Iowa DNR Urges “Smart Salt” Approach to Fight Ice and Protect Water Quality

As winter weather brings heavy snow and plunging temperatures across Iowa, the Iowa Department of Natural Resources is reminding homeowners that a safer sidewalk doesn’t have to come at the expense of local waterways.

Salt is a common go-to for icy steps and driveways, but the DNR warns that using too much can damage pavement and landscaping — and it can also pollute nearby streams and groundwater. According to the agency, just one teaspoon of salt can contaminate five gallons of water to toxic levels. And when temperatures rise, that salt doesn’t vanish; it washes into soil and storm drains, eventually making its way into creeks and rivers.

To reduce waste and limit environmental impact, the DNR is encouraging Iowans to follow a “less is more” mindset with four practical steps.

Start with the shovel. The agency says the best de-icer is still manual removal. Shoveling or snow blowing soon after snowfall can prevent snow from compacting into ice. If pavement is clear and dry, no salt is needed.

Use a light scatter, not a solid layer. Salt works by breaking the bond between ice and pavement, not by melting everything instantly. The DNR recommends spreading grains so there’s visible space between them — just enough to loosen the ice so it can be removed more easily.

Know when salt stops working. Standard rock salt (sodium chloride) becomes far less effective below 15°F. In extreme cold, the DNR says salt may sit on top of the ice without helping. In those cases, sand can provide traction, or homeowners can choose a de-icer rated for lower temperatures. Mixing a small amount of salt into sand can also help sand settle into the ice instead of blowing away.

Sweep up after the storm. Once surfaces are dry, the DNR recommends taking a moment to sweep up leftover salt crystals. Any salt left behind can be carried into storm drains during the next rain — but sweeping it up allows homeowners to reuse it for the next freeze.

The DNR says small changes in how Iowans use salt can improve winter safety while also protecting property, saving money, and improving water quality statewide.