I had a great opportunity to discuss the tips and tricks of planning rainwater harvesting systems with Tom Spencer from Central Texas Gardener on KLRU Austin.
The focus of the interview was residential rainwater collection systems used for irrigation purposes.
We started off the interview discussing how I and my company got into designing and installing rainwater harvesting system after my business partner and I completed our service in the US Peace Corps.
We then discussed how you should determine your goals or intent of the system. This is very important since there are so many different design variations in rainwater catchment systems. Without a goal, you could potentially end up with a system that doesn’t meet your needs or with a system that could be overly complicated for your needs.
We discussed the various rainwater tank options that are available to homeowners. I highlighted some of the pros and cons of each type of tank.
We ended the interview discussing the options for using the harvested rainwater from the tank. It can be very simple with a hose bibb or more complex by connecting the rainwater system to an irrigation system with the help of a pump system.
It was a faced paced interview but it is a great primer for people just starting to think about rainwater collection. It is also a great resource for people who have been thinking about installing a rainwater harvesting system and just need a bit more information to solidify their plans.
You can also read more about the rainwater harvesting system planning interview on the Central Texas Gardener website.
About Central Texas Gardener
Central Texas Gardener is one of the longest-running KLRU productions, having premiered in the late 1980s. Originally conceived as a monthly show on Saturday afternoons, the show went weekly in 1999. Since a month in Central Texas can span at least two seasons (sometimes in 24 hours!), viewers wanted more. In 2006, KLRU began distributing the show to other PBS stations around the country and today more than 20 stations in 8 states air the program.
Central Texas Gardener is actually filmed in the famous KLRU Studio 6A which is the original home of Austin City Limits. I couldn’t pass up the opportunity to snap a picture standing the same stage that so many great musicians had jammed on over the 35 year history of Austin City Limits filming in this studio.
Interview Transcript
Tom: What an amazing space. Thanks so much for opening your garden gates for us right now. We’re gonna be talking about stormwater collection, rainwater harvesting. I’m joined by Chris Maxwell-Gaines from Innovative Water Solutions. Welcome to the show!
Chris: Thank you Tom!
Tom: I understand your interest in this whole topic got started when you were in the Peace Corps. Tell me a little bit about that.
Chris: Correct. My wife and I served in the United States Peace Corps, 2000-2002, in Suriname, South America and while we were there, rainwater harvesting was our only water supply and so living on it, you soon appreciate the preciousness of water. And so, once we got through with our service and came back here, my business partner was also a fellow Peace Corps volunteer in our same group, and so we decided to start a business from our experiences that we learned in the Peace Corps.
Tom: Well, it seems to make perfect sense. I bet your customers love hearing about all of that.
Chris: Absolutely and it’s just you know that the thought of experiencing not having the ability just to turn on a tap and water is there but actually having to wait for the next rain event, that really hits home and we can bring that to our customers and that experience.
Tom: Well speaking of hitting home, Austin is home to probably the epicenter of rainwater harvesting in the United States, the application of rainwater and stormwater capture. When you’re meeting with a customer, what are the first things they really need to consider? Is it the scope of the project?
Chris: Correct. When you think about it, it’s the goal. When you start out with a very nebulous “I just want to collect rainwater”, we can go many places with that. So it’s really the goal. If its irrigation use, how do they want to use the water. Is it going to be a manual operation or do we want to have some sort of pump and pressurized it into an irrigation system. So it’s really the kind of the goal and then from that, we get into the thought of type of tank, size of tank, placement of the tank because some of these can get rather large and so they can take up a lot of room in your backyard and so making sure that you have an appropriate placement and so that’s how we start off in any interaction with a potential customer or someone interested in rainwater harvesting.
Tom: The actual capture of the rain that is largely done just from roofs, correct?
