Good morning. My name is Mark. I’m known as the Pond Guy around here, but you could also call me the Waterfall Guy. That’s what today’s seminar is about: how to build waterfalls.
How many people are first-time builders? Okay, good. That’s a good portion of you. Welcome, and thanks for coming.
I started the business back in the late ’80s. Today, this is my only job. They keep me jammed behind this table talking whenever anybody shows up.
We’ve grown quite a bit over the years, and what you see here today is just one piece of the business. I designed this whole garden back in 2022–2023, and we opened the doors of the building in January of 2025.
Before this, we were at the intersection of Route 30 and 83. If you know where Round the Clock Diner is, we were behind Cheddar’s and Sheetz. We had a very similar setup there, but on one-third of an acre. Here, we have about five acres, so we have a little bit more room to play.
The idea of the garden was to create a place where you could come, get inspired, and see exactly how to create something in your own backyard. Hopefully, there’s something in this garden that will fit perfectly in your space.
Today, we’re going to talk about how to build a waterfall. We’ve been building and designing these features for over 35 years now, so I view my role today as teaching you all the dumb stuff I did early on so you don’t have to repeat it.
We’ve made a lot of mistakes. I went to school for landscape architecture, but we didn’t really study how to build these types of features. We just picked up a shovel and started doing them.
Today, we build about 100–120 features a year. We build everything from acre-sized lakes to bass ponds in your front yard. We were even on a project this week where we built a water wall in a master bathroom. It had cool LED lighting and everything.
We also work on wetland filtration, using native plants to filter pollutants out of large bodies of water. We currently have a project at Milton Hershey School. If you’re familiar with that campus, they have lots of lakes and water features. We’re working on a wetland project there, recirculating the water and pumping it through a wetland filter to improve water clarity, fish health, and the aquatic environment.
So, we get into a lot of different things. One hundred percent of our projects today involve water on many different scales.
The building here is set up for people crazy enough, like yourselves, who want to try to do it yourself. If you decide you want someone else to do it, we have the crews and expertise to do it for you.
But if you want to take the plunge and do it yourself, that’s what we’re here for today: to walk you through, step by step, how we build our disappearing waterfalls.
Some people call them pondless waterfalls. Some call them disappearing streams. These systems are actually more stream-like than anything else because we’re constantly recirculating and moving the water, just like a stream would.
Getting Started
In your booklet, you should come across this diagram. The DIY kit information is on page 11, and that’s probably a good place to start.
The rest of the booklet deals with ecosystem ponds. If anybody’s interested in talking about ponds, you’re about three weeks too late. We’re not giving that information out anymore.
No, the whole garden here is set up with ecosystem ponds, so if you have questions about those, we can definitely talk about them. But today we’re going to focus specifically on disappearing waterfalls: how they go together and what’s involved.
How many people have seen a disappearing waterfall?
Anybody see the disappearing waterfall we did at UPMC Hospital?
That’s a big example of a disappearing waterfall. Behind that waterfall is actually a large courtyard with a 100-foot-long koi pond.
That disappearing waterfall out front has 50,000 gallons per hour of water crashing down through it.
When we talk about our pondless waterfalls, you can see that the pumps in these kits range from around 2,000 gallons per hour up to our largest, which is about 9,000 gallons per hour.
At the UPMC project, we were moving 50,000 gallons per hour. That’s a lot of water, and if you put that in your backyard, hopefully you have a pretty massive backyard.
For most backyards, these other kits will fit just fine.
Where Should You Put Your Waterfall?
When we talk about waterfalls in the backyard, one of the first questions is:
Where do I put it?
I’d love to have the sound of water in my backyard, but where should it go?
I start with two rules of thumb.
The Kitchen Window Rule
Go to your kitchen window and look outside. Hopefully, there’s a view or a vignette where your water feature should go.
Our water features stay running all winter long. If yours is going to stay running all winter, you want to be able to enjoy it year-round.
When you’re sitting there drinking your coffee and looking out the kitchen window, you should be able to enjoy it in the wintertime.
At my house, it doesn’t work that way. My water features are way over there, and my kitchen window is here. But that’s my first rule: the kitchen window rule.
Up Close and Personal
The second rule is up close and personal.
