why is it illegal to collect rainwater in colorado

Why is it illegal to collect rainwater in Colorado?

Colorado is home to some of the country’s most beautiful scenery and weather, but the state prohibits anyone from collecting rainwater.

It is important to examine the history and current status of Colorado’s ban on rainwater collection in an effort to better understand this peculiar statute.

So, why exactly is that?  Is it truly a law in Colorado to not collect rainwater?

It is illegal due to Colorado’s semiarid climate and the ‘prior appropriation’ theory, which is in place to maintain equitable water distribution.  

The Importance of Rainwater Collection

the importance of rainwater collection

In some US states there is a water crisis. It is especially severe in the West where urban population expansion has increased demand.

With the threat of global climate change impacting future supplies, rainwater is considered a valuable commodity. 

In the US, rainwater harvesting is regulated by individual states.

The regulations are not monitored by a federal agency, although the Federal Energy Management Program has stepped in to collate information on the individual states harvesting regulations.

However, demand for water is outstripping supply, particularly in Colorado. And that is why many people ask, “Can you collect rainwater in Colorado?

And if you cannot, can you legally collect rainwater in Colorado using any method? 

Background on Rainwater Collection Laws

background on rainwater collection laws

Collecting rainwater is typically a rural activity. It is only lately that ideas of modern self-sufficiency have made rainwater harvesting fashionable.

However, in areas with little or no available water, collecting rainwater has never been a lifestyle choice, just essential for survival. 

And that is exactly the reason why it has become a pressing issue in Colorado.

Fact: The Colorado Water Conservation Board is responsible for overseeing the state's water supply and defending its water rights during interstate water compact discussions. 

Overview of Water Rights in the Western United States

water rights in the western united states

Historically, the United States has adopted two approaches to ensure that everyone has access to water.

The water-rich eastern states defer to the Riparian Rights Doctrine, a centuries-old approach that gives each person along a body of water an entitlement to it, provided it is for reasonable use.

The abundant water means the Riparian Doctrine places no one person’s need above others even when the water source is running low.

On the other hand, the doctrine of Prior Appropriation allows for setting priorities for who and what gets limited access to limited water, the population or mass agriculture and all bodies of water are the property of the state. 

Fact: The Doctrine of Prior Appropriation developed in the dry western states, stands in stark contrast to the Riparian Rights Doctrine. 

Evolution of Water Laws in Colorado

evolution of water laws in colorado

Colorado has four major watersheds and eight aquifers, but a huge population growth between 1900 and 2010 has constantly strained the water supply.

The local archaeology and historical Hispanic records suggest the fair distribution of water has always been an issue.

Colorado adopted the Doctrine of Prior Appropriation into the Colorado Constitution in 1876.

Water rights were only given if the water was put to ‘beneficial use’ and an order of priority was set, domestic, agricultural, and industrial.   

Why Is It Illegal to Collect Rainwater in Colorado?

illegal rainwater collections in colorado reasons

To get a better idea of why it is considered illegal to collect rainwater in Colorado, you have to pay attention to the history of the state.

Here are some explanations as to why you cannot legally collect rainwater in Colorado:

Prior Appropriation Doctrine and Its Impact

Hispanic settlers built an irrigation ditch in 1852. The People’s Ditch which is still around today, was supplied by water from Culebra Creak.

Back then the whole region was in Mexico not the USA.

When it came to water distribution, the Spanish principles and laws were adopted using acequias water distribution systems.

prior appropriation doctrine and its impact

There were strict rules governing sharing in times of short supply and a communal responsibility was applied to good water management.

It was only when Colorado adopted and backdated its Doctrine, that shared rights to the water in the Ditch and elsewhere changed. 

Senior Water Rights and Potential Conflicts

Under the Doctrine of Prior Appropriation water rights can be bought, sold or inherited. They can also be relocated or altered by use.

Although there is also the proviso that changes should ‘not injure or impose’ on anyone else when water is scarce, they invariably do and with legal dominance as a senior right.

The older the claim, the more right it has.

