Why You Should Start Collecting Rainwater

Aug 14, 2018 by Colin Thomas with Veterans Off-Grid in Sustainability
Why do we not usually take baths in ditches, brush our teeth in lakes, or serve up a glass of ice-cold ocean water? The reason is that there are limited sources of natural clean water sufficient for us to drink. We will likely continue putting massive amounts of river, aquifer, and seawater through intricate water treatment facilities, but a more sustainable and personal method should be implemented.

Individual rainwater collecting is as easy as directing rain from your roof to storage tanks. It requires zero treatment before usage for things such as gardening and showers, and only involves UV purification or boiling before human consumption. Unfortunately, it is highly regulated in nine states, because it reduces stream flow and some people attempt to claim private rainwater rights. Most of these states still allow for some sort of rainwater collection. For example, the water may be collected if it falls off your roof.

Gardeners find that rainwater is much better for their plants than city water. Nitrates, acidity, and absence of other chemicals make for healthier gardens. Additionally, rainwater collection systems can help improve the value of a house by giving it credits towards LEED certification— a method for classifying environmentally friendly buildings. Household rainwater storage tanks can also provide water for firefighters if the house is out of range of a fire hydrant. This method is not as conventional but can prove useful in an emergency. Finally, storage tanks can be stacked to increase capacity if one decides, later on, that rainwater collection is more advantageous than they previously thought.


Groundwater Recharge

It may be counterintuitive to think collecting rain would help more water soak into the ground. By taking our water from the aquifers underground, we have a dependency on them that may not be meeting supply. Overdrawing water can lower the water table in any area, and it may take decades to replenish. By getting our water from the sky instead of the ground, we give the aquifers time to refill. Our paved parking lots, streets and sidewalks, and urban areas are preventing over half of the rainwater from sinking into the ground. When the rain does flow to a spot where it can infiltrate the soil, the ground is too soaked to absorb the water and it pools or continues flowing. A rain garden is one simple solution because they're planted with grasses and flowering perennials, which reduces runoff.

City water must pump energy through miles of underground pipes thus having a large carbon footprint. Collecting rainwater not only reduces that footprint but also protects the local watershed, drought/flood-proof, and restores the hydrologic cycle. Yes, pollutants may mix with rain, but the amount is too small to affect water quality and human health and is still one of the cleanest sources of water. Besides, when water evaporates, it evaporates as pure H2O.


Cost of our Current Infrastructure

The infrastructure for providing clean water for every home within the city is not cheap. In fact, the Value of Water estimates that $4.8 trillion needs to be invested in water utilities over the next 20 years to keep it in a good working condition. National and local governments pay for water infrastructure with tax money and will likely spend less than $4.8 trillion to maintain by building less than ideal water systems. Rainwater collection will not completely replace utility companies, it can, however, lower the demand and reduce costs of maintenance. With all those savings, maybe the government can invest in rainwater collection subsidies.


Implementing a System at Your Home

On average, an American spends $200-$300 a year on water. For a household, that can easily be over a thousand dollars per year. If a family thinks their area gets enough rainwater to replace municipal water use completely, they may need to spend $5,000 or more to purchase 8,000 gallons of storage tanks.

The extent of the system will determine the cost. If you are living in a high rainfall location, the catchment area and tanks will not need to be as large vs. those living in more dessert, or infrequent rainfall, areas. The BlueBarrel system has products starting at $180, but costs will raise depending on the size of the tank. The startup cost may be more expensive than paying for municipal water, take heart. Conserve Energy Future estimates it will take 10-15 years for the system to pay for itself. Luckily, maintenance is simple because tanks only require simple cleaning and inspection for cracks and leaks every couple of months.

Note: Current Results lists the average rainfall for every state and the Value of Water averages annual water usage at 64,000 gallons per year per person.