Stormwater Ponds 101

Stormwater Ponds 101

Well-maintained stormwater ponds can become attractive amenities that also improve water quality. Photo credit: Carrie Stevenson, UF IFAS Extension

Prior to joining UF IFAS Extension, I spent three years as a compliance and enforcement field inspector with the local Florida Department of Environmental Protection (FDEP) office. It was a crash course in drinking water regulation, wetlands ecology, stormwater engineering, and human psychology. For about half of that time, I worked in the stormwater section with an engineer, certifying the proper construction and specifications of stormwater treatment ponds built for residential and commercial developments. During a construction boom in 2000-2003, my coworkers and I traversed back roads from Perdido Key to Freeport, trying to catch every new project and make sure it was done right. If they weren’t, it also fell to the 3 of us to make sure mistakes were corrected.

Since 1982, Florida Statutes have required that rainfall landing on newly constructed impervious surfaces (rooftops, streets, parking lots, etc.) must be treated before turning into runoff that leaves the property and ends up in local water bodies. The pollutants in stormwater runoff—heavy metals, fertilizer, pesticides, trash, bacteria, and sediment—are the biggest sources of water quality problems for the state, more so even than industrial and agricultural sources.

The most common stormwater ponds have sandy bottoms, grassed berms, and piped inlets with riprap to slow the influx of water. Photo credit, Michelle Diller

Therefore, new developments are required to treat that runoff. This may be accomplished by several means, including regional stormwater ponds. However, the most common are still curbs and gutters, which drain to an often-rectangular hole in the ground with a chain-link fence around it. Ideally, water pools into these dry ponds while raining, reducing flood risk and holding water long enough to allow it to soak into the soil. Most of the ponds in northwest Florida have sandy bottoms that percolate easily. Maintenance is required, however, and when heavier soils, trash, or muck accumulate they must be cleaned out to function properly. Depending on the geology of any given location, the ponds may need sand filters or “chimneys” added to allow water to soak into the native soil.

Admiral Mason Park, adjacent to the Veterans’ Memorial Park along Pensacola Bay, is an example of a regional City stormwater treatment facility that also serves as a park. Photo credit: Visit Pensacola

If an area is naturally low-lying, close to the water table, or has highly organic, water-holding soils, it may be necessary to construct a “wet” stormwater pond. In these, water stands to a level below an overflow device, and can become a water feature for the development. Many residential developers will sell lots around a stormwater pond as “waterfront property” and a well-maintained one really can be a nice amenity. However, at their core, these are stormwater treatment mechanisms. A wet pond functions differently than a dry one and is dependent on healthy stands of shoreline vegetation to take up extra nutrients, metabolize them, and render them into harmless compounds. Many of these ponds have fountains to aerate the water and keep them from becoming stagnant. The City of Pensacola and Escambia County have several great examples of these types of ponds that serve as regional stormwater detention and community amenities. These were constructed in lower-lying areas to handle chronic problems with stormwater in areas that were built up and paved many decades before stormwater rules came into effect. Many other innovative and newer stormwater treatments exist as well, including bioretention, rainwater harvesting, green roofs, and pervious pavement.


Aquatic Weed Control – Common Salvinia

Aquatic Weed Control – Common Salvinia

Common Salvinia Covering Farm pond in Gadsden County
Photo Credit – Shep Eubanks UF/IFAS Gadsden County Extension

Close up of common Salvinia
Photo Credit – Shep Eubanks UF/IFAS Gadsden County Extension

Aquatic weed problems are common in the panhandle of Florida.  Common Salvinia (Salvinia minima) is a persistent  invasive weed problem found in many ponds in Gadsden County. There are ten species of salvinia in the tropical Americas but none are native to Florida.  They are actually floating ferns that measure about 3/4 inch in length.  Typically it is found in still waters that contain high organic matter.  It can be found free-floating or in the mud.  The leaves are round to somewhat broadly elliptic, (0.4–1 in long), with the upper surface having 4-pronged hairs and the lower surface is  hairy.  It commonly occurs in freshwater ponds and swamps from the peninsula to the central panhandle of Florida.

