Yes, it is legal to collect rainwater in Oregon.

• You can legally collect rainwater from your rooftop without a permit.

• Oregon law (House Bill 2080, 2009) explicitly allows rooftop rainwater harvesting for personal, non-potable use.

• You cannot collect water from natural sources like rivers, streams, or groundwater without a water rights permit.

• Indoor use (e.g., flushing toilets) is allowed but requires code-compliant systems with backflow prevention.

• Large cistern systems may need local permits for excavation or plumbing.

• HOAs may restrict visible installations even if state law allows them.

I can’t count how many calls I’ve gotten over the years from folks asking if they will get fined for setting up a rain barrel.

The truth is, Oregon has some of the most rain-harvesting-friendly regulations in the country. But the internet is full of outdated myths, mostly borrowed from headlines in other states like Colorado and Nevada.

Oregon law makes a clear distinction: If rainwater hasn’t touched the ground yet, meaning it’s captured directly from your roof, it’s yours to use. No permit. No water rights battle. No red tape.

The key is doing it right. 

Whether you're a homeowner trying to slash your water bill or a prepper building out a self-sufficient system, collecting rainwater is legal and encouraged, as long as you follow a few smart, simple guidelines. And that’s exactly what we’re going to break down for you in this article.

Why People Think It’s Illegal (And Where the Confusion Comes From)

Despite Oregon’s clear green light on rainwater harvesting, the question “Is this legal?” still echoes across search engines, message boards, and even conversations with local officials. So where does the confusion come from? Let’s set the record straight by looking at the two biggest sources of misinformation.

Myths from Other States (Looking at You, Colorado)

Much of the legal paranoia around rainwater collection traces back to high-profile restrictions in other states, especially Colorado, which for decades had some of the strictest water laws in the country. 

In Colorado, all precipitation was considered the property of downstream water rights holders, making rooftop collection a legal gray area until fairly recently. Media coverage of these restrictions spread far and wide, and unfortunately, many readers assumed the same rules applied in Oregon.

They don’t.

Oregon’s laws are completely different. 

Plus, things are different in Colorado now, anyway. Homeowners in Colorado can collect a maximum of two rain barrels with a combined storage of 110 gallons or less at each household.

Here, water rights apply only to natural sources like rivers, lakes, and groundwater. Once that rain hits your rooftop, it’s yours to collect, no permit, no problem. The state has made it clear that rooftop rainwater harvesting is legal and even encouraged when used responsibly.

Misunderstandings Among City Workers & HOAs

Surprisingly, some of the misinformation comes from the very people homeowners turn to for answers, like municipal staff and HOA board members. There have been cases where city employees incorrectly told residents that rain barrels weren’t allowed, or that permits were required for rooftop collection. In reality, many of these employees are simply unfamiliar with the nuances of Oregon’s state-level laws.

Then there’s the issue of Homeowner Associations (HOAs).

While Oregon law allows rainwater harvesting, HOAs are private entities and may enforce their own aesthetic or architectural rules. This means that while your rain barrel is perfectly legal under state law, your HOA might restrict where or how you install it, particularly if it’s visible from the street or doesn’t match the neighborhood’s design standards.

This creates a frustrating disconnect: legal under state law, but blocked by private covenants. That’s why, at AquaBarrel, we often recommend disguising or painting barrels to blend in. Not only does it improve curb appeal, it avoids unnecessary drama with the HOA.

What Oregon Law Actually Says About Rainwater Collection

Oregon’s water laws strike a thoughtful balance between conservation, public health, and personal freedom. While rumors and misinterpretations are common, the actual statutes are refreshingly straightforward, especially when it comes to rainwater harvested from your roof.

Rooftop Rainwater Is Yours to Keep

Under Oregon law, you are fully allowed to collect rainwater that falls on your roof or other impervious surfaces. 

This is because the state only regulates water that has entered a natural waterway, like a river, stream, or aquifer. Rain that lands on your rooftop has not yet joined any natural system, and therefore does not fall under the state’s water rights regulations.

What that means in plain English: If the water hits your shingles first, it’s legally yours.

That’s why the state passed House Bill 2080 in 2009, to officially confirm what many sustainable homeowners had already been doing for years. 

This bill explicitly legalized rooftop rainwater harvesting for personal use, without a permit, making Oregon one of the more progressive states in water conservation policy.

What You Can’t Do: Diverting Streams or Groundwater

Where Oregon draws the line is natural water sources. If you’re thinking about piping water from a nearby creek, spring, or underground well into your rain barrel, you’ll need to apply for a water rights permit through the Oregon Water Resources Department.

Why?

Because once rainwater has entered the natural ecosystem, it’s considered part of a shared public resource. Diverting it without proper authorization could impact downstream users, ecological balance, or public supply.

So yes to rooftops, but a hard no to rivers, streams, and the water table unless you’ve gone through the legal channels.

Can You Collect Rainwater for Indoor Use?

This is where things get a bit more technical. 

Yes, you can use collected rainwater indoors, for tasks like flushing toilets or running a washing machine, but only if the system meets specific plumbing code requirements.

For starters, the system must be completely isolated from your potable (drinking) water supply to prevent contamination. That usually means installing backflow preventers, separate plumbing lines, and possibly even filtration or treatment systems depending on intended use. These safeguards are helpful to protect public health and avoid code violations.

While indoor use is legal, it’s not always straightforward. That’s why most homeowners stick to non-potable outdoor uses, like watering gardens or washing vehicles, where regulations are more relaxed and the plumbing is simpler.

Do I Need a Permit to Collect Rainwater in Oregon?

The good news keeps coming: most Oregon homeowners do not need a permit to collect rainwater, so long as you’re harvesting it from your roof and using it for outdoor, non-potable purposes like watering your garden, washing your car, or even hydrating your backyard chickens.

Let’s break down the details.

No Permit Needed for Most Homeowners

If you're installing a simple rain barrel system, say, a 55-gallon drum hooked up to your downspout, you’re in the clear. There’s no permitting process, no paperwork, and no registration required. 

As long as you’re collecting roof runoff and keeping it for personal, non-drinking use, Oregon law gives you a thumbs-up.

This makes rainwater harvesting one of the most accessible sustainability upgrades for homeowners. No red tape. No inspections. Just smart, responsible water reuse.

In fact, Oregon’s Department of Environmental Quality and local municipalities encourage it, especially in urban areas where reducing stormwater runoff helps prevent flooding and erosion.

Exceptions for Large-Scale Systems or Cisterns

Now, if you’re planning something larger and more complex, like an underground cistern that stores hundreds or thousands of gallons, you may trigger additional regulations. 

It’s not that collecting the water becomes illegal, but the installation itself may need to meet local building, safety, or plumbing codes.

For example, let’s say you’re in rural Eastern Oregon and want to install a 2,000-gallon underground tank to supply water to a small homestead. That kind of system might require:

• A grading or excavation permit

• An inspection from the local building department

• Plumbing approval if it connects to indoor fixtures

These regulations exist to ensure your setup is safe, won’t collapse underground, and doesn’t pose a risk to you or the environment.

At AquaBarrel, we often consult with off-grid homeowners and small farmers who want more than just a backyard barrel. We can’t issue permits ourselves, but we can absolutely help you build a system that’s compliant, efficient, and tailored to Oregon’s climate and code environment.