Storm water runoff is the main contributor to non-point source pollution entering the Bayou Vermilion. During a heavy rain, pollutants such as harmful chemicals, fertilizers, oil and sediments are flushed from streets, parking lots and yards into storm drains, ditches and coulees that empty into the Vermilion River.
Pervious pavement allows water to seep into the underlying soils to recharge ground water supplies instead of rushing over impervious surfaces, picking up pollutants on its way to the bayou. When large amounts of storm water are diverted directly into the bayou instead of being allowed to absorb into the ground, increased flooring, decreased water quality and erosion occur.
PERVIOUS PAVEMENT WILL:
Recharge ground water
Reduce pollutants in the bayou
Help to prevent flooding
Conserve space that would have been used for detention pond
TYPES OF PERVIOUS PAVEMENT
Advantages: The process for laying pervious concrete is similar to laying regular concrete. Considerably less expensive. Shrinks less than conventional concrete.
Disadvantages: Require some degree of maintenance compared to other types of pervious pavement to be cleaned periodically to prevent the system from clogging.
INTERLOCKING BLOCK PAVERS
Advantages: Can be laid in beautiful designs and patterns.
Disadvantages: More expensive than other forms of pervious pavement.
PLASTIC GRID SYSTEMS
Advantages: Very durable
Disadvantages: May not be applicable in all areas
SIMPLE PLANNING TO PREVENT COMMON PROBLEMS
1. Choose the type of pervious pavement which fits your uses and needs. Some types of pervious pavement are used for their strength, while others are favored for their looks.
2. Pervious pavement is not meant to handle runoff from other areas. If possible, plant a buffer zone upslope of the pavement to help prevent the system from becoming clogged with sediment.
3. Underlying soils should be permeable enough to provide adequate drainage. If the soil in your area has high clay content, consider replacing it with aggregate reservoir.
4. Regular maintenance of your pervious pavement surface will ensure that it will continue to function as intended for many years. Vacuum-sweeping pervious concrete removes sediment which may become trapped in the pores and clog the system. A properly maintained system will last for decades.
5. Surrounding the pervious pavement area with an infiltration trench which connects to the stone reservoir below will allow the water to enter the reservoir in case the system becomes clogged.
6. Using pervious pavement on the surfaces meant for automobile use will reduce glare and increase tire traction.
7. Interlocking pavers can be laid in beautiful patterns to pave sidewalks, driveways or courtyards.
8. Plastic grid system can be planted with grass or filled with gravel and are great for use in areas with heavy equipment or vehicles.
9. Interlocking pavers and plastic grid systems are extremely strong and easy to replace if needed.
10. Incorporating pervious pavement into your home or business area will reduce your reliance on the local storm-water management system and may decrease your storm-water impact fees.
Links for more information
PERVIOUS PAVEMENT IS PART OF A LARGER PICTURE
Every time it rains, the water that lands in your yard has to go somewhere. Some of it either soaks into the ground or evaporates, but during a heavy rain most of that water will become “surface runoff.” Surface runoff water will flow across your yard, into ditches and coulees eventually making its way in to the Bayou Vermilion.
Along the way, this water picks up pollutants such as oil, pesticides, loose soils, excess fertilizers and trash. This storm water runoff, and the pollutants it carries, is the biggest threat to the water quality of the Bayou Vermilion.
Through a grant with the Louisiana Department of Environmental Quality, the Bayou Vermilion District is able to demonstrate five approaches that homeowners can use to improve the quality of storm water entering the Vermilion River:
1. Wetland Plant Nursery
2. Rain Garden
3. Pervious Pavement
4. Rain Barrels
5. Detention & Bio-Retention Ponds