Rainwater Harvesting Blog

New Rainwater Harvesting Class

2011-10-05T11:02:00.000-05:00

The Texas AgriLife Extension Service is holding its third "Rainwater Harvesting for Landscape Professionals" course in Houston on Friday, November 4 from 8:30 am to 4:00 pm. This course is open to the public and will provide participants the information that they need to get started in rainwater harvesting. It is geared towards those looking to use rainwater harvesting for irrigation purposes, but there is also useful information provided for those using it for indoor use. Please see https://agriliferegister.tamu.edu/events/details.cfm?id=903 for more information.

In-Home Use in Texas

2011-09-22T16:42:00.000-05:00

As of September 1 of this year, it is now legal for Texas residents connected to municipal water to use rainwater for indoor potable purposes. Prior to the 1st, residents with a city-water connection could use rainwater for anything except drinking. With rainwater harvesting gaining popularity in all parts of the state and water supplies decreasing, politicians were pressured into updating the law in HB 3372. The main delay in this new law and emphasis made is the prevention of backflow from a rainwater system into a city water systems. Municipalities are concerned that poorly maintained RWH systems could leak contaminated water into city mains. With HB 3372, backflow prevention devices are required to address this concern.

Youth Education

2011-06-20T13:45:00.004-05:00

With the current drought situation leaving most of Texas exceptionally dry, now is a opportune time to teach our state's youth of water conservation. The Texas AgriLife Extension Service is currently taking part in a project aimed at educating youth about water conservation. In addition, they focus on educating teachers and Master Gardeners to teach youth about water-related issues. This helps to multiple the impact that Extension has on the state's water literacy. The topics that the Extension Service focuses on are watersheds, vegetation's importance in water conservation, and rainwater harvesting.

Current Research

2010-05-12T16:47:00.003-05:00

Because rainwater harvesting has only recently become mainstream, the research available is limited. Many times, Extension employees are unable to answer a client's question because there is no or limited data to support an accurate answer. Part of our mission in educating people is doing the research so that those questions can be answered. In the coming weeks, we will discuss the various research that we have completed or are currently doing.

In the picture above, we have 12 rain barrel-sized containers that each hold 55 gallons of water. There are three sets of four barrels. Each set has four different colors and is under a different shading: full sun, partial shade and full shade. We have inserted a temperature probe into each barrel to measure water temperature over time.

High temperatures in rainwater harvesting tanks may compromise water quality or effect plant growth. From this experiment we hope to determine what particular color of water tank and what amount of shading helps keep the temperature moderated and cooler during the hot Texas summers.

Water Security

2010-03-08T12:36:00.001-06:00

In the summer of 2009, a U.S. District Court told Atlanta that they have until 2012 to resolve water issues with neighbors Florida and Alabama or the city would have their supply of water cut off from Lake Lanier. The lake supplies 3 million Atlanta residents with water, but it is being done illegally. A federally-funded, Corps of Engineers reservoir, Lake Lanier was originally built (in 1956) for hydroelectricity and flood control. As Atlanta's population grew, so did its water demand. It was not made for public water supply. After the drought of 07-09, Alabama and Florida challenged Georgia in court since both states rely on water flowing downstream from the lake. Now Georgia is passing a bill that includes several water conservation policies, such as prohibiting daytime (10-4) outdoor watering and using more efficient devices. If practices such as these are put into place, millions of gallons could be saved, which could lessen the tension between neighboring states.

If problems are not resolved, officials will be rushing to find a new water source for millions of Atlanta residents. Rainwater harvesting on homes and apartments could supply people with water without the massive infrastructure needed to pipe in water from a remote source. It puts the responsibility and ownership of water in the user's hands. This ensures the user has water regardless of what fate may become of Lake Lanier.

Rainwater Harvesting in Haiti

2010-02-02T16:44:00.005-06:00

Even before the earthquake in Haiti last month, water and sanitation conditions were extremely poor. According to the World Health Organization, only 11% of of Haiti's population had drinking water piped into their dwellings in 2006. 42% of the population had unimproved drinking water sources, which includes unprotected wells or springs, surface water, or tanker trucks.

Needless to say, the earthquake destroyed much of infrastructure used to transport clean water. Aid organizations have been working tirelessly in distributing water to Haiti's people. UNICEF itself is distributing nearly 700,000 gallons of water every day.

