An excavated pond, also commonly known as a dugout pond, is a type of artificial water body created primarily by digging a depression into the ground. Unlike embankment ponds, which rely on building a dam across a natural depression or watercourse, excavated ponds are formed by removing soil and material to create a basin that collects and holds water.
These ponds are particularly well-suited for flat land areas where the construction of an embankment-type pond might not be practical or efficient. Their design depends heavily on the surrounding soil characteristics and the local water table.
Key Characteristics and Construction
The construction of an excavated pond involves earthmoving equipment to dig out a basin of the desired size and depth. The success and longevity of such a pond hinge on several critical factors:
- Topography: Excavated ponds are generally constructed in relatively flat terrains. This makes them a preferred choice when there isn't a natural valley or slope suitable for building a dam.
- Water Supply: A reliable and adequate water supply is paramount. This can be assured through various means, including:
- Natural Sources: Surface runoff from rainfall, underground seepage, and natural springs.
- Artificial Sources: Outflow from subsurface drains, or by pumping water from nearby wells, streams, or other sources.
- Soil Type: The soil's ability to hold water is crucial. Clayey soils are ideal as they are less permeable. If the soil is too porous (e.g., sandy or gravelly), a pond liner (such as bentonite or geomembrane) may be necessary to prevent excessive seepage.
- Water Table: In areas with a high water table, excavated ponds can fill naturally as the dug basin intersects the groundwater, allowing it to seep in.
Why Choose an Excavated Pond?
Excavated ponds offer distinct advantages, making them a popular choice for various applications:
- Versatility on Flat Land: They are the go-to solution for creating water features where topographical conditions don't support dam construction.
- Reduced Dam Failure Risk: Without a large embankment, the risk of catastrophic dam failure is significantly reduced.
- Flexible Design: The shape and depth can be easily customized to suit specific needs, from shallow wildlife habitats to deeper irrigation reservoirs.
- Material Utilization: The excavated material can often be used on-site for landscaping, creating berms, or other construction purposes.
Applications of Excavated Ponds
Excavated ponds serve a multitude of purposes across agricultural, recreational, and environmental sectors:
- Agriculture:
- Livestock Watering: Providing essential water for farm animals.
- Irrigation: Storing water for crop irrigation, especially during dry periods.
- Fire Protection: Serving as a crucial water source for fire suppression on rural properties.
- Recreation:
- Fishing Ponds: Stocked with fish for recreational angling.
- Swimming: Providing a natural swimming area.
- Boating: Suitable for small boats, kayaks, or canoes.
- Wildlife and Environment:
- Wildlife Habitat: Creating vital ecosystems for amphibians, insects, birds, and other animals.
- Stormwater Management: Collecting and slowly releasing excess rainwater, reducing runoff and erosion.
- Aesthetics: Enhancing the beauty and value of a property.
Construction Considerations and Best Practices
Successful excavated pond construction requires careful planning and execution. Here are key considerations:
- Site Selection: Choose a location with suitable soil, adequate water supply potential, and minimal environmental impact. Resources like the USDA Natural Resources Conservation Service offer valuable guidance.
- Permitting: Depending on local regulations, permits may be required for pond construction, especially concerning water rights and environmental impacts.
- Design: Determine the optimal size, depth, and slope of the pond banks. Consider a safety shelf around the perimeter for easier exit and wildlife access.
- Excavation: Use appropriate heavy machinery. The excavated soil should be managed properly, either spread evenly or used to create beneficial features.
- Sealing: If natural soil isn't sufficient, consider sealing options:
- Clay Lining: Compacting a layer of bentonite clay.
- Geomembrane Liners: Installing synthetic liners for maximum impermeability.
- Inlet and Outlet Structures: Design proper systems to manage water flow into and out of the pond, preventing erosion and maintaining water levels.
- Maintenance: Regular maintenance, including bank stabilization, vegetation management, and desilting, is crucial for long-term health and functionality. Information on pond management can often be found through university extension services, such as those provided by state university extension programs.
Comparison: Excavated vs. Embankment Ponds
| Feature | Excavated Pond | Embankment Pond |
|---|---|---|
| Primary Construction | Digging a depression in the ground | Building a dam across a valley or watercourse |
| Ideal Topography | Flat or gently sloping land | Natural depression, valley, or drainage way |
| Water Source | Groundwater (high water table), runoff, springs, pumped water | Stream flow, surface runoff, springs, groundwater |
| Risk of Failure | Lower (no large dam to fail) | Higher (dam failure due to overtopping or seepage) |
| Excavated Material | Often used for landscaping or berms on site | Can be used for dam construction or spread |
| Suitability | When a dam is impractical or undesirable | When a natural depression allows for dam construction |
In summary, an excavated pond is a practical and versatile solution for water storage and management, particularly effective in flat landscapes where other pond types are not feasible. Its success relies on thoughtful planning, proper construction, and a reliable water source.
