by Kathy Danforth / Published Apr 2014
The grounds of a community are often one of its most attractive assets, but the lakes and other undeveloped areas are usually not just created for aesthetic reasons. “Practically all lakes and ponds are part of a drainage system that the homeowner association is responsible for maintaining, and most permits require inspection every two years,” states David Miracle with St. Johns Water Management District.
“They’re not just lakes and ponds; they’re retention areas for flood protection,” according to Laura Corry with South Florida Water Management District. “You need to maintain the drainage, grates, and culverts to make sure nothing is clogged up. The associations are the tertiary system for flood protection, which feeds into the local water districts and then into the large water management districts. If the HOA’s water cannot drain into the secondary system, it will never get to us.”
Peter Nabor with Cardno Entrix explains, “The project engineer designed these ponds under strict regulatory requirements to catch and retain stormwater that falls on the impervious areas of the site (roofs, parking areas, driveways, and streets) and also the landscaped areas (fertilized turf areas and planting beds). The runoff from these areas flows down the street drains or into swales and ditches into a stormwater pond. These stormwater ponds have two primary purposes: to help prevent flooding and to remove pollutants from the water before it can drain into the groundwater or leave the site.”
The combination of ditches, swales, dry retention ponds, effluent filtration areas, wet detention ponds, and control and connecting structures are designed to hold water for percolation or movement off-site. Ramzi Chehaib with Southwest Florida Water Management District notes, “A dry retention system is designed to have a half-inch runoff percolate in 72 hours.” These swales generally just require mowing and avoiding buildup of sediment or plants/plant material, and there may be a concrete overflow structure to keep clear. “However,” Chehaib notes, “sediment may accumulate from minor erosion from any areas that are not sodded. Greases from cars can wash in after a storm event, and with time, they can seal up the bottom of the pond.”
“An effluent filtration system may be used, depending on the groundwater elevation,” Chehaib says. “A screen such as clean sand is used, with perforated pipe to carry the filtered water away. The system should recover in 36 hours after a rain event, with no flow over the control system. If not, the system has clogged, and the sand may need to be scraped or replaced.”
The most visible part of the system, wet retention ponds, requires maintenance to do their job of accommodating and filtering runoff. Fortunately, an environmentally healthy pond is largely an aesthetically pleasing one for residents also—algae blooms don’t benefit anyone. The first maintenance for ponds involves what goes in; Corry cautions residents, “Everything you allow in the drain—leaves, grass clippings, trash, spills, bottles—will end up in the water system.”
Nabor comments, “Unfortunately for residents living on the ponds, the runoff often carries fertilizers that were applied to turf and planting beds. These nutrients can cause the pond to bloom with undesirable algae and underwater plant growth. Standard lake management treatments can combat this growth, but it’s a reactionary treatment. There is no preventative herbicide treatment available to control algae growth. Once in the pond, nutrients must either settle out to the bottom of the pond and be tied up in the sediments or be used up by plants.”
Miracle advises, “There are no water management district regulations for fertilizer use, but common sense advice on fertilizer is to only fertilize when needed, don’t fertilize before a rain, use slow-release types, and leave a buffer area around the pond. The association has a vested interest in keeping the lakes looking good; you don’t need to fertilize every week and open yourself up to weeds and algae blooms.”
The plant life at the pond’s edge can be beneficial and help avoid erosion, which fills in your available space for water, as well as filtering contaminants and using nutrients before they reach the water. Nabor observes, “Some residents see the plants as weedy and undesirable and want grass down to the water with no plants anywhere to be seen. Others see the flowering plants as attractive.” From a functional point of view, Nabor points out, “These plants provide habitat for lake life (fish, turtles, birds, etc.), use up nutrients that would otherwise feed algae growth, stabilize the shoreline against erosion so they do not end up with a little cliff along the lake, and hide the fluctuating water levels that would otherwise leave bare soil visible around the lake. From our experience, a general rule is that the more native plants there are, the less that algae blooms are a problem within a lake.”