Yet, the tenfold increase in the population along with the agriculture needed to support it, demands massive amounts of water.

Rights were lost as necessity governed the best use of the water.

There have been a series of diversions like the People’s Ditch, the vast majority for agriculture. 

Concerns over Downstream Water Availability

concerns over downstream water availability

If water is diverted, logic dictates there will be less water to make it downstream and still in the 1930s, the State began commissioning studies into the largest diversion yet.

It was to transport water from the Western Slope to the dry eastern plains.

Another, the Twin Lakes project, 1933, moved 20,000 acre-feet of water each year from the Roaring Fork watershed to the Arkansas River.

Today Twin Lakes supplies 38,000 acres-feet. Colorado is in drought, with temperatures predicted to increase as rivers are at their lowest, which explains the illegality of collecting rainwater. 

The Role of Water Scarcity in Colorado

the role of water scarcity in colorado

Population growth prompted a change in how water was used as Colorado’s landscape changed from rural and agricultural to increasingly more urban and suburban.

Agriculture remains the dominant industry in Colorado, and it is the state’s greatest water user.

But, this might change as labor shortages, high costs and unpredictable returns make farming less attractive.

The demand for water is expected to continue increasing.

And with the difficulty of obtaining new water storage permits, municipalities turn to the ‘buy and dry’ process and buy up any senior agricultural water rights they can find.

Fact: There are nine primary river basins in Colorado, and there are seven Water Courts responsible for allocating water throughout the state. 

Efforts to Change Rainwater Collection Laws in Colorado

Because water is such a scarce commodity, successive Colorado administrations have enforced strict water laws encased in senior water rights.

It is so strict that it is illegal to collect rainwater, a nonsensical law when so many need water.

rainwater collection law reform in colorado

Many people argued that it was time to put rainwater to ‘beneficial use’ rather than drain the exhausted Colorado River.

They did not mention that the law was rarely enforced.

Recently, good sense prevailed with new rain barrel legalization that allows people to store 110 gallons.

The change in legislation, H.B. 1259, is described as ‘a symbolic step towards a more modern way of thinking about water.’

No one claims that being able to harvest rain as an individual will ease the pressure on the falling waters of mighty Colorado.

But it is a junior water right that could help ease the pressure of drought at the individual level.   

Potential Solutions and Compromises

potential solutions and compromises

In an effort to improve things, there have been many suggestions and compromises made to change laws surrounding rainwater collection. 

Implementation of Regulations for Rainwater Collection

Rainwater collection systems catch and store rainwater draining from rooftops.

It can be used to flush toilets, wash cars and irrigation taking pressure off the treated federal supply although it can be filtered and cleaned to drinking water standards.

It is an example of how deep-set thinking around water rights and prior appropriation are outdated as Colorado and the western states face the impact of climate change. 

Integration of Rainwater Collection into Water Management Plans

the role of water scarcity in colorado

California, another state feeling the impact of climate change, passed similar legislation in 2012.

Moreover, many other western states since have set about encouraging the traditional homesteading approach to harvesting water and have added it to water management plans.

For instance, Rhode Island, Texas and Virginia offer tax incentives, and Colorado can also follow suit. 

Education about Responsible Water Use

Water ’22, was a yearlong celebration of Colorado’s water.

The focus was understanding how upstream and downstream are connected, and the value of water.

education about responsible water use

It primed Coloradans to think as a community standing together through a persistent drought.

The campaign celebrated Colorado’s water management firsts, the River Compact centenary, The Clean Water Act and the 20th year of Water Education Colorado

Fact: The doctrine of prior appropriation also applies to groundwater in Colorado, with rights separated between certain basins and the rest of the state. 


Why is it illegal to collect rainwater in Colorado? Colorado’s laws regulating rainwater collection are intricate.

This is mainly due to the state’s complicated history with water rights concerns and the pressing need to manage its semiarid climate.

Despite the apparent lack of logic, these statutes ensure a just allocation of water resources.

Also, efforts have been made recently to strike a fair balance between individual liberties and long-term environmental health.