Let’s put the waterfall where we can see it from the kitchen window. Then, when we go outside, let’s not put it way back in the corner of the yard where it’s muddy and we don’t know what to do with it.
Let’s put it right next to the patio, where we can sit, have a glass of wine, drink our coffee in the morning, and enjoy the sound of the water.
So, if the kitchen window says the waterfall belongs here, but the patio is here, start there. Then create a meandering stream between the two.
That’s how we connect those two rules.
Designing the Water Feature
Siting and designing a water feature can be very interactive.
When you see our water features out here, you’ll notice that the big boulders are designed so you can climb around and walk through them.
We just finished a pond for a customer with a big waterfall. The patio was here, the lawn was there, and the waterfall crossed through the middle.
So how do you get across?
We used a combination of things. We put a couple of stepping stones across one section of the stream and a bridge across another section.
We want you to be able to interact with the water and enjoy it.
And when you build it, the wildlife will come.
We have birds, butterflies, frogs, dragonflies, and all kinds of wildlife around our water features.
We actually have a crow living on our big waterfall.
This winter, foxes were hanging out by the pond out back. We call that our habitat pond, and wildlife has absolutely taken it over.
We’ve got bass, bluegills, minnows, and turtles in there. There’s a huge stream and waterfall, so throughout the winter it becomes a water source for local wildlife.
Deer come in and get drinks of water. All throughout the summer, all kinds of different birds show up.
We even had a pair of ducks nesting back there until some geese came in and took over. The ducks moved over to the swim ponds.
If you look carefully from where the purple chairs are, you’ll see a price sign for the swim ponds. Right underneath the sign is Mama Duck. She’s been sitting there for about three weeks.
She hopped off the other day to get a snack, stretch her legs, and spread her wings, and there were seven eggs in the nest.
So I’m looking forward to seeing what happens.
At our old location on Torita Street, it was a regular occurrence to have Mama Duck come back. I don’t know whether it’s the same ducks or not, but it would be cool if it was.
We even left little cards around with our new address, so when she came back in the spring and noticed we were gone, she knew where we went.
Waterfalls Attract Wildlife
If you build it, they will come.
Anybody a beekeeper?
I used to keep bees. It’s a lot of work.
My beehives were right behind my stream and waterfall, and I had all kinds of plants planted in the stream. We’ll talk about plants in a minute, but the bees would come down, sit on the leaves of the plants, and get a drink from the stream.
So when you build a water feature, you’re going to attract wildlife.
You can’t have fish in a disappearing waterfall, but you will get frogs. They’ll come in and lay eggs in the waterfall and be very happy in that habitat.
Dragonflies are another great example.
People always ask, “If I put water in my backyard, am I going to get biting insects and mosquitoes?”
With a properly built system, you’re going to attract frogs and dragonflies and create an entire ecosystem around that moving water.
You’re actually going to have less biting insects with a properly built water feature than you might have without one.
Dragonflies are amazing. They can sit there and hover in midair, waiting for another insect to go by, and then just dart after it.
They’re fascinating creatures, with lots of different colors, shapes, and sizes.
So, everybody want one now?
Good.
Sizing the Waterfall
Now let’s talk about sizing.
We’ve talked about how the waterfall might connect the patio and the kitchen window. We might have bridges and stepping stones crossing the stream.
That’s the basic design.
But how do we determine:
- What size pump we need?
- What size pipe?
- What size rocks?
- How big does the basin need to be?
Let’s look at the actual layout.
If we start at number one on the diagram, that’s the diffuser.
The water comes into the back of the diffuser and spreads out. Instead of having a garden hose stuck between two rocks with water shooting straight out the end, the pipe comes into the back of the diffuser, hits the diffuser, spreads out, and flattens.
When the water comes out the front, it looks very natural. It’s a calm, even spread of water.
We have two different sizes of diffusers: a 12-inch model and a larger one. They’re very similar, just different sizes.
Sometimes we want a more formal effect. In that case, we use a different spillway. The plumbing comes in from the bottom, fills the box, and the water flows out the front.
If you’ve seen the water wall with our sign on it, that’s the type of unit we have embedded into the side of the building. The water shoots out the front to create a small waterfall.
Today, though, we’re focusing on natural boulder waterfalls.
Building the Stream
The water flows out of the spillway and down a series of drops.
