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If you want to outsmart the rain this year, start now.

Making drainage and rain-collection improvements this summer will help ensure that water doesn’t wreak havoc in your yard or home this winter, and it’s much easier to do these projects now than during a December rainstorm.

Even if you haven’t had problems in the past, consider adding drainage to your summer to-do list. Winter precipitation is projected to increase in the Northwest as part of climate change, according to the U. S. Environmental Protection Agency. So let’s dig in.

First, decide what you want to accomplish with your drainage improvements. Goals could include eliminating basement flooding, even after major storms; handling all rainwater running off the roof or paved areas on your own property; and collecting as much rainwater as possible for watering your yard.

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Keeping a basement dry in Western Washington poses a daunting challenge. Seattle averages 21 inches of precipitation during the November-through-February period.

Homeowners often address their basement-flooding problem within the home by installing a sump pump or putting a coating on the basement wall. You’ll have better results, however, by diverting water away from your house on the outside.

Keep gutters clean so they don’t overflow. Add splash blocks or extenders to downspouts to keep water away from the foundation.

Make sure the grade of soil slopes away from the foundation. You may need to bring in soil for this.

To help prevent water from seeping in through basement window wells, install window-well covers, available at hardware and home-improvement stores. As a less-expensive alternative, one Seattle resident reports she kept water out simply by placing a sheet of Plexiglas at an angle over her window well.

If taking those steps doesn’t solve your wet basement problem, consider more elaborate drainage improvements such as a “French drain.” Named after 19th-century Massachusetts farmer and judge Henry French, who popularized it, this usually consists of a perforated pipe surrounded by crushed rock in a trench, which directs water away from an area.

Some Seattle homes have their downspouts connected to the city’s combined sewer system, where mixed rainwater and wastewater go to a sewage-treatment plant.

Disconnecting downspouts from this system helps reduce sewer overflows and protects local streams, according to Seattle Public Utilities. However, if you disconnect, you need to be careful not to flood neighbors’ property or public sidewalks with this water. For information about disconnecting downspouts and managing stormwater at home, King County residents can contact the Garden Hotline ( at 206-633-0224.

A rain garden ( makes an excellent destination for water from downspouts. Build a rain garden by scooping out an area in your yard, adding compost, and planting native plants such as grasses and flowering perennials. Convey water to the rain garden with a French drain, or other piping or trenching.

Many creative variations exist on French drains and rain gardens. For example, a “soakaway,” common in England and parts of Canada, is a below-ground holding area containing coarse stone and lined with porous landscape fabric, where water goes before filtering into the ground. Check with local authorities before making any soakaway-type system that is deeper than it is wide.

Keep water on your own property and out of storm sewers by installing permeable walkways, patios and driveways whenever possible. Permeability means water flows down through tiny or sizable gaps in concrete or stonework, rather than running off.

If you have the space, install rain barrels ( or a cistern to capture rain from your roof, then use that liquid sunshine during dry periods to water your garden. A cistern, which is typically a large concrete storage tank, may allow you to reduce your municipal water use significantly.

OK, that’s enough reading about rain during this summer season. But if you take action soon, you’ll thank yourself next winter.

Tom Watson is project manager for King County’s Recycling and Environmental Services, and EcoConsumer is his biweekly column. He can be reached at, 206-296-4481 4481 or via

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