Assessing drainage around buildings

Listen to this radio show (MP3 download) or read below.

Radio interview source: Chuck Schwab, ag and biosystems engineer, Iowa State University Extension

The downspouts off our house were a pain because they had to be long enough to take the water far away from the basement. But every time we mowed the lawn we had to remove the downspouts, then put them back. Last year, we dug a trench across the lawn and put in an underground pipe to drain the water off the roof into the ditch. We rigged the same system for our shop. We also have a French drain in the basement that pumps water from underneath the house into the ditch. You'd think we live in a swamp! But, it's just the way the buildings sit on the property.

Chuck Schwab, an ag and biosystems engineer with Iowa State University Extension, says no matter where your house sits, the length and position of downspouts makes a huge difference. Other factors come in to play as well.

"Consider the types of soils that you have," Schwab says. "Does your soil drain real well after a heavy rain? Do you see any water standing or does it seep right through? Those are the key elements of the length. And again, it also depends on where that gutter comes out. If it's in a corner of the house, meaning that it shoots it out right next to another part of your wall, then you probably want to have a longer distance."

Thousands of gallons of water fall on the roof during a heavy rain. On steeply sloping, well-drained lawns with no basement water problems, a splash block may be all you need to carry it away. Or, you might need the water dumped at least 5 to 10 feet from the house.