One of the most important things to understand about constructing the stream is that it’s not built at an angle.
If we excavated everything at an angle, all the rocks we put on it would slide down like a sliding board.
Instead, we build steps.
Just like you have steps in your house, we’re going to have steps in the waterfall:
Flat → vertical → horizontal → vertical → horizontal → down.
The longer the stream is, the more water it holds, and the bigger the basin at the bottom needs to be.
When you look at number seven in the diagram, that represents the AquaBlox.
There are two different sizes. The small one holds about 16 gallons of water, and the large one holds about 32 gallons.
Let’s say we have a 10-foot stream that’s 3 feet wide and 3 inches deep. We can calculate how many gallons of water that stream holds.
When we size the basin, we typically want it to hold at least three times the amount of water that’s flowing in the stream.
There’s going to be a test after this.
We have it all figured out for you already.
Let’s say we’re finished with the project and ready to fill it.
We fill the basin with water and plug in the pump.
I don’t want the basin to completely drain while the pump fills the stream before the water has a chance to return.
That’s why we use the one-third rule.
One-third of the water is used to fill the stream, while two-thirds remains in the basin and continues circulating.
The same thing happens in reverse when we shut the system off.
Let’s say we plug it in, fill the stream, and then add more water with a garden hose or from rain. The basin fills completely.
Then we unplug the pump.
All the water in the stream has to return to the basin.
If the basin is too small, you’re going to have a problem.
For example, if we put a 100-foot-long stream on a 10-gallon basin, the water is going to flood everywhere.
We don’t want the design to be too top-heavy. We want the basin to be able to handle the amount of water flowing through the system.
We do all of this math for you when we put our kits together.
We’ll size each basin based on stream length, and we’ll size the pump based on elevation and other factors.
AquaBlox and the Pump Vault
Let’s say we need a basin that’s 10 feet by 10 feet.
Going back to the hospital project, the basin there is probably 30 by 30 feet and six feet deep.
For that project, we used three layers of AquaBlox and pump vaults underneath them.
Most smaller waterfalls will use one layer of AquaBlox and one pump vault.
But there are lots of ways to expand the system.
The more water you need, the more AquaBlox you need and the more square footage you need underneath the waterfall.
We’re going to excavate the basin to fit the AquaBlox.
Number three on the diagram is the pump vault.
The pump vault goes at the very bottom of the hole, so it’s the deepest part of the excavation.
The AquaBlox sit around it.
These AquaBlox come flat and are assembled on-site. They have central ribs that give them tremendous strength.
When properly constructed, they’re actually H-20 rated, which is a commercial highway rating.
We have them underneath our parking lot, so you’re actually driving over AquaBlox when you’re out there.
They’re an amazing piece of engineering.
The pump needs to be at the lowest point in the entire system.
Underlayment and Liner
We’re going to dig the hole, dry-fit everything, clean up the excavation, and then put down some padding.
The goal of the padding is to protect the liner from small, sharp rocks in the soil.
This material is pretty tough. It’s difficult to push a screwdriver through it.
For really rocky soil, we use a thicker material called a rock pad.
For most applications, the thinner underlayment is perfectly fine.
On top of the underlayment, we install a 45-mil EPDM rubber liner.
We use the same type of rubber liner in fish ponds and waterfalls.
It’s fish-safe, which is important.
Roofing rubber is different. Over time, roofing rubber can degrade and contain chemicals that could be harmful to fish and frogs.
So we always use a fish-safe liner.
The liner goes into the excavation on top of the underlayment.
Then we install the pump vault and AquaBlox.
Our kits include a little extra underlayment because we want to put another layer on top of the rubber before installing the AquaBlox.
Why?
We don’t want the corners of the AquaBlox rubbing against the rubber over time.
So we sandwich the rubber between two layers of underlayment.
That’s an important little detail.
Remember when I said I wanted to teach you the lessons we’ve learned over the years?
We’ve actually gone back and fixed projects because we noticed that over 10 years, things move just a little bit.
That extra piece of underlayment is a really good insurance policy to protect the liner.
The Pump
Once the rubber, underlayment, and AquaBlox are in place, the pump goes down inside the pump vault.
The big vault is essentially empty, and you can actually put multiple pumps in it.
Two pumps fit in there very nicely.
