Stormwater retention areas, necessary in Florida to control flooding and to filter pollution from rainwater runoff, can be simple grassy pits or fully landscaped ponds. Either must be safely enclosed to prevent accidental drowning.
The common pit surrounded by chain link fencing suffers from several problems. Because it is empty during the dry season it can be traversed and provide a place to hide at night in its low spots. People may circumvent the fence to ride bicycles and motorbikes up and down its slopes.
Maintaining it can be hazardous to groundskeepers mowing its steep slopes. Often located near the edge of the school grounds, they attract illegal dumping and their depressions collect trash
Retention pits are also not as effective in filtering pollution as ponds. Finally their unattractive appearance creates a hostile barrier between the school and the nearby community.
The retention pond, while requiring more room, has many advantages. Designed to hold water even during the dry season, they can be used to form a physical barrier or moat to prevent trespassing to certain parts of the school. They can help segregate play and pedestrian areas from areas of heavy vehicular traffic.
The water in a retention pond allows it to support indigenous water plants that are effective in filtering heavy metal pollution washed from school parking areas by rainwater. Plants absorb excess nitrogen from fertilizer runoff. Shade trees planted along the banks of the pond help regulate a cool water temperature allowing the native flora and fauna to flourish. In this way it is possible to have a natural self regulating system that lowers maintenance costs.
An attractive landscaped retention pond can become an asset that serves to link the school and the local community. An alternative to utilitarian fencing can include landscaped low walls and wrought iron fencing. This facilitates the need for a protective barrier while permitting clear views to the pond.