Designing a Backyard Pond System

[Ellen Roelofs]

My partner, Molly, and I are buying a house together in Grand Rapids, Michigan and are excited about building an AP pond system , despite the fact that we don't really know what we're doing.

I would like to dig a pond in the back yard which is flat and level with the house. I am imagining 20-25 ft diameter with 3-7ft depths, and enclose it with raised AP gravel beds around the edge (relatively), except at a small dock.  In this configuration, the pond would hold around 4 times the volume of the GBs. I am hoping to keep yellow perch in the pond year-round, and to use lava rock for its porosity, covered with a layer of river rock for easier gardening.

 

We are taking a lot of landscaping queues from the forest garden model, as a means of both growing our own healthy food and of shielding the house from the very busy road.  I plan to water these fruit trees,etc., in the yard with water from the fish pond, and to top off the pond with water from the rain barrel or the city.  

 

This system is, in my mind, as much of a landscaping feature as it is a means of intensive food production. I am not interested in cramming as many fish as possible into that pond.  I am interested in keeping maintenance manageable!

 

I need to figure out what flood/drain mechanisms will be best suited to this application.  I first thought of using a loop siphon but didn't think our real estate agent would approve of a whole bunch of loopy hoses hanging into the pond. She keeps reminding us that we will one day need to sell the house... 

anyway, are there more elegant solutions we should be considering?  I've wondered about putting a 90 degree bend in the stand pipe of a bell siphon, so it's plumbed through the side at the bottom of the GB.  Would this work?

[TCLynx]

If the beds are deep enough, you can definitely plumb out the side instead of the bottom.

[Ellen Roelofs]

Thanks TC!  That's what I was hoping to hear!  It seemed like it should work, but asking is so much easier than finding out the hard way!

[Tom OBrien]

I dug a much smaller garden pond last summer. My ambition for this summer is to add some elevated grow beds with plumbing hidden underneath that will discreetly run the outflow pipe to a nice stream or waterfall feature that returns it to the pond. It's probably easier and smarter just to run the pipes out the side, but raising the beds and running the pipes underneath is probably what I'm going to try.

Are you going to try running it through the winter? I moved the fish and the pumps inside because I thought the small pond would likely freeze solid but we have had a very mild winter so far this year in northern Illinois.

[Ellen Roelofs]

Hi Thomas!  I was thinking I'd shut down the GBs at around 50 degrees, but we'll see how it goes. I definitely drain everything (but the pond) and tuck it in for the winter :).  I've heard from several unconfirmed sources that a pond needs to be 4ft deep to be fish safe here (Grand Rapids, MI).  I'm counting on the size of the pond to protect the fish.  I was also planning to keep a small air hole open through the winter.  Speaking of winter, you and I live not too far off the same lake... not much ice, huh?

This winter has been... unsettlingly warm.  But maybe I'm just too easily unsettled.  We'll probably make back our average by having record cold once I've got my pond full :P.

Your Phase II project sounds lovely!  What kind of fish are you keeping?  Molly is also very keen on having a stream/waterfall.  Using the GBs as a pre-filter to keep the stream a little cleaner definitely sounds like a good idea.  I was thinking of using this fiberglass barrel (2000gal) as a sump tank between GBs and waterfall. A guy north of town has been trying to sell it for a long time.  

It's a lot of extra work, but I think my better half will prevail.  I will have to rent a backhoe with good reach... I am seriously going to tear up the back yard.  The waterfall is a good long term investment (ie. it looks pretty if we ever sell the house) and it would just be harder to do it later... plus the extra tank adds flexibility to the system.  My initial thought was to pump air up through structured media, but I could put anything in there, as the system demands evolve.

The raised bed look is cool - and gives you a lot more grow area for your media!  Filling 2.5 ft deep with expanded shale is not going to be cheap.  I liked the idea because it seemed simple and provided lots of media space.  Also, the extra depth is going to make cleaning out any clogs a nuisance - something I hadn't considered before.  I wonder if anyone else is doing deep beds sitting on the ground, I don't know that I've seen it done.  Maybe for good reason? 

[Tom OBrien]

Hi Ellen. I'm not sure about 4 ft deep being safe, at least where we are. I read a couple websites that said 7-10 feet was min. for northern Illinois and southern WI. Maybe it's warmer on your side of the lake, but having a portion of your pond at 7 or 8 ft deep sounds like a good idea to me.

I was thinking yellow perch when we dug our pond, but my partner was not interested in AP at the time. We have 15   Shubunkin goldfish instead. I don't know how those taste, but they do look pretty.

As for grow beds, TCLynx has a variety of stuff in her yard. I watched one of her videos. She might be a good one to ask for ideas. Are you thinking of wood frame beds with liners? I haven't really thought about how I'm going to do the beds yet.

TKO

[TCLynx]

I do 2' deep grow beds all the time.  Just make sure the gravel guard is big enough for your arm and that you can pull the stand pipes out to clear the holes around the base of them since certain plants will send roots to the plumbing and simply pulling the stand pipe out to clear the roots is pretty easy as long as you catch it before they actually fill the drain line.

As to ponds and winter protection.  It largely depends on how much extra protection you might give the pond for the winter.  For may years my mom's 2 foot deep ornamental pond in Alden, Michigan kept the goldfish alive without even an air hole but then they got one really cold winter without much snow and the pond froze to the bottom and the fish all died that winter.  Some form of insulating cover might be all you need in case of not being buried in snow.  I would not recommend a large fish load over winter though.

[Tom OBrien]

If you don't mind my asking TC, how do you make your deep beds?

[TCLynx]

Most of my deep beds are actually just 100 gallon rubbermaid stock tanks that are 2 feet deep.  I just plumb them into the system and fill with gravel.

Here is a link to a blog post from when I first stared building it.

300 gallon system

[Tom OBrien]

Thanks. Those tanks are pretty sturdy.

[TCLynx]

Yep.  Make sure they are well supported.  compact and level the ground under the blocks well since fixing it when the bed is full of gravel is challenging.

[Tom OBrien]

I like your fruit tree landscaping idea as well. We haven't gone full-out forest, but we have a couple mature asian pears, two smaller pears, and 2 cherries we added last year. The asian pears have been wonderful, but keeping the bugs off without noxious chemicals is a challenge. My wife laughed at me when I put little nylon stockings on some of the fruit, but it sure helped keep the moths at bay.

[TCLynx]

if only that would keep squirrels at bay