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Green Roof at Denver Botanic Gardens

Denver Botanic Gardens – Mordecai Children’s Garden Green Roof

This site was added to our list of BMP test sites in April 2011. Almost 0.5 acres of this 3-acre garden sits on top of a parking structure. MHFD, working with Denver Botanic Gardens, constructed a sampling manhole designed to collect runoff from the green roof underdrain. Grade is built up on the north side of the structure and meets the portion of the garden that is a green roof. This is a very active area with wide trails, a faux mountain structure and lots of garden space with varying depths of green roof media.

Along with the sampling manhole (see photo), we also installed a rain gauge and anemometer on the west wall of the garden. When both flow is detected at the underdrain outlet and rain is detected at the rain gauge, an automated sampler starts collecting water from the underdrain and measuring flow. The anemometer allows us to correct rain gauge data to account for losses in measurement associated with wind speed.

MHFD plans to collect data for a minimum of four years and will report on volume reduction and stormwater quality runoff.

Denver Botanic Gardens provides data on their first green roof, built in November 2007. 
A dry landscape with scattered plants, a driftwood piece, and a pergola-style structure in the background.
Mordecai Children’s Garden Green Roof shortly following construction.
A child by a "Market" signpost on a garden path, with plants around and a shadow in the foreground.
Stormsewer Sampling Manhole.
Urban rooftop with weather station instruments, railing, buildings in the background, and blue sky with clouds.
Rain gauge and anamometer.
A dry landscape with scattered plants, a driftwood piece, and a pergola-style structure in the background.
A child by a "Market" signpost on a garden path, with plants around and a shadow in the foreground.
Urban rooftop with weather station instruments, railing, buildings in the background, and blue sky with clouds.