Brad Peterson

P.E., CFM, LEED AP

Vice President

Low Impact Development - Main Street Water QualityIn July of 2012, the Arkansas Natural Resources Commission (ANRC) awarded a $900,000 federal grant to the City of Little Rock to develop a water quality demonstration project for implementation on specific blocks along Little Rock’s Main Street. In September 2012, the City selected Crafton Tull as the design consultant. Over the next several months, Crafton Tull worked closely with City Staff, ANRC, community stakeholders, and the University of Arkansas Community Design Center (UACDC), which was responsible for conceptual designs and technical guidance on the project. The project demonstrated ways Low Impact Development (LID) infrastructure benefits municipalities. Following are a few examples.

Improves Water Quality

It is safe to say all communities place water quality among their top priorities. The Little Rock Main Street project sought to improve water quality using LID techniques. Crafton Tull selected a variety of Water Quality Best Management Practices (BMP) for implementation. Among the selection were porous pavers, rain gardens, filter strips, vegetated walls, and a bioswale . BMP’s were laid out so that a “treatment train” developed as stormwater runoff flows from impervious areas. This filters heavy suspended solids before stormwater reaches BMP’s that promote infiltration and soil mass retention. Due to the demonstrative nature of the project, similar BMP’s were constructed in varying ways to include installing two types of pervious paver, constructing two styles of rain gardens, and surfacing parking areas with either pervious pavers or pervious concrete. Other notable water quality features are a disconnected roof drain on the 200 block; a pervious paver gateway with light garden in the 300 block; and bioswale boardwalk with LED lighting in the 500 Block. Installation of a Silva Cell, which is a modular support system that promotes tree health and runoff retention, represents a new technology used on the project.

Community Enrichment

As an educational component, the City of Little Rock partnered with eStem Public Charter School. An outdoor classroom space bordered by vegetated walls on the 200 block is one of the notable results of their partnership. Upon completion, eStem incorporated aspects of the Water Quality BMP designs allowing students at all grade levels to use the project as a living example of the benefits of water quality and Low Impact Development. EPA Administrator Gina McCarthy recently observed eStem students using Main Street as an outdoor laboratory. While there, she saw the benefit of using hands-on lessons to teach students about sustainable development.

Low Impact Development

Economic Impact

A catalyst for redevelopment, this portion of Main Street now serves as an example of urban Low Impact Development and environmental education to the state and region. Through the EPA’s and City of Little Rock’s combined commitment of financial resources, the return on investment is apparent. Beyond the environmental and social benefits, new private development, currently estimated at $100 million, has occurred at a large scale across the entire project area. These developments include a broad mix of restaurant, retail, office, and entertainment. Not only does the project represent an exceptional engineering and design achievement, but also provides an example of how infrastructure redevelopment can jump-start a community.