Platte River Recovery Implementation Program
The Platte River Recovery Implementation Program was formed to improve the management of the Platte River for the health of the ecosystem and the people that depend on it. Working collaboratively, the U.S. Department of the Interior (USDI), states of Nebraska, Colorado and Wyoming, water users and conservation groups are striving to restore and protect habitat land for four federally listed threatened and endangered species:
- Endangered whooping crane (Grus americana)
- Endangered interior least tern (Sterna antillarum)
- Endangered pallid sturgeon (Scaphirhynchus albus)
- Threatened piping plover (Charadrius melodus)
HDR and its teaming partners were selected based on their expertise in handling complex problems associated with river hydraulics, geomorphology, and navigating federal and state permit requirements.
One of the program's goals is to assess impacts on the pallid sturgeon that may be caused by program or new water-related activities in the central Platte River covered by the states or federal depletion plans. A lower Platte River Stage Change Study was commissioned to assist in determining the effects of flow changes over time on river stage and associated physical parameters. Physical parameters considered include flow quantity, depth, velocity, temperature, turbidity, sediment, and sandbars and bedforms at selected sites throughout the study reach.
Additionally, a sediment augmentation adaptive management action was evaluated to test Priority Hypothesis Sediment #1: Average sediment augmentation near Overton, Nebraska, of 185,000 tons/year (t/y) under the existing flow regime and 225,000 t/y under the flow regime proposed by the Governance Committee achieves a sediment balance to Kearney, Nebraska. A feasibility study was developed to assess the potential of achieving sediment balance in the Platte River downstream of the J-2 Return. Eight sediment augmentation experiment alternatives were assembled. A hydraulic and sediment transport model was developed for the study and was used to evaluate the potential response of the river to assess the reduction of the sediment deficit associated with each alternative. The recommended action was to design and implement a pilot-scale experiment and to develop a monitoring plan to determine if the experiment is successful.
To assess the Program's Flow-Sediment-Mechanical strategy as part of the Adaptive Management Plan, a detailed hydraulic and sediment transport model was required. A one-dimensional hydraulic and sediment transport model was developed and calibrated for 210 miles of the central Platte River. The model is being used to estimate potential indirect effects of sediment augmentation in downstream reaches and estimate the attenuation of short duration high flows.