Parking lots linked to heat, flooding and pollution

QUAD CITIES, Iowa/ Ill. (KWQC) - Large parking lots are doing more than just giving people a place to park.

Experts said asphalt surfaces can contribute to heat, flooding, and polluted stormwater runoff all at once.

When rain hits asphalt, it can pick up contaminants from vehicles, pavement surfaces, and other debris before flowing into nearby waterways.

Dr. Jennifer Drake, an associate professor of civil and environmental engineering at Carleton University, said zinc from brake pads can add heavy metals into runoff.

She also said tire wear creates microplastics and can release forever chemicals into the water.

Asphalt also absorbs heat during the day and releases it back into the air, which can make cities 10 to 20 degrees hotter than surrounding areas.

That same heat can impact fish and other aquatic life when stormwater runoff flows into rivers and creeks.

“The water picks up all that heat and that thermal energy from the hot pavement and then moves that down into the river,” Drake said. “If you have a creek or a river that has fish that expect cool temperatures, sometimes you can actually make it to be toxic just because of the heat exposure that they’re having to suffer through.”

Those hard surfaces can also increase the risk of flooding because water can’t soak into the ground and will instead flow quickly into storm drains, rivers, and creeks.

Some cities are now looking at solutions, including permeable pavement, rain gardens, and more shade trees to help reduce heat and stormwater runoff.