When you've been in the pond business as long as I have, you're bound to note the ebb and flow of various trends. Homestead ponds for fish and livestock water were especially popular in the Seventies, but the pendulum later swung toward water gardens, recreational ponds, and impoundments for landscape accents. Now interest in renewable energy is sparking pond designs oriented toward geothermal reservoirs for household heating and cooling, and hydro power for electricity.
But one trend has long been on a continuous rise: the search for supplementary water. Why? Because naturally watered pond sites are getting harder to find. Wetland regulations often prevent pond construction in the boggy places they used to go. And many of the best naturally wet sites have been taken.
Water deficits may be obvious, or suspected, before pond construction, so that plans for supplemental water can be made ahead of time. Or an existing pond can reveal a low water problem that needs to be addressed after construction.
Probably the best solution to a lack of water in the pond site is to tap or develop a supplementary source of clean water that will flow by gravity to the pond. Perhaps you have a flowing stream upslope from the pond which can be tapped. Often a cistern type pool is installed in or near the stream, with a pipe leading to the pond.
Depending on the seasonal need for water, the pipe might be buried below the frost line so it can run year round, or perhaps a simpler flexible pipe laid on the surface, which is disconnected in cold weather to prevent freezing. Keep in mind that tapping streams or other natural water sources may be subject to the same wetland regulations that cover ponds.
Upslope springs can also be developed in a similar way, using a cistern and pipe to the pond.
The watershed above the pond is sometimes developed to catch precipitation efficiently, with the water then directed to the pond by ditch or underground French drains. Swales, ditches, and buried perforated pipe can often be used to increase the yield of watershed runoff. Crushed stone or gravel is sometimes used to check erosion in such ditches, or to backfill perforated pipe, which can then be buried.
Roofs can also be tapped for water, and again function most efficiently when located upslope from the pond. Water can be captured directly by a gutter system, or caught at ground level in foundation drains and wells, and then piped downhill to the pond.
Of course, if any of these sources are located below the pond they may have the potential to be pumped up the pond, using an electric or solar powered pump, wind powered pump, or hydraulic ram.
Finally, dug or drilled wells are often used to fill or supplement pond water. Sometimes in a domestic situation a household well will have enough capacity to add a split feed to the pond. These sources are often controlled by a household timer or float switch in the pond, to conserve water. Sometimes a separate pump for the pond feed is installed in the well.
If an existing well is not sufficient to supply the pond, a special well may have to be drilled for the pond.
Finally, ponds with supplemental upslope water sources are sometimes equipped with recapture systems downstream. That way, overflow can be pumped back to the pond, limiting waste.
Topics vary from month to month and provide great information when researching where you want to build a pond, or how to keep it clean. Other areas of interest are pond use for more than swimming, and how to keep fish happy in your pond.