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Staggering Amount of Water

Recently we were asked to measure for a local College Station apartment complex for the rainwater harvesting potential. We knew there would be plenty of roof space for harvesting but the sheer amount of water that can be collected was mind blowing, even for us since we work with these numbers every day. 

If we collect from every surface in this apartment complex, one inch of rain harvests 53,181 gallons of rainwater. Unfortunately it will not be feasible to capture from every surface since we have limited space for tanks to hold the water. On average (taken from data from the past 10 years) we have had 35 inches of rain annually in College Station, Texas. This means that we could capture 1.8 million gallons of water from this one apartment complex alone in town. 

This is a staggering amount of water that can be harvested and used for numerous purposes. Landscaping is the first use that comes to mind. Filling pools or fountains to beautify the property is another. Potable water use is also an option for drinking, showering and washing clothes etc. 

It is more of a challenge to retrofit an existing complex, but it can be done. We are going to propose capturing from the roofs nearest the areas the owner would like to see the water be used for since that makes the most sense from an economical standpoint. It seems a shame to waste the rest, but since we simply don’t have an empty lot to put a 50,000 gallon tank on the property, we are faced with doing the best we can with the allotted space. 

It is easier to plan for rainwater harvesting with new construction because you can plan where the tanks and everything will go from the start. Retention ponds and drainage can be placed and set where those can be collection points as well into tanks to reduce evaporation issues. 

I am thrilled to see business owners starting to step up and attempt to at least see what it would cost to increase their green footprint. Food for thought is that maybe one day, in areas of severe drought, water of this magnitude could be harvested not only for use, but to be purchased by the cities for treatment and usage for consumption. 

As always, comments and/or questions are always relevant and welcome. 

RainDrop Harvesting Solutions, LLC


Catchment Surface: Rainwater Harvesting Term of the Week

This week’s word of the week is Catchment Surface. Generally a Catchment Surface is a roof of some type of structure. Pictured below is one type of many different configurations of Rainwater harvesting systems showing the roof as the catchment surface.
Catchment is defined as the following according to dictionary.com
the act of catching water.
something for catching water, as a reservoir or basin.
the water that is caught in such a catchment.
1840–50; catch + -ment
The square footage of your catchment surface or roof determines roughly how much water you can store. You measure your square footage by measuring the outside of your building on each outside wall. For example in the drawing below we have a very simple drawing to show the measurements. One outside wall is 30 ft and the other wall is 40 ft. Multiply these together to get your square footage of 1200 sq ft roof catchment surface. If the roof is guttered where it should be, then you can capture from this entire surface. If it is not guttered where it needs to be then the roof catchment surface is diminished by that factor.

It is important to have guttering installed properly and in the right places to ensure you can capture all the rainwater your catchment surface can provide. Did you know that you can even have the guttering installer put your downspouts in the right location when the gutter is installed? If you are unsure about whether you have the proper guttering to install a system designed to capture all the rainwater your roof can provide, give us a call. We specialize in estimating and designing a system that is tailored to your needs with maximized water efficiency in mind.

Next week we will discuss and define another Rainwater Harvesting System Term.  Follow our Blog so you don’t miss it! Thank you for sharing this info with your friends or people you think are interested in it. 

Comments and/or questions are Welcome!

RainDrop Harvesting Solutions, LLC

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Rainwater Harvesting: What is a Dry System?

There are a few types of Rainwater Harvesting Systems. I expect that there will be more variations as we learn more in the future. In a nutshell, a Dry Harvesting System takes water from one downspout on a partial roof area of the catchment surface. A catchment surface is most often a roof. It can be any type of roof: on a home, on a barn, an area over a bench to shield from water. Any surface that can be guttered can effectively harvest rainwater.

A Dry system is so named because no water stands in the pipes except for the First Flush Diverter which empties within 24 to 48 hours. All the water collected goes into the cistern or tank. If the tank is not large enough to hold all the rainwater collected, then the overflow diverts water to a pre-designed area for the runoff. This allows for a more orderly use for the rainwater and overflow. If you have drainage issues, collecting rainwater and designing the system properly can alleviate many of those issues.
Systems can be designed with the purpose of adding additional storage at a later date, however it is far more economical to attempt to estimate how much water you can collect over a period of time and purchase the most storage at that time. It is far cheaper per gallon to design the system that way from the initial install than add on at a later date. Adding on later can cost more depending on several factors, the first of which being inflation. However it is a viable option for those wishing to spend less now and still capture rainwater.

A Dry system is the simplest system to install. Many homeowners simply install a rainbarrel. These are great to have, however since an inch of rain on a 1000 sq ft roof yields 623 gallons of water approximately, a typical rainbarrel will overflow in a hurry.

A system, custom designed to fit your needs is a great alternative. Our systems are designed in such a way that there is no issue with mosquitos since the pipe flows directly into the tank. We listen to what you want and design a system that meets your unique needs. Rainwater harvesting systems can be beautiful and efficient. Contact us today to start your custom design.
Questions and comments are welcome below.

RainDrop Harvesting Solutions, LLC