As a property manager, representative of an HOA or member of a community in Florida, you likely already know that hurricane season is defined as June through November – but did you know that the National Hurricane Center characterizes mid-August through October as peak season?
You’re also likely well-aware of what goes into prepping in the event of a severe storm. But do you know that properly maintaining, preparing and recovering community lakes, ponds, retention ponds and stormwater ponds can prevent further damages and health risks?
Why Does Florida Have So Many Stormwater Ponds, Retention Ponds & Canals?
The infamous and deadly hurricanes of 1926 and 1928 led to a state-wide effort to implement flood control measures. One such effort was draining Lake Okeechobee into the Gulf of Mexico and the Atlantic Ocean. This reduced water flows to the Everglades and created the infrastructure needed to support new agricultural land and development. Since then, five water management districts have been established throughout Florida to provide the drainage needed to support the state’s three key economic drivers: agriculture, tourism and development. Today, the majority of lakes and ponds engineered and developed within Florida are non-natural systems.
With an average of 60 inches of rain per year and hurricanes that produce as much as 2 inches of rain during an event, drainage and flood control are vital to protect land/water resources, the population, and the economy. They are also not just designed to prevent flooding, but to also clean up stormwater run-off, restore water resources and recharge aquifers for drinking water. For stormwater systems to function at their highest and most efficient use, it is important to understand that ponds need healthy dissolved oxygen levels and native plants along their edges to maintain strong shorelines.
What are the Impacts Storms and Hurricanes Have on Stormwater Ponds, Retention Ponds, Lakes & Canals?
After a storm, there are four main ways that lakes, ponds, canals and other waterways are often affected – nutrient overloads, fish kills, sediment/shoreline erosion and standing water for pest breeding.
Nutrition Overload: In the wake of heavy rains or flooding – especially after a hurricane or storm – run-off in the form of fertilizers, clippings, pesticides, herbicides, waste, oil and gas are washed into the water. This can overwhelm the nutrient load and lead to algae formation, Harmful Algae Blooms (HABs), attract midges who breed in nutrient-rich waters, invasive plant overgrowth and other undesirable symptoms. Learn more on how to prevent run-off and preserve water quality in our guide, 3 Things Every Site Manager Needs to Know About Stormwater Ponds.
Fish Kills: Closely linked to nutrient overload, a fish kill occurs when there are sudden drops in dissolved oxygen (DO) levels. Algae tend to eat away at DO and strong winds from a hurricane can quickly pull up oxygen-poor water from the bottom of the waterway. While not necessarily indicative of a fish kill, hurricanes can also pull in salinated water – which can harm fresh or brackish water fish.
Sediment/Shoreline Erosion: As time goes on and waters repeatedly rise and fall during storms, hurricanes or even heavy rains, they begin to eat away at shorelines. The more erosion there is, the more likely land is to collapse and the more likely roads and homes are flooded or even sunk into waterways. This can also unearth cables and electrical lines – expensive repairs for municipalities and HOAs.
Standing Water/Pest Breeding: Standing water following a significant weather event like a hurricane or tropical storm is extremely common. Even after floodwaters recede, the ground remains saturated, and pockets of standing water will likely remain in low-lying areas. It also may take some time before fountains and aeration equipment can be safely turned back on in a stormwater pond, depending on how infrastructure and utilities were impacted by the storm.
This all creates ideal conditions for mosquito breeding, and communities that experience a flood event will often find themselves dealing with a significant mosquito hatch-off in the days and weeks following. Not only are these mosquito populations extremely annoying, but they also amp up the potential for mosquito-borne disease transmission such as West Nile Virus.
Prepping Lakes and Ponds Ahead of Storms and Hurricanes
While many Floridian waterbodies are designed to handle hurricanes and other large storms, ongoing maintenance is needed to ensure that their systems are working correctly and fit to face unpleasant weather.
As part of your ongoing maintenance and management plans, you should make sure your aquatic management team includes the following in their practices:
- All inlets and outlets – as well as drainage pipes, spillways and ditches – should be maintained and kept free of any blockage such as trash, vegetation or sediment build-up.
- Make sure that your waterbodies are also kept free of trash and debris (and that run-off in the form of clippings and leaves are bagged up rather than washed down to shorelines) as these can go on to later cause blockages when drudged up by winds.
- Ensure that aquatic plants and vegetation are kept in check within the waterbody with a proper aquatic plant management plan.
