Rick Stuebing - Johns Lake Association

November 1, 2021December 18, 2022

Hydrilla and Carp Control Update 11/21

November 1, 2021

Hydrilla and Carp Control Update 11/21

Rick Stuebing

Florida Fish and Wildlife (FWC) is planning to add four hundred (400) carp to Johns Lake in the near future. They typically put carp in the lake every few years. The primary purpose of the carp is to assist with controlling Hydrilla. There is a delicate balance to maintain with the number of carp in the lake. If the population grows too large, they will eat not only the Hydrilla but the important native plants as well, which could negatively impact the eco-system of the lake. FWC monitors the growth of the hydrilla to determine how many carp to add and what frequency to put them in Johns Lake.

There is no way to accurately say exactly how many of the carp stocked in the past are alive because we don’t have accurate numbers for stocking mortality (predation by largemouth bass when they are young, etc.). We are working to get better numbers on the natural grass carp mortality curve. From what some have observed, you start to lose 10-20% per year after age 6 or so. Most do not live past the age 10-12 years old. The maximum length of a grass carp is 4.6 ft (1.4 m), and the maximum weight is 97 pounds (44 kg). Adults look identical to juveniles, and they are not able to reproduce.

Plants Preferred by the Grass Carp

Hydrilla
Coontail
Muskgrass
Naiad
Slender and jointed spikerush

Plants Preferred by the Grass Carp

Water hyacinth
Water lettuce
Water lilies
Torpedo grass
Hygrophila
Cattail

February 23, 2020February 19, 2022

Johns Lake Quality Indicators

February 23, 2020

Johns Lake Quality Indicators

Rick Stuebing

Over the years, the Johns Lake Improvement Association (JLIA) has dealt with numerous potential problems and threats to Johns Lake. JLIA has recently identified five Quality Indicators that will be monitored and reported in the newsletters moving forward. They included Lake Levels, Water Quality, Invasive Vegetation, Drainage, and Habitat.

An easy to understand reporting tool has been developed using a stoplight approach with a brief explanation for each quality indicator. The JLIA will use data provided from the county and other organizations and will make some subjective measurements. The intent is for lakefront owners to be able to easily see where the JLIA feels issues involving the lake need attention or additional discussion in the newsletters.

Let’s all continue to do our part to keep Johns Lake an enjoyable place to live!

Lake Level

Improving

The lake level has receded somewhat from the recent high level but significant rainfall or future hurricanes could push it too high. With reduced rainfall at this time, the trend here is improving.

Also, we are hopeful that the county will maintain the drainage canal to Lake Apopka after their study is completed. A county study is underway to do an assessment and recommend options to address this important issue.

Water Quality

Stable

Water quality has been steadily improving during the past ten years according to county testing. Long-term, frequent participants in lake sports activities (skiing, wake-boarding) have reported a significant improvement in water clarity.

Invasive Vegetation

Improving

Hydrilla, Cuban Bulrush, and other invasive species are an ongoing concern for Johns Lake. The county will continue to treat as needed and additional grass-eating carp will be added to the lake to augment their efforts. This quality indicator is constantly changing and a combination of weather and treatments can affect the status either way.

Drainage

Being Studied

Johns Lake drainage (aka outfall) is an ongoing concern. Recent water levels are higher than previous years and there is a concern that the current outflow is not sufficient. We will keep you posted on this issue.

Habitat

Stable

Even with the new developments around Johns Lake it is still a vibrant habitat for wildlife. We have otters, alligators, turtles, bald eagles, osprey, ducks and many other species of water fowl. And, as always, the lake is a premier fishing site.

October 1, 2019April 6, 2022

Johns Lake Water Level Update

October 1, 2019

Johns Lake Water Level Update

Rick Stuebing

Lake levels are measured by using the North American Vertical Datum of 1988 (NAVD 88). It is similar but not the same as measuring from “Sea Level”. The official recorded lake level as of September 20, 2019 was 96.70 feet above NAVD 88 and the Normal High Water Level is 97.36 NAVD 88. This level is less than one foot below the Normal High-Water Elevation.

