The decision to replace an existing pond offers a unique opportunity to redesign a portion of your landscape, focusing on low-maintenance aesthetics or ecological function. The space the pond occupied can be transformed into a completely dry area or repurposed into a specialized habitat that manages water differently. A successful transformation requires meticulous preparation of the former pond site before introducing any new feature.
Decommissioning and Site Preparation
The first step involves safely managing the existing aquatic life and water. The water should be drained using a pump after fish and other inhabitants are carefully netted and relocated, perhaps to a neighbor’s pond or a local aquarium store. Once drained, all electrical components, including pumps and filters, must be disconnected and removed.
Removing the pond liner is a crucial next step, as leaving it in the ground can create a subsurface bowl that collects water, leading to saturation and future sinkage. For concrete ponds, the material must be broken up and removed or fully fractured to allow for drainage.
The resulting cavity must then be filled in layers with a compactable material like fill dirt, sand, or gravel. Avoid using large rocks or organic debris that will decompose and cause settling.
Each layer of fill material, ideally no thicker than 6 to 8 inches, should be thoroughly compacted using a plate compactor or hand tamper before the next layer is added. This compaction is necessary to create a stable foundation and prevent the ground from settling unevenly. The final layer should consist of high-quality topsoil, and the area should be slightly mounded to account for minor settling.
Transforming the Area into Dry Landscaping
For homeowners seeking a low-maintenance solution that completely eliminates standing water, transforming the space into a dry landscape offers several versatile options. The simplest approach is to extend the existing lawn or create a traditional flower bed, provided the newly filled soil is properly compacted and graded. The new soil layer must be rich in organic matter to support healthy plant growth, contrasting with the structural fill material beneath it.
A more elaborate option involves installing a patio or small deck, which requires a highly stable sub-base to prevent shifting. For a patio, the compacted sub-base, typically made of Type 1 MOT aggregate, should be a minimum of 4 inches thick for pedestrian use, though 6 to 8 inches is recommended in areas with freeze-thaw cycles. The sub-base must be laid with a slight slope (approximately 1:80 or 1.5% fall) to ensure surface water drains away from nearby structures.
Creating a permanent rock garden or Zen garden is another popular choice, capitalizing on the aesthetic of stone and requiring minimal upkeep. This design focuses on excellent drainage, often achieved by amending the soil with coarse sand or gravel. For visual authenticity, rocks should be grouped and partially buried to look naturally embedded, with larger boulders serving as anchor points. Plant selection should focus on drought-tolerant species like sedums, creeping phlox, or alpine varieties that thrive in well-drained, lean soil.
Creating Ecological Water-Retention Features
For those managing drainage issues or wishing to maintain a specialized habitat, the former pond site can be converted into a feature that manages water differently.
Bog Garden
A bog garden utilizes the existing depression to create a permanently damp, acidic environment for moisture-loving plants. This is constructed by lining the excavated area, often with the old pond liner, and perforating it with a few drainage slits to prevent waterlogging while retaining moisture. The planting medium consists of an acidic, organic-rich mix, typically a 4:1 ratio of sphagnum peat moss to sand, which supports specialized species like pitcher plants, sundews, or Yellow Iris.
Rain Garden
A rain garden is a functional depression designed to capture and filter stormwater runoff from roofs or paved areas, allowing it to soak slowly into the ground. The soil mix is engineered for high infiltration, typically composed of 50–60% sand, 20–30% topsoil, and 20–30% compost. Native plants with deep root systems, such as Swamp Milkweed, Joe Pye Weed, or Blue Flag Iris, are planted because they tolerate both saturated and dry conditions, effectively absorbing water and filtering pollutants.
Dry Stream Bed
A decorative dry stream bed or swale offers a natural-looking solution for managing drainage flow during heavy rain events without retaining standing water. This feature involves digging a shallow, concave trench, lining it with heavy-duty landscape fabric to prevent weed growth and erosion, and then filling it with a mixture of river rock and gravel. Varying the size of the stones, with larger rocks placed along the edges for visual impact, mimics a natural waterway that only becomes fully functional when water is actively running through it.