Catching water from the roof in the landscape is often more efficient than using rain barrels. Here’s how rainwater harvesting transformed my front yard garden on my suburban homestead.
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I envisioned this rainwater harvesting project as a way to jumpstart the productivity of my edible landscape, but I had no idea how much I would learn and grow in the process!
In this article, I’ll share the step-by-step process that I used to create a front yard edible landscape with a built-in rainwater harvesting system that captured 12,000 gallons a year from the roof.
It eliminated the need for hand watering, which was a pretty amazing accomplishment that saved a lot of time. It was also the catalyst for creating an edible and ecological oasis in the middle of a lawn desert.
Here’s more about my edible landscape.
My Front Yard: Before Rainwater Harvesting
In the years leading up to the rainwater project, I replaced the traditional hedge lining the front porch with shade-tolerant, edible currant bushes. A few other bushes nearby were replaced with a surprisingly beautiful black raspberry patch.
As I neared the next garden season, I was feeling spunky and wanted to expand my edible front yard. I also wanted to figure out how to incorporate rainwater from the roof into the design.
After all, why send rainwater to the sewer to muck up rivers and fresh waterways, when I can harvest and hold it on site for free irrigation?
Designing a rainwater harvesting system is always unique and depends on the specific characteristics of a site. Things like soil type and health, climate, sun exposure, slope, budget, and skill of the homeowner, all come into play.
Allowing permaculture principles to inform the design process, I set out to create a closed-loop system to harvest rainwater from the roof to hopefully reduce the number of times I have to drag out the hose and pay to water the garden with my time and money.
The best place to hold water is….
In conventional gardening, a rainwater harvesting discussion usually focuses on acquiring a rain barrel or two. This sounds like an easy option that doesn’t take a lot of creative thought…until you go to water your garden that has expanded in size, and realize how long it takes to use a watering can!
I decided to hold the water in the soil. Luckily, with a bit of physical labor on my part (and Mr. TAF!), it’s also the cheapest! It’s mathematically impossible to hold more water in a tank or barrel than in the soil, as soil can expand to three times its size to absorb water.
Observations pre-rainwater harvesting system
In the photo above you can see how the water naturally wants to run off the property to the right (blue arrows). The downspout is on the right side, but the majority of the new gardens are to be uphill—to the left of it.
My goal was to harvest the rainwater coming from that downspout, and reroute it uphill.
My plan was to use a trench and berm to capture water in the landscape while using a rain garden as a fail-safe backup.
If my gardens had been downhill from the downspout (to the right), the system would look completely different. Again it depends on where you’re catching water and where you want to take the water to.
This sketch outlines in blue how I plan to direct water through the system.
Want to grow fruits, vegetables, and herbs in your front yard landscape without sacrificing curb appeal? Check out my mini guide, The Permaculture Inspired Edible Landscape.
Goals of a Rainwater Harvesting System
#1: Catch Water
Catch water on site using earthworks and build up healthy soil, which acts as a sponge. As the structure of the soil improves, its ability to regulate moisture levels also improves.
You can add organic matter to speed up the process. However, be aware that homemade compost can be contaminated with herbicides, even if you don’t spray. Likewise, store-bought soil can be contaminated, even if it’s organic-approved. Manure can also be contaminated.
Learn more ways to improve soil quality.
#2: Hold Water
Hold water in the soil as much as possible. Mulching on top of the healthy soil with straw, leaves, and plants keeps the water from evaporating away, and allows it to slowly trickle into the deeper soil horizons.
#3: Recycle Water
Earthworks direct and store water underground in what is called a water lens, which can be accessed naturally by plants during dry spells.
As such, recycling water in the soil is a good first step. Later, you can add above-ground rainwater harvesting in tanks or barrels, as needed.
The front yard looked really ugly for a while while I dug and created my system! The neighbors were anxious, but the end result was totally worth it. Having a vision on paper really helped me keep my eye on the prize.
Downspout is off, rain chain is on. Now I have to paint the post!
The 9-Step Process for Creating my Rainwater Harvesting System
Step 1: Disconnecting the Downspout
I disconnected the downspout and installed a rain chain. The rain chain is not essential, it just makes watching rain a beautiful event!
The rain chain guides the water down to a conveyance trench. Alternatively, you can attach a flexible extension to your downspout and direct the water to where you want it.
