Daylighting Stormwater 

by Christopher Cardany

Although I only majored in architecture for my first year in college, one early lesson quoted from Louis Sullivan always stood out for me: “Form ever follows function.” Now as a civil engineer, much of the form and function of my work is out of sight below ground, but this design principle is visible in many aspects of site planning, particularly in managing stormwater.

We are all seeing an increase in higher intensity rainfall in our communities and elsewhere described in the news. As a result, stormwater management is shifting from the “collect and bury the runoff” approach to visible and natural approaches that are more efficient in conveying and storing water while treating it through filtering, infiltrating, and recharging groundwater. Rain gardens and bioswales provide an important drainage function and offer an aesthetic landscape form designed by the amount of water they receive, topography of the land, and underlying soil conditions.

Although there is a resurgence of the open stormwater concept, it is not a new one. Look to the Back Bay Fens in Boston originally designed in the 1800s. Frederick Law Olmsted’s park within the Emerald Necklace was a stormwater solution to alleviate flooding and control the tides, but it was also a mix of gardens and recreational trails that connected the public to water within this section of the city. And it still does.

Today, we have good examples of open stormwater in Connecticut cities:

  • Stamford’s Mill River restoration has significantly reduced flooding while creating recreational opportunities and ecological enhancements in this urban watershed.

Mill River Park, Stamford, Conn.

  • The new 14-acre Meriden Green daylights and restores Harbor Brook, which had been buried under a retail shopping mall in the 1960s. The project’s primary purpose was to alleviate flooding by providing nearly 60-acre-feet of flood storage, but a new town green and community space were created in the process. Now a flowing brook, walking paths, and an amphitheater are all within the new area providing flood storage in the heart of downtown Meriden.
  • As part of the historic Swift Factory’s renovation in Hartford, rather than just piping stormwater from one side of the site to the other, improvements will include a new bioswale that will receive surface and roof water into an open landscaped runnel along the front of the building and the public sidewalk. Through grading and a series of weirs, water will be collected, stored, and conveyed visibly throughout the site, including the use of bridge plates where walkways into the building cross the swale.
  • In New Haven, planning for future development is underway in the Long Wharf section of the city. A linear greenway is proposed to connect each of the development districts that will provide flood storage and recreation areas for walking and biking.

These are just a few examples where stormwater is being collected and conveyed in the open but also provides a public amenity. The flood improvements and parks are leading to economic development in these communities, as well. Perhaps Sullivan and Olmsted were onto something over one hundred years ago . . .

Christopher Cardany

 

Christopher Cardany is a principal/vice president working in Langan Engineering and Environmental Services’ New Haven, Conn. office.