Tiny water garden in top of rain barrel

I'm sure people think about this all the time, so I'm not sure if the reason I can't find much info is because it's impractical or because Google can't tell the difference between "water garden" and "water garden." Anyway, we have a small garage and I want to put a rain barrel on the patio and a tiny water garden on top of the rain barrel. The gutter water currently leaks down the side of the garage, so something is needed, and there's not a great place nearby to store water in the soil. This seems about the same effort/complexity as having a self-watering planter on top and I have no water garden at all currently. Anyway here are my ideas so far.

If the diagram isn't clear or link is broken when you're reading this, the basic idea is that there's a 8" deep basin set into the top of the barrel. The flexible pipe goes down to the bottom (to slightly reduce turbulence) and a pot or two of very tough water species (cattail? water chestnut?) are set into the basin. I may also put rocks or a piece of plastic about 2-3" below the surface so it makes a better birdbath. Still trying to figure it out. There are very large cuts around the sides such that rainwater easily overflows the basin into the rain barrel. The rain barrel is elevated on two rows of cinder blocks. I can use it for regular rain barrel stuff plus have my little water garden, which is hopefully low maintenance despite it likely being highly evaporative. (We're in New England, so we're not known for very dry summers, although they are getting drier.) I really want to build this and try it out so I can report back on whether this works! My hold up at the moment is finding something to set into the top (I don't want to use the top of the barrel, I will lose too much height, plus with my specific barrel it might not even work). Keeping an eye out for a good used plastic tote or even a huge bowl.

By the way, the rain barrel itself has an overflow pipe in the back, not pictured.

Since I'm on hold on it anyway, I figured I'd offer it up for critique and feedback before I build, and ask if anyone has come across something similar. Thank you!

there are some commercial ones out there and they are nice search rain barrel planters. but i think you are on the right track by making your own. Your design will work as long as you get the right plants in it you could also loose the mosquito screen and put small fry in there to eat the larvae and eggs.  you could also do about anything if you use rockwool or other aquaponics grow media in the basin for the plants to root into.  i had the same idea a few years back when i was stationed in CT but military housing shot it down quick LOL  as for plants there are tons of plants that do well in New England. Hosta, black eyed Susan, day lilies, and ferns to name a few. I say go for it.  you can also search Rain Gardens for ideas of plants that would do well with a rain barrel planter. Best of luck!

@Zach Whisen hmm, I will have to look into the rockwool! As for fish I definitely want some but my partner is concerned about whether we'll be leaving them to die during the winter, so I have to figure that out more carefully before committing to it. I would also love fish in the top part since I can't net it but I am worried they'd just be swept out into the main barrel. Hmm... thanks for your thoughts!

This is great idea!
I have a water barrel with a 5 gallon charcoal and sand filter set into the top.
I never planted into it , there are slits cut into the very bottom,  so it doesn't stay wet unless its very full.
With your overflow design, that wouldn't be an issue.

If your drain is below the grade of your growing medium,  you will have no open water,less evaporation and no mosquito issue.

If you want open water without mosquitoes or fish, a solar powered fountain would keep the water moving,but also increase evaporation.
An aerator might work without any extra evaporation,  but I've not found any solar powered aerators that seem worth paying for, yet.

Some container options you might consider include dishpans, steam table pans and oil change pans.

OK, Griffin, I think I get what you're trying to do, and it would certainly look nicer than most rain barrels!