Invasive species, however, go too far and too fast and can cause clogging. “Cattails are the worst because they spread so fast,” according to Miracle, “but duckweed is bad as well. Most associations are paying close attention because they don’t want weeds out of control.”
Nabor advises, “Most native, littoral plants will not grow in water deeper than about three feet. Species such as cattails, torpedo grass, and primrose willow can quickly become overgrown and out-compete desirable native species.” Corry sees hydrilla as being the biggest offender in clogging lakes and canals further south.
Fountains can contribute to the health and appearance of a lake. Janis Coquillard with Wesco Fountains points out, “Adding aeration does provide health benefits to the lake, plant life, and fish. An important factor in aerating a lake is to penetrate the thermo-barrier layer at the top that prevents oxygen from getting to the depths of the lake. Especially in Florida, when the temperature is hot in the summer, algae blooms create the thermo-barrier that leads to fish kills because of low oxygen in the water. This also leads to additional algae blooms, creating more of a stagnant layer. The fountain pump is sucking water from below the water surface and throwing it in the air, thus breaking this barrier.” To determine the area benefiting from a fountain, Coquillard explains that the extent of the ripples is a good approximation of how far the oxygenation is extending. As a bonus, she notes, “Fountains also provide an improved value to the property.”
For permitting purposes, staff will need to inspect the complete system, usually every 18–24 months. HOA attention can prevent flooding and catch problems when they are smaller and cheaper. “Associations need to pay attention to any control structures—concrete spillways or boxes that may crack or have the structure collapse,” Miracle advises. “A visual inspection should check for erosion, excessive aquatic growth, blockage of incoming pipes, and any concentrated sources of water, possibly due to lack of vegetation or gutters directed at a pond bank.” Corry comments, “Usually culverts are the issue because they’re not seen, but we’ve seen grates with a big rock over them. The dry season is a good time to check for leaves, rocks, debris, or even dead animals any place in the drainage system where it can become clogged.”
It is not just the lakes that may have a prior commitment to environmental and stormwater purposes. Miracle states, “The storm water system is more visible, but many communities also have buffers or conservation easements. The developer records it in the public record, and it goes with the land recorded on the survey of the lot.” “Conservation easements are fairly restrictive in that the land has to be left alone,” Miracle points out. “The back 20–30 feet of a lot may be under an easement, and the homeowner is tempted to clear it and put down sod because they don’t realize there are restrictions. We’ve seen swing sets, fire pits, and more. You don’t have to remove invasive species; just leave it alone. From a compliance standpoint, that’s our number one issue: homeowner activity in an upland buffer or wetland conservation easement, or occasionally working in a drainage swale. If the homeowner disturbs vegetation, they do have to rectify the situation by removing structures and replanting with native vegetation. Potentially there could be fines, but we tend to just want to see it fixed.”
Russell Martin with the Southwest Water Manage-ment District reports that they will see wetland mitigation areas specifically created to offset wetland impact, but when the developer turns over the property to the HOA, they are unaware of the requirements for monitoring and maintenance. “In conservation areas behind houses, there are frequently encroachments with people dumping yard waste,” he recalls. “Another problem is with drainage easements at the back of a property. Homeowners may fence through the easement, putting in pavers and patios that block the flow of water. The HOA needs to notify property owners of easements and those should remain clear for maintenance people to mow to keep the water flowing freely.”
Miracle acknowledges, “A homeowner association can get very involved and educated, but as boards or management turnover, it’s a challenge to keep that institutional knowledge.” Communicating to residents the nature of their ponds, undeveloped areas, and any easements can create harmony between the association, the environment, and the environment’s local guardians.
Florida’s regional, water management districts are available and eager to provide assistance in determining requirements or providing support regarding stormwater management systems, conservation, and other water issues. For more information, visit: