A Flexible Pond Leveler Saves Flooded Beaver Ponds

Pond levelers are devices that passively maintain water level around a desired high point.

In beaver ponds, however, ordinary pond levelers fail, and modified designs are needed to counter the impulse of beavers to dam running water.

Today I will share my experience installing and maintaining a Flexible Pond Leveler for managing water conflicts with beavers.

As a farmer, I appreciate that beavers provide security against drought and also increase wildlife diversity. But I need a pond leveler that preserves the advantages of beavers without flooding my farm or neighboring properties.

The Flexible Pond Leveler design promises to be the water management system I need.

Follow along for insights about this essential technology that you won’t find in published literature or online videos.

Table of Contents

• What is a Flexible Pond Leveler?
• In-Pond Position of The Flexible Pond Leveler is Key
• Keep the Inlet of the Flexible Pond Leveler Away from the Beaver Dam
• The Outlet of the Flexible Pond Leveler is the High Water Level
• A Domed Exclosure Is the Ideal Form
• Materials, Tools, and Costs of the Flexible Pond Leveler
• Important Points About Flexible Pond Leveler Materials
• You May Need Help Installing the Flexible Pond Leveler
• How to Monitor and Maintain the Flexible Pond Leveler
• Storms May Wreck Your Flexible Pond Leveler
• Check for Downstream Impacts
• Is it illegal to break up a beaver dam?
• Don’t Wait! Start Planning Your Flexible Pond Leveler Today

What is a Flexible Pond Leveler?

The Flexible Pond Leveler is an ingenious device designed and trade-marked by Mike Callahan of Beaver Solutions, LLC. (Note that I have no affiliation with Beaver Solutions).

For the benefit of both humans and beavers, Mike generously shares instructional tips for DIYers like myself.

There are two main components to the Flexible Pond Leveler: 

• 20 to 40 feet of flexible, corrugated pipe, 10 to 15 inches in diameter; one end is the water inlet and the other is the outlet.
• One 4 to 6-foot diameter, domed “cylinder” of wire fencing, or exclosure, to keep beavers from plugging the inlet.

Water flows through the exclosure and fills up the pipe. When the pond level reaches the outlet high-point on the beaver dam, water flows out the pipe and downstream.

What could be more straightforward?

Well, of course, the devil is in the details.

Let’s start with an overview of field operation and then return to the particulars of Mr. Callahan’s design.

In-Pond Position of The Flexible Pond Leveler is Key

First principle: You cannot allow beavers to detect water movement into the leveler pipe.

If they detect inflow, they’ll start packing mud and other debris into the exclosure, fouling up the works.

To “hide” inflows, you first find a deep spot in your pond where you’ll position the exclosure and inlet. Then you float the exclosure out with the connected pipe and drop the entire contraption off at depth.

Depth matters because the more water surrounding the inlet, the less likely beavers will detect the water moving into the pipe.

Think of a sink full of water after you open the drain. You can’t feel the water flowing until the level is low enough that a vortex forms over the drain.

The same thing happens in your pond. For example, if your deep point is six feet, nearly five feet of water is above a 12-inch diameter inlet secured inside the exclosure.

And if your exclosure is five feet in diameter and five feet tall, then the closest beavers can get to the inlet is about two feet from the side and four feet from above.

This space is too wide for beavers to feel the flow, so they never develop an interest in the exclosure.

How shallow is too shallow?

I placed the inlet in my beaver pond with only three and a half feet of water above the pipe. So far, beavers haven’t impacted the exclosure.

You may use even shallower water, but it could be risky.

Cutting an L-shaped notch at the inlet reduces the vortex that might form as the pond naturally draws down.

Key point: If beavers can’t detect flow into the inlet, you have solved one of the main challenges for beaver pond levelers. However, ponds less than three feet deep may not be appropriate for the Flexible Pond Leveler.

Keep the Inlet of the Flexible Pond Leveler Away from the Beaver Dam

Beavers excavate earth and other materials from the upstream side of their dam. Therefore, you might find that the deepest part of the pond is along the dam.

But do not put the exclosure/inlet combo close to the dam!

I have observed that beavers will eventually incorporate most objects on or near the dam into the dam.

It could be a tree stump, your leveler pipe, or a ’66 VW Bug. Over time the beavers will pack the object with mud and twigs until it looks like it belongs where it is.

Even if your exclosure is fully submerged, beavers will build out from the dam and clog the wire mesh.

In the Flexible Pond Leveler design, you can use up to 40 feet of corrugated pipe. This length gives you room to explore the pond bottom for a suitable location away from the dam.

Key point: Try to find a spot for the exclosure and the inlet that’s at least 20 feet away from the dam, even if it’s in water that’s less than ideal depth.

The Outlet of the Flexible Pond Leveler is the High Water Level

To lower the pond level, you dig a trench through the dam where you’ll place the pipe outlet.

When you dig your trench, don’t forget that the high point in the pipe sets the level for the pond.

In other words, the high point has to be at the outlet on the active beaver dam and not somewhere else along the pipe.

