10 Apr

Assessing Stormwater Damage

By Chelsea Ruiz

A powerful storm front recently swept across the eastern U.S., delivering heavy rains throughout the Midwest and East Coast. Events like this serve as critical reminders of the growing intensity and frequency of stormwater challenges. For landscape professionals and property managers, it's a key moment to assess how systems are performing under pressure—and where improvements may be needed to adapt to a changing climate.

Quick Tip - Assessing Stormwater Damage
 
This past strong storm front swept the east side of the country, bringing deluges of precipitation throughout the Midwest and East Coast.
 
After weather events like this, it’s important to get out there and visually assess your properties. As stronger storm events become more common, flooding that once happened every ten years is starting to become an annual event. While the initial evaluations of the property accounted for floodplains and low-lying areas, seeing the after-the-storm pressures in action may make you recalculate how you want to design landscapes now and for the future.
 
For North Creek, the strong storms enable us to see how our recently re-graded rain gardens and storm swales in our trial gardens are handling the influx of water and if we’re seeing any washout. Plants that were originally planned to be on margin edges are now in standing water with high levels of sediment building through the sites. This is where the rubber meets the road - all the planning and site evaluation put into practice.
 
As the season progresses, routine site visits reveal occasional plant failure as higher levels of sediment, duration of standing water, velocity of running surface water, and soil disturbance reveals which systems and plants are withstanding the trial. For some areas, these water levels are unprecedented, especially as more urban and suburban areas are paved, and runoff is funneled into taxed stormwater systems. The funneling creates powerful currents during rain events, straining stormwater systems to their breaking point.

In our experience, an often overlooked element in rain garden and stormwater system design is the inclusion of a robust percentage of evergreen, soil stabilizers such as members of the Carex, Scirpus, or Juncus genera. In nature, you often spot these plants colonizing roadside ditches, marshlands, wet meadows, river edges, swamps, and along creeks. Their evergreen presence provides biomass all year long to slow water flow, filter sediment, and furnish wildlife habitat cover.
 
Frequently, the desire to make a seasonally dynamic display means flowering, deciduous perennials are preferentially planted in higher numbers in a design. While this is lovely in summer, it can mean stormwater areas are bare and prone to erosion in winter and early spring. We recommend a mix of evergreen, strong-rooted perennial sedges and rushes to provide ground cover throughout the year. Add in swathes of seasonal color and verdant, contrasting texture to provide complex and tough plantings with diversity that can meet the moment, no matter the season. As you assess your landscapes after rain events, it’s a great time to see what areas are working and what areas might need help. Noting the strengths and troubleshooting the weaknesses of a system is all a part of maintenance, ensuring the longevity and performance for many seasons, and the storms they bring, to come.

Here are some of North Creek’s recommendations for plants that stabilize soil and can handle standing water in stormwater systems:
 
Evergreen Presence

 
Seasonal Flowers

 
Verdant Filler

Click Here for the Email