If you’re adding additional pumps, you can cut additional holes for more water flow.
For a disappearing waterfall, we typically modify the kit slightly.
Instead of using the check valve we use in ecosystem ponds, we come off the pump with a short section of pipe, add an elbow, and then use a threaded union.
That way, you can simply unthread the union and service the pump when necessary.
It’s rare that you’ll need to get to the pump, but when you do, that union makes it much easier.
From there, the pipe runs all the way to the top of the waterfall spillway.
Pump Sizing
We size pumps based on elevation change and waterfall width.
A good rule of thumb is approximately 2,000 gallons per hour per foot of waterfall width.
So, if you have a waterfall that’s 24 inches wide—two feet—you want at least 4,000 gallons per hour.
If you put a 1,000-gallon-per-hour pump on it, it’s going to look pretty pathetic.
On the other hand, if you put a 10,000-gallon-per-hour pump on a six-inch-wide waterfall, you’re going to have water shooting everywhere.
A group of friends of mine recently did a project in Missouri where they were moving 60,000 gallons per hour through an eight-inch waterfall.
It was insane. It was basically a tube of whitewater.
Then the next waterfall was about 12 feet wide, so the scale changed dramatically.
When you’re playing with water, you generally want a little extra capacity.
If the math says you need 4,000 gallons per hour, bump it up to 5,000.
But here’s something important:
The number on the front of the pump box isn’t necessarily the amount of water you’re actually going to get.
The real information is on the side of the box, on what’s called the pump curve.
For example, if I put a 4,000-gallon-per-hour pump on a waterfall with 30 feet of elevation change, I’m going to get essentially zero gallons out of that waterfall.
If I put that same pump on a system with two feet of elevation change, I’ll probably get close to 4,000 gallons per hour.
The more head pressure—or elevation—the pump has to overcome, the less water you’re going to get.
Our Aqua Surge pumps work very well for waterfalls around five, six, seven, or eight feet high.
Once we get above 10 feet of elevation change, we switch to another line of pumps designed for higher head pressure.
If you take a pump designed for high head pressure and put it on a system with only two feet of head, you can burn that pump out prematurely.
Most DIY projects have an elevation change of around two to five feet, and that’s where the Aqua Surge pumps work really well.
Head Pressure
When we start looking at higher flow rates, higher elevation changes, or long pipe runs, we also have to account for friction.
As water moves through the pipe, it creates friction against the walls.
So, if we have a 300-foot pipe run, even if the elevation change isn’t huge, we still have to account for that.
We call all of this head pressure.
It’s not just elevation change. It also includes fittings, pipe length, and other factors.
We calculate all of that when we put the kits together.
Basin Extensions
If you have a really long stream, say 100 feet, we may need a deeper basin.
This system allows us to go deeper using extensions.
The extensions slide together, and you can keep adding them to make the basin as deep as necessary.
The larger AquaBlox fit on top of these extensions.
One important point when calculating elevation change:
We’re measuring from the top of the water at the bottom to the top of the water at the top.
It doesn’t matter how deep the pit is.
The pump only has to move the water from the top of the water in the basin to the top of the water at the waterfall.
So even if the pit is 10 feet deep, we don’t count that 10 feet in the head-pressure calculation.
Pipe Sizing
Let’s talk about pipe.
This is one-and-a-half-inch pipe.
In this type of application, one-and-a-half-inch pipe can move roughly 2,000–2,500 gallons per hour.
If I put a 10,000-gallon-per-hour pump on it, I’m still only going to get around 2,200–2,300 gallons per hour through the pipe.
It doesn’t matter how big the pump is. The pipe itself creates a limitation.
With two-inch pipe, we use a rule of thumb of around 5,000 gallons per hour. Technically, it’s probably closer to 4,800 depending on the conditions.
Beyond that, we move to three-inch pipe.
Three-inch pipe can get close to 10,000 gallons per hour.
At the Milton Hershey project, we were using eight-inch welded pipe. It was massive.
For most DIY situations, you’re going to be dealing with one-and-a-half-inch or two-inch pipe.
Most of our kits use glued fittings, although our entry-level kit uses corrugated pipe with insert fittings and clamps.
Rock Work
Now we’re getting to the fun part.
We have the components in place and the steps built into the garden.
