So, Is It Illegal To Collect Rainwater in Idaho?

Being prepared for tough times means not only having a stash of supplies and resources ready to go, but also a plan and the capability for continually acquiring those supplies over the long term.

One of the single most important resources you have is water, and one of the best things you can own to ensure that your access to it is a rainwater collection system.

Humans have been catching rain for thousands of years, but I’m sad to say that not every state in the US has legalized the practice.

As far as those states are concerned, that rain belongs to them! Let’s look at Idaho. Is it illegal to collect rainwater in Idaho?

No, it is not illegal to collect rainwater in Idaho. However, citizens may only collect rainwater that falls on their property and hasn’t yet entered any existing waterway, and if the collection doesn’t interfere with the water rights of others.

So while you might say that Idaho does have regulations concerning the collection and use of rainwater, these restrictions are so minimal and so common sense they are barely worth mentioning.

And for the record, the State Attorney General already affirmed citizens’ rights to collect and use rainwater in a letter, so that is that. But there is more you’ll probably want to know, of course, so keep reading and I’ll tell you all about it.

Is Rainwater Harvesting Illegal at the State Level in Idaho?

No, the collection of rainwater is not illegal at the state level in Idaho. Just the opposite, the practice is entirely legal and generally encouraged. However, state law mandates that folks may only collect diffused surface rainwater that falls on their property.

Essentially, diffused surface waters are those that have not entered any other watercourse such as a stream, creek or river, but this does not cover rainwater that has merely struck the surface of the ground or any structure.

Said another way, as long as the rain has fallen on your property and you collected it before it enters a natural waterway, it is yours and you may store it as you see fit and only you have the rights to it.

However, the harvesting cannot interfere with the water rights of anyone else. This is unlikely to be a problem, but something to keep in mind, especially for those with very large-scale rain collection systems.

Is It Illegal at the County Level?

No. I was not able to find even a single county in Idaho that explicitly outlaws the practice of rainwater collection. That being said, it is entirely possible, perhaps even likely, that your local county and city laws might be more stringent than the state laws.

You’ll have to abide by these laws when it comes to the design and installation of your system, and potentially even how much water you are allowed to collect and store.

Even though the state of Idaho does not forbid the practice in any significant way, you must still take care to follow all applicable local codes and laws. Failure to do so might see you slapped with serious fines, forced to remove your system or even charged with a crime!

When Can Folks Collect Rainwater in Idaho?

Citizens in Idaho are only allowed to collect water that falls on their property and has not yet entered any natural waterway.

It is permissible to collect and impound, or contain, diffused surface water. This is rainwater that has hit the ground but not yet made its way into one of the aforementioned watercourses…

This means that you can set up a rain collection system on your house that’s tied into your gutters, set up a free-standing system, or even a below-ground system that collects drainage from your drive, a French drain or something else.

You cannot collect any water that does not fall on your property, or direct water falling on someone else’s property to yours. You also cannot harvest any that has already entered a stream, creek, river, or other water source.

You are also forbidden in Idaho from collecting rainwater if it directly interferes with anyone else’s water rights. Highly unlikely in all but the most extraordinary circumstances, but something you must keep in mind if you don’t want to get sued. But as long as you do that, you are in the clear…

Is There a Limit on How Much Rainwater You Can Harvest?

There is no limit explicitly stated in Idaho statutes concerning the amount of rainwater you’re allowed to collect. As it clarified by the State Attorney General, and quoted from prior case law, captured precipitation must be put to beneficial use.

But that just concerns the state law: it is entirely possible that local county or city laws might place a restriction on the amount of water you’re allowed to collect over a given period of time, or the total amount of water you can store on your property across any number of containers.

It’s also worth mentioning that state or local authorities might temporarily restrict, throttle, or even outright ban the collection of rainwater during droughts, high fire-risk periods or other emergencies, but you’ll just need to keep your ears perked for those.

What Does Idaho Allow Rainwater Use For?

Idaho law allows residents to use rainwater for any legal purpose. This means it must not conflict with other existing state or local laws.

Typically, collective rainwater is used as non-potable water, and the most commonly used outdoors. This means tasks like watering the garden, watering crops, washing your car, and so forth.

Now, Idaho state law doesn’t explicitly forbid the use of rainwater for potable purposes, but that use cannot conflict with any other local or state laws.

This is where health codes might prevent you from using your rainwater as drinking water without proper filtration and sterilization being implemented.

And of course, your local laws might have further restrictions on use. In any case, you’ll definitely want to filter your rainwater before using it as a source of drinking water, even emergency drinking water.

Why? Because rain water that touches any surface, including your roof and gutters, is going to get pretty contaminated with germs and solids, including heavy metals and animal feces. Nothing you want to drink, believe me!

Any Special Equipment and Inspection Requirements?

No, Idaho state law does not require any special equipment for rain collection systems. To be specific, this is not required at the state level, only that any rainwater you collect is from your own property.

However, local building and plumbing codes might well mandate the use of specific materials and best practices when it comes to setting up your collection system, storage tanks, and especially when making connections to other existing plumbing infrastructure.

Even for a standalone system that goes directly into a tank, separate from the plumbing in your house or any other plumbing, you might be forced to adhere to these codes. Check with your local authorities.

Does Idaho Offer Incentives for Rainwater Collection?

No, sadly. But though the State of Idaho doesn’t have any incentives or tax rebates for rainwater collection your local water provider, if you have one, or municipality just might…

Bottom Line: Is Idaho a Good State for Rainwater Harvesting?

Overall, yes, Idaho is a great state if you want to collect rainwater.

Any uncertainty over the law was cleared up by that previously linked State Attorney General’s letter, and there are no state-level laws that will seriously interfere with what kind of system you can install, how much water you can store or what you can use the water for.

You will, though, need to check all the applicable local codes, laws, and guidelines for your system and for rainwater collection.

But the good news is that Idaho gets quite a bit of rain each and every year, so you’ll quickly get a great return on your investment and you’ll have a dependable source of off-grid water in times of trouble.