A water leak that prompted the evacuation of a 33-story high-rise in Houston was caused by an underground utility line break. The subsequent damage from flooding, including a heaved area of slab, did not appear to compromise the 18-year-old building’s structural capacity, according to an independent engineer’s report. Still, the 253-unit building will remain empty of residents until repairs are made.

The post-event structural observations brief was prepared by Joshua White and Jeremiah Fasl of Wiss, Janney, Elstner Associates Inc. on Aug. 12, the day after the leak and evacuation of the Royalton condominium building on Allen Parkway. The WJE engineers noted their opinions were based on observations and structural drawings, so additional conditions could be exposed during repairs. 

“Based on our site visit and review of structural drawings, WJE did not identify conditions that represent an immediate concern related to the structural integrity of the primary vertical and lateral systems of the building due to the underground water utility break and subsequent damage to the slab-on-ground,” the engineers wrote.

Heaved Area of Slab

The WJE engineers observed a 12-ft x 30-ft heaved area of slab-on-ground along the southeast end of the 550,000-sq-ft building near the break in the water line, part of the building's sprinkler system for fighting fires. Water ponded and soil accumulated around the heaved section. But there was no apparent structural cracking in visible parts of structural shear walls or elevated slabs. 

A city building inspector reported observing extensive water damage, with elevator shafts partially filled with water, and some floors’ sprinkler heads blown off, records show. The WJE engineers also reported seeing saturated floor finishes and soffits, particularly on upper levels of the building. 

Despite local reports that the building’s certificate of occupancy had been pulled, Erin Jones, a spokesperson for Houston Public Works, says that’s not the case. However, residents will still need to wait for repairs to be made before they can return to their units.

The Royalton has determined what caused the fire line break and purchased emergency plumbing permits to make the repairs, says Jones. However, as of Aug. 22, the city had not yet received any formal applications for additional repairs. 

FirstService Residential, the Royalton’s property management firm, did not respond to inquiries. Jones says the property manager had notified residents to prepare for a long-term evacuation.