Lincoln, Neb., reduces flooding and revitalizes popular bike trail
The goal to protect homes and businesses from flooding is not an uncommon one. But when the Lower Platte Natural Resources District (NRD) and the City of Lincoln, Neb., set out to control flooding along the Antelope Creek, they had several objectives in mind. Taking homes and businesses out of the floodplain was one, but preserving and improving a nearby bike path also was a priority. The Lower Platte South Natural Resources District (NRD) and the city of Lincoln partnered on the $2.5-million project, which included new retaining walls along Antelope Creek’s west bank, among other improvements, including additional box culverts under a bridge, a "detention cell" to hold water temporarily, two flood-control berms and a wider recreational trail.
Finding the right solution for lining the creek channel posed a challenge for project designers. Since there was no room to excavate for geogrid, the NRD and city initially considered using a poured-in-place wall and sheet piles.
However, a meeting with local Redi-Rock manufacturer and retailer Workman Precast led the NRD and city to a more ideal solution. By using massive, 1-ton Redi-Rock blocks , engineers were able to design gravity retaining walls up to 16.5 ft tall to create a channel for Antelope Creek. Once the owner saw Redi-Rock and the price, the decision was made to specify Redi-Rock with the ledgestone face (no other options or equivalents allowed).
Benefits of the system in storm channel applications include:
- Minimized excavation: The massive size of each Redi-Rock block allows tall walls to be built with minimal excavation. This allows walls to be built closer to property lines—or in the case of this project, the gravity solution preserved space that could be used for widening the bike/pedestrian path.
- Fast installation: Redi-Rock blocks stack like giant Legos, making them quick and easy to install using an excavator and a small crew.
- Durable components: Each block is made of wet cast, 4,000-psi air-entrained concrete—ensuring that it will stand the test of time.
- Strong aesthetics: Redi-Rock’s ledgestone texture creates walls that look like natural, random stone walls. Ledgestone blocks have the same dimensions and engineered capabilities as other Redi-Rock blocks, but with the look of natural, stacked ledgestone.
Out of Harm’s Way
In total, the project utilized 14,000 sq ft of Redi-Rock retaining walls along 2,000 lineal ft of Antelope Creek. The NRD estimated that when all phases of the project are complete, the flood control measures will take about 100 homes and businesses out of the 100-year floodplain.
The final phase of the project is scheduled for completion in 2012 and includes replacing the South Street Bridge, additional channel stabilization, water main relocation and sanitary sewer construction.