Some wet basements are easy to cure simply by clearing gutters and by diverting gutter water away from the foundation. But if the problem comes from other sources—water flowing toward the house on the surface, seeping in from underground, or backing up through municipal storm drains—you must take more aggressive action.

Here are eight strategies to keep water out of your basement.

1. Add gutter extensions

If downspouts are dumping water less than 5 feet away from your house, you can guide water farther out by adding plastic or metal gutter extensions.

But extensions aren’t the neatest or most effective long-term solution, especially if you’re likely to trip over them or run over them with a lawn mower. Permanent, underground drain pipe is invisible and capable of moving large quantities of gutter runoff much farther from your house.

For about $10 a foot, a landscaper or waterproofing contractor will dig a sloping trench and install pipe to carry the water safely away.