The lake that Spring Lake Park in Omaha, Neb., was named after silted-in during the 1930s, but recently was recreated as part of Omaha’s Combined Sewer Overflow Program. Now, fed by the park’s natural springs and storm water runoff, the lake can store up to 12-acre-ft after a 100-year rain event.
The entire green infrastructure project, which includes 22 best management practice features, achieved its goals of improving water quality and managing storm water runoff, while providing a green space for the community. Additionally, some combined sewer pipes were converted to storm-only and smaller pipes were used for sewage, resulting in cost savings.
“From the community perspective, the restoration of the lake and protection of the wonderful woodland areas was primary, but the fact that it would be a practical part of the storm water management for the sewer separation would be the clincher for maintenance and longevity of the space,” said Janet Bonet, president of the the Spring Lake Park Team, a local advocacy group.
The project involved successful collaboration between the city of Omaha, contractors, designers and the public, who played an important role in providing vision and inspiration for “bringing back the lake to Spring Lake Park,” said Pat Slaven, retired park planner for the Omaha Department of Parks.
During construction, the site’s topography presented several challenges to the project. The valley where the lake was built was ringed by a series of ravines with slopes of loess soil over glacial till and sand lens. These areas coupled with seeps on the hillsides and springs in the valley floor made nearly 10 acres of the park unusable for recreation, but suitable for storm water treatment. Excavation during construction exposed springs and seeps that de-stabilized side slopes and increased saturated soils. These problems were mitigated by adjusting the shoreline, constructing rip-rap bridges and using long-reach excavation equipment.
While many trees were removed to construct the lake, 300 native trees and 700 native shrubs were planted in the park. The new lake includes a fishery and has become a popular community amenity.
“The overall result is a beautiful lake which immediately became an attraction for bird watchers, fishers, and those wanting to stroll around the lake,” Slaven said. “It was an innovative solution to a real problem that resulted in a wonderful amenity for the city of Omaha.”
The green infrastructure project now is nearly complete, excluding an area south of “F” Street where a natural stream environment is under construction.