The Potential Of Rainwater As A Renewable Resource

By Katie Brenneman

As water resources become more stressed, continuing to “waste” rainwater becomes increasingly inadvisable, perhaps even irresponsible.

Precipitation has increased by a rate of 0.04 inches per decade1 around the globe since 1901. While this has caused flooding and surges in some areas, many other regions have seen drought and desertification. This points toward widespread water mismanagement and highlights the reality that rainwater is a renewable resource whose value has been overlooked.

While turning rainwater into a commodity is ethically dubious, there is no doubt that the harvesting and reuse of precipitation will become a point of contention as climate change progresses. This means we must start to consider the potential of rainwater to combat scarcity issues and mitigate the impact of a warming world.

Treating rainwater as a resource can aid public campaigns to reduce water waste, too. Folks are far more likely to minimize their waste when they see the value of rainwater, and they may be more likely to invest in things like water butts and collection devices in their own homes.

History And Benefits Of Rainwater Harvesting

Rainwater harvesting is not a new idea. Civilizations have treated rainwater as a scarce, important resource for millennia. Archaeologists have even identified water butt-like devices in ancient cities like Dholavira, located in the Indus Valley, which may date back 4,500 years.

However, the increased efficiency of our water supply means that many have overlooked the potential that rainwater still holds. Today, the U.S. Geological Survey (USGS) estimates that 40% of our drinking supply comes from groundwater while most of the remaining supply comes from surface sources, like rivers and lakes.

But, as increased strain is placed on the water tables due to drought and increased pumping during hotter seasons, conventional supply may not be enough. Conversely, failing to store and manage high rates of precipitation during storms leaves urban areas vulnerable to floods. This is why many wastewater companies face a period of uncertainty in the coming years as climate change is set to exacerbate existing issues.

In response to these pressures, the American Rainwater Catchment Systems Association (ARCSA) was established in 1994 to alleviate droughts and improve precipitation management. Groups like the ARCSA support public programs to treat rainwater as a resource and put pressure on politicians to change laws that currently restrict collection. Supporting these efforts is crucial as, according to the U.S. EPA, the benefits of collecting rainwater include:

• improved stormwater management;
• reduced contamination in areas near agricultural sites;
• reduced water bills; and
• provision of an emergency supply during droughts.

Before you start collecting rainwater, you will need to check local laws to ensure that your efforts are legal. Some states have strict laws on how much rainwater you can collect, while others outlaw the practice altogether.

Harvesting Laws

Understanding harvesting laws is crucial for citizens and organizations that want to treat rainwater like a renewable resource. This could result in hefty fines and lawsuits if the legal ramifications and expectations of rainwater harvesting are ignored. Currently, states that limit rainwater collection include Colorado, Utah, Nevada, Illinois, and Arkansas.

Some codes are expected to be updated in the coming years, as more states adopt progressive stances toward rainwater collection in hopes that doing so will reduce strain on water systems. However, folks who do wish to collect rainwater may also need to stay up to date with regulations that may impact how rainwater is collected.

Similarly, those who choose to collect rainwater may find that they are eligible for grants or incentives. For example, cities like Tucson, AZ, offer incentives like the Tucson Water Rainwater harvesting rebate, which offers up to $2,000 to those who invest in rainwater harvesting.

Existing Systems

Treating rainwater as a resource likely means that we’ll need to revise the way we harvest water from precipitation. Refining largescale approaches to rainwater harvesting is crucial, as it is rainwater that feeds much of the groundwater and surface water supply that we rely on today.

Organizations interested in increasing the efficiency of rainwater harvesting can look toward innovative, climate-resistant solutions2 like those utilized in Kazakhstan. Firms in Kazakhstan, which is one of the driest countries in the world, utilize solar-powered atmospheric water generators (AWG) to pull water from the air. This improves the taste of the water and ensures that a constant supply is always available.

Similarly, more must be done to take advantage of rainfall events like storms. According to a recent Q&A session hosted by the USGS, a large storm will drop around 1 inch of water. For a home situated on half an acre of land, that translates to 13,577 gallons of water across the yard. More mild rainfall can be beneficial, too. If just one-tenth of an inch of rain falls onto a 20-by-30-foot roof, a homeowner who collected this water could fill a 37-gallon water butt in just one weather event.

Urban Rainwater Collection

Rainwater collection is easy to imagine on rural lots where water butts and runoff systems can be easily established. However, for rainwater to reach its potential as a resource, harvesting efforts must take off in urban areas.

Improved water management will play a central role in building sustainable cities for the future.3 As urban populations expand, more must be done to improve wastewater treatment and reduce pressure on freshwater sources. Rainwater harvesting systems will be key to these efforts and will provide a perfect replacement for non-drinking purposes like toilet-flushing or gardening.

Green innovations, like rain gardens and bioswales, can help alleviate stormwater runoff and reduce the risk of floods, too. This is crucial, as more intense storms are predicted across the globe in the face of climate change and warming.

Conclusion

Rainwater is an underutilized natural resource that could be key in the fight against climate change. Properly managing rainwater will refill supplies and help cities become more resilient following a weather event like a storm. By treating rainwater like a valuable resource, governmental agencies can improve responses to droughts and alleviate the burden placed on the water table in years to come.

References:

1. https://www.epa.gov/climate-indicators/climate-change-indicators-us-andglobal-precipitation
2. https://www.kreo.net/news-2d-takeoff/6-innovations-from-around-the-worldthat-can-make-structures-more-climate-change-resilient
3. https://pvcase.com/blog/what-urban-living-of-the-future-might-look-like/

About The Author

Katie Brenneman is a freelance writer and regular contributor to Water Online, covering environmental, technology, and utility management issues. She can be reached at katiebrennemanwrites@gmail.com.