- Monitor each waterbodies’ shorelines for muskrat holes or depressions in the soil. These can easily overflow and collapse during a storm, leading to eroded shorelines.
- Keep your water moving via aeration systems and fountains to help prevent mosquito and midge breeding as well as to keep water quality and nutrient loads optimal.
- Have a contingency mosquito/midge control plan in place for lesser storms that do not trigger state responses (We’ll detail those later.). Companies such as Clarke can respond timely and directly to your community’s needs by having an IMM contingency agreement in place.
There are also several actions you can take when you know a hurricane or tropical storm is imminent.
- Turn off any fountains, diffusers or other installed aeration systems. If possible, remove them and safely store them.
- Consider installing a debris guard in your overflow pipes to help reduce inlet clogs.
- Double-check pipes and drainage sites for debris if this can be done safely.
- Secure yard and shore items – potted plants, porch furniture, fishing equipment, boats – to keep them from being blown or washed into the lakes and ponds.
Lake & Pond Clean-Up & Recovery After a Storm
Once a storm subsides and conditions are safe to move around waterbodies, it’s important to clean up and provide any needed maintenance. For lakes, canals and stormwater pond systems, this includes:
- Provide Maintenance to Waterbodies and their Structures
- Take Precautions to Prevent Pest Breeding caused by Standing Water
- Monitor Water Quality and Nutrient Loads from Run-Off
Provide Maintenance to Waterbodies and their Structures
One of the first things you should do prior to turning back on any equipment or resuming any use of the waterbody is making sure that it is in safe, operable shape.
Start by checking where water enters and leaves the lake or pond. This includes pipes, dams and drains. Any debris that has accumulated on these will need to be removed to allow water to flow freely. Please take caution as large blockages can cause outbursts of water or even create a suction effect. It is recommended to use rakes, hose sprays and other similar methods to remove debris rather than your own hands to prevent injury.
This is also the time to check on any docks, boats, fountains or aeration equipment that may have weathered the storm. You will also want to survey the shoreline for any signs of erosion from heavy winds, waves or rain – or even unearthed trees or poles – and undertake any shoreline restoration as needed before conditions worsen.
Take Precautions to Prevent Pest Breeding caused by Standing Water
As mentioned before, standing water and moist soil are prime environments for mosquito and midge breeding. When it comes to mosquito control following a serious storm event, you should know that your state’s relevant agencies will likely have a contingency program in place with a service provider that is qualified to provide wide-scale applications, often by air if ground conditions are too difficult, to knock down mosquito populations.
In Florida, for example, this work is typically contracted through the Department of Agriculture and Consumer Services (DACS) in coordination with other state and even federal agencies like FEMA. This article on aerial mosquito responses programs provides additional context on how these wide-area response programs work. In addition, public health mosquito control companies such as Clarke may be able to supplement a wide-area response with hyper-targeted community efforts to further improve resident comfort.
To prevent midges from having similar hatch-off rates, you should make sure that your water stays moving and aerated. Midges lay eggs, hatch and develop in slow-moving water, which makes ponds and lakes with non-functioning or non-existent fountain and aeration systems major targets. Ensure that your equipment is turned on when safe to do so or consult an aeration expert to develop a custom system.
Monitor Water Quality and Nutrient Loads from Run-Off
After storms, heavy rains and flooding, run-off, storm surge and damage to aquatic plants can take a toll on water quality. Waters moved from brackish or salt waterbodies can increase the salinity of your lake or pond. Run-off in the form of fertilizers, oil from roads, new bacteria and much, much more can also enter your water and cause havoc.
You will also want to have an aquatic plant specialist check for changes to the aquatic vegetation in your waters and lining their shores. The same forces that can cause shoreline erosion can also damage plants – and large plant die-offs, overgrowth and other factors can lead to algae blooms.
For a complete water quality assessment, have a professional perform a series of water quality tests, which may include some of the following:
- Secchi disk test and depth
- Harmful Algae Blooms (HABs) monitoring
- Algae identification
- Microbial bacteria
Choosing Clarke Aquatic Services
Clarke brings a wealth of experience and knowledge to successfully addressing aquatic invasive species, including Phragmites, for municipalities, agencies at the national, state and local levels as well as lake associations and subdivisions.
Our in-house staff includes biologists, environmental scientists, regulatory agents, helicopter pilots and licensed applicators, each working to keep Clarke OSHA compliant, DOT certified and NPDES compliant.
Contact our team here or at 1.800.323.5727