Unlike backyard ponds and small decorative water features, man-made lakes are not something you can really DIY. Even if you only want a 1- or 2-acre lake for your farm or estate, you’ll need the help of a lake designer and hydrology engineer to create a safe and durable design that holds water. Even the smallest lakes hold hundreds of thousands of gallons, posing many safety hazards if the dam breaks down or the depression overflows during a storm. Getting professional engineering and design help for your man-made lake project is essential for these reasons and more.
State and Federal Approval
Once you’re covering multiple acres of ground and impounding hundreds of thousands to millions of gallons of water, there are half a dozen or more different agencies who will get involved in your project. This ranges from the federal level with the Environmental Protection Agency (EPA) and the Army Corps of Engineers, to state departments of natural resources and environmental quality. Each agency may require multiple permits and inspections, adding up to a dozen or more permits needed for a single project. An experienced lake project manager that works in your local area will have familiarity with all these steps, helping you secure each permit in sequence to avoid delays and extra costs.
Careful Design
It’s not as simple as digging a hole in the ground or building a dam in a valley from dirt to create a stable, safe, and useful lake. Man-made lakes start with a watershed assessment to determine how much water flows into them during the worst possible storms. An experienced designer can help you achieve any shoreline style and natural look you want, while an engineer can determine how much wake will affect your shores from recreational use and wind. A properly designed lake will last longer and return more on the initial investment over its lifespan thanks to reduced leaks and lower maintenance needs.
Cost and Scale
Speaking of an investment, man-made lakes are not inexpensive projects. Even a small 1 acre lake with a 20 foot depth will generally cost between $50,000 and $200,000, depending on the amount of excavation and prep work needed. With man-made lakes around the world ranging in size from half an acre to over 1,600 acres, the installation costs can run into the millions for major dam projects. Fees for engineering and design work will only cost a fraction of the installation costs. Considering that repairing a damaged or leaking lake can cost nearly as much as the original installation, design assistance along with the use of quality materials, is the best kind of insurance against future problems.
Dam Safety
Soil and stability testing ensures that you can build an earthen dam with what you excavate. If that’s not possible, you can still build a safe dam by bringing in new soil and adding binders like concrete to the core. Dams begin with digging to a layer of impermeable rock, clay, or bedrock to act as the base. Layers of dirt with a decent clay content are then compacted until the dam reaches the designated height to prevent overflow during a 25, 50, and 100-year flood. Many earthen dams are then finished with geomembrane liners, rock cover, or vegetation to stabilize the surface and prevent erosion. With a dam collapse representing the potential for extensive property damage, you must have an engineer’s help for its design and installation.
Water Loss and Gain
You can’t guess the amount of water that a man-made lake will gain or lose over the course of a year. Using outdated or incorrect data on local rainfall can also throw off your designs and result in a lake that quickly deteriorates or requires more maintenance than usual. Hydrology engineers have access to the latest figures and flood plain information from the United States Geological Survey (USGS), ensuring your lake is built to the latest standards and projections for future rainfall. An engineer can also show you how much water you’ll lose to an unlined or naturally lined lake compared to one that features a custom fabricated geomembrane.
It’s possible to handle the aesthetic design work on your own if you must, but don’t skip the step of hiring an experienced lake engineer for the technical steps. Determine what kind of fish you want to raise or the activities you’ll use the lake for, then explain your plans to your engineer. For help narrowing down your choices on liners, you can always contact us here at BTL Liners for help.
