While each state has its unique challenges for pond construction, California’s natural conditions can be particularly hard on liner materials. Like many Western states, some parts of the state are desert and the extreme heat and sun exposure can shorten the lifespan of even the toughest materials. The soil of southern California, in particular, is often hard on liners that aren’t reinforced to prevent ripping when loose materials shift under the surface. In Northern California, rocky soil and freezing conditions can cause problems instead, not to mention organic material left behind during the clearing of the site. Careful liner selection, in addition to thorough site preparation, is key to successful liner installation on any new California pond.
Clay and Sand Composition
A successful pond project largely depends on the amount of clay in the soil, even for ponds that are lined with a geomembrane. However, there are ways to overcome loose and shifting soils that are mainly made of sand. Making the pond’s embankments as shallow as possible and using an underlayment under the liner are just two techniques for overcoming the likelihood of soil shifting. When loose soils move out from under the geomembrane, the material becomes stretched and stressed by the sudden lack of support. Soils that are higher in clay content are easier to compact and keep in place, allowing for steeper sides and embankments for small ponds.
Organic Material and Stumps
Any site where there is plenty of topsoil and vegetation will need extra preparation to avoid the breakdown of the organic material later. If you install a geomembrane over buried materials like stumps, chipped trees, and other debris, voids will open up over time. This creates the same issues as with shifting soil, stretching the liner and increasing the chances it will tear and leak. Using reinforced liner material is the one step in preventing this kind of damage, but it can’t entirely replace the need to prepare the site by removing all the organic material first.
Drought and Annual Rainfall
Exposed liners break down faster, and ponds that dry out seasonally tend to expose the liner no matter how much sand and stone are installed over the top. Keeping the pond from drying out usually relies on annual rainfall alone, but parts of Southern California experience only a limited amount of precipitation per year. Drought further reduces the supply of surface water, increasing the likelihood of the pond running dry. Of course, using a liner is the best way to prevent a pond from running dry over the summer, especially during a drought. Just be sure to keep the liner well-covered with sand and gravel to keep the liner from breaking down early due to UV exposure, or use a UV-resistant RPE liner from BTL Liners.
Soil for Dams and Embankments
Not all ponds are made solely by excavating into the ground, since digging and grading is a costly part of the process. Building embankments or dams around the edges of the excavation is the best way to raise the height of its water holding capacity while creating a place for the extra soil to go. However, loose and sandy soils don’t make very good embankments or dams. Thick clay soils are needed, at least for the core of these structures, to ensure they don’t wash away from water pressure lapping up against the edges of the pond.
Site selection is key if you are trying to reduce the costs and labor needed for a new pond. Turning a forested site that’s on a slope into a flat, clear area ready for holding water is a lot more work than starting with a flat piece of land that’s already cleared. Look for natural valleys, gullies, depressions, and other areas ready to transform into ponds with just a carefully placed dam. No matter how you work around the climate and soil challenges common to California, BTL Liners has the geomembranes to help you achieve your goals.