Natural Irrigation Ponds and the Question of Lining

High demand for specialty growing methods, including biodynamics, organic farming, and Korean Natural Farming, has led many winery owners to embrace alternative methods of management. This can extend to irrigation and decorative ponds added to the properties, often to their detriment. There’s a common misconception among many pond owners, residential and commercial alike, that natural ponds can’t have a polymer liner. Yet, there’s nothing inherently unnatural about a pond with a reliable liner as long as it’s planted and adapted to the surrounding landscape. You can have all the habitat enrichment and low-maintenance beauty you want from the pond by adding a flexible liner. In fact, trying to remain “completely natural” will only make the pond harder to keep healthy, attractive, and fit for irrigation.

Issues with Unlined Ponds

Adding no liner at all and avoiding any effort to compact the clay soil will result in a very leaky pond. Even clay soils only seal so well, no matter how much you work on smoothing and compacting the surface. Natural ponds often have high seepage and leakage rates yet appear completely stable due to a steady supply of replacement water. Springs, high ground tables, and regular rainfall all make natural ponds appear to be leak-free without a liner. Unfortunately, the soil under the pond tells a different story with thousands of gallons migrating into the ground each year. Some of the water re-enters local water tables for reuse, but plenty is lost for long periods of time until it percolates somewhere else. If you’re trying to make the most of every gallon, you can’t afford to let it simply seep away from using an unlined irrigation pond. Don’t forget the prevalence of thick mud, high sediment levels that clog irrigation equipment, and water quality issues that effect the grape vines.

Why Bentonite and Other Clay Sealants Can’t Compare

When faced with the need to line an irrigation pond to avoid waste loss, it’s common to make the assumption that so called “natural liners” like bentonite clay are a good choice. Bentonite clay absorbs water and forms large, sticky particles that bond together to help block the seepage of some amount of water. Yet even with a perfect application of anywhere from 12 to 16 inches of bentonite powder or granules, some amount of water still seeps through the gaps between particles. You’ll have to apply new layers of clay every few years. Notice also that these products don’t come with guarantees or warranties, while flexible liner manufacturers can tell you exactly how long they expect their products to last. With no way to know if a bentonite liner is working until the water level unexpectedly drops, you’re left potentially facing the loss of valuable irrigation water when you need it the most.

Going Natural with a Flexible Liner

It’s perfectly possible to build a natural and healthy pond with the use of a flexible polymer liner. The addition of the liner doesn’t harm wildlife, scare away natural bacteria that clean the water, or interrupt any important biological processes. You don’t necessarily need to add filters or aeration to an irrigation pond just because you’ve lined it either. A pond with a liner can look indistinguishable from any other non-lined pond with careful edging and plenty of cover material. In fact, you’ll find that these lined ponds often look more natural more quickly than other new ponds because the liner helps speed up the establishment of plant life around the edges by controlling seepage and bank erosion.

Fish, Plant, and Food Safe Materials

Irrigation ponds are generally not a good habitat for fish. The high levels of fertilizer or pesticide runoff from nearby fields and other quality issues make it hard to stock fish in the same water that’s safe for watering plants. This means there’s generally no reason to choose a fish safe liner, in particular, for an irrigation pond. Water that escapes the irrigation system and reaches nearby waterways won’t be any more likely to harm fish if it came from a pond without a fish-safe liner. However, you may want a plant and food safe liner to ensure that nothing enters the soil that could be absorbed by the vines. This isn’t required by most states for agricultural irrigation supplies, but it is an extra step taken by some concerned organic farmers and vineyard owners.

There’s no conflict between the idea of a natural pond and a lined one. Even ponds designed solely for wildlife use or habitat restoration are commonly lined to help them last longer and perform as designed. Unless you don’t mind losing valuable water or allowing your pond to dry up seasonally, you’ll need a liner to maintain steady levels of irrigation supply. Make sure you’re starting with the right liner by choosing a product from BTL Liners. All of our RPE and RPP liners are perfectly compatible with natural pond keeping methods.


Liners by BTL

AquaArmor Pond Liner

The most versatile liner on the market today, AquaArmor maximizes protection from harmful UV rays, tear resistance and punctures that cause leaks. Simply the best liner on the market.

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