Reproduction is by spores, or fragmentation of plants, and it can proliferate rapidly allowing it to be an aggressive invasive species. When these colonies cover the surface of a pond as pictured above they need to be controlled as the risk of oxygen depletion and fish kill is a possibility. If the pond is heavily infested with weeds, it may be possible (depending on the herbicide chosen) to treat the pond in sections and let each section decompose for about two weeks before treating another section. Aeration, particularly at night, for several days after treatment may help control the oxygen depletion.

Control measures include raking or seining, but remember that fragmentation propagates the plant. Grass carp will consume salvinia but are usually not effective for total control.   Chemical control measures include :carfentrazone, diquat, fluridone, flumioxazin, glyphosate, imazamox, and penoxsulam.

For more information reference these IFAS publications:

Efficacy of Herbicide Active ingredients Against Aquatic Weeds

Common salvinia

For help with controlling Common salvinia consult with your local Extension Agent for weed control recommendations, as needed.

Celebrating Choctawhatchee Bay – National Estuaries Week

Celebrating Choctawhatchee Bay – National Estuaries Week

Rocky Bayou Aquatic Preserve - Niceville, Florida

Rocky Bayou Aquatic Preserve – Choctawhatchee Bay, Niceville, Florida – Photo by Laura Tiu

September 17-24, 2016 was the nation’s 28th time to celebrate America’s coasts and estuaries during National Estuaries Week.  This week helps us to remember to appreciate the challenges these coastal ecosystems face, along with their beauty and utility.

Estuaries, semi-enclosed bodies of water with both fresh and saltwater, dot the Gulf Coast of the United States from Brownsville Texas to Key West, Florida. These estuaries are important as they serve as drainage basins for many of the large river systems, and play a significant role in the nation’s seafood industry.

Florida’s six major Panhandle estuaries, which includes Perdido Bay, Pensacola Bay (including Escambia Bay), Choctawhatchee Bay, St. Andrew Bay, St. Joseph Bay and Apalachicola Bay, are unique ecosystems teeming with life and diversity. Critical habitat includes important seagrass beds that support both the larval and adult stages of fish and invertebrates. In Choctawhatchee Bay, there is also critical foraging habitat for the federally protected Gulf sturgeon (Acipenser oxyrinchus desotoi) and stream habitat for the endangered Okaloosa darter.

Choctawhatchee Bay is in Okaloosa and Walton counties in the Florida Panhandle. It is approximately 30 miles long and from three and a half to six miles wide, with a total area of 129 square miles. It is relatively shallow varying from 10 to 40 feet deep. Large portions of the western half of Choctawhatchee Bay are militarily restricted (Eglin Airforce Base).  The Bay is fed by the Choctawhatchee River and numerous small creeks that feed into several bayous.  The only opening to the Gulf of Mexico is the East Pass, which ironically is at the Western end of the Bay in Destin, Florida.  This is where the saltwater and freshwater mix.

Continued industrial and residential development in the watershed regions that drain into many of these estuaries has impacted them in a number of ways. Pollution comes from storm water runoff, lawns, industry and farms. The shorelines are impacted by development, which causes sedimentation and in turn loss of vegetation.  This reduces water clarity and habitat for wildlife.

Many organizations work to protect this estuary and reach out to others through education, restoration, and recreation events. Choctawhatchee Basin Alliance (CBA) is one such organization committed to ensuring sustainable utilization of the Choctawhatchee River and Bay.  They, working with their partners, provide leadership for the stewardship of the Bay. Alison McDowell, director of the CBA, notes that 75-85% of commercially and recreationally important species that are caught in the Gulf spend part of their lifecycle in the Bay. McDowell says a key factor in the Bay’s health is monitoring the water quality and reducing erosion, and the Oyster Reef Restoration program started in 2006 does just that.

There are often opportunities for the general public to join in some of the conservation efforts taking place in the Bay. For more information, like the Okaloosa or Walton County Extension Facebook page.