Let’s say we’ve carved out the waterfall and our vision is for the water to flow through here and drop over the edge.
What we’re going to do is use as big a rock as we can physically lift and fit into the space.
You’ve probably seen waterfalls built with lots of small stack stone.
What we want to do instead is use larger boulders and make the waterfall tell a story.
We want it to look like one big rock face where water naturally eroded through the stone.
That does a couple of things.
When we use lots of small stacked stones, chipmunks and other small animals can tunnel behind them because there’s so much void space.
Then they can chew through your liner.
If they create a hole behind a bunch of stacked stone, now you’ve got to take all that stone apart to find the leak.
With one large boulder, there’s much less void space for animals to get behind.
Sometimes I love the look of stack stone, but most of the waterfalls we build use larger boulders.
A good rule is that the size of the boulder should correspond to the size of the waterfall.
For example, if we’re doing an 18-inch-high waterfall, we might use a 24-inch boulder.
The water races across the rock, making it look like it eroded through the entire rock face.
The bottom or toe of the rock is buried underneath.
The Frame Rock Technique
One of the simplest waterfall-building techniques is:
Frame rock + frame rock + middle rock.
We’ll put one large rock on each side.
Then we’ll place another rock in the middle.
The water comes out of the spillway, travels across that center rock, and splashes down.
You could build almost all of your waterfalls using that basic technique.
Waterfall Foam
Another secret weapon is waterfall foam.
It’s an expandable foam that we use to control where the water flows.
Without foam, the water might simply disappear between the rocks instead of flowing over the front where we want it.
Remember, the rubber liner is underneath everything. The water will stay contained within the liner, but we don’t want to see water disappearing behind the rocks.
The foam seals those gaps.
For DIY kits, you’ll probably use a one-use can like this.
Once you open it, you have roughly half an hour to use it.
On the professional side, we use a reusable foam gun.
You can shoot the foam into the joints and then tighten the gun. The can can stay attached and remain reusable for up to six months.
When I first started building waterfalls, we used a Hilti foam gun that cost around $300.
That’s a ridiculous investment for a foam gun.
Now you can get these for under $30.
If you’re building multiple waterfalls, it may make sense to get one.
Don’t touch the foam until it’s dry.
It sticks to your fingers and can stay there for a long time.
The goal is simply to seal those gaps in the back of the waterfall.
Designing Water Flow With Rocks
Every rock I see, I try to imagine how water will move over it.
For example, if water flows across this rock one way, it might hug the entire surface.
That could be the look we’re going for, but it won’t be very dramatic.
If we flip the same rock around, suddenly the water can break off the edge and splash out in front.
The same rock can create a completely different waterfall simply by turning it around.
That’s why every waterfall ends up looking different.
We’re using the same pumps, rocks, liners, and techniques, but every waterfall has its own personality.
Sometimes you want a lot of noise.
At our old location, Route 83 was right there, so we needed waterfalls that were loud enough to block the road noise.
In a quiet backyard, that same waterfall might be too loud.
So every waterfall needs to be designed for its surroundings.
Different Rock Techniques
Another technique is to sandwich two rocks together.
Instead of separating them, push them together and let the water shoot through the little canyon between them.
You can also stack a boulder so that the water hits one rock, creates whitewater, bounces off another rock, and continues down to the next level.
If you’re looking for a really noisy waterfall, that’s one way to do it.
Every time water hits a hard surface, it bounces and creates noise.
Water depth also affects the sound.
If water is dropping into a deep pool, you’ll get a deeper rumble.
If it’s dropping into shallow water, the sound will be higher-pitched and more “pingy.”
Having different depths of water throughout the waterfall creates different sounds.
Overhangs and Echo Chambers
Another technique is to use a rock with a large overhang.
Water can break free from the edge and create a little pocket underneath the rock.
That pocket acts like an echo chamber, reflecting the sound back out.
It’s a completely different effect from water simply dropping straight down.
Naturalizing the Waterfall
I love moss and lichens because they help naturalize the rock.
You’ll notice that many of our boulders already have moss and lichen growing on them.
You can add moss to your own waterfall.
You can put a little foam into the cracks and crevices and then stick moss into it.
You’ll also see driftwood throughout some of our waterfalls.
A piece of driftwood can tell the story that a tree once grew there, died, and is now becoming part of the edge of the waterfall.