During the rebuilding process, rainwater harvesting should be considered as a long term water source. Compared to complex underground infrastructure, it is relatively inexpensive and would be a job that locals could participate in. It could be installed quickly to lessen the burden on aid organizations. And education is key: 40% of Haiti's population are below the age of 14. Teaching them the basics of sanitation and water treatment would prevent many of the water-born diseases that kill countless people every year.

Rainwater Harvesting on Campus

2009-12-16T08:44:00.007-06:00

Texas A&M University recently opened the Mitchell Physics Building in College Station. This building, like all new construction on campus, is LEED certified. LEED, which stands for Leadership in Energy and Environmental Design, is a national rating scale that focuses on sustainable building practices. The Mitchell Building was built at the silver standard of LEED certification, and it includes rainwater harvesting.

Rainwater and air conditioning condensate are captured from the rooftop and sent to an underground cistern (diagram below). This water is then used to irrigate landscaping in the front of the building (picture upper right) and the roof-top garden (picture upper left). This is the University's first roof-top garden.

Cold Weather

2009-11-23T15:31:00.003-06:00

If you live in a region that receives significant freezing weather in the winter, you may be concerned about storing rainwater. However, with proper planning and construction, you may have nothing to fear. Usually the most vulnerable location that is prone to freezing is the piping. Be sure to wrap any exposed piping in insulation and when possible bury them below the freeze line. It may also be helpful to plan for a "dry-line" system which has no standing water in the pipes. Valves, pumps, and treatment equipment should be protected in a pump house or insulated box. As for the tank itself, round tanks with straight sides do better than round tanks or corrugated sides. Insulation around the tank can be used in extremely cold regions, and you must make sure that the roof can handle a heavy snow load.

Keeping Our Streams Full

2009-11-02T12:25:00.004-06:00

Constructing a rain garden is an excellent way to harvest rainfall that may otherwise become detrimental runoff. Generally a rain garden is a depression filled with plants that slows down stormwater and allows it to infiltrate into the soil. It is often referred to as a "passive" or "simple" rainwater harvesting system. Unlike "active" or "complex" systems, you are not using tanks, pipes, and pumps to collect and use water.

Many people can understand the benefit of reducing runoff that rain gardens provide. Slowing down the water's flow can prevent land from eroding and streets from flooding. However, there is a common misconception when it comes to the water's infiltration. Some believe that by preventing runoff, we are reducing a water source for river and streams.

The truth is in fact quite the opposite. Streams and rivers (especially in the West) receive a large portion of their flows from groundwater. This is called base flow and is why streams still run during droughts.

Rain gardens replenish aquifers with water which eventually contributes to streamflow. This may be delayed as it can take anywhere from days to decades for water to reach a stream after infiltrating into the ground.

A Good Foundation is Key

2009-10-26T14:34:00.004-05:00

When planning the construction of a rainwater harvesting system, one of the most critical aspects to consider is the ground beneath the future tank. Water weights 8.34 pounds per gallon. This can add up to tremendous weight under a tank:

Two extremes to look out for are soils with high clay or high sand content. Having a large amount of clay in a soil can result in shrinking and swelling. This can result in shifting tanks or broken pipes. A large amount of sand may be prone to erosion around the base of the tank.

An ideal base for tanks over 500 gallons would be concrete. However, you can also place a layer of pea gravel over a clay base to lessen the impact of swelling.

Barrel Coverings

2009-10-19T15:56:00.007-05:00

One concern of many who consider a rain barrel is the bright color and "industrial" appearance of the barrel. You can alter the appearance of a barrel by painting it or adding a decorative covering.

To paint a barrel, clean and lightly sand the outside. You can then add either a spray paint specific for plastic or a latex paint with brush. One color or fancy designs: the possibilities are endless. See this website for several creative barrels in Kentucky.

The decorative covering seen on the right can give you an old-fashioned-barrel appearance and is easy to assemble. Take 14 wooden fence pickets and cut them as long as your barrel is tall. Purchase 6 inch flashing and cut them into three strips that are 2 inches wide. Lay the pickets in a row (separated by an 1/4 inch) and attach the flashing. You can then attach the two ends and slip the covering over the barrel. Wooden coverings for the overflow and top can also be made from pickets.

Where does the rainfall go?

