Provo School District staff told the board on Sept. 19 that three engineers reviewing the failed Wasatch retaining wall disagree on the correct remedy, and staff are seeking a seepage study to identify where groundwater is entering the slope.
Facilities Director Devin Daley said one independent engineer advised the district that the vertical drains proposed by a contractor cannot be guaranteed unless a seepage model is completed. Daley told the board that the engineer emailed early the morning of the meeting and wrote that "the proposed vertical drains can't be guaranteed as a good solution unless we have a seepage model study." Daley said the district is arranging that study and will seek costs and timing estimates.
Contractor IGES had proposed vertical drains in the latest design; earlier proposals discussed what staff and engineers referred to as back drains or a more extensive blanket drain. Board members repeatedly urged a durable, long-term solution rather than a less-invasive option that might leave the district exposed to future failure. Board members also asked who would bear costs for different solutions.
Daley said the blanket-drain approach is more comprehensive but “a lot more disruptive and a lot more expensive,” and could require excavation depths of up to 40 feet that would affect the adjacent road and require further coordination with the city and neighbors