Plants
All of this rock work takes a lot of rock to get everything set just right.
Once the rocks are in place, they shouldn’t move.
But when you look at the waterfall, it would be nice to soften all those rocks.
That’s where plants come in.
We have about 350 different varieties of aquatic plants, and maybe closer to 400 depending on the time of year.
I love using combinations of plants:
- Something tall
- Something medium
- Something short
- Different leaf colors
- Different textures
- Different flowers
For example, you could combine a red-leaf plant, a variegated plant, and a plant with pink flowers.
That combination really softens the rock work.
Parrot Feather
Parrot feather is one of my favorites.
It can grow deep in a pond—up to about three feet deep—or it can grow in just two inches of water in a stream.
You can simply place it in the water and let it spread.
Corkscrew Rush
Corkscrew rush is another favorite.
It adds a completely different texture and shape.
Bog Bean
Bog bean is one of the first plants to grow in the spring.
It has a white flower and is a great stream plant.
My personal stream is about 60 feet long and meanders through my backyard.
There’s not a lot of elevation change, but I have two or three main waterfalls.
Bog bean grows throughout the stream and lines the edges.
Creeping Jenny
Creeping Jenny is another very common choice.
You might put parrot feather on one side and creeping Jenny on the other to soften the rocks.
Plants and Shade
A question I often get is about plants for shady areas.
Most of these plants will do well in full sun and many will also do fine in full shade.
The difference is that in shade, the leaves may get larger and you’ll generally get fewer flowers.
Water lilies are probably the most sensitive plant when it comes to sun versus shade.
Some varieties can tolerate shade, but they may not produce flowers.
If you’re planting in a shady situation and want to encourage flowering, fertilizer tabs can help.
Plants and Algae Control
Plants aren’t just decorative. They also play an important role in the ecosystem.
There will be nitrates in the water.
If you don’t have any plants, there’s a good chance you’ll get stringy, fuzzy algae growing along the stream.
That algae grows because of excess nutrients in the water.
Plants consume those nutrients.
So the more variety of plants you have, the more nutrients they’re able to remove from the system, and the less string algae you’ll typically have.
Different plants take up different nutrients, so having a variety of leaf shapes, colors, and flowers isn’t just visually appealing. It also benefits the ecosystem.
Lighting
We didn’t get a chance to talk much about lighting, but lighting is another great way to enhance a waterfall.
We use low-voltage lighting.
It takes standard 120-volt electricity and converts it to 12 volts.
That’s much safer for landscape applications.
For a smaller waterfall, we might use a small light positioned directly underneath the falling water.
For a larger waterfall, we can use a three-watt light that shines five or six feet.
You can also use a larger six-watt light for even greater distances.
I have a 100-foot-tall black walnut tree next to my pond, and a six-watt light in the ground can illuminate the branches at the very top.
We also have colored lights that you can control with an app on your phone and change to different colors.
Algae Treatments
Stringy, fuzzy algae is a reality.
If you don’t use plants, you’re definitely more likely to see it.
A little bit of string algae is normal, and I don’t mind it.
But if you want a more polished appearance, we have simple dosing systems that add treatment to the water.
We have products called Prevent, Clean, and Clear.
The Clear treatment is designed to really polish the water and reduce excess string algae.
We have some ponds at restaurants where they don’t want to hear me explain that a little algae is normal.
They don’t want to see any string algae at all.
In those situations, we’ll use a dosing system along with plants, and we can get those systems looking extremely clean.
The treatments are safe for dogs, kids, and butterflies when used as directed.
One bottle of treatment can last an entire year, so it’s a very simple system.
The dosing system can also be hidden within the rock work so you barely see it.
Maintenance
One of the questions that came up was filtration.
With an ecosystem pond, we have two types of filtration:
Physical filtration is handled by the skimmer, which does about 90% of the work by removing leaves, twigs, and debris.
Biological filtration converts ammonia to nitrites and nitrites to nitrates, helping keep the fish healthy and the water clear.
A disappearing waterfall doesn’t have deep water or fish, so we don’t need that type of filtration.
Instead, the gravel over the AquaBlox provides physical filtration and keeps debris from reaching the pump.
There’s no skimmer basket to empty.