Step 2: Digging the Conveyance Trench
I dug the conveyance trench 12-inches deep and lined it with gravel. Its purpose is to encourage water to run away from the house and down to the infiltration trench.
The conveyance trench leads water to the infiltration trench.
Tired of generic permaculture design advice that you can’t apply to your specific goals? If so, check out my Permaculture Design Program and get the tools and support needed to create and implement your own permaculture design.
Step 3: Building the Rainwater Harvesting Infiltration Trench
I dug the infiltration trench 12-18 inches deep and filled it with gravel and large rocks. Infiltration trenches hold water until it can slowly soak (infiltrate) into the ground.
In this case, the trench gets progressively deeper as it moves to the left to encourage the water to run uphill to the rain garden, which holds more of the water before soaking in.
Make the infiltration trench a walkable path! By filling in the trench with gravel or wood chips, the rainwater harvesting trench becomes a walkable path, which means more functionality in a small space, and no trenches to fall into.
Another solution is to make the trench shallower and wider if space allows. It holds the same amount of water, only in a different shape. A shallow trench is less of a hazard in a residential area, and it can easily be seeded with clover or grass, which may be easier to maintain.
You can see the grade deepening as the infiltration trench reaches the rain garden.
Step 4: The Rain Garden as a Rainwater Harvesting Back-Up
The rain garden is the final overflow catchment for the really rainy periods. Water stores here and slowly infiltrates into the lower yard areas over the next 48 hours after a rain.
The bowl-shaped rain garden is 12-18-inches deep. I planted it with native, deep-rooted wildflowers like echinacea, aster, and blue-flag iris.
The infiltration trench and asparagus berm work so well that water never pools up in, or overflows, the rain garden.
I planted the berms surrounding the rain garden with edamame, swiss chard, carrots, and cayenne peppers in the first year.
Get details for building a rain garden here.
I meticulously saved the topsoil from the sod I dug up and used it for the berms, saving on the cost of importing soil.
The rain garden digging is complete and ready for planting.
Rain garden and berms are planted.
Step 5: The Asparagus Berm (Turned Strawberry Berm)
I created the asparagus berm by taking topsoil from the trench and piling it up on the downhill side. The berm absorbs water from the infiltration trench and discourages water from running off.
Then, I covered all of my garden beds with a deep mulch to discourage evaporation and erosion of soil nutrients.
Deep-rooted perennials, like asparagus, also help to encourage infiltration. In fact, wild asparagus can often be found growing in ditches along roadsides, so I think it prefers this job of soaking up rainwater!
Post Note: Asparagus is a good choice for an infiltration berm because the roots can grow to a depth of ten feet.
However, in my quest for the perfect, functional water harvesting system, I completely ignored the aesthetics of having 6-foot-tall asparagus run through the middle of the front yard!
So I moved the asparagus to the backyard, and replaced it with strawberry plants. They’re also a good choice for a water system, since their roots can grow to a depth of 6 feet.
With both asparagus and strawberries, the important thing to note is that they don’t like standing water. They work on the berm because the yard slopes downward, so water drains through the berm but doesn’t sit there.
Learn more about edible perennials for growing in wet soil.
Rain doesn’t always wait until you’re finished! The infiltration trench is full and the asparagus berm hasn’t been created yet to help it soak in.
Summary: Rainwater Harvesting in the Front Yard Garden
I built this system during the wettest year on record, so I couldn’t have planned it any better. If it held up to this much precipitation, I’m confident it can hold up to anything!
This was the planting sketch I made for the 2011 season.
The rainwater harvesting system is not entirely complete. There is still one downspout connected to the sewer. I would like to install a rain tank to the right of the front porch to give additional capacity for watering in times of drought.
I also intend to expand the growing area of the front yard gardens.
A strawberry berm replaced the asparagus a couple years later.
Tips for Getting Started on Your Own Rainwater Harvesting Design
Every design is different because it is based on the unique layout, drainage, soil structure, etc. of a particular site. Observe how the rain runs on your property. Where does it pool up? Where is your preferred garden area? Remember, an imperfect design is better than doing nothing at all.
My design wasn’t perfect, but it’s not meant to be. Part of the permaculture design process includes observing and evaluating how things are working, then making adjustments over time.
