LINCOLN – A year-long study of the Salt Creek Floodplain shows it is currently well managed and recommends non-structural solutions to mitigate the effects of climate change. Lincoln Transportation and Utilities (LTU) and the Lower Platte South Natural Resources District (LPSNRD) released the Salt Creek Floodplain Resiliency Study last week. The two agencies partner on management of Salt Creek, a major stream that runs through the west part of Lincoln and collects the majority of water run-off around the city.
The Salt Creek Floodplain Resiliency Study evaluated the best practices for flood damage reduction from across the country and analyzed how Lincoln’s floodplain management program can benefit from these practices. To address future resiliency, the study also examined how a changing climate may impact flood levels in Salt Creek in the future.
Study results showed floodplain management and resiliency in Lincoln are being actively addressed to protect lives and property through ongoing City and LPSNRD partnerships. The study’s future projections related to climate indicate by the year 2100, Lincoln’s landscape and climate may include more severe droughts, more severe rainstorms and floods, and ultimately may result in flood levels two feet higher than current levels. The study recommends the consideration of additional non-structural solutions to mitigate the changes in climate throughout the next eight decades.
“Since their construction in the 1960s, the Salt Creek levees have prevented about $103 million in property damage,” said Donna Garden, LTU assistant director. “These structures have been well worth the investment. Now we have important information to adapt and assist with flood damage reduction for the next 80 years.” Garden said the study results would also be incorporated into the Lincoln Climate Action Plan currently being developed.
LTU and LPSNRD will review the study recommendations and examine how proactive policy changes can reduce the risks associated with flood events for Lincoln residents. LPSNRD Manager Paul Zillig said this includes incorporating updated data into new floodplain maps, develop higher floodplain standards and develop additional strategies to keep the Salt Creek floodplain resilient.
“As with any city, Lincoln’s landscape is forever changing,” Zillig said. “The study indicates that the existing flood levels are an average of 0.8 feet higher than shown on the current regulatory floodplain maps. This means we need to make calculated adjustments to our guidelines moving forward.”
LTU Watershed Management Supervisor Ben Higgins said Salt Creek has experienced 100 flood events since 1900 with 17 classified as major floods and 30 classified as moderate floods. He said the study showed that the levee system can handle most flood events but cannot handle major floods.
“Study recommendations to consider are revising the standards for retention projects, requiring structures and developments in the floodplain to be elevated to a higher standard, and providing wider and longer flood corridors to continue to protect future generations,” Higgins said.
The Salt Creek Floodplain Resiliency Study was conducted by Olsson, a local engineering and design firm, and Michael Baker International, a firm specializing in floodplain management and policy.
The study cost $254,000 and was funded by the City, LPSNRD and other partners, including Bison Industries, UNL, Lincoln Industries, Lincoln Airport, and Lincoln Electric System. The City’s share of the cost came from stormwater bond funds set aside for studies.