Instead, you simply unplug the pump, let the stream dry out, and use a leaf blower to blow the debris out of the stream.
Then plug the pump back in.
That’s basically it.
It’s very easy.
Winter Operation
Another question was about winter.
We leave our waterfalls running all winter long.
The entire garden stays running.
The pond at the hospital has also run year-round, with the exception of about three weeks this past winter.
The reason we shut that one down was because it was next to a sidewalk and I was concerned about winter winds blowing water onto the sidewalk and creating an icy condition.
For the most part, though, we love the ice formations.
If you want to enjoy your waterfall in the winter, you can absolutely leave it running.
The biggest issue is that ice can build up.
Remember the one-third rule.
The pump is taking water from the bottom and sending it to the top. That water can freeze before it gets back into the basin.
If enough ice forms, the water is still there, but it’s no longer available to the pump.
Eventually, you may have to drag the garden hose out and refill the system.
The first time isn’t bad.
The second time you’re thinking, “This is getting annoying.”
The third time you’re probably saying, “I’m just unplugging this until it warms up.”
When my kids were little, refilling the waterfall was their job.
Then they left, so I started shutting mine down.
If I’m around, though, I generally leave it running.
Applying Waterfall Foam
Another question was whether the rocks should be wet before applying foam.
Waterfall foam actually works better on slightly damp rocks than dusty, completely dry rocks.
If we were building this in a real setting, I’d wet the rocks first and then apply the foam.
As the foam dries, it expands.
You can cut or tear away the excess foam to shape it.
Sometimes I’ll push it down while it’s still somewhat soft, add a thin additional layer, and then put moss directly onto it to help hide it.
Fish and Winter
A disappearing waterfall isn’t designed for fish because there isn’t enough deep water.
In our ecosystem ponds, however, fish stay in the ponds year-round.
We build fish caves where they can go deeper.
They don’t technically hibernate, but they get close.
They stop eating in the fall and generally don’t start eating again until the weather warms up.
They’re very easy to care for over winter.
Pond Depth for Fish
For a typical fish pond, we recommend a minimum depth of around 24 inches.
The fish will stay down in the deeper water during winter.
You’ll get a layer of ice on top, but the pond doesn’t freeze all the way to the bottom.
It’s important to maintain a hole in the ice for gas exchange.
An aerator is one way to accomplish that.
We leave an aerator running on our ponds, and we also leave the waterfall running.
Some people choose to shut their waterfall down during the winter, especially during particularly cold winters.
Every winter is a little different.
Wrapping Up
Well, that was Pondless Waterfalls 101 and 102.
Nobody fell asleep, so that’s awesome.
What questions do you have?
Question: What size pipe should be used? Is there anything smaller?
We do have smaller pipe, all the way down to half-inch.
The problem is the flow rate.
If we’re building a waterfall that’s one foot wide, we want around 2,000 gallons per hour.
To move 2,000 gallons per hour, we need at least one-and-a-half-inch pipe.
That’s a limitation we see sometimes.
Someone will say, “I’ll just put a bigger pump on it,” but they’re still not getting the flow they need.
The problem is that the pipe is too small.
Question: Can you convert a pond into a pondless waterfall?
Yes, we do that.
You have to change how the pump is installed, and sometimes we have to re-excavate the pond to fit a system like this.
But yes, you can definitely convert a pond into a disappearing or pondless waterfall.
Question: How do you remove sediment from the basin?
We can do cleanouts on disappearing waterfalls.
We use a larger pump with a tighter intake and put it down inside the pump vault.
One pump will only be able to pump the water down so far.
With the other setup, we can pump it down deeper and flush the debris out.
A pond vacuum can also work.
Drain the system as much as possible with the pump, then use the pond vacuum to remove the remaining debris from the bottom.
Question: How deep does a pond need to be for goldfish?
For the ecosystem ponds, we recommend around 24 inches as a minimum depth.
The fish stay in the pond year-round.
You may get a layer of ice on top, but it generally won’t freeze all the way to the bottom.
An aerator helps maintain an opening in the ice.
Every winter is different, though. Some winters are much tougher than others, and sometimes people decide to shut their waterfalls down.
Good questions.
Any other questions before we wrap up?
Awesome.
Thank you guys very much for coming. Have a great day, and let me know if you have any questions.
We’d love to help you out.