Things that concern me:
1. Water is *heavy* - rocks, plants and soil also. You discuss the barrel being up on blocks, but I'm wondering if you would consider piling bricks up inside the barrel for the basin to rest on?
2. I don't know the weather pattern where you are - is rainfall predictably regular? For example, my sister is in Ontario, and they get more rain in the summer than I do, but it tends to all come at once in a thunderstorm and then possibly none for 3-4 weeks. If that is the case, so long as you plan on using some of the water in your reservoir to top up the basin, it should help make sure the plants don't dry out too much. However, also be aware that as you use the water in the barrel, the whole thing will become top-heavy. My sister never empties hers below 1/4 or the wind blows it over. I can think of several ways to make sure that doesn't happen in your case, but I expect you can also!
3. This system does decrease the capacity of your water storage system. A fellow I met, (and I've seen pictures on the web) did a series of bathtubs (cheap or free from a "used" forum) at different heights so that the water filled the first, overflowed into the second, over flowed to the third and then into an underground pipe. We don't normally get much freezing weather, but I think he figured the shape of the bathtub would cope when we do. He could add grey water to it when we were in drought conditions.
4. I support your partner about the fish, but the temperature does make a big difference. We get some freezing, and my friend had a half-barrel water garden and gold-fish overwintered in it for several years. She tucked it up against the house where it was sheltered by the eves in the winter, and there was a center breeze block which seemed to protect the fish.

I'm totally sure you can find a good way to do this. My concerns aren't meant to scare you off - just to get you thinking through potential issues and hopefully coming up with great solutions.

Jay, this is exactly the kind of advice I was looking for, thank you so much! I had not thought about the top-heaviness of the barrel and I'm going to think about the best way to mitigate it. My area is much windier than it used to be due to climate change, so we're all learning one disaster at a time ... I'm not sure the best way to reinforce it, but I'm glad it's part of the design process now, not when I have to replace my garden dish because it fell over and cracked open. Maybe just some big rocks in the bottom would do, or to keep it at least partly full like your sister does. I doubt the garage is structurally sound enough to anchor the barrel to without risking a bigger disaster.

The other two points are also important. After several weeks without any good used finds, I ended up buying a cheap laundry tub from my local Asian grocery store, and it's not very strong. I think I will use rope or steel strapping to support it from the bottom instead of relying on the sides. That way I can also avoid cutting holes into the sides of the washtub and preserve what structural integrity there is. I got some free pickerelweed from someone in my area who took out a leaky pond, and I want the full depth of the washtub (8" or so) to support it.

I've been thinking about the bathtub system too. There was so much pickerelweed available that I bought another 24" planter to hold it, and I think I will design the rain barrel to overflow into it first and then drain from it into the yard. I'm not so worried about water storage capacity right now because we actually have no set use for the water in the barrel itself -- the impetus was to get the water off the side of the rotting garage. I'm sure we will use it for houseplants, seedlings etc but we have much larger roof areas available elsewhere and I plan to store that water in the ground.

I'm mostly including my thoughts on here for anyone else who may be thinking through a similar project for their own conditions -- the advice I've gotten so far is definitely enough to go on and I am excited to post pictures of the finished product! (For a given value of finished, anyway )

William, thank you! I have my eye on one of those floating solar fountains they sell for cheap. The oil pan suggestion piqued my interest, especially since they are strong -- maybe if the washtub I ended up buying breaks I will end up going for one of those. Thanks for the reply and the thoughts! Now I am thinking about whether I want to equip a second barrel with a filter (attached to a different downspout we have) so we can have drinking water right on the patio do you consider the water potable after it goes through your system?

All right, I actually built it! It's 95% done, and will probably stay 95% done for the next two years. I attached pictures below.

I just need fittings for the overflow so it will go into the second water pot, and then there's some cosmetic stuff, like making the chains the same length and hiding the cinder blocks (maybe). But it works great! We had some nice rain last night that filled the water pot and then filled the barrel about 2/3 full. The current plan for not letting it tip over is not draining all the water. The pickerelweed doesn't seem to mind the water coming in one bit. It's incredibly forgiving, at least so far, and I would recommend it for small water gardens. I let mine get pretty dry sometimes and it just keeps chugging. Check out that bumble on the flowers! (Pickerelweed is edible for people, too! Although probably not as much food per area as I could get with some other water plants.)

Thanks to everyone who weighed in! Hope this is helpful to anyone looking for ideas on the topic.