Kayaking Choctawhatchee Bay

Kayaking Choctawhatchee Bay – Photo by Laura Tiu



Florida Master Naturalist projects impact local communities

Florida Master Naturalist projects impact local communities

On "project day" students share their knowledge with the class. Photo credit: Carrie Stevenson

On “project day” students share their knowledge with the class. Photo credit: Carrie Stevenson

The Florida Master Naturalist Program is a 40-hour experiential learning course offered by UF IFAS Extension. While we spend time in class with presentations, by far everyone’s favorite aspects of the course are field trips and “project day.” As part of the course, each participant produces an educational tool—a display, presentation, skit, or lesson—that delves deeper into a topic of interest. The students and instructors are able to use these tools again and again to teach others.

Master Naturalist students walk "The Way" boardwalk in Perdido Key. Photo credit: Carrie Stevenson

Master Naturalist students walk “The Way” boardwalk in Perdido Key. Photo credit: Carrie Stevenson

One example of a multi-year student project is “The Way” nature trail, located at Perdido Bay United Methodist Church. Master Naturalist Jerry Patee worked with volunteers from his church and community to design and permit a boardwalk and nature trail leading to Bayou Garcon. The unique trail is less than a mile, but traverses upland, freshwater wetland, and coastal habitats, making it a perfect ecological teaching tool. The trail is open to the public and maintained as a place of quiet contemplation. The project is ongoing, with educational signage planned, but it is an excellent new resource for the community.

“The Way” is just one of many positive contributions made by Master Naturalist students over the years. To enroll in a Florida Master Naturalist course near you, visit the FMNP page or talk with an instructor at your local county Extension office.

Springs of the Western Panhandle

Springs of the Western Panhandle

The Panhandle Outdoors LIVE team, with Extension Agents from eight counties, hosted an outdoor field day on August 26, 2015. Twenty-three participants from over eight counties in Florida attended the event and traveled to three local springs: Vortex, Ponce de Leon, and Morrison Springs. The goal of the day was to learn about spring characteristics, history, biodiversity and management issues. These popular springs in the western Panhandle are managed by three different entities – the private sector, local government and a state agency.

The day began at Vortex Springs. Three generations of the same family have owned and managed this popular dive resort in the Panhandle. The current owners shared the history of the spring along with a family photo album highlighting the growth and development over the years.

Vortex Springs Dive Resort

Vortex Spring produces 28 million gallons of crystal clear water daily at a year-round temperature of 68 degrees. Depths in the spring basin range from about 50 feet for a cavern dive and up to 115 feet for a cave dive. The bottom of the spring bowl is sandy, with limestone near the vent. Vortex waters flow out of the 225-foot-diameter spring pool to form Blue Creek, which flows over a half-mile before entering the Choctawhatchee River. Fish at the spring are tame, coming right up to visitors, and include bluegills, channel catfish, American freshwater eels, gar, redhorse suckers, shadow bass, and exotic species such as koi and goldfish ( One of the biggest environmental challenges the owners face is controlling an invasive aquatic plant, hydrilla, which rings the basin.

The next stop was Ponce de Leon Springs State Park where participants learned about the springs and had lectures on water quality, Florida Friendly landscapes and storm water management. Managed by a state agency, this beautiful spring is named for Juan Ponce de León, who led the first Spanish expedition to Florida in 1513 – as legend has it – in search of the “Fountain of Youth”. Visitors might well regain their youth by taking a dip in the clear waters where the temperature is a shocking 68 degrees F. year-round.


Leon County Extension Agent, William Sheftall, shares information on watershed management

The main spring produces 14 million gallons of water daily into a crescent-shaped basin with depths averaging five feet but increasing to 16 feet over the vents. The bottom is sand and limestone and gives the popular swimming area a light greenish blue appearance. The spring-run is approximately 350 feet in length and flows into Sandy Creek, a blackwater stream, which subsequently flows out of the park and into the Choctawhatchee River (


The spring run at Ponce de Leon Springs flowing into Sandy Creek

Our final destination was Morrison Springs. Morrison Springs is managed by Walton County, whose Commissioner and Habitat Conservation Plan Coordinator shared the history of the springs and the development work that has been completed. The large, sandy-bottomed spring is surrounded by a 161-acre park and is a popular spot for swimming, snorkeling, diving, birding, photography and nature walks . Morrison Spring discharges an average of 48 million gallons of crystal-clear water each day to create a 250-foot-diameter spring pool and a spring run that flows into the Choctawhatchee River ( The springs are home to a healthy fish population with largemouth bass, bluegill, carp, white mullet, and pickerel all being seen that day.


