Crews rebuilding Riverfront Boulevard in Dallas dug down to where a large storm drain junction was supposed to sit and found soil too soft to hold it. Dallas County commissioners are scheduled to vote Tuesday on a $273,511.24 change order to fix the problem.
The county manages the reconstruction of Riverfront Boulevard from Cadiz Street to the Union Pacific Railroad tracks. Commissioners awarded the construction contract to Harper Brothers Construction on March 4, 2025, for $99,979,953.78. A first change order added $49,273.20. This second one would bring the contract to $100,302,738.22 and add 10 working days to the original 700.
What crews ran into
According to the county's briefing, excavation for a special junction box, three 12-foot-by-12-foot concrete box culverts and a retaining wall on a drainage line called Trunk Line A reached soft, unsuitable soil below the planned foundation level. Groundwater seeping into the holes made it worse.
The memo says the material was still unstable at the deepest removal the plans allowed, 4 feet, and that simply backfilling with compacted select fill would not work because it would keep pumping and settling.
The fix in the change order: dig out the bad material to as much as 4 feet below grade, replace it with crushed stone, filter fabric and geogrid, then pour a 4-inch layer of flowable concrete as a level working surface for the structures.
Without it, the briefing says, the structures would rest on unstable ground and face a greater risk of settling, shifting and joints separating.
The excavations are open now, the county says, and it wants the foundation work done before the rainy season raises groundwater and complicates the digging.
