Accomplishing the goal of maintaining a stormwater retention pond that reflects the characteristic of Lakewood Ranch is no effortless task. Before we embark on attempting to understand the challenges, we must first understand some basic concepts. It is reality that developers are offering lots on storm water systems as premium waterfront real estate. While this is generally a very good practice that promotes sophisticated designs, it may cause some problems if people are not aware that the man-made system’s purpose is to capture and accumulate pollutants. The ponds are created to resemble and function as natural water bodies. Consequently, it may appear contaminated if it is simply doing its job, or performing its designed function. This may prompt misdirected requests for action to clean it up or even protect it. The design and maintenance of these ponds are regulated by state agencies. Limitations are placed on the amount of chemical that can be used in treating algae. Areas of shallow planted zones are permitted and regulated annually by Southwest Florida Water Management District (SWFWMD). As a rule of thumb, for every surface area of a storm water retention pond, 30% must be planted and maintained to SWFWMD standards. These areas are known as littoral zones and act as a filter before our storm water reaches the Braden River and eventually the bay. Conceptual ponds can be considered sponges that retain water during storm events and filter pollutants before they reach the waterway. It should also be noted that man-made systems that connect to waters of the state may be regulated as waters of the state.
Why is there so much algae in my stormwater retention pond?
Nitrogen and phosphorous are the principal nutrients of concern in urban storm water. In excess, they increase primary biological productivity and may cause unwanted and uncontrolled growth of algae and undesirable aquatic weeds. It is no surprise that the very same basic elements that make our plants green also promote surface algal scum, water discoloration, and the release of toxins from sediment. The major sources of nutrients in storm water are urban landscape runoff fertilizers, detergents, and plant debris. We must make the connection between our lawns and our ponds.
Acknowledging the fact that storm water ponds are considered premium lots, what can be done to increase the aesthetics of my pond?
The limited and regulated use of chemical to eradicate the unattractive algae is a pond maintenance practice currently employed by Lakewood Ranch. It’s only effective to the extent that the amount of allowable chemical is greater than the amount of nutrients present. This is not always possible with the amount of nutrients entering our ponds, especially during summer rain events. Large amounts of nitrogen and phosphorous travel from our landscapes and into our ponds during such rain events.
We must take care not to use too much chemical in our ponds, thus killing beneficial oxygen producing aquatic vegetation. Removal of dissolved pollutants is generally optimized through biological processes. Ponds are generally much easier and less expensive to maintain if oxygen levels are high. This is promoted by diverse aquatic plant life. Proper levels of dissolved oxygen are critical to maintaining water quality and aquatic life.
The Lakewood Ranch Community Development Districts have placed into their landscape maintenance contracts a provision that mandates our pond bank areas receive zero fertilizers. In addition to this, the Districts also utilize a biological method of plant control through the use of the triploid carp (sterile carp).
The key to maintaining our ponds in an attractive, sustainable manor is to reduce the amount of nutrients entering the water. The only way to accomplish this is to work together as a community and change our landscape practices.