Up on the Roof: Denver EPA

Last Wednesday, the Berry Center staff - including Greg Brown (Director), Dorothy Tuthill (Associate Director), Kyle Bolenbaugh (Graduate student) and me (Office Manager) - took a road trip.

Ok, not that kind of road trip.

Remember when the folks from the Environmental Protection Agency in Denver came to visit the Berry Prairie?  We made a return visit to learn more about what their green roof is like and what they hope to accomplish through collaboration.

The EPA's Green Roof

Their green roof is on top of an 11 story building in central Denver, and the EPA crew is interested in revamping it to be more diverse and sustainable. The current green roof is a common commercially-installed green roof, with lots of trays and sedum and gravel-like soil medium.  From what we could tell, the 5 year old plantings were about 30-85% living, depending on the area and the trays.

The EPA's green roof, set near downtown Denver.

The green roof is set on three different stories.  It was planted in 2006 to be a research site, coordinated by Colorado State University, to examine green roof design and impacts on the building below.  Approximately 19,200 square feet were planted with five species of sedum in these 4'x2' trays that are about 3 inches deep. The EPA waters these plants for about 15 minutes per day, every day, and water allocations vary from level to level - with the most of the water allocated to the top level where wind shear and evaporation rates are the highest.

Located on the top three stories of the skyscraper, the green roof experiences significant wind shear, which is one of its biggest problems.  Here, Greg and Dorothy face the elements to examine the plants.

The So-What

The EPA and the Berry Center are trying to find ways of partnering to advance green roof research, and by the by, hopefully help this Denver green roof become a more biodiverse and successful space.  Along the way, we would anticipate answering questions like:

How do we select plants for this specific location and for this urban environment?  How can we help make this green roof sustainable - both in terms of biology and maintenance?  How does increasing depth of soil influence plant success and survivability?  How can we make this roof educational, in addition to functional and beautiful? 

Weather monitoring is an important component to the green roof.  Here wind speeds, humidity, pressure and temperature can be assessed on a daily basis.

We haven't formalized any working relationships yet.  But putting feelers out to these great resources is a good way to put the Berry Prairie into perspective and to good use!

Written by Brenna Wanous, Berry Center