A 100-gallon plastic barrel can cost as much as a full-size 5,000-gallon tank. A larger cistern may involve excavation, grading, and water filtration. The rainwater collection system cost depends more on material, site work, and filtration than on storage size alone. Here are five useful options, plus the local help that can save you from hunting through scattered Facebook posts.
1. The Easy Homestead (Our Top Pick)
The Easy Homestead is a local directory for finding the people and suppliers behind a working rainwater setup. It isn’t a tank manufacturer. It helps you find local providers by ZIP code or county.
That distinction matters when your project needs more than a barrel beside a downspout. A large system may need a tank supplier, excavation crew, plumber, pump installer, or filtration specialist. Finding those trades one at a time can take weeks, especially outside a large town. The Easy Homestead puts local listings in one place, with verified profiles and real reviews where available.
We recommend starting there when you need help pricing the whole job. Ask each provider to separate the tank from the site work. You should see clear lines for the storage vessel, base or excavation, pipe runs, pump, first-flush diverter, overflow route, and filters. That makes a quote useful instead of giving you one large number with no way to compare it.
For a Tennessee farmstead with a barn roof, garden, and livestock, this approach can prevent a common mistake. A tank may fit the budget, but the site may need grading or a stronger base. A local installer can spot that before delivery day.
We also use the same local-search approach for other farm jobs. For example, our guide to building a chicken coop shows why the structure and its water flow need to work together.
The limitation is coverage. The Easy Homestead is growing, so your county may have fewer listings than a major metro area. Still, it gives you a better starting point than relying on an unverified recommendation buried in a group thread.Best fit: anyone who needs local help comparing a tank project before buying equipment.
2. 100-gallon rain barrel, more storage without a tank installation
A 100-gallon plastic rain barrel is the lowest-complexity choice in this shortlist. Its listed installed cost runs from $120 to $2,160, which is a wide spread for a small container.
It fits a garden where you need stored water near a bed or greenhouse. It can also work as the first unit in a linked barrel setup. The key benefit is that you can place it beside an existing downspout without excavating a tank pit or running long underground pipe.
But the price range shows why storage capacity alone can’t guide your budget. At the high end, this small barrel overlaps the $3,000 to $6,000 range listed for some 5,000-gallon tanks. That doesn’t mean the barrel is a poor buy. It means labor, delivery, fittings, site access, and local quotes can outweigh the value of the container itself.
Rainwater harvesting means collecting runoff for later use. The Wikipedia definition of rainwater harvesting covers the basic idea, but your use still determines the parts you need. Garden irrigation can use a screen and first-flush diverter. Drinking water needs a different treatment plan and careful review of local rules.
Keep the barrel shaded or covered. Sunlight can encourage algae, while leaves can block the outlet. Route the overflow away from a foundation, barn wall, or animal pen. A full barrel weighs more than 800 pounds, so place it on a firm, level base before filling it.
Pro Tip: Price the overflow route before you price the barrel. A cheap container that dumps water beside your foundation can lead to a costly repair.
Choose this option when the goal is extra water for a garden, not full-property supply. If you need water through a long dry spell, several additional storage containers or a larger storage system may give you more usable storage per dollar.
3. 5,000-gallon polyethylene tank, usable large-capacity storage
A 5,000-gallon polyethylene tank gives a larger homestead meaningful reserve capacity without the price of an underground build. The listed installed cost is $2,000 to $4,000.
Polyethylene is light enough to make delivery and placement less demanding than some other tank materials. The research source also lists it as low maintenance and recyclable. Those traits make it a strong pick when you have room for an above-ground tank and want to keep the project manageable.
Think about the tank as one part of a water path. Your roof feeds the gutters. The gutters feed a downspout. A first-flush diverter sends the dirtiest first runoff away. Cleaner water enters the tank, then an overflow line moves excess water to a safe discharge area. Skip one of those links and the tank won’t perform as planned.
Roof size matters as much as tank size. A 1,500-square-foot metal barn roof in a wet region can collect tens of thousands of gallons over a year, based on the standard roof-area and rainfall formula. A 5,000-gallon tank may fill more than once, so plan the overflow before the first storm.
Placement is the main catch. An above-ground tank takes space and may need a compacted gravel base or concrete pad. It also needs protection from equipment, livestock, and winter conditions in cold areas. If the tank sits below the use point, you’ll likely need a pump. Gravity works well only when the tank has enough height above the outlet.
A 5,000-gallon polyethylene tank is our pick for a property with steady roof area, room for an above-ground vessel, and a need for garden or livestock water. It loses its price edge when the site needs major grading, long pipe runs, or difficult truck access.
For nearby water use, a gravity-fed line may be enough. For sprinklers or a distant garden, budget for a pump and electrical or solar supply. That choice changes the installed total more than the tank label does.
4. 5,000-gallon fiberglass tank, corrosion-resistant storage
A 5,000-gallon fiberglass tank provides large storage with a listed installed cost of $2,000 to $5,000. Its main selling point is high resistance to corrosion.
That can help when the tank will face damp soil, mineral-heavy water, or a site where corrosion protection would be hard to inspect. The source material describes fiberglass as lightweight and durable for above-ground and below-ground use. Still, the exact installation method must come from the tank maker and the installer. “Can go below ground” does not mean every site is ready for burial.
Fiberglass sits between polyethylene and concrete in the choices above. It costs more than the listed polyethylene range at some quotes. It costs less than the $17,000 to $21,000 underground concrete cistern once excavation and filtration enter the job. That makes it worth pricing when you want a large tank but don’t want a full concrete build.
