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Where Is It Illegal to Collect Rainwater?

Water is one of the most important commodities people need to live. Without a proper water system, most of the civilized world will not exist. That is why people are always looking for ways to conserve it. And one of the best ways is to collect rainwater.

Rainwater harvesting as one of your primary water supplies is a relatively new concept and industry. And because of it, people are wary of the laws surrounding it. So, if you want to harvest rainwater for your home but don’t want to get into trouble with the law, this article should put your mind at ease.

Is It Illegal to Collect Rainwater?

If you are wondering if it is okay to collect rainwater, you’ll be relieved to find out that, for the most part, you can harvest rainwater legally. Governments will only typically regulate large bodies of water like rivers or lakes, especially if it’s the primary water source.

In the US, most states deem it legal for you to collect rainwater. Some even encourage them. But some have some strict regulations on rainwater harvesting. A good example is Colorado, where you are only allowed to collect a maximum of 110 gallons of rainwater. Utah is the same. But at least they let you have a maximum of 2,500 gallons. Other states that have regulations on rainwater harvesting will either prevent you from using rainwater for drinking purposes or require you to follow the state’s plumbing code or both.

If you live in the UK, nothing will prevent you from collecting rainwater. Water companies even encourage citizens to do so, especially those living in the drier southeastern counties where rainfall is lesser than those along the west coast. However, there are standards and regulations you need to follow, especially if you connect your rainwater harvest with your main water supply. There are also regulations on potable water supply, along with general health and safety standards.

Canada will not also prevent you from collecting rainwater. But, there are provincial laws, codes, and regulations that will regulate such practice. For the most part, states and provinces will require you to follow a strict rain-harvesting building code. Cold Canadian weather can pose significant problems to rainwater harvesting. You could get freezing pipes and sewer blockage, especially during winter seasons when temperatures drop below zero. Most provincial guidelines ensure that harvested rainwater cannot freeze by placing it in a controlled environment.

Provincial laws and regulations also ensure that rainwater is safe and free from contamination.

Why Do Some Places Regulate Rainwater Harvesting?

Because different places will have various water availability, each of them will have its doctrines on how residents can use their water. For example, the Eastern States of the US will have a more abundant water supply than the drought-heavy Western States. So naturally, they’ll have different water laws.

Water laws aim to strike a balance between your rights to access a water source and protecting such water sources from pollution and unfair use.

While it is true that water laws will differ from place to place, most of them will follow the “reasonable use” law doctrine, which allows anyone to reasonably use water as long as it does not restrict others as well.

The Hydrologic Cycle

Groundwater replenishes by letting rainwater seep into the earth’s crust. This is what you call the hydrologic cycle. And some people believe excessive water harvesting can disrupt the natural flow of runoff water into the soil.

Fortunately, the Scientific World Journal published a study that shows rainwater harvesting in individual homes has little to no effect on the hydrologic cycle on a macro level. But this has not stopped places like Colorado and Utah from limiting people on how much water they can harvest.

Health and Safety Concerns

As you have read, health and safety concerns are also a main driving force for laws and regulations for rainwater harvesting. People will typically collect rainwater on their rooftops, which means there could be bacteria, animal feces, and other contaminants in the water. This can pose a significant risk to your health if you drink unfiltered rainwater.

That is why most places will only let you collect rainwater if you don’t drink it or have the proper filtration system.

Prior Appropriation Laws

Other reasons for state regulation on rainwater harvesting is due to prior appropriation laws or similar laws which implement first-come, first-serve basis to early settlers, especially in the time of the Old West in the US.

Prior Appropriation law typically applies to groundwater and surface water. But some states consider rainwater as part of the Prior Appropriation doctrine.

Will Rain Harvesting Ever Become Illegal?

If governments continue the current trajectory, then no, rainwater harvesting will not become illegal. More and more places now use rainwater harvesting systems for public and government buildings. Some provide incentives to those who harvest rainwater. And it seems to have become a growing trend.

In the US, organizations like the American Rainwater Catchment Association continually work with governments to help rain harvesters in their country.

Rainwater harvesting is also a good solution for stormwater retention issues in east Texas and water availability in West Texas. Keeping rivers and lakes clean through stormwater retention is more important to the NPDES than who has rights to stormwater runoff.

What You Need to Know

Since water laws will vary from place to place, it would be best to check your state’s legislation before you build a rainwater harvesting system in your home. There could be places like Colorado or Utah that require you to have a permit before you can implement a rainwater catchment system. That said, there will also be places with no problem with rain harvesting.


If you are concerned about water conservation, rainwater harvesting is one solution to your problem. Yes, some places have certain laws and regulations about it. But for the most part, they are just minor, easy to comply with, and will not prevent from collecting rainwater. But remember to research as legislation may shift due to the changing climate.

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