The only golden rule is that you want the water to run AWAY from your house. Everything else can be tweaked as you observe!
Resources
- Gaia’s Garden: A Guide to Home-Scale Permaculture by Toby Hemenway (Includes an excellent chapter on catching, conserving, and using water.)
- Rainwater Harvesting for Drylands and Beyond, Vol. 2 by Brad Lancaster
- Consult with a live, qualified expert. You never want to risk flooding your basement or that of a neighbor. A permaculture designer can save you money and shave years off of your garden development! See: 3 Reasons to Hire a Permaculture Designer
Do you have a rainwater harvesting system? What features does it have?
READ NEXT:
- Contour Gardening to Minimize Irrigation & Maximize Yields
- How to Build a Permaculture Swale
- How to Use the Power of Observation in Permaculture Site Design (+ Free Worksheet)
Scott says
Really nice to see all of the diagrams. Also the action photos of the rain storm. Where I live it is illegal to store rain from the roof and later use it to water. We have a “first use” law. So, the first use of the rain was to wash the roof. We can’t reuse it to water a garden. By not storing it but just creatively distributing it as it is raining, I think we can get around that law. Anyway, I am inspired and looking forward to doing the trenching before the spring planting.
Amy Stross says
The local laws on rainwater seem to be a little archaic, eh? Washing the roof is really important!!! Yes, storing it in the landscape is a way to get around the “catchment” issue. In fact, that’s the theme of the class we’re teaching in just a few hours! You will get a lot of benefit from reading Toby Hemenway’s book Gaia’s Garden. Chapter 5 explains in detail the best ways to store water in the ground.
Scott says
Thanks for the tip. I look forward to reading that.
Alexis says
Great, informative post! I’m getting ready to do something similar in my front yard. I love seeing your garden evolve over time.
Amy says
Thanks for stopping by! Good luck with your front yard project!
lynn says
This is soooo incredible and inspiring! Love that rain chain…..and your sketch of the entire plan…..fantastic!
Amy says
Oh yay! I’m happy to share and glad it is helpful. Thank you!
lynn says
You are so welcome…..I am still thinking how very inventive…..copied and sent it out to friends too.
Dr,Visal a.Khan (dr_visa@yahoo.com says
It may be useful for the areas of low rainfall mansoon, but not useful for India tropical as there is rainfall of ranges 30 inches to 60 inches average yearly. India India there is ony 1 to 2 percent rainfall used for greens the other more than 98 percent go as runoff and every year there flood reports and wastage of land properties and lives, also the areas after rainfall season meet the crisis of water shortages or drought. I am as an irrigation expert of India is search of water storage reservoirs made by cultivators themselves without acquiring any extra land useful as green and cost free underground storage reservoirs (Using excavated earth for building bricks to cover the cost of livelihood of them) and to some extent I am successful to construct underground reservoirs in some villages of India, I hope if my designs came of successful in future too India shall be free from foods or water crisis and every village shall have their own water storage for drinking water or irrigation water round the cock
Shay says
This is great! I just attended a landscaping workshop on catching rain water (San Diego area). I used to live in Phoenix and was going to do more of a desert landscaping like was done there, and the workshop advised to do a water catchment approach. That same weekend, my property and garage flooded from water coming over from the street (in addition to own roof, sky, etc.). Ugh! I’ve started digging trenches already while laying out plans for swales, etc. to direct water. I love your use of edibles! I figure if I am going to have to do yard work, I better get something out of it (I am nowhere on your level of edibles, but I was thinking rosemary bushes, herbs, etc.). I was also eyeing water chains online so I double impressed with your work! Thanks for sharing!
Linda says
Hello, and thank you for this article. I am concerned about using the water from our asphalt roof. Isn’t there arsenic in asphalt shingles? Is there a way the earth filters the water from your drain pipes to the edible plants? What kind of roof do you have that you are safe in using the runoff ? I’d really like to use our rain water but haven’t because of the asphalt shingle roof. Thanks for your reply.
Amy says
According to The Center for Rainwater Harvesting, “It was widely thought that [contaminants] were coming from deteriorating asphalt shingles on homes… [Research shows] that the [contaminants] coming off asphalt roofs are no more than what comes off of a metal roof. This suggests that [contaminants] are deposited on roofs and not sourced from roof material deterioration.”