To have a high point on the dam, you must completely submerge the pipe during installation and make sure it stays submerged.

By ripping a shallow vent along the entire length of the corrugated pipe, you allow air to escape. The pipe can then sink and flex along the contours of the pond bottom—this is why it’s called the Flexible Pond Leveler.

To keep the pipe submerged, wire two cement blocks on top for weight.

If the pond level drops below the high point that you set on the dam, then water stops flowing.

If you set it too high, then you’ll get water backing up on your property.

The ideal pond level depends on your needs. In my case, I chose a depth that could accommodate a solar-powered pump for irrigating nearby crops.

Protect the Outlet

Of course, you have to keep the beavers from plugging the outlet and raising the high water point. I covered the outlet with branches and wide slabs of pine tree bark that allow water to exit freely while also denying beavers access to the pipe.

Water will flow from underneath the vegetation cover and down the dam if your leveler is working. The confused beavers will try to block the stream but instead pack mud fruitlessly into the tail of the flow.

Key point: Choose your pond’s high point wisely and conceal the outlet with natural materials.

A Domed Exclosure Is the Ideal Form

Round structures with domed tops are extraordinarily resistant to collapse.

If you don’t believe it, you will after you finish the exclosure for the Flexible Pond Leveler.

Even though the exclosure is held together with just hog rings and the elastic tension of the dome top, it is rigid and supports many pounds of weight.

In contrast, a square box with a flat top will collapse under beavers or other critters—I also have alligators—that haul themselves onto the exclosure.

The other benefit of a cylindrical exclosure is that you can build it on your lawn and then roll it onto a trailer or truck bed for transport to the pond.

Key point: You may want to build an exclosure not shaped like a domed cylinder, but don’t do it. Stick with the tried and true exclosure configuration of the Flexible Pond Leveler.

Materials, Tools, and Costs of the Flexible Pond Leveler

A convenient feature of the Flexible Pond Leveler is that the materials are available at your big box, hardware, or farm-supply stores.

Item	number needed	Price per unit
10-in x 20 ft ADS brand, non-perforated, single-wall corrugated pipe	2	165
10-in ADS split coupler to join pipe sections	1	28
Heavy-duty cable ties to the secure coupler to sections	2	2
Galvanized screws to prevent rotation of pipe sections	2	2
50-in x 8 ft 6 ga. wire panels 6×6-in mesh or similar	3	40
Cement blocks to hold down the pipes in the pond	2	2
Hog rings, a box of 100	1	10
Hog ring pliers	1	14
Tension wire 9 ga. 10 lb coil	1	28
24-inch bolt cutters	1	32
6-in x 6 ft green sewer drain pipe #3034 as pontoons to float exclosure	2	45
6-in removable end caps for pontoons	4	12
	Total	$704

Important Points About Flexible Pond Leveler Materials

You only need about 20 feet of 9 gauge tension wire, two cable ties, and two galvanized screws. Scrounge what you can from your workbench.

How To Choose Flexible Corrugated Pipe

You can use 10, 12, or 15-inch diameter single-wall corrugated pipes in 20-foot lengths. Use the “solid” style pipe, which does not have perforations.

The best diameter to use will depend on the size of the pond, pond inflows, and your budget.

My pond, for example, is an acre that is two to five feet deep plus another two acres of bog. A 10-inch diameter pipe leveled the pond four days after a storm dropped three inches of rain.

When choosing a pipe diameter, keep in mind that the purpose of the Flexible Pond Leveler is not to prevent water from breaching the beaver dam after storms.

Instead, the leveler returns the pond to the high point you established during installation.

A larger pipe might indeed level the pond faster, but the final level will be the same provided regular inflows from streams, springs, and runoff don’t exceed the pipe’s maximum flow.

I recommend that you consider installing a large pipe if you need insurance against increased inflows.

There’s also a suggestion that a single-walled pipe on the dam might be vulnerable to beavers chewing leaks in the plastic.

Using a short length of double-walled pipe is an option for the outlet. However, I have found that shielding the exposed span of a single-walled with natural debris is sufficient protection against beaver teeth.

Wire Containment Panels for the Flexible Pond Leveler Exclosure

You will need two containment panels for the sides and one for the bottom.

You make the dome top out of the remnants from the bottom panel. 

Containment panels are cumbersome to work with, so I stay away from panels longer than 8 feet. Of course, you can cut long panels to size.

The exclosure can be no taller than the width of the side panels. Panel widths of 50 to 72 inches are suitable sizes.

When you form the dome top of the exclosure, you lose a little vertical height, but the final build is tall and wide enough to keep beavers away from the pipe inlet.

I think you should avoid using large-mesh panels. Anything larger than 6 x 8 inches allows small-framed beavers and other critters into the exclosure.

You can also use epoxy-coated reinforcement mesh designed for concrete pillars and foundations. This material is lighter than livestock panels, and the epoxy protects against corrosion.

Wire mesh in 6-gauge provides a good balance between strength and workability in both livestock panels and reinforcement mesh. Welded fencing stored in a roll is too flimsy and unsuitable for the Flexible Pond Leveler exclosure.

