The Integrated Pipeline is a joint water supply project between Dallas Water Utilities and Tarrant Regional Water District. It involves building 150 miles of pipeline to transport up to 350 million gallons water daily from three East Texas Reservoirs into the Metroplex to increase reliable water access. The project recently reached a new milestone when the new tunnel under Trinity River was completed. Workers are now beginning to add 50‐foot sections of 108‐inch diameter steel pipe.

Stiver Engineering performed full design work for the IPL tunnel. The design/build project scope included construction of approximately 3,802 linear feet of 108‐inch water line including 2,614 linear feet of tunnel under the Trinity River and the remainder in deep open cut segments along the proposed alignment of Section 17.

Other aspects include tunnel launch and retrieval portals/shafts, deep open cut approach ramps with temporary shoring at approximately 12:1 slope, pipe laying within approach ramps and tunnel initial support, pipe encasement with flowable fill and reinforced concrete, tunnel grouting, a 15.6‐foot diameter custom designed tunnel boring machine, and precast segmental tunnel lining.

Due to a number of issues, there was a 1.1-mile gap in the Trail at Lady Bird Lake in Austin, Texas. Along this gap, visitors had to divert onto the narrow sidewalk and travel along busy Riverside Drive, crossing six lanes of I-35 access roads to travel east or west and use the south side of the trail.  There are currently 3,000 to 15,000 people using this trail every day of the year. The client retained Stiver Engineering provided structural design through design review services for the construction of each of the boardwalk precast sections.  

Stiver Engineering reviewed the design of more than 2,300 different shaped precast panels that were required to complete the trail. This process included the analysis of the reinforced concrete panels for lifting, transporting, and installation.