The Springdale Municipal Airport is seen Tuesday Dec. 1, 2020. (NWA Democrat-Gazette/J.T. Wampler)
SPRINGDALE — The City Council on Tuesday is set to approve $100,000 for environmental mitigation in an effort to prevent flooding downtown.
The city plans to build a regional detention pond on the northwest side of the airport to hold and slowly release stormwater from Spring Creek and an unnamed tributary that crosses the airport’s property.
Because the banks of the creeks and some emerging wetland areas will be damaged when the pond is built, the city’s mitigation payments will help restore and protect stream banks and wetlands in other areas of the Osage Creek and Illinois River watersheds.
Ben Peters, director of the city Engineering Department, said the goal is to keep the floodplain of Spring Creek within its banks in the event of a 100-year flood.
Mayor Doug Sprouse explained Spring Creek is a creek that rises fast and drains fast, and, historically, it has flooded downtown.
The federal Urban Renewal project in the 1970s sought to prevent flooding by containing Spring Creek in box culverts as it ran through the city’s downtown, Sprouse said. This also created Shiloh Square, a gathering place for the public.
Modern efforts to revitalize the city’s downtown area started about 20 years ago, with the removal of some of the culverts to open or “daylight” part of the creek bed. Retaining walls for the creek floods helped create Turnbow Park, Sprouse said.
Today, maps from the Federal Emergency Management Agency show that in a 100-year flood the creek waters would leave the banks near Emma Avenue — the heart of the downtown area. The floodplain stretches through Luther George Park further down Emma.
And near the site where Spring Creek leaves the airport, several houses and the Razorback Greenway lie deep within the flood areas. That area south of Emma Avenue is set for redevelopment, but developers can’t get funding or commit to projects with the land in the flood zone, Sprouse said.
“There’s millions of dollars of development waiting on the new maps,” he said.
Sprouse said the city was not expecting the requirement to buy the mitigation credits.
The city’s Airport Commission in 2019 approved the pond, and the City Council quickly followed with its approval.
And the city has been waiting since for permission from the U.S. Army Corps of Engineers to build the pond.
The Corps determined the creeks are waters of the United States — generally meaning they are navigable — putting them under its jurisdiction, Peters said.
The city two years ago received a bid of $800,000 to build the pond project, but Sprouse said it likely will cost more now.
The city received a $300,000 mitigation grant from the Arkansas Department of Emergency Management to help pay for the detention pond, he said.
Then the Corps proffered the city a permit if it bought mitigation credits, Peters said.
The city will buy 2.77 watershed credits for $55,784 from Watershed Conservation Resource Center in Fayetteville.
The city will buy 3.69 stream bank credits for $55,400 from the Streamworks Mitigation Services of Little Rock.
Watershed Conservation Resource Center is a nonprofit in Fayetteville that works with landowners for watershed management through restoring ecological features such as stream banks and riparian habitat, explained Sandi Formica, executive director of the program.
She said the money Springdale pays for the credits will go to maintain projects the group has completed.
“I guess it’s OK to spend $100,000 from the grant for the mitigation,” Sprouse said. “It lessens the pain.”
The U.S. Army Corps of Engineers reviews projects to avoid or minimize environmental impact on resources such as streams and wetlands, said Erin Jimenez, a public affairs specialist for the Corps’ Little Rock office.
The Corps policy allows “no net loss” of wetlands on projects. When loss is unavoidable, the Corps can require the city to pay for restoration on other locations, she said.
The city has no opportunity to restore the stream banks and wetlands after the detention pond is completed, Peters said.
John McCurdy, director of Rogers’ C0mmunity Development Department, said his city completed a stream bank restoration and stabilization process on Osage Creek, where it runs under Interstate 49 and by Cross Church.
“That was a big section of the creek that flooded regularly,” he said.
And he was pleased to see the restoration work was not washed away by another heavy flood. McCurdy said the city plans to map and model water flow on all its waterways and is rewriting city regulations using best practices from the emergency management agency, the Illinois River Watershed Partnership and other agencies.
Morgan Keeling of the Illinois River Watershed Project said she had hoped to work with Springdale for some low-impact measures in its detention pond, but the project was designed and the city ready to move.
“I think mitigation credits might not be the entire answer for protecting the watershed, but it can be an option or useful tool,” said Leif Kindberg, executive director of the Illinois River Watershed Project. “No plan for protecting the watershed is 100% perfect.”
Council members Amelia Williams and Randall Harriman during last Tuesday’s Finance Committee meeting asked Peters if the city could develop its own mitigation bank. The city owns land protected with conservation easements.
The city could establish a mitigation bank, with requirements from the Corps. But the process takes more than a year for approval, followed by multiple years of establishment, maintenance, reporting and monitoring to release of generated credits, Jimenez said.