Alright, once you’ve found the perfect piece of ground, it’s time for the fun part: drawing the blueprint.
You probably already know this, but it’s worth mentioning anyway: you’re not building a swimming pool. Let’s set aside those urges for clean lines, neat sections, and clear depth changes; instead, focus on creating a messy, shallow, and wildly productive wetland. The more irregular and complex you can make your design, the more birds you’ll attract and hold.
Still, when you get right down to it, you really only have a few variables to play with: the shape of the shoreline, the depths across the bottom, and the structures you place within it. Let’s break down those three elements, and then we’ll talk about the engine that keeps the whole system running: the water control structure.
The Shape of the Shoreline
Hearkening back to that goal of a “messy, shallow, and wildly productive wetland,” your first challenge will likely be fighting the urge to draw a simple shape. A perfectly round or rectangular impoundment might be easy for your surveyor and excavator, but it’s the makings of a biological desert. In ecology, this is known as the edge effect. The “edge”—that shallow zone where water meets land—is by far the most productive part of any wetland. It’s where the most food is found and where the best cover grows. Simply put: more edge equals more ducks.
So, how do you create more edge?
Long Shorelines
Design long, winding shorelines. Think less like a farm pond and more like the jagged coast of Maine. Every cove, point, and bay you add increases the total linear footage of your shoreline and, with it, the productivity of your impoundment.
Peninsulas
Did you ever think of a peninsula as a great windbreak? Long points of land that jut out into the impoundment do more than add edge. They break up the open water, creating sheltered, calmer pockets where ducks can escape the wind. (Whitecaps aren’t a duck’s idea of fun.)
Coves and Points
Create distinct hunting zones. An irregular shape with multiple coves and points can be used to create several distinct hunting locations that are visually isolated from one another. This lets you rest certain areas while using others, which helps manage pressure on the birds throughout the season.
The Power of Contouring (Water Depth)
After establishing a long, meandering shoreline, the contour of your impoundment’s floor is the next priority. An impoundment that features several areas of varying depths supports the most diverse ecological system and will attract the most ducks. So fight the instinct to create a simple, flat-bottomed “bowl.” Your goal is a gently sloping basin with carefully scattered depth zones.
The Dining Hall: Shallow Feeding Benches (6-18 inches)
We’re going to be straight with you here, since getting feeding zones wrong will make the rest of your efforts irrelevant.
Shallow feeding benches should make up the vast majority—at least 70-80%—of your impoundment’s total surface area. This is the magic depth where all the seeds and invertebrates you’ve grown are available to dabbling ducks. Engineer the slopes leading into these benches to be very gradual (a 10:1 slope or flatter is ideal) to maximize the productive feeding area.
The Lounge: Deeper Loafing Zones (2-4 feet)
Within your large feeding flats, make sure to incorporate a few pockets of deeper water. These are “loafing” zones where birds can raft up to rest and preen during the day. Place them toward the center of the impoundment, away from the banks, to give the birds a sense of security from terrestrial predators. These zones don’t need to be massive, but do be sure to offer several options.
Room and Board, Courtesy of the Drainage Gutter
While the primary function of the drainage gutter, or main drainage channel, is, well, drainage (we’ll cover that function in our chapter on water control), it has a significant impact on wildlife, making it one of the more subtle yet crucial features of a high-performance design.
The gutter is a channel that runs through the impoundment, perhaps a foot or two deeper than your feeding benches. Because it’s the lowest point in the impoundment, it serves as a magnet for waterfowl in two key seasons.
The First Welcome Mat (Fall)
As you begin the slow flood in the fall, the channel is the first area to fill with water. It creates a winding “river” through your otherwise dry impoundment. For early-migrating birds, this channel becomes the primary loafing and travel corridor, providing them with a secure, water-filled highway to access the newly wetted edges of the feeding benches as they flood.
The Spring Protein Buffet (Spring)
During the spring drawdown, the channel’s role is even more critical. As water recedes from the shallow flats, it flushes aquatic invertebrates (such as insects and snails) into the gutter, concentrating them. This turns the channel into a protein-rich buffet for pre-nesting hens who desperately need this fuel for egg production. It becomes the last, best feeding spot before the impoundment goes dry.
Finishing Touches: Islands and Other Structures
With the shoreline and bottom contours finalized, the final step is to add internal structures. Don’t let anyone on your team minimize their importance by referring to them as simply decorative features. They are essential pieces of habitat “furniture” that provide critical security and make your impoundment a place where waterfowl will want to set up house.
Islands: A Safe Harbor
A well-placed island is one of the best structures you can add. It provides a secure, fortress-like sanctuary from terrestrial predators. Ducks and geese instinctively know that a fox or coyote can’t surprise them on an island, making it a five-star location for safe resting and preening.
Still, if you’re going to build an island, make an effort to build it right. A small, hastily-piled mound of dirt will erode into nothing in a few seasons. An effective island needs to be substantial—with the emergent portion at least the size of a pickup truck—with gently sloping sides and a solid clay core if possible. An irregular or long, thin shape is more natural and provides more of those vital “edges” than a perfect circle.
Loafing Logs: The All-Important Resting Spots
Since ducks don’t actually spend their entire day in the water, they need secure places to climb out, dry off, and preen their feathers, which is essential for feather maintenance and energy conservation. This is where loafing logs come in.
Don’t short-change yourself by just tossing any old log in the water; it’s going to rot away in just a few years. In contrast, logs of naturally rot-resistant wood, such as cedar or Osage orange (hedge), will last for decades. Anchor them securely in your shallow feeding zones with a simple cinder block and rot-resistant rope so they don’t all blow to one end of the impoundment on a windy day. Scattering a half-dozen of these around gives the birds plenty of options and prevents them from concentrating in one predictable spot.
Even better, you won’t just be building for ducks. You can expect to see a variety of other wildlife using these logs, especially turtles like sliders and painted turtles, enjoying a safe place to bask. You may hear from waterfowl managers concerned about predation from snapping turtles, but the ecological benefits of having a diverse, thriving wetland far outweigh the minimal risk of losing a few ducklings.
