Project Name: Popo Agie Flood Risk Management Study
Location: Lander, Wyoming
Authority: Section 205 of the Flood Control Act of 1948, as amended
Sponsor: City of Lander
Current Phase: Design and Implementation (D&I)
The city of Lander (non-Federal sponsor) is partnering with the U.S. Army Corps of Engineers (Omaha District) on a study to evaluate possible flood risk management solutions along the Popo Agie River and Dickinson Creek in Lander, Wyoming.
The problems caused by high-water flood events in the study area are potential life loss, property damage, emergency response costs, and transportation network disruptions including emergency access routes. Flooding along the Middle Popo Agie River is compounded by the very high velocities associated with the steep gradient of this river which contribute additional life safety risks and can cause significant erosion along the channel.
Project Update: The Omaha District, in cooperation with the City of Lander, recently completed a feasibility study with a recommended flood risk management plan for the Middle Popo Agie River. The Final Integrated Feasibility Report and Environmental Assessment was approved and signed in June 2021.
The plan includes:
- Construct a concrete floodwall that would average 3.7 feet(ft) in height above grade and extend 1,900 ft from the Middle Popo Agie River west to approximately 600 feet west of Dickinson Creek;
- Excavating a shallow drainage swale to allow ponding water from the floodwall to return to the flow channel. The swale will run through an existing gravel parking lot approximately 350 feet south of the new floodwall and Dickinson creek control structure and then through four 5-ft by 3-ft culverts beneath City Park Drive before emptying into Middle Popo Agie River.
- The culvert outfall will include riprap scour protection consisting of approximately 300 cubic yards (cy) of rock riprap with a D50 of 12 inches.
- The River Front Properties LLC Trailer Park & Storage Units property will be purchased and removed as a nature-based measure for safety and resiliency. The vacated property will be converted to parks and open space for the city.
The Omaha District and the City of Lander’s design team has begun work on designing the recommended plan.
The tentative schedule, pending funding and any major delays, is to complete the design by June 2023, advertised and award a construction contract in September 2023.
For more information, contact Project Manager, Rachel Williams at firstname.lastname@example.org or RaJean Stube Fossen with the City of Lander at (307)332-2870 Ext. 117.
April 2020 Public Meeting Materials