Chris: Correct. The rainwater harvesting, the definition is kind of roof based. Stormwater harvesting definition is maybe something from the ground. But yeah, probably 99% of what people see out there is active rainwater harvesting which is off of a roof and into a cistern. And so from that, there are two methods and this is an important kind of planning step. There are two methods of collecting water off a roof and as through a “dry method” and a “wet method”. And so a dry method is basically like a rain barrel and your downspout comes down, empties into the top of that rain barrel and then that pipe dries out. That’s a very simple system. The drawback is maybe limited space where you can have a large tank because now it has to be against your house. You have windows, all that stuff. But it’s a simple system for people to get into by using a dry system and then from that we explore maybe a wet system. And so that is where we actually pull water from multiple downspouts, all the way around the house, if the person really wanted it to and we route this into basically a underground PVC trunk line. All of the downspouts in this case have to be glued PVC downspouts and so not to draw anyone back on that. They can be painted. They match really well but essentially what you’re doing is you’re creating a p-trap. So therefore you can take all this water from your entire roof, all your gutters, all your downspouts and route it underground. Then you can take it to a location where you want to put a cistern. So therefore it doesn’t have to be against your house. It can be in that back corner of your lot.
Tom: The placement really does matter a lot in terms of where you can put the storage?
Chris: Absolutely, because you want to install as large a cistern as you possibly can because of our feast and famine rainfall. So if you have something too small, we have this large three-inch event that comes through, overflows, and then you are essentially wasting an opportunity. So we really push people to consider the largest volume that either you can fit into that spot or something that can fit well into their budget.
Tom: We see galvanized tanks. We see the poly tanks. What are the strengths and advantages of both?
Chris: So the poly tanks offer just the advantage of being less expensive. There are a couple companies out there and so there are some different styles of poly but the color, you’re kind of limited and so that’s kind of a drawback but there are many different sizes that’s a benefit of the poly tank. And in terms of just the robustness of a tank, it’s gonna stand the test of time and so it’s gonna really be there for long, many decades.
Tom: I like the aesthetic of the galvanized tank.
Chris: Yes, and most of our customers do because it fits well aesthetically with gardens. You can plan a garden feature with it and it really sets it off and so yeah that is a very popular choice. The galvanized tanks that we use actually have an epoxy liner on the inside so the metal is protected from the water. It’s not like the old farm cisterns with water sitting up against the metal.
Tom: Ok, so the next big consideration seemed to me, is it going to be gravity operated or is it gonna actually require mechanics?
Chris: Correct. And so obviously the simplest is having a hose bib on the bottom of this tank where you can connect a hose and you get a little bit of gravity pressure out of it to be able to water some plants. And so definitely for the smaller tanks, this is the better way to go. When you do want to step up into the thought of making it more automated or potentially connect it to an existing irrigation system…
Tom: Right, and you can integrate it with an irrigation system?
Chris: Absolutely, you absolutely can and there’s some logistics and one of them obviously is installing a pump system. With the pump system, it does trigger some City of Austin regulations which is very important for people to understand. And similarly, these regulations are similar in other cities as well but just maybe not as out there as much as City of Austin’s.
Tom: Alright, and you can actually put them underground as well and this is would be very attractive I would think for people who are limited by say, homeowners restrictions or something like that?
Chris: Correct. There are lots of applications of how we can install these. We have options for pillow tanks which are basically can be installed underneath the deck or a crawlspace of your house.
Tom: Yeah, pier and beam homes. Perfect.
Chris: That’s right but the underground tank in particularly our area, is challenging because of the bedrock. So definitely, the less expensive option is an above ground tank.
Tom: Ok, well you know their concerns that people have, kind of swirling concerns about this. Real briefly, mosquitoes, algae, are they really big concerns? Are they easy to deal with?
Chris: They can be a big concern and it depends on how the system is designed and installed. And so for our systems, and really any rainwater standards that you see coming out, it’s about closed connection points. So by having an open hole or even a screen inlet and the pipe just kind of coming into it, that presents opportunities for a screen to tear and for mosquitoes to get in. So it’s really how the system is designed, overflow pipes having a flapper valve so that mosquitoes can’t fly up in them. So while mosquito larvae potentially can get into the tank, if you just keep everything closed, it won’t affect and increase mosquito population.
Tom: Well you know Austin as I said is the capital of stormwater capture and I can see why. You’re a busy man these days. Great, simple explanation about a system that I know a lot of our viewers are gonna be really interested in. So Chris thanks so much for being on Central Texas Gardener!
Chris: You’re welcome Tom. Thank you for having me.
Tom: All right and coming up next is Daphne.