The millions of Americans who have driveways may not realize the environmental hazards those driveways can produce. Don’t be surprised if your community or homeowners’ association introduces rules in the future regarding driveway runoff.

Most property is in a watershed and drains to a nearby waterway, even when that property is not located close to a lake or river. Analyses in heavily populated counties indicate that 17 percent of a typical suburban watershed is made up of driveways, according to the Conservation Foundation.

So what’s the problem with our driveways? They direct rainwater runoff into stormwater systems, where it is then directed, usually untreated, to our waterways.

Auto and household hazardous waste tends to accumulate on driveways, and some environmental experts think they are a more dangerous source of pollution than roofs or lawns. In the summer, the elevated heat of asphalt driveways creates a higher temperature of runoff that could potentially harm certain fish species. The coal tar used to seal asphalt driveways on a regular basis produces dangerous levels of hydrocarbons that have been linked to mutations in fish.

So what could potential ordinances or covenants look like regarding our driveways? Shorter front yard setbacks would create shorter driveways. Limits could be placed on the length and width of driveways. The crown and pitch of a driveway could be sloped to direct runoff to porous areas and not to the street.

The future may see more “ribbon” driveways, which basically are two paved strips for a safe driving surface, with the rest of the area being short grass or a native grass. Another option could be the use of more permeable pavers as a driveway surface.

Experts also suggest that you sweep your driveway clean, rather than hose it and create even more runoff into the local waterways.

Rain barrels and the creation of rain gardens on your property are becoming popular alternatives to having gutter spouts pouring onto a driveway surface.

Here’s something to consider about your driveway: If you had a 1,250-square-foot driveway, it is estimated that in a climate that generally produces 34 inches of rain per year, your driveway would potentially contribute up to 26,500 gallons of runoff per year.