Although variations in lake elevation are very good for the health of the lake and fish habitat if it gets too high it could flood some of our homes and cause damage to our docks.

June 6, 2019February 19, 2022

Triploid Grass Carp

June 6, 2019

Triploid Grass Carp

Rick Stuebing

Introduction

The use of Triploid Grass Carp is one of several methods to control the hydrilla in Johns Lake. Triploid grass carp are unique, olive-green, cigar-shaped fish often observed basking in the sunshine in shallow water as they soak up warm surface temperatures. What sets these fish apart from others is their intense appetite for a wide variety of underwater plant life. Often, plant problems in ponds and lakes are due to invasive, exotic species such as hydrilla, which have no natural enemies in Florida. It is in everyone’s best interest to prevent these plants from spreading and taking over our waterways.

Grass carp come from Asia and also have no natural enemies in Florida. The triploid “grass carp” is a sterile version of the white amur. It has been used in private and public Florida waters for the control of noxious aquatic plant species since 1972. Triploid grass carp are considered a natural method for controlling aquatic vegetation and macro-algae. They can live for many years (20 plus years in some cases). Their ability to live long typically makes them significantly more cost effective than herbicides.

Grass carp usually take six months to a year to be effective in reducing problem vegetation, although they provide much longer term control than other methods, often up to five years before restocking is necessary. When used in conjunction with herbicide treatments, control of problem vegetation can be achieved quickly, and fewer carp are required to maintain the desired level of vegetation.

Physical Characteristics

Grass carp are actually members of the minnow family. Grass carp grow to an average of 15-20 pounds and 20-35 inches in length. In larger lakes with large numbers of plants, they can grow up to 50-60 pounds and exceed 50 inches in length. In Florida, the largest reported grass carp weighed 75 pounds.

Grass carp sometimes appear silver in color, but often display an olive green or dark gray hue on top with light gold or pale yellow sides. Their belly is silvery or bluish-white and fins are light green or gray. Unusually large fish scales are another distinguishing characteristic.

Grass Carp Sterility

When grass carp are able to reproduce, they are called “diploid”. Florida law dictates that grass carp used for weed control must be sterile, or “triploid.” “Triploid” grass carp are hatchery-raised fish that have been sterilized by “shocking” fertilized eggs. This leaves the fish unable to produce viable eggs. This technique is used to eliminate reproduction in Florida waters.

Permitting

In Florida, only triploid grass carp are allowed and a permit is always required, even when stocking privately owned waters. Permits may be obtained by contacting the Florida Fish and Wildlife Conservation Commission (FWC).

What They Eat

They are normally readily available for purchase year round in several sizes but require a permit. The smaller ones are cheaper but have a higher chance of being eaten by bass. Most grass carp are shipped at about 11 inches. If stocked at a proper rate, at correct sizes, targeting proper plant species, and the right time, you will achieve significant vegetation control the first year, depending on the severity of the problem.

They prefer softer, pliable aquatic vegetation such as hydrilla and milfoil. Fortunately, hydrilla is their favorite food. This desire for delicate vegetation reduces tendencies to eat most desirable emergent and floating aquatic vegetation species. Grass carp’s selective diet is perfect because it allows floating plants such as watermeal, and emergent species as pickerelweed, lilies and duck potato, to coexist with the fish. This allows these floating and emergent species to both serve as refuge for fish and wildlife, while also helping to manage influxes of nutrients that occur over the growing season.

Plants Preferred by the Grass Carp

Hydrilla
Coontail
Muskgrass
Naiad
Slender and jointed spikerush

Plants Preferred by the Grass Carp

Water hyacinth
Water lettuce
Water lilies
Torpedo grass
Hygrophila
Cattail

Conclusion

In May of 2019 FWC added approximately 1,000 sterile grass carp to Johns Lake. 500 were released near the public boat ramp and 500 near the Deer Island Cove. There were also 1,000 stocked in April/May 2015 and 750 in Feb 2016. There is no way to accurately say how many of those carp are alive because we don’t have perfect numbers for stocking mortality (predation by largemouth bass when they are young, etc.). From what some have observed, you start to lose 10-20% per year after age 6 or so. Most do not live past age 10-12.

