(Newswire.net — October 5, 2020) — As natural wetlands have disappeared from the landscape and as built, development has replaced natural topography, so too have more standing bodies of water appeared across America’s urban and suburban landscapes, acting as stormwater runoff management systems, with countless thousands in most states.
These can either become a serious burden of maintenance to keep safe, dredged, unpolluted and free of disease – or they can become a valuable amenity of the community. Much professional thinking is now going into making these ponds beautiful ecosystems that serve as an attraction for social gathering and a natural habitat for fish and wildlife, landscaped and interlaced with native foliage, while still remaining in working order for their purpose.
Why Ponds?
Some ponds occur naturally from the lie of the land, and farmers have always dug ponds for irrigation and livestock, and even these are part of a water management plan, but municipalities face the larger burden of water management nowadays.
Flood waters carry debris and surface chemicals and pollutants into the natural waters of the land, as well as eroding river banks and washing soil and silt downstream – and severe flooding of course causes huge devastation. Much of the need is to check the surge of storm water and to regulate its flow.
Detention ponds and retention ponds capture the initial surge of water, and release it at a measured pace into the existing water management system. Often these ponds are fed water from multiple tributaries. Also called dry basins and wet basins respectively, a detention pond is usually empty and will eventually drain dry, while the more common retention pond is created as a permanent pond, with capacity to take extra volume during storms.
Dry basins are often built from concrete to allow cleaning equipment to clear debris, while wet basins can have a variety of foundations. Many of those dug in surrounding earth will have a geomembrane bed, perhaps of rock and sand, and often with a large, specially fabricated PVC liner, or other such synthetic material.
Retention ponds stop the damage of flooding, but in turn present a variety of other hazards. They can accumulate pollutants, harbor mosquitoes and breed disease, as well as simply becoming stagnant and smelling bad. Removing the sediment and other debris that fills the bed of the pond is another large maintenance issue.
Water that looks clear can still be toxic, and when it seems inviting, no amount of fencing or signage can be enough to keep children out of the play space and what looks like a swimming hole. The most common cause of death for children up to four years old is from drowning – in fact, pediatricians now recommend that kids can begin swimming lessons from as early as age one. Retention ponds are usually much deeper than they look, and they can be deadly.
Whither Ponds?
The idea of habitat restoration is growing as a long-term investment policy for retention ponds, with the thought of turning a permanent body of water into a natural feature that becomes an attractive asset for its community rather than a deteriorating liability.
Not all retention ponds are maintained by municipalities. Many are built in subdivisions with a homeowners association bearing the cost and responsibility of maintaining the pond, and finding it quite costly for the community. But the retention pond in a subdivision or office complex lends itself readily to beautification, which in turn adds property value and quality lifestyle.
The banks and borders of the pond are a natural place to add foliage and vegetation, as buffering against storm surges and to protect against erosion, but also to begin the process of designing attractiveness. Grass clippings often get into a pond and are a pollutant, and a border around the pond serves to keep the lawn at a distance.
Decorative railings and plants around the banks can also keep kids advised that this is a pond and not a swimming hole – while ducks and geese swimming on the pond will do the job even better. Introducing the right fish can bring the pond alive and help keep the insect balance healthy.
Algae growth is the bane of the retention pond, accelerated by pollutants in the water, combined with the lack of sunlight reaching the pond floor. Fish again can help diminish the algae and even clean the bed of the pond with the right bottom feeders.
As a community retention pond is beautified and transformed into a self-balancing ecosystem, it takes on value as a place to gather and simply to watch the wildlife. Building a gazebo or a decorative bridge, and landscaping the surroundings can add great charm.
Involving the community in the process to get residents to understand the purpose of the pond can find stakeholders being more careful about the chemicals and contaminants that can enter the pond. The water from the pond is ultimately finding its way back in the natural and treated water systems, so it makes sense to keep it as clean as possible – and with the community’s central attraction at stake, this becomes much easier.
The retention pond aims primarily to slow down and diffuse storm water flood surges, but it also acts to take debris out of the flood – and this means that the buck stops right there at the pond. Every possibility taken to enhance the self-sustaining nature of the pond can cut the cost of maintenance, reduce the need for chemicals, and add value for humans and wildlife.