Building a water feature transforms a static landscape into a dynamic, sensory environment. The continuous movement and sound of a running stream offer a peaceful retreat and enhance the appeal of an outdoor space. Constructing a recirculating stream or waterfall requires careful planning, precise excavation, and methodical installation to ensure a leak-free, natural-looking result.
Planning and Sizing the Water Feature
Thoughtful design and accurate calculation are necessary to ensure a successful flow. Selecting the right location is paramount, ideally situated away from large deciduous trees whose roots could puncture the liner and whose leaves would constantly clog the pump and filters. The stream’s path should mimic nature, utilizing gentle S-curves rather than straight lines to create an authentic visual experience as the water meanders toward the collection basin.
The height differential between the stream’s source and its lowest point, known as the total dynamic head, determines pump selection. A robust flow requires a pump moving 100 to 200 gallons per hour (GPH) for every inch of the stream’s width. For instance, a 12-inch stream needs a pump rated for at least 1,200 GPH. This rating must account for flow loss due to the height the water is pushed. Conceptual design and measurements must be finalized before physical work begins, as they dictate material capacity and dimensions.
Material Acquisition and Site Preparation
The design begins with gathering specific materials, including a flexible Ethylene Propylene Diene Monomer (EPDM) liner, geotextile underlayment, a submersible pump, flexible tubing, and various sizes of natural rock and gravel. EPDM is preferred for its durability and resistance to UV light, contributing to its long service life.
Site preparation starts with excavating the stream bed and the reservoir, the lowest point where the pump will reside. The stream channel should be dug 6 to 12 inches deep, maintaining a gradual slope from source to basin to facilitate consistent water movement.
The basin must be significantly deeper, typically excavated to 18 to 24 inches, to accommodate the submersible pump and hold the system’s water volume when the pump is running. Throughout the excavation, remove all sharp debris, such as roots and stones, which could compromise the liner’s integrity. Using a line level across the banks ensures the edges of the stream are level, preventing water from escaping over the sides.
Construction Liner and Plumbing Installation
With the ground prepared, the next step involves lining the excavation with a protective barrier. The geotextile underlayment is rolled out first, covering the entire dug area, including the basin, to provide a cushioning layer against the soil. This fabric shields the liner from potential punctures caused by remaining sharp objects or shifting ground.
The main EPDM liner is then carefully draped over the underlayment, allowing it to conform naturally to the contours of the stream bed and the reservoir. Minimizing large folds is accomplished by gently pushing the liner into the curves and corners of the excavation. The liner must extend several feet past the edges of the stream and reservoir on all sides, providing a secure perimeter that will be hidden later.
The submersible pump is placed within the basin, and the flexible tubing is connected to its discharge port, running discreetly beneath the liner and rocks to the stream’s planned source or waterfall spillway. This plumbing setup ensures the water continuously cycles back to the top without being lost to the surrounding soil.
Finishing Touches and Aesthetic Integration
The functional liner system is transformed into a natural stream through the careful placement of rockwork. Large “ledge” rocks and boulders are strategically positioned along the banks and within the stream channel to conceal the black liner edges. These rocks are also used to create drops, turns, and natural-looking riffles in the water flow, which adds sound and visual interest.
Smaller, rounded river gravel and pebbles are then spread across the bottom of the exposed liner, serving to protect the material from ultraviolet degradation and providing a natural substrate. The reservoir is then filled with water, and the pump is started for the first test run, allowing the water to fully saturate the rockwork and find its natural operating level.
Only after the system has run for several hours and the water level is stable should the excess liner be trimmed, leaving a small lip that can be completely hidden by the surrounding soil and plants to achieve a seamless look.
Long-Term Maintenance and Care
A recirculating water feature requires regular attention to preserve its appearance and functional integrity. Due to constant movement and exposure to air, the system will naturally lose water through evaporation and splash-out, necessitating routine topping off, particularly during warmer months.
Algae growth is common, and it can be controlled through biological water treatments containing beneficial bacteria, or by incorporating an ultraviolet (UV) clarifier into the plumbing system. The pump’s intake screen and filter mats should be inspected and cleared of debris weekly to prevent clogs and maintain the calculated flow rate.
In climates that experience prolonged freezing temperatures, the water feature must be winterized to prevent damage to the pump and plumbing. This process involves disconnecting and storing the pump indoors, draining the flexible tubing, and ensuring the water level in the basin is low enough to accommodate the expansion of ice without damaging the liner or surrounding rockwork.