Two new outfall release structures, integral parts of the Juvenile Fish Bypass System Improvements at Bonneville Dam in Oregon, have been constructed in the Columbia River, approximately two miles downstream of the Bonneville Second Powerhouse. INCA Engineers provided the structural design for the outfall structures and engineering during construction services. The high and low outfall structures each extend approximately 400 feet into the river from the Washington shore and are designed to release juvenile salmon into the river at above-water discharge elevations for improved survival rates.

Project awards include Seattle Post SAME “1999 Design Excellence Award”; CECW Honor Award 2000; Washington Aggregates & Construction Associates “1999 Excellence in Construction Award”; Oregon Concrete & Aggregate Producers Association “1999 Excellence in Concrete Award”.

Tetra Tech INCA performed preliminary and final design for the fixed and floating upstream guide wall for the new lock structure at Bonneville Dam on the Columbia River. This 830-foot long barrier guides barges and other traffic into and out of the new navigation lock. It consists of five separate post-tensioned concrete pontoon structures. Four of these pontoons span between the 52-foot diameter sheet pile cell support structures (span distance varies between 80 and 130 feet). The pontoons are 13-feet high by 33-feet wide concrete box girder type structures with a structural steel face along the navigation channel to resist large impact loads. The floating structure is a 400-foot long, 26-foot deep by 48-foot wide pontoon, with a composite steel impact face.

INCA provided construction services for the pontoon construction and installation, including shop drawing reviews, graving site visits, and approval of pontoon fabrication, float-out, and transport procedures.

Tetra Tech INCA provided a detailed survey and condition assessment of the 430-ton bridge crane; evaluation of various alternatives for refurbishment, life extension, and upgrade of the two crane trolleys, each with one main and one auxiliary hoist, bridge drive and crane rails; and preparation of plans, specifications, and cost estimates to implement the recommended work.

INCA studied and provided recommendations to rectify crane structural, travel, and rail problems that had existed since its commissioning in the late 1970s.

The Bonney Lake Park-and-Ride Lot is located on approximately five acres of land located within the City of Bonney Lake. The facility provides a regionally important linkage with local as well as regional buses to support Sound Transit’s rail and bus services.
 
INCA Engineers provided conceptual, preliminary, and final design services; survey and mapping; field investigations; project management; and coordination with multiple agencies and community stakeholders. The site development included 2,970-square-yards of 8-inch-thick PCC bus lane pavement; 1,800 LF of new sidewalks; an infiltration system to accommodate zero discharge; and one new signalized intersection. INCA coordinated with the City of Bonney Lake’s transit-oriented development plans for future connections from the transit center to the downtown core into their design.

The Bonney Lake Park-and-Ride project was one of “2000 Washington State Top Public Projects.”
 

Tetra Tech INCA inspected and rated 42 bridges throughout Washington State, of which 16 were pedestrian and 26 vehicular. Each bridge was thoroughly inspected and the results compared with previous inspection reports.

INCA performed load ratings based on current WSDOT bridge load rating procedures utilizing WSDOT’s BRIDG software. INCA subsequently prepared a report outlining the condition and physical aspects of each bridge. Structures inspected included prestressed concrete, spandrel arch concrete, steel truss, glulam beam, and suspension bridges.