As of Tuesday, May 8, 2018
Poor drainage can cause problems including standing water, mud, dead grass, and even structural damage or water intrusion. These issues can affect the aesthetics and property values of our homes. As we work on our yards this spring, we should plan on how to best convey and treat our runoff during the next rainy season.
Proper drainage can be accomplished with surface or subsurface drainage systems. Capturing the drainage also provides an opportunity to treat the rainwater for pollutants such as nutrients, chemicals, and sediments before it makes its way to our streams and rivers.
Surface Drainage options to consider include:
• Grading – Slope is the most important issue to consider for proper surface drainage. The ground should be sloped to convey runoff away from any structure’s foundation. A grading plan can help you visualize and model the runoff.
• Creek Bed – Ditches can be rockscaped to look like creek beds that will direct water and capture sediment.
• Vegetated Swales – A vegetated swale will also carry water to an area where it can be released safely, such as a rain garden with good drainage or a buried dry well. The vegetation will help reduce peak flows, promote runoff infiltration, and remove pollutants. The addition of a perforated pipe laid in gravel underneath can help accommodate heavy water flow.
• Rain Garden – A rain garden is a garden of native shrubs and flowers planted in a small depression, that temporarily holds and soaks in rain water. Rain gardens are effective in removing nutrients, chemicals, and sediments from the rainwater runoff.
• Downspouts – Downspouts are the first line of defense in controlling roof runoff. However, one of the most common drainage problems we encounter with downspouts is the failure to carry water far enough away from the house. Water can be lead far from the house by extending the downspouts to a series of buried drainpipes.
Subsurface drainage options to consider include:
• French Drain – A French drain is the most popular subsurface drainage system. The basic assembly is a perforated pipe surrounded by gravel and wrapped in filter fabric to keep mud and particles out. A French drain can be directed to “daylight”, so that the end of the pipe is above ground, or the drain can send water to a drywell.
• Catch Basin – A catch basin, or inlet, can be used in conjunction with a drain pipe system to collect water from downspouts, planter areas, or low spots in landscaped sections.
• Channel Drain – A channel drain functions like a catch basin while providing more overall open surface area to handle larger volumes of runoff. Ideal applications for channel drains include areas hardscaped with concrete or pavers.
• Dry well – A drywell is an underground perforated storage well that collects, retains, and infiltrates stormwater on-site. Because drywells can become clogged, sediment control practices should be used to protect them.
Our engineering services can help you get the look you’re going for while minimizing costs by utilizing our expertise in building materials.
If you would like to learn more about Hood River Engineers and what we do, visit our website at www.hoodriverengineers.com. If you have any questions for me or one of our engineers, email us at GorgeExpert@hoodrivernews.com We are glad to offer an opinion or quote at no cost.