Flotation for the Exclosure

To position the leveler in the pond, you must float the exclosure and the connected pipe onto the water.

To serve as removable pontoons, you can use two green sewer drain pipes (not schedule 40). Shorten each length to about five and a half feet and seal with watertight end caps.

However, some livestock panels can be heavy, about 20 US lbs each for an 8-foot-long panel. A heavy exclosure may sink your pontoons, taking the exclosure down before you’ve put it where you want it.

A test float with the exclosure in shallow water is probably a good idea.

Alternatively, you can tie down the exclosure/inlet combo onto the back half of a small jon boat. When you’re over the deep spot, untie the contraption and push it off the stern.

A boat will also keep you from getting in the water where you may not be comfortable wading.

Other Necessary Tools

You need a circular saw to rip a straight vent down the corrugated pipe. Without a vent, it will not sink to the pond bottom.

And it would help if you had a power drill for making small holes in the pipe to receive the 9-gauge tension wire that secures the inlet to the exclosure. You’ll also have to drill holes for the wire that attaches the two cement blocks to the pipe.

Since it’s more convenient to assemble the leveler pond-side, cordless tools are pretty helpful.

You May Need Help Installing the Flexible Pond Leveler

Constructing the exclosure is easily a one-person operation. So is installing the inlet through the exclosure’s side and then coupling pipe lengths.

With pontoons deployed underneath the exclosure, you can stand on the dam and then use the connected pipe to push the floating exclosure into place.

Note that you should have already adjusted the total length of the pipe to reach the deep spot. 

If you keep the outlet from taking on water, the entire pipe will float with the exclosure, even with the cement blocks attached.

With the exclosure where you want it, you then wade out to remove the pontoons and make sure that the pipe and exclosure both settle upright on the pond bottom.

If you’re working in a small boat, you’ll have to ride along with the exclosure as an assistant pushes out the pipe with you and your cargo on the end of it.

Regardless of your choice of floatation, I recommend that you get some assistance for your first installation. You’re working in water, so there’s no telling what could happen.

How to Monitor and Maintain the Flexible Pond Leveler

After you install your leveler and watering flows, the next step is to patiently watch the beavers’ reactions.

They will be wary for a few days while getting used to the new object on their dam.

Soon enough, the beavers will start packing mud and vegetation as they try to block the flow out of the vegetation barricade on the outlet.

Let them do their thing for several weeks to see what happens.

If the beavers get into the outlet, clean out their trash and install a better barricade. This time install a cylinder of fencing with a diameter just wide enough to fit over the outlet and long enough to extend out over the dam three to four feet.

Also, I like to monitor the exclosure and see the beavers are jamming debris into the mesh.

A potato rake or a clam rake helps remove debris. I modified the handle on a potato rake to have a ten-foot reach.

Storms May Wreck Your Flexible Pond Leveler

Although my installation has survived large inflows, I have seen reports of Flexible Pond Levelers wrecked by big surges.

There’s no telling if these failed levelers result from poor installation or reflect a limitation of the design.

But if you are concerned about big water moving through your pond or lake, take some precautions.

First, be sure to rip a straight, clean vent along the entire length of the corrugated pipe.

If there are air pockets trapped in the pipe and it’s floating slightly above the pond bottom, surging water may shift the leveler and restrict outflows.

And second, add more weight to the pipe to keep it down. Also, consider driving t-posts alongside the exclosure and wire it in place to keep it from moving with the inlet.

Check for Downstream Impacts

It is an ethical and, possibly, legal duty to ensure that your beaver mitigation project does not damage downstream interests.

For example, a beaver pond leveler may solve your flooding problem while restoring flow to a dry streambed. Beavers might then colonize the restored stream and create new dams on downstream properties.

To reduce tension in the future, consult with your neighbors before leveling your pond.

And who knows? You may also get a friend on board to help with expenses and labor.

Is it illegal to break up a beaver dam?

In many US states, you need a permit to remove or alter a beaver dam.

For example, nearly all of the states of the New England region require approval to install a beaver pond leveler legally.

In contrast, I am not aware of any states in the South Eastern US that regulate beaver mitigation efforts.

To be on the safe side, check with the state wildlife agencies before you start working on the pond leveler.

Don’t Wait! Start Planning Your Flexible Pond Leveler Today

As soon as you observe beaver activity in your pond, you have to make a decision.

One option is to eradicate beavers from the pond using trapping or hunting. This course of action is not a permanent solution because beavers will recolonize your vacant pond from adjacent watersheds.

You will, therefore, have to be dedicated to beaver trapping or hunting over the long haul.

But you can expect many late nights and empty game bags because beavers are nocturnal animals that you can’t easily fool with traps.

A second option is to install a flow-control device such as the Flexible Pond Leveler. I took this path, and now my farm and business have a reliable water supply and abundant pond life.

In some cases, the best thing to do might be to combine occasional beaver removal with the pond leveler solution. After all, the world is complex, and there’s not always a perfect solution.