David Casaletto, Executive Director, Ozarks Water Watch

 

 

A couple of weeks ago I attended the Multi-Basin Regional Water Council meeting in Rogers, AR. The speaker was Jeremy Kyle with Ewing, a company that sells irrigation and other water related products. Much of his talk centered on rain water collection and the alternatives to the conventional rain barrel. Jeremy's presentation spurred me on to do a little research on the subject.

 

 

Conventional wood rain barrel system

 

 

Each year there are hundreds of rain barrels sold in the White River watershed. And I am sure many of you have said, I need to do that. I need to get a rain barrel and do my part to save water and reduce stormwater runoff. And you can. But before you do, I encourage you to also do some research. In this newsletter, I am going to highlight some, but not all, of the issues of which you need to be aware. I encourage everyone to research rain water collection before you make your purchase. I have provided some links at the bottom of this article.

 

Dual 343 Gallon Rain Barrels

 

I think the first question you need to answer is, "Why am I investing in rain water collection?" If your answer is to save money, you better stick with tap water. Almost everywhere in our area, tap water is relatively low cost. More than likely your answer is to be a good steward of the environment.

 

Overflowing rain barrel. Without an overflow pipe, water can flow into foundation.

 

So what are you going to do with the water and how much water will you need? The conventional rain barrel is a 55 gallon drum. The rule of thumb calculation for the amount of water generated in a 1" rain is to take the square footage of your roof times .623. So if you have 2,000 sq. ft. of roof area and it rains 1" there will be 1,246 gallons of water available to collect. If you have one rain barrel, you will collect less than 5% of the available water. And you only have 55 gallons in storage to use which will not water many plants for very long.

 

240 gallon rain harvesting tank

 

One of the things Jeremy talked about is the availability of large collection tanks from his company or others. They come in all sizes and shapes. I think a good size to consider for the serious residential rain harvester would be 350 to 500 gallons. Some systems include a pump, filter and drip irrigation instead of just relying on gravity.

 

Multiple barrels for 275 gallons of storage

 

The next consideration is the quality of the water you are going to collect. Your roof is not the cleanest collection system. In addition to the larger items such as leaves, twigs and insect bodies that can be filtered out, your roof also catches dust, pollen, bird droppings, pesticides, etc. A lot of this pollution can be avoided with the addition of a "first-flush diverter" to your collection system. It is recommended that the first 10% of rain water be diverted away from your tank. A simple diverter can be purchased in the $35 range.

 

First-Flush Diverter Kit available online

 

The composition of your roof can also cause pollution. For example, asphalt shingles may leach various complex hydrocarbon compounds and it is recommended not to water plants meant for human consumption with this type of roof. There are other roof types to avoid so, again, be sure to perform additional research.

 

System with filter, diverter, pump, overflow and more! For info, see link below: "Pt. 3: All the Parts"

 

There are also considerations for the water now sitting in your tank. It has to be protected from mosquito larvae, algae and freezing. To keep mosquitoes out, cover your barrel with a fine mesh or cloth or use the water within 10 days before larvae can hatch. If your tank allows sunlight to penetrate, algae will grow and it will need to be painted. Finally, you can drain tanks in the winter to prevent freezing.

 

Algae growing in clear/white rain barrel.

 

I encourage rain water harvesting. Not only does it help reduce water usage and prevent stormwater runoff (in proportion to tank size), it is a great educational tool for young children and a great conversation starter with those not yet environmentally enlightened. But as is true in every situation in life, be sure you know what you are getting in to and what will be required of you to maintain the system. 

 

Links:

 

Rain Water Harvesting for Your Home - 3 part series:

Pt. 1: The Basics

Pt. 2: Water Storage 

Pt. 3: All the Parts

 

University of Arkansas Extension: Building Rain Barrels 

 

Texas Manual on Rain Water Harvesting