2009-10-13T11:21:00.003-05:00

Besides providing a free source of water, rainwater harvesting is one tool landowners can use to reduce runoff. In this video, Billy Kniffen of AgriLife Extension demonstrates how various land uses contribute differently to runoff and infiltration.

Importance of Overflow

2009-10-09T12:33:00.006-05:00

As I waded through the lake of a parking lot this morning, I noticed the incredible speed at which the runoff collected and found its way to the storm drains. This is often how many fearless drivers get caught during floods. The power of water is usually underestimated.

The same can be said about roof runoff. Especially with rain barrels, the power of the runoff is often underestimated when making an overflow. The overflow needs to be at least the same diameter as the pipe/downspout leading into the tank. If not, water can spill out of the top of the barrel and run down the sides. This concentrated spilling water has the potential to erode away or ruin the integrity of the ground beneath the barrel.

Pipes from the overflow should lead to another barrel or be directed to an area where the water can drain safely. It is recommended that this be at least 10 feet away from a building's foundation.

Another important step to remember is equipping the overflow outlet with a device to prevent the entry of pests. A 1/16" mesh screen will keep out mosquitoes. If larger pests, such as mice, are an issue, larger, more sturdy screen may be needed. Do not use one with openings larger than 1/4".

A Bountiful Harvest

2009-10-07T13:19:00.003-05:00

One comment often made by the rainwater harvesting naysayers during dry times is, "There's no rain to harvest!"

Well, it is true that during the months of July and August this year, College Station received just over 3 inches of rain. However, there is a reason that we refer to rainwater catchment as rainwater "harvesting." Like any agricultural crop, the harvest of rain must be preserved and used in moderation. That one harvest needs to last until the following harvest.

The naysayer would be one who never had to rely on their own vegetable garden to get through the winter: "Just go to the grocery store." Sadly, for many people that same mentality is taken with water: "Just turn on the tap." A rainwater harvester understands the value of water because they have to make it last from harvest to harvest.

For the rainwater harvesters, it has recently been a bountiful harvest. In College Station, we recorded over 7 inches of rain in September and nearly 1.5 inches already in October. A bumper crop indeed.

It is truly an exciting time when harvesting the rain, just as it is with harvesting vegetables. It gives the rainwater harvester a sense of accomplishment, which the naysayer would have difficulty finding at the grocery store or while turning on the tap.

We as rainwater harvesters need to quell these naysayers by sharing our bountiful harvest. Share with your knowledge and enthusiasm. Just like the Victory Gardens of the 1940s, we can convince many to join us in the joys of rainwater harvesting.

Risk of Legionella Bacteria in Rainwater

2009-06-09T15:37:00.004-05:00

Information provided by Dr. Dennis Lye, an EPA Research Microbiologist

The causative agent of “Legionnaires Disease” is Legionella pneumophilia. This organism is ubiquitous in the environment. It can be found in ponds, pools of water, and even in eves/gutters of buildings. The mere presence of this organism is not enough to be a risk to humans. This is why most rainwater collections systems will not pose a risk to healthy humans.

However, we must be cautious and concerned when any of the following occurs:

The rainwater collection system is not treated and a biofilm build up within the system.
The water is heated at some point before usage.
The water is aerosolized in some manner (fountain, showerhead, mist, etc.) in a way that humans could be exposed to the aerosol.
Immunocompromised individuals (including infants and some elderly) coming into contact with any of these aforementioned water because they are more likely to be infected with this organism than a healthy individual.

Any of the following will help to eliminate concern about this risk:

Maintain a chlorine residual in the rainwater system.
Do not heat the water or aerosolize the water before usage.
Use the water for landscaping.

There is a Center for Disease Control (CDC) site with more information if you need it –

http://www.cdc.gov/legionella/patient_facts.htm

Welcome to Rainwater Harvesting!

2009-04-08T17:07:00.005-05:00

The Texas AgriLife Extension Service offers practical, how-to information describing methods to collect rainfall. Specifically, the Rainwater Harvesting program educates individuals with up-to-date ways of preserving and protecting our most valuable natural resource- water. Through this program, we hope to provide information that allows Texans to become better stewards of our water resources, and thereby leaving a lasting legacy for future generations.

The information published through this blog will provide timely information on rainwater harvesting topics as well as information about up coming classes and other educational opportunities. This blog will allow prospective participants to preview a class and stay updated with the progress of the Rainwater Harvesting program through the Texas AgriLife Extension Service.