Street flooding from outdated stormwater systems meant new culverts and piping were needed in Pittsburg, Kansas. But it was soon discovered that the sewers were home to the endangered gray bat, requiring permitting and a new approach to completing the project.
The city of Pittsburg, Kan., has long suffered street flooding from its outdated and undersized stormwater system. When city officials solicited the help of Burns & McDonnell for infrastructure improvements, the solution seemed relatively simple: upgrade the existing 30-inch system to an 8-foot by 4-foot reinforced concrete box culvert tapering to a 48-inch reinforced concrete pipe.
But soon after the design for the project was under way, Rick Besancon, Burns & McDonnell project manager, received some surprising news from Melissa Goerlitz, Burns & McDonnell permitting specialist. Pittsburg’s storm sewers are a critical habitat for the endangered gray bat (Myotis grisescens). That meant Burns & McDonnell would have to follow strict federal regulations and obtain approval from the Kansas Department of Wildlife and Parks and the U.S. Fish and Wildlife Service.
While Burns & McDonnell determined the sewer in question was not part of the system that the bats had previously inhabited, it was still necessary to adhere to construction restrictions, including limiting or ceasing construction during certain times of the year to avoid human disturbance to the bats — one of the main causes of their endangered status.
Although creating a new potential habitat was never required, providing the additional opportunity for the bats was the right thing to do. So Burns & McDonnell proposed a solution to make the sewer bat-friendly.
“It was more goodwill,” Besancon says. “The city had the opportunity to do something good for an endangered species, and it didn’t really add that much cost to the project.”
While securing the funding — estimated at roughly $50,000 additional cost for the entire $1.7 million project — from the city was relatively easy, creating the proper conditions for the bats to potentially inhabit took some creative thinking. Personnel with Scurlock Industries, the precast concrete company for the culverts, discovered the most cost-effective method was to drag a garden rake across the top of the box, creating inconsistent ridges from which the bats could hang.
Cost-effective, of course, doesn’t always equal easy. The ridges had to be gouged into the formed concrete because no mold could create the required rough surface. That meant someone had to manually scrape the garden rake across each culvert top. “It was just one guy out there dragging this rake across the concrete. It just wore him out — I felt sorry for him,” Besancon says.
The results were perfectly imperfect. The bats have a new place to potentially inhabit, and the city of Pittsburg gets credit for taking an environmentally friendly step. While it could be months before it’s known if the bats will live in the new sewers, the innovative solution has already won an award from the Kansas Ready Mixed Concrete Association.
“This is our first project on Pittsburg’s stormwater utilities — we have 11 more to go,” Besancon says. “This effort will simplify the permitting process for the remaining projects because it goes a long way toward showing the state and federal governments that the city is trying to help the bats.”
For more information, contact Rick Besancon, 816-822-3950.