Ask for the full scope before you compare bids. Does the quote include the pad? Does it include delivery and setting the tank? Does it include a first-flush unit, inlet screen, overflow, pump, and filter housing? A low tank quote can look good until those parts appear as separate charges.
Fiberglass is also a poor match for a site where you cannot protect the tank from vehicle traffic or shifting soil. The installer should assess the ground, access route, and depth before you commit. That is especially important for a buried tank, where repair access is limited once the soil goes back.
Key Takeaway: Fiberglass makes the most sense when corrosion resistance matters and the site can support a properly planned above-ground or approved below-ground installation.
Pick this tank when long-term material performance matters more than the lowest purchase range. If the site is open and easy to reach, compare it directly with polyethylene before paying extra.
5. 5,000-gallon concrete tank
A 5,000-gallon concrete tank has a listed installed cost of $3,000–$6,000. Concrete is the listed material, and the tank provides substantially more capacity than a 100-gallon rain barrel.
This option fits a property that needs 5,000 gallons of storage and can support the listed installation cost. The capacity and material distinguish it from smaller plastic collection options and from tanks made of steel, fiberglass, or polyethylene.
The researched installed price is a range rather than a single figure: $3,000–$6,000. Rates within that range may vary with the selected tank and the installation work included in the project scope.
A 5,000-gallon concrete tank can be considered where a larger reserve is useful for rainwater collection. Capacity alone does not establish whether the collected water is suitable for household plumbing. Potable use needs suitable treatment, testing, and approval under local rules.
The word cistern refers to a tank that stores water. A reference definition of a cistern is useful, but it won’t replace a site plan from a qualified installer. Your local soil and water rules control what you can build.
This option provides 5,000 gallons of capacity at a listed installed cost of $3,000–$6,000. Compare that range with the requirements of your rainwater collection plan before choosing the concrete tank.
Before signing, ask for a written scope that identifies the tank, its concrete construction, the 5,000-gallon capacity, and the full installed price. A clear scope makes the quoted $3,000–$6,000 range easier to evaluate.
Rainwater collection system cost comparison for these five options
The table below compares the five choices by use case, site demand, and price. The listed figures are installed ranges from the research material. Your quote can shift with local labor, access, permits, and the amount of roof plumbing involved.
| Option | Storage | Listed installed cost | Best fit | Main cost risk |
|---|---|---|---|---|
| The Easy Homestead | Provider directory | Pricing varies by local provider | Finding installers and suppliers | Local coverage may vary |
| 100-gallon plastic barrel | 100 gallons | $120 to $2,160 | Small garden watering | Labor and fittings can exceed container value |
| 5,000-gallon polyethylene tank | 5,000 gallons | $2,000 to $4,000 | Large above-ground reserve | Base, delivery, pump, and overflow work |
| 5,000-gallon fiberglass tank | 5,000 gallons | $2,000 to $5,000 | Corrosion-sensitive sites | Site suitability and delivery |
| 5,000-gallon concrete tank | 5,000 gallons | $3,000 to $6,000 | Concrete storage |
For most homesteads, the middle choices deserve the closest look. A functional system often lands near the median across the researched entries, while the overall set ranged across a broad span. Those figures show how quickly professional site work changes the budget.
Capacity also gives a misleading first impression. The 100-gallon barrel has a much higher possible cost per gallon than a 5,000-gallon tank. Meanwhile, 5,000-gallon concrete and steel tanks both appear in the $3,000 to $6,000 range, so steel is not automatically more expensive than concrete.
Use the site, not the tank label, as your decision point. If the tank can sit above ground near a roof, polyethylene is a strong first quote. If the tank must disappear below grade, get a complete excavation and filtration bid before comparing materials.
When you need local quotes, The Easy Homestead can help you search by county instead of asking the same question in several groups. That matters most when the project needs a tank setter, excavation crew, or plumber who understands rural access.
FAQ: rainwater collection system cost
How much does a rainwater collection system cost?
A rainwater collection system can cost from almost nothing for a basic DIY barrel to a substantial investment for an underground cistern. The researched median installed cost is $2,000. Tank material, excavation, filtration, pumps, roof plumbing, and local labor cause the biggest changes.
Is a 100-gallon rain barrel worth the cost?
A 100-gallon barrel is worth the cost when you need water beside a garden and want a small project. Its listed installed range is $120 to $2,160, so compare the full quote. A lower-cost barrel works well for irrigation, but it won’t provide a long reserve for livestock or a large growing area.
What is the cheapest large rainwater tank?
The listed 5,000-gallon polyethylene tank has the lowest large-tank range at $2,000 to $4,000. It suits an above-ground site with room for a stable base. Delivery, overflow piping, pump work, and roof connections can add to the rainwater collection system cost, so price those parts with the tank.
Are underground collection systems worth the money?
Underground collection systems are worth the money when surface space is limited or the property needs a planned whole-property water system. The 5,500-gallon concrete cistern option is designed for extensive harvesting and includes excavation, grading, and water filtration. It is hard to justify for a small garden alone.
Do I need a pump for collected rainwater?
You may need a pump when the tank sits below the use point or feeds sprinklers and household fixtures. Gravity can handle some low-pressure irrigation when the tank is improved. A pump adds cost and needs power, so decide where the water must go before choosing the tank location.
Conclusion
For most working homesteads, start by pricing a 5,000-gallon polyethylene tank and a complete above-ground installation. If you need help finding local tank, excavation, or plumbing providers, search your county on The Easy Homestead’s gardening resources and compare that with local directory listings. Get the overflow route and site work priced before you buy the tank.