According to this research, any contaminants are deposited on the roof from airborne toxins and animals, rather than from deteriorating shingles.
The soil is nature’s filtering device, so run the water through the soil. It will be as clean as rainwater at this point. Be sure to water the soil rather than the plants themselves to avoid adding contaminants directly to edible plants.
This is still preferable to using chlorinated municipal water, which will damage beneficial soil organisms that help to keep soil and plants healthy.
Kelly says
Amy, I just love reading your articles! They are so inspiring! We live on a town lot in rural Wyoming. There are obvious limitations, but thanks in large part to your writings, we are trying to slowly reclaim our yard into farmland. Our latest thoughts have been about using the roof runoff in our landscape/garden. My biggest concern is to avoid creating ice dams on the roof in the winter. We get a lot of snow at 6100 ft elevation! Any advice?
Amy says
I don’t have any experience in high-snow areas, but I wonder what collecting roof runoff would have to do with ice dams? Are you afraid the water will freeze inside the downspout? If so, how would you handle this problem if the downspout was directed toward the sewer? I would assume that the same preventative measures should be in place, but I can’t say for sure. Not my area of expertise 🙂
Beth says
Thanks, Amy. This is a posting I will return to often as we modify our existing plan. The diagrams are extremely helpful, adding a visual confirmation to what can be a confusing but interesting process. I’ll be anxious to see how you manage water at your new site.
Lish says
Thank you Amy. The thorough and really great job you did on your project, really shows the benefit and how to best use berms and swales. Our utility company is tearing up our front yard as I write and I hope to convert (what was once grass) the desert they’ve now created into a well-watered oasis once we get new trees planted next Spring. Thank you for helping me know what to do.
Amy says
I love that you’re looking for ways to turn “annoying” into “opportunity”! Good luck!
Rachelle v Hijazi says
Hi. This was such a great article as I’m trying to add onto my garden and see the need to add a swale and bearm, items I’m unfamiliar with.
I had a concern about the water from the roof but i saw that answered.
But now can you explain the rain garden portion a bit more? I assumed it would be deeper/lower, but it seems fully planted and level with the rest?? It’s supposed to be fumed in with soil and then planted??
How do you extract water from this to use in the garden or is it more the idea of the path assuring and slowly releasing..?
Thanks!
Amy says
I explain the depth of a rain garden under “Step 4: The Rain Garden” above. The second picture in this section demonstrates the depth best. A light layer of topsoil is added to plant in. Over the years, mulch will build up. But the base still remains lower than the berms surrounding it, which are also planted.
This is not active irrigation — water is not extracted from the rain garden. Rather, it is passive irrigation: Gravity slowly pulls the water from the rain garden downhill, watering whatever is below it under the surface level.
Pin-An says
Hi Amy,
Love love your blog!! I dream to do similar design in my yard but with low rain water in San Diego, I need to do more research. I am confused though with this design. Is it dug on contour line? or if you can level the bottom of the trench, you can have the same effect? Thank!
Amy says
We did not dig along the contour line for this particular design due to space limitations. But yes, we were able to level the bottom of the trench and that was important for this design to function. But there are very few “rules”, except to never direct water TOWARD your house. Always direct water AWAY from a structure. Outside of that, each situation will be unique. Perhaps you want to direct water into a certain area that it might not naturally drain to, in which case, your trench can have a slight grade to it. It all depends on your goals, but as long as your building structures are safe, there’s nothing you can’t undo or tweak as you go along. Sometimes by experimenting we find the best solution.
Jami says
We are moving to Columbus soon from a more rural area and I’ve been searching for ways to bring my larger scale gardening to the big city. Thank you so much for the beautiful and thorough insight! The pictures will be very helpful in convincing my husband to give me what I want. I mean he is dragging this wide-open-spaces woman to the on-top-of-each-other suburbs😉 Happy gardening Ohio neighbor!!
Amy says
I totally understand the claustrophobia, but hopefully the challenges will keep your brain and spirit young. 🙂
Sharon says
I am in Columbus, and (fingers crossed) just converted some former tree bits that the city didn’t like into my first attempt at Hugelkultur in my front yard – hopefully solving several problems at once. It’s planted with thyme and other perennials, and after I watered them in, later last night we had a lovely thumping storm, so they should be happy. I have two rain barrels ganged on one corner of my house, which have met watering needs for almost a decade now, but we can do better.
