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How to Build an Artificial Fishing Lake

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Les Rouvets "Man-Made" Coarse Fishing Lake in Guernsey

Les Rouvets "Man-Made" Coarse Fishing Lake in Guernsey

How to Build an Artificial Lake or Fishing Pond

Ideally, when you decide to build a fishing lake, you need first to find a suitable piece of land and then have the "vision" to imagine how that piece of land will look once flooded with water.

The most suitable locations are to be found on low-lying land. This ensures that water will naturally and frequently drain into the lake to avoid it drying up. An added bonus, if a stream flows alongside the lake, is that this can naturally provide a supply of water that will drain through to the newly built lake (if you build a small ditch from the stream to the lake at the lowest point of your new lake).

Do not be tempted to allow the stream to directly feed into the lake itself because, in a matter of a year or two, the silt build-up in your new lake will have reached levels that require urgent attention. This is not only expensive to resolve but often hard to achieve once your surrounding trees have become established, making it difficult for machinery to access the silted-up areas.

It may even require you to drain your lake to enable the silt to be safely removed. However, this leaves you with the new problem of figuring out what to do with your fish stocks whilst the work is completed.

Common Problems With Fishing Lakes

Naturally, it is very tempting to simply dam the stream and allow the man-made lake to fill to the point it overflows the dam (as was done at Les Rouvets Lake pictured above). The risks here are that once the wooden dam degrades or begins to rot, it could give way at any time, in which case, where is all that water going to go? Also, the silt does gradually ruin the lake unless removed every few years.

In the case of Les Rouvets Lake above, the problem has been that the end of the lake where the stream enters is now only a couple of feet deep due to the large level of silt that has accumulated since it was first dug out in 1963.

In the years since the lake was first built, the surrounding trees and shrubs have matured, and now, the only way to remove the silt would be to drain the lake to around half full, then allow a number of weeks for the silt to dry out before getting ramps built to enable a digger to access the silt and remove it, without itself sinking into the silt buildup. Even then, a number of the mature trees and shrubs would have to be removed to allow access to a JCB (construction equipment) of suitable size to complete the work, and this in itself would prove a very costly exercise.

Make sure that if you do have a stream running next to your new lake, the bank between them should be high enough that if the stream is flooded after heavy rains, it will not affect the lake and will follow its own natural course as usual.

At the deepest part of the lake, a "monk" should be built, which allows the water level to be controlled but also allows the lake to be drained completely if required.

Do Trout Need Running Water?

It used to be believed that for trout to thrive, they required running water, but this has proven to be a false assumption.

So long as the water is clean and deep, trout will flourish. It has been proven over and over again that trout have successfully survived in man-made concrete reservoirs and artificial ponds with no flow of water running through them.

Depths and Temperatures

The depths you choose for your lake will largely depend on the fish you intend to stock it with later.

Temperature-wise, any water that remains over 20 degrees Celsius over the summer is ideal for coarse fish; cooler water that does not go above 20 degrees Celsius in summer is better for trout.

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