Great job! The only thing I might suggest is a piece of window screening under your bowl and fitted around the chains so you don't end up with too many mosquito larvae in the lower part of the barrel.

I really like what you've done.  The only concern I see right now is the screws you're using to keep the chain from slipping through the holes.  In one picture it appears that one is badly bent and I'm not sure how much weight the water plants would actually have or if it would be an issue at all. I'm just imagining trying to fish a container full of plants out of the bottom of a barrel.  

I've also thought of keeping a few goldfish in ours and worried about them being swept out.  My mental idea is to somehow construct a screen of sorts to prevent that.  My barrel is also stored during the coldest months so goldfish would have to either be rehomed to small pond or spend the winter inside.

Update to pickerelweed water barrel:

Everything went great over the summer! As expected, I occasionally had to manually bucket water from the bottom back into the top as the water evaporated. I probably only did this 2 or 3 times the whole summer. The water was shaded, we get a fair bit of summer rain where I am (South-central Connecticut) and pickerelweed is very hardy and can take some drying out. I did not end up harvesting the seeds to eat, as I kept missing them. Maybe next year, and I’m looking forward to trying the shoots this spring if they come back.

I did add the overflow hose so the large pot next to the rain barrel stayed nice and full. I couldn't find good fittings to do it so I just used a spigot, even though it seemed a bit silly because I'll ~never want to close it. I had an old, holey hose with the connector still attached that I used a few feet of to direct the flow into the bottom of the pot. I wonder if old hose pieces would make good pipes for deep-watering fruit trees, actually.

I left everything where it was over the winter. I considered moving some of the pickerelweed into the basement to overwinter there in case the unprotected pots were too cold, but ultimately didn’t. It seemed like a lot of work, and we don’t have a good spot that is unheated but protected. It hasn’t reemerged yet this year, so it might be dead, but I did seem to see a few green shoots when I was messing with the barrel earlier so I am hoping it just isn’t time yet.

Michelle, you were very right in your concern. The nail that was already bent held fine, but overall, the system for holding the chains in place failed – probably because I had really cheaped out on one of the chain holders because I was out of useless screws and used an old jigsaw blade. Definitely don’t try that, it’s not strong enough. That chain had come out of the side of the barrel, but the other two chains were fine, so the pickerelweed tub was suspended from the sides and all I had to do was lever the tub up onto the side of the barrel, letting as much water out as possible, and then move it over to another barrel I had next to it. The disc was then floating in the water. I tried replacing the screws, but it was not possible because the floating disc would not maintain tension on the other two chains, and I lost a couple screws into the barrel this way. In retrospect, I could have just dropped the water level so that gravity would provide the tension I needed. However, it was a big pain to mess with and I decided just to buy some 2 inch stainless steel (“stainless steel”) carabiners. They are long enough on the unbroken side to span all the holes, so it doesn’t matter how strong the clip itself is, it’s just an insurance policy while doing the setup. I figure it will be worth it because I may eventually want to move, scrub or otherwise mess with the barrel. If I had to do it again, though, I would buy 3-inch carabiners because the rounded edges make them more liable to want to slip through the holes during setup than I had anticipated; probably not an issue during use but we will see.

We use BT dunks in the water, so this also serves a third purpose as a mosquito trap. It’s a very attractive place to lay eggs and then the larvae are eaten. They also provide some small amount of fertilizer for the pickerelweed, although I imagine it’s going to need more feeding eventually. I picked up some organic liquid fertilizer at a yard sale last year for pretty much nothing so I’ll start with that, but for others reading this thread, any ideas for a home-grown fertilizer for a water garden? Comfrey tea, maybe? I definitely don’t want to add manure or urine, my usual easy fertilizers of choice.

Jay: that's a good idea, but the window screen would probably get slimy, like most of the other equipment involved. We didn't notice too much of a problem in the barrel itself last year, and the water that overflows from the pickerelweed tub does have some BT in it as well.

Thanks for all the tips, everyone!