Page 5 - CEC_Elements_Winter_2016
P. 5
elements WINTER 2016


Taming Stormwater
at the Nashville Zoo

These stately saddle-billed storks live in a habitat supplied by the natural stream that feeds from the stormwater retention basin at the Nashville Zoo.

With the focus shifted from The goal was to enhance the water quality of partners presented on the design,
simply displaying animals the small headwater stream by retrofitting engineering, construction and results
to educating the public an existing stormwater detention basin at of the retrofit.
about protecting them the Zoo. Both basin inlets were modified to Though the innovative project is nearing
capture debris. CEC also implemented water the final stages, there already has been
(and the environments in which they quality control berms to spread, slow and marked improvement in the health of
live), today’s zoos must emulate the filter outlet flow and maintain usability of the water and habitats. “It is absolutely
characteristics of native habitats: the land between the basin and stream. This amazing how quickly a stream can
environments that most likely do not six-acre brushy area underwent extensive recuperate thanks to a good erosion
occur naturally within hundreds or even removal of invasive, exotic plants followed control and infiltration project,” said Dale
thousands of miles. Yet, many major zoos by seeding and planting of native vegetation. McGinnity, the Nashville Zoo’s ectotherm
are planted smack-dab in the middle of The transformation restored the area to curator. “This stream segment had always
an urban or metropolitan area. This historic regional conditions as a native been composed of a strictly brown silt
has created a unique set of challenges, grass prairie, creating a habitat for a future substrate. Now there are rocks and gravel
particularly for managing stormwater, native elk and bison exhibit—and numerous evident, and it has the appearance of
at zoos across the nation. educational opportunities for visitors. a healthy streambed that can support
macroinvertebrates and biodiversity. I really
When stormwater runoff from a business Through the grant, the project also created did not expect the character of the stream
park was negatively impacting property a unique opportunity for the Zoo and to change so dramatically, so quickly.” n
at the Nashville Zoo, including a small Cumberland River Compact to educate a
headwater stream that flows through its different audience, specifically design-build CEC Principal Steve Casey, design engineer for the
grounds, Zoo officials joined forces with and stormwater professionals, on the use project, explains the stormwater best management
local experts to correct the issue. Working of stormwater best management practices practices implemented at the Nashville Zoo during a
with the Cumberland River Compact, a to meet their own development goals and professional training workshop.
regional nonprofit whose primary focus is improve water quality, as well as to promote
improving and maintaining the quality of collaborative approaches to stormwater
water in the Cumberland River Basin, the Zoo retrofit projects.
secured partial funding for the project via a
Clean Water Act 319 grant administered by CEC provided in-kind support to help
the Tennessee Department of Agriculture. develop a one-day professional training
CEC’s Nashville office was engaged as a workshop and behind-the-scenes field
key partner on the project team, having event at the Zoo, including creation of
previously helped the Zoo obtain an the syllabus, presentation materials
individual National Pollutant Discharge and literature. “The Magic of Stormwater
Elimination System (NPDES) permit—the Retrofits” event was held in November
only zoo in Tennessee to have one. 2015, during which all of the project
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