FWC agreed to stock the additional 1,000 carp because of the way the hydrilla expanded so quickly in September 2018. When you get the right balance of carp, you shouldn’t have to treat with as much herbicide. All lakes are different and the stocking of carp should always be in conjunction with small, sometimes frequent, herbicide treatments.

From an FWC perspective Johns Lake looks great. We have good coverage of submersed vegetation and the water clarity is good. We are seeing an upward trend in our largemouth bass population and noticing more ducks as well.

April 6, 2019February 19, 2022

Lakefront Fertilizer Guide

April 6, 2019

Lakefront Fertilizer Guide

Rick Stuebing

Many fertilizers contain nitrogen and phosphorus. Excess nitrogen and phosphorus are known to cause excessive hydrilla growth, algae blooms, fish kills, and other water quality problems. Anyone applying fertilizer in Orange County should understand how to prevent pollution from the nutrients they spread on their landscape.

Orange County has regulated fertilizer application since 2009 to help protect our lakes, rivers, springs and groundwater. This ordinance was updated in 2017. Lake County has a similar ordinance.

Stores that sell fertilizer must display information about our ordinance
Never use fertilizer containing phosphorus (unless a soil test proves it is needed)
Never use fertilizer containing nitrogen in summer months (trained people are exempt)
If you choose to apply fertilizer with nitrogen, make sure 50% is slow-release nitrogen type
Keep fertilizer more than 15 feet away from wetlands and water bodies
Use a broadcast fertilizer spreader that has a deflector shield up fertilizer that spills or could end up on sidewalks, driveways, or streets
Keep your grass clippings and yard debris out of roads, gutters, and storm drains
Ensure your landscape contractor complies with the fertilizer ordinance, too!

You can buy fertilizer that contains zero nitrogen or phosphorus. Look for products that contain minerals such as iron and magnesium, or are labeled as containing, “micronutrients”. When shopping for fertilizer, please use the following helpful information that is found on the fertilizer bag:

Where to use the fertilizer (turf, trees, plants?)
Percentage of Nitrogen, Phosphorus, and Potassium
How much of the nitrogen is “slow-release” type
How much to apply
How much area your bag of fertilizer will cover
Which number to choose on your spreader dial

Soil Tests in Orange County

In Orange County, you must always get a soil test before applying fertilizer that contains phosphorus – all year long, not just during the rainy season. Contact the Orange County Agricultural Extension Service (also known as IFAS) for information about having your soil tested: 407-254-9200.

More Information

Conclusion

Together we can all help to keep Johns Lake clean and beautiful. Improper fertilizer application, over fertilizing, and fertilizing within fifteen feet of the lake shore or berm will cause long term problems.

Improper use of fertilizer is what caused Lake Apopka to become so polluted. So let’s not let this happen to Johns Lake!

April 1, 2019February 19, 2022

Lakefront Berms and Swales

April 1, 2019

Lakefront Berms and Swales

Rick Stuebing

Background

As more and more development occurs around Johns Lake, it is imperative that residents understand that we can have a significant effect on water quality. If we want to minimize hydrilla infestation, other invasive plants, algae blooms and pollution, we need to adhere to a few simple guidelines that will help immensely. This includes the proper use of berms and swales.

Purpose

“A berm and swale is a low hill and associated depression incorporated into the landscape, typically parallel to the shoreline. This area slows and captures runoff and allows water and pollutants to percolate into the ground. This prevents pollutants and excess nutrients from entering the lake from your yard.”

Shown below is a fairly typical depiction of a berm and swale configuration:

Here are some of the main benefits of the “berm and swale” system:

Provide a drainage path for rain and storm water runoff
Act as a filter between the water and chemicals that have detrimental effects on the lake (e.g. fertilizer, pesticides, etc.)
Provide a buffer between the lake and residential/commercial sites that have septic tanks or other potential pollutants, even drainage from swimming pools.

