Any irrigation system, no matter how advanced the technology which underpins it, is only ever going to be as effective and reliable as the water source it relies upon. For an individual household, the amount of water needed for effective irrigation might be such that the domestic supply is sufficient, but larger properties such as commercial concerns, golf courses and gated communities will need to choose between pumping water from an irrigation lake or a wet well in order to ensure sufficient amounts of water are available whenever needed. The example of a gated community is particularly relevant for two reasons; the first is that Florida, where we're based, is home to more gated communities than any other US state with the exception of California. The second is that a large part of the appeal of the gated communities which are present across Florida lies in the landscaping that surrounds the properties.
Given the variable and often unpredictable nature of the Florida climate – ranging from drought conditions to tropical downpours – a reliable water source is the key to effective irrigation, and although irrigation lakes form a major part of many community and commercial developments, the continued use of wet wells in some cases makes it worth comparing these two sources of water supply.
Lifespan of a Wet Well vs. A Lake
In simple terms a wet well is a culvert, ranging between 6ft and 8ft in diameter, which is 20ft deep and 100ft in length. These dimensions may vary from location to location, but the basic principle of the wet well is always the same – it draws water from a nearby source such as a pond or river and that water is them pumped into the wider irrigation system. Unlike an irrigation lake, a wet well is a man-made construction which, like any other man made construction – and particularly one which undergoes a constant flow of water – has only a finite life span. In the majority of cases a wet well which is regularly maintained and built to the highest engineering standards in the first place can provide a source of irrigation for a maximum of thirty to thirty five years, after which it will need to be replaced. An irrigation lake requires maintenance of course, as does the landscaping surrounding it, but as long as this is happening, it has the potential to last as long as the water cycle is able to sustain the required water level.
Water Quality
Mention of the water cycle brings us to another of the issues which anyone relying on a wet well will have to confront. Whereas an irrigation lake is fed by the water cycle, and by the subterranean aquifers which are the ultimate source of all of the fresh water in Florida, a wet well forms its own unique aquatic environment cut off from the wider ecosystem. A landscape designed with sustainable irrigation in mind and an irrigation lake at its heart will have been shaped – from the slope of the lawns down to the choice of plants, trees and flowers – in order to maximize the amount of water returned to the irrigation lake.
The water sitting in a wet well is, by its very nature, stagnant and lifeless. For this reason, chlorine and other chemicals will need to be added to the water in a wet well in order to deal with the bacteria and other undesirable contaminants likely to be present. In the worst case scenario, these contaminants could include materials taken from the sediment found at the lower reaches of the water source and even the decomposing bodies of creatures such as fish and turtles which have died in the water source. The use of chemicals to maintain the quality of the water taken from the wet well is something that many people tasked with managing irrigation requirements might object to on principle, as it introduces a non-organic element to the water being used to maintain the landscape, but perhaps even more worrying is the fact that no matter how often the wet well is cleaned and maintained it is impossible to be certain – given the nature of the way in which a wet well draws water from the source – that matter such as sand and even rocks don’t become problematic.
Deal With Contaminents at Source
When an irrigation lake is used, on the other hand, the problem of contaminants can be dealt with at source. Careful placing of the intakes across the irrigation lake will minimize the risk of contaminants being drawn into the system, as will the use of state of the art filter systems. By placing the intakes at the right height, the people behind the design and installation of a lake-fed irrigation system will be able to ensure that the water is being taken from spots well away from the bottom of the lake.
Water Supply
As previously stated, an irrigation lake is a naturally self-sustaining body of water based within the natural cycle of precipitation and evaporation and, unless hugely extreme drought conditions prevail, the water levels will only fluctuate within acceptable parameters. A wet well, on the other hand, is always completely dependent upon the water level of the water source being used or of the wider water table. Some wet wells, for example take the form of a concrete well placed within a body of water such as a lake in such a way that the water from the lake either sits over the open top of the well or flows across periodically. A wet well of this kind offers the advantage of taking cleaner water from close to the surface of the lake rather than sediment heavy water from the bottom, but runs the risk that if the level of the lake drops below the top of the wet well then the well will quite simply no longer function. Water intakes floated a few feet off the bottom of the lake, on the other hand, avoid the risk of sediment intake at the same time as still functioning while the level of water in the lake remains at a reasonable level.
Lakes Can Be Landscaped
One final aspect of an irrigation lake which elevates it above a wet well is that a lake, as well as feeding the irrigation system that maintains the wider landscape, will play a key role in the visual appeal of that landscape. To put it in the bluntest possible terms, nobody ever chooses to go for a pleasing stroll around a wet well or sit and admire the views across a wet well! By combining functionality with aesthetic appeal, an irrigation lake can sit at the heart of a location such as a gated community whilst playing a key role in maintaining that community.