We are gifted with fine Ohio CLAY.
I’m looking at the rain diversion/rain garden with an eye to my back yard. When it rains, the rain RUSHES down the path from our back gate toward the alley. I’m thinking of digging and gravel/stoning the existing path, then curving gently into the area which currently has (useless) grass to dig my rain garden… which would also be much appreciated by the sour cherry and pawpaw trees nearby. Does that sound something like a plan?
Amy says
Worth a try, and it can be undone if it doesn’t work out. Calculating slope, the volume of water that the rain garden needs to hold (thus, it’s size), and identifying the contour are all things that can help you make fewer mistakes. But trial and error can be fun!
Doreen says
Thank you Amy. I have been reading your articles, and they are wonderful. We are about to move into our home, we will need some swales, and redirect water. Hoping to use many of your ideas. Keep up the good work, love the practical advise, diagrams and pictures. Blessings to you all.
Jennifer says
HI, I was wondering if volume 2 of the rainwater harvesting book is better than volume 1 for someone with a yard size plot? (ie 1/2 acre)
I noticed you recommended volume 2.
I am ordering some books but wasn’t sure which volume to order, or both?
Thanks!
Amy says
Volume 1 is a great read. It focuses on the principles needed for creating the right design for your site. Volume 2 dives into the “how to” of various water harvesting techniques. Both valuable for different reasons. 🙂
Robyn says
Thank you for this excellent article. I really like the way you present your ideas and remind people to pay attention to their own climate and situation. I find the information in the way you present it more useful than most things on the Internet. The quality of your information and presentation is leading me to order your book today!
Amy says
Thank you, Robyn. I hope you enjoy the book! 🙂
Rachel says
I suppose I should stay away from this with a leaky basement and not a very good slope away from the house (ie the grading was I’ll thought out)? Any tips?
Amy says
Every situation is different, but I personally would not try to capture rainwater in the ground where gravity will encourage it to settle around the foundation of the house. What you can do is collect rainwater in a rain barrel or cistern and direct the overflow to the sewer.
Christina Sparks says
I do t understand how any of this persuades water to run against gravity uphill? What am I missing?
Amy says
The infiltration trench in this example is not level. It starts out 12-inches deep at the confluence of the conveyance trench, and becomes deeper to 18-inches where it connects to the rain garden. This creates a downhill affect to run the water from right to left (uphill), even though the slope is opposite.
Ally says
Hi Amy. Thanks so much for the lovely articles and photos. Just wondering-do you use the trenches as walkways through the garden? In the photo with the strawberries on the berm, is the trench filled in with mulch or is the trench above the strawberries and then you have a mulched path below? Thank you!
Amy says
Hi there, the trench is fill with rocks, gravel, and mulch to double as a walkway. The soil from the trench was used to build up the strawberry berm.
Nan Bailey says
Hi Amy, do you find with heavy rain the woodchip on the flow trenches washes down into the catchment area? We have very heavy tropical downpours at times and I think the wood chips in this case would not be heavy enough. I think I would need to use rocks. I live your plan and how it turned out. Thanks. Nan
Amy says
If your downspout is pointed directly into the walkable trench, then you’re probably right that rocks will work better to stay in place and slow the water. In step two above, you can see that I’ve used gravel in my conveyance trench, as that is where the water has the highest velocity. In an area with tropical downpours, I would add larger rocks to this conveyance trench to slow down that water.
BevB says
Hi Amy, this may be completely out of the realm of your expertise, but I’m hoping you can direct me. What resources can I go to to help me identify the weeds that are growing in my yard? Since some of them are edible (and some or not), I would like to know who (what professional) I would contact for help in learning to identify them.
Thanks for any tip you can give me.
Miranda says
Hello. May I ask what you used for mulch? I’ve used wood chips from ChipDrop, but they’re much lighter in color and in bigger chunks. The kind that you’re using is more aesthetically pleasing. Thank you for the wonderful article and photos of your process!
Amy says
Hi there, I used wood chips as well. Different types of chippers create different sized chips. You may need to call various tree companies and inquire about the chipper they use. If it were me, I would specify that I’m looking for “chunky” chips as opposed to fine chips. That’s probably not official terminology, but hopefully that helps.