Habitat Restoration & Enhancement
  Eugene Delta Ponds | Tres Rios Ecosystem | Ponca State Park

Tetra Tech provided feasibility planning and design services to the Los Angeles District for habitat restoration at the confluence area of the Gila River,  Agua Fria, and Salt River in Arizona.  Key study issues included habitat design, water quality, water supply, recreation, flood conveyance, habitat sustainability, and maintenance. Tetra Tech completed the Feasibility Report. Integral to the analysis of this large-scale ecosystem restoration project was the use of the Incremental Cost and Cost Effectiveness Analysis (ICA) to show trade-offs between a large number of project features and costs.

The selected plan uses water treatment discharge and pumped irrigation return flows to help create open-water marshland and wetland/riparian habitat. Constructed wetlands serve to both polish the treatment plant discharge and dampen out diurnal differences in flow volume. By moving vast areas of invasive salt cedar, flood reduction benefits were also achieved. This project recently won the “Study of the Year” award at the SPD Planning Conference.