Park Avenue Detention Basins and Channel Improvements

Tetra Tech prepared the preliminary and final design with plans and specifications for the Park Avenue Detention Basin and Channel Improvements in Tucson, Arizona under contract to the U.S. Army Corps of Engineers (USACE) Los Angeles District. The project is part of an overall plan to reduce damages that result from frequent flash flooding from Arroyo Chico/Tucson Arroyo, an ephemeral watercourse that drains to the Santa Cruz River.

The Park Avenue Detention Basin will provide 500 acre-feet of flood storage by means of three individual on-line basins and one off-line basin interconnected by concrete arch culverts, weirs, and pipes. The combined detention basin system reduces flood peaks to a level that can be conveyed within the existing channel and culvert system downstream. Project features include:

• Excavation of about 800,000 cubic yards from the four basins
• Construction of dam embankments, culverts, spillways, retaining walls, box channels, flood walls, and side drains
• Construction of new office, locker room and training facilities for baseball, softball, soccer and football fields for Tucson High School
• Recreation trails, habitat restoration, and mitigation
• Landscaping and irrigation facilities for the entire project

Tetra Tech was the lead designer on this project and was responsible for civil design, structural design, hydrologic and hydraulic design, construction documents, CADD drafting, specifications, cost estimating, and a comprehensive Design Documentation Report. Tetra Tech also participated in the Value Engineering study prior to initiation of the design effort.

Tetra Tech has worked closely with state and local agencies and the Tucson Unified School District to resolve issues including dam safety, effects of the project on existing groundwater remediation efforts, and permitting. Tetra Tech attended numerous community and neighborhood meetings to resolve design and construction issues with nearby residents and to provide a project that will meet the special requirements of the community and the Tucson City Council.

The plans and specifications and the final design report for this $25 million project were completed in 2004 and partial construction of the project was initiated in 2007. Tetra Tech is currently under contract with the Corps to provide engineering during construction services.