Beautiful cypress trees and knees ring Morrison Springs

Field day participants (86%) reported an increase in knowledge of the springs after the event with 59% indicating that they would change their behavior based on the information presented. Behavior changes mentioned were cleaning up trash, controlling personal fertilizer applications, making sure their lawn care company was certified, controlling erosion, conserving water and planting native plants. All of the participants (100%) reported being interested in attending future Panhandle Outdoor Live events. That is just the kind of encouragement the team needed, so be sure to watch our website for future event announcements.




National Estuaries Week! – What is an Estuary?

National Estuaries Week! – What is an Estuary?

Welcome to National Estuaries Week! Each year in the fall NOAA and other agencies try to educate residents about estuaries. The vast majority of humans on our planet live on, or near, an estuary – many not realizing the importance those bodies of water have on our economy and quality of life. We live on them, consume food from them, swim in them, recreate on them, and maybe make your living from them. They are an integral part of our lives and many are under stress. Over the next seven days we will post articles discussing some of the benefits and problems our local estuaries are having. Let’s begin with What is an Estuary?

An estuary... where rivers meet the sea. Photo: University of California.Berkley

An estuary… where rivers meet the sea.
Photo: University of California.Berkley

Estuaries are defined as semi-enclosed bodies of water where fresh and salt water mix. Typically freshwater enters at the head of the bay. In the Florida panhandle most of our estuaries are fed by one of two types of rivers; alluvial and tannic. Alluvial rivers are large, fast flowing streams that begin far up in the watershed (Georgia or Alabama) and typically are quite muddy; Escambia, Choctawhatchee, and Apalachicola Rivers are examples.

Tannic rivers are generally smaller in size, flow slower over coastal flatwoods, and build up tannins from the decomposition of leaf litter that settles to the bottom due to the slow currents. Due to the high levels of tannin, these rivers general have a lower pH and “blackwater” “ice tea” coloration to them; Blackwater and Perdido Rivers are examples.


Freshwater from these rivers is less dense than seawater and tends to flow across the surface of the bay towards the mouth of the bay; where it meets the Gulf of Mexico. There are several types of estuaries found around the world and the ones in our area are drowned river valleys. They formed when ice from the last glacial period melted and flowed towards the sea. As they reached the coast areas of “low land” filled with water and became bays. Drowned river valleys typically are very wide and very shallow. Mobile Bay is 35 miles long, 10 miles wide, and not much deeper than 11 feet across its area. I remember as a kid scalloping in St. Joe Bay and being able to stand up at distance from shore that I could barely make out my car!

The Escambia River. One of the alluvial rivers of the Florida panhandle. Photo: Molly O'Connor

The Escambia River. One of the alluvial rivers of the Florida panhandle.
Photo: Molly O’Connor

As seawater enters the bay it tends to remain near the bottom and will “finger” it’s way towards the head forming two layers of water within the bay; freshwater on top – seawater on the bottom. This “fingering” movement is called a salt wedge and forms a halocline which impacts the distribution and diversity of aquatic species. On windy days the top and bottom layers will mix and the salinity of the bay becomes more brackish with no noticeable halocline; this too will impact the diversity and distribution of aquatic life. Creatures who live in estuaries must be hardy and prepared for drastic environmental change over the course of the day.

In the Florida panhandle our estuaries experience diurnal tides; 1 high and 1 low tide each day. The incoming tides are generally weaker than the outgoing ones; I have, more than once, been caught in an outgoing tide in Pensacola Bay… VERY difficult to swim out of.

A salt wedge. Graphic: NOAA

A salt wedge.
Graphic: NOAA

We have seven estuarine systems along the Florida panhandle; Perdido, Pensacola, Choctawhatchee, St. Andrew’s, St. Joseph, Apalachicola, and the Apalachee. Each is unique and important to their communities and provide benefits that are truly priceless. Enjoy the other articles we will post during National Estuaries Week and GO OUT AND ENJOY YOUR ESTUARY! It’s the perfect time of year for it.