In order to preserve the water quality of Johns Lake we need to be responsible. Homeowners should feel a responsibility to the environment to do their part to keep the lake as pristine as possible. There are really only a few precautions and actions needed to accomplish this:

Do’s

Reduce Chemicals. Minimize herbicide, pesticide and fertilizer use. Never apply these chemicals before heavy rains. Spread mulch to prevent weeds and erosion. Identify pests before spraying and use the least-toxic pesticide available. Follow label directions for all pesticide, herbicides, and fertilizers.

Manage Yard Waste. Never blow lawn clippings into streets, lakes, or storm drains. Use leaves and pine needles as mulch. Compost yard waste and kitchen scraps. Pick up trash, litter and pet waste.

Conserve Water. Plant native or Florida-friendly plants. Turn off irrigation systems during the rainy season (June 1 – Sept. 30) or make sure your rain gauge is working properly. Install a moisture sensor on old irrigation systems, or make sure your sensors are working correctly. Direct sprinkler heads toward the landscape, away from pavement. Inspect sprinkler heads often and repair when needed.

Obtain Permits. If you plan to change anything on your lakefront like removing or planting vegetation or changing some aspect of the berm or swale, permitting will ensure it’s done properly and within guidelines. It only requires filling out a form and paying a small fee and it is the proper way to conserve our water quality.

Don’ts

Modify a Berm or Swale. Lakefront home owners should never fill in a swale and remove or relocate a berm. These features are not designed for individual properties, in nearly all cases, berms and swales are tied into adjacent properties, sometimes through whole subdivisions and for miles in some instances. Any changes made to them can negatively affect other berms and pollute the lake. Also, modifying the berm can start the process of erosion which will eventually make the berm ineffective.

Dump Chemicals in Berm or Swale. Do not dump anything hazardous into the vicinity of the berm system since this defeats its purpose. Automotive fluids, petroleum products and even drainage from a swimming pool are harmful. You should drain swimming pools slowly, on your land, and not into the berm and swale system or anywhere near the lake.

Plant Any Unapproved Vegetation in Berm or Swale. The lakeside of the berm is very important and presents the “filtered” side of runoff and drainage to the lake. Planting anything on that side of the berm that requires fertilizer or pesticide should be avoided and completely defeats the purpose of the berm and swale feature.

Never Place Anything in the Swale Do not put yard waste trash, clippings or leaves in the swale. This impedes storm water runoff and increases the amount of pollutants that would flow into the lake.

Additional Information

The berm and swale system are actually living ecosystems. As water is directed into the feature, micro-organisms thrive and support vegetation which make the berm largely self-maintaining and create a water reservoir in the system.

It may be alarming to see standing water in the swale at times (particularly after heavy rains), but this is how it is designed. The swale collects water and temporarily holds it so that any pollutants, sediments, etc. will take longer to be processed by the vegetation and soil. Water may pond in the swale for 24 to 36 hours. This is perfectly normal gives the swale more time to percolate and cleanse the runoff.

Conclusion

The picture below is a good illustration of good practices in maintaining the quality and function of a berm and swale system. No fertilizers or pesticides should be used on the lake side of the berm and eco-friendly vegetation should be maintained along the shoreline.

Older subdivisions around Johns Lake have street-side storm water drains and retention ponds that drain directly into Johns Lake. The same precautions should be used for these features as well.

Subdivisions developed after 1985 have storm water permits with SJWMD which establish an obligation to maintain the berms and swales and ensure their proper function. So, HOAs (Homeowner’s Associations) and homeowners have a duty beyond just “good practices” to keep these important features intact and unspoiled…

Sadly, some lakefront property owners are unaware of, or just disregard, the environmental standards that are the reasons behind the berms and swales. There have been instances where residents have tried to backfill the swales and/or remove the berms, or, relocate them.

If homeowner’s have any questions about regulations concerning permitting or maintaining their lakefront berms and swales they can contact

SJWMD (Saint John’s Water Management District) Customer Service during business hours at:

386-329-4570

Together, we can maintain the high quality of life we now enjoy!