April showers bring May flowers, right? Well unfortunately showers don’t always seem limited to just one warm month; they seem to appear all throughout the summer. One of the major things you want to avoid is the water gathering on your roof and risk damaging your building. Facility managers it is important to assess your property’s risk of storm water flooding. The assessment should evaluate not only probable volume but velocity, as the force of storm water can cause its own damage. They should also investigate any storm water utility fees that may apply to their facility. Typically they are calculated on the impervious area of a property, including roofs, parking lots, roads and driveways. Retrofitting these areas as part of a storm water strategy minimizes the fees.

Look to your roof, the place that is collecting a majority of the water as a solution. A modular vegetated roof is a great option. Some advantages to this system are:

  • Modular systems consist of interlocking trays with pre-grown vegetation
  • They are mobile so they are able to be carried to the roof for easy installation
  • They can be removed if roof repairs are needed
  • Comparatively light weight


It is also a good idea to get tray systems with water reservoirs because these have capacity beyond that of the soil itself. The trays hold an inch or so of addition which reduces water running off and promoting deeply rooted plants because the roots grow down to access the reservoir water. For rain storms that are high frequency but low volume, the tray system’s soil and water reservoirs can often hold or absorb all of the water without runoff.


Another great option to look into is high-capacity swales. Vegetated swales are typically larger, deeper and more linear than rain gardens. They are designed to handle specific volumes of runoff from large impervious areas while providing variable filtering and infiltrate capabilities. Some advantages to this system are:

  • They intercept the first runoff until the soil is saturated, at which point swales acts as a channel that directs further runoff to other areas.
  • Can handle large amounts of storm water run off
  • If the space is there, they can be expanded to catch even more water if they feel the first installment was not enough depth.


Either option is a great way to help with excess storm water and can protect your building from damage that could cost you problems financially.