels connected at the bottom with a short hose. Both use basic tools and off-the-shelf parts from hardware stores.

Can you give an example of a system that supplies indoor fixtures?

Yes. A common example of an indoor-supply system is a 2,500–5,000 gallon underground cistern connected to toilets and outdoor hose bibs, with a pump and pressure tank. This type of example always needs to follow local plumbing codes and usually requires permits and professional installation.

Are there examples of rainwater tanks that work in cold climates?

Definitely. In colder regions, examples include buried cisterns below frost depth, insulated above-ground tanks with freeze-proof hydrants, and seasonal systems that are drained before winter. Many northern U.S. and Canadian homes use these approaches.

What are examples of maintenance tasks for a rainwater tank?

Real examples of routine maintenance include cleaning gutters a few times a year, rinsing inlet screens, checking for mosquito entry points, inspecting overflows, and occasionally flushing sediment from the bottom of the tank.

Where can I find more technical examples and design standards?

State extension services and universities often publish design guides with diagrams and worked examples. Searching for “rainwater harvesting” on .edu or .gov sites (for example, state cooperative extension programs) will turn up detailed manuals you can adapt.

If you take anything from these examples of 3 examples of building a rainwater storage tank, let it be this: start small, copy a proven example of a system that looks like your home, and let your setup grow with your confidence. The planet doesn’t need perfect systems; it needs millions of decent ones quietly catching the next storm.