by Charlene Burgi
| Misty checks out a nature-made rain garden
Lately not a day goes by without weather warnings notifying me of blasting blizzard conditions, flash flood warnings, ice on the roads and recommendations to stay indoors. The warnings, however, are not exclusive to us here in Lassen County. While watching the Bay Area news this week, I saw highway and road closures throughout Marin, evacuation and flooding in San Anselmo, and Corte Madera Creek rising to flood stage. I even saw videos of people surfing and boogie-boarding down rain-swollen Mill Creek.
These news warnings are a reminder that we need to be extremely careful when landscaping to keep our homes safe. Standing water or flooding can be an indicator of drainage design flaws. Sometimes these flaws do not reveal themselves until we experience what is known as the 100-year-storm scenario. A mild or modest rainfall may have no ill-effects on our property, but then an unusually big storm exposes the problem. An example of this occurs when water can no longer percolate down into the soil before running off. If the runoff exceeds the drain capacity on the property, or if the grading was crowned or sloped toward the house, excess water can end up under the house—or in
the house if the home is on a slab. A good drainage design calculates for the worst historical rain conditions to draw water away from the house.
There are steps we can take to correct design flaws and help stormwater "slow down, spread out and soak in." If you live on a hillside, you can create multiple bioswales, such as bark-filled troughs, along the width of the hillside. Stormwater collects and slowly percolates into in each swale before continuing to the one below, thus eliminating the rush of unrestrained water flowing off the hillside.
|Functional dry creekbed
Trenches designed as functional dry creekbeds can divert water away from the house and into a rain garden—a simple, shallow, pond-like area where the water can safely collect. Landscape your rain garden with plants able to withstand a lot of water in winter and minimal irrigation in the summer. Many iris, Monarda
, asters and even the monarch-butterfly-attracting Asclepias
are great for sunny rain gardens. Or choose ferns, blue-eyed grasses and Mimulus
for shade. For more plant ideas, visit: raingardenalliance.org
If you live in a flood zone, be prepared to evacuate if instructed to do so. In addition, plan ahead by stocking cupboards with extra food and water in case you are told to "shelter in place," lose power or are unable to get to a store. Keep extra warm clothing and shoes in your autos and do not attempt to drive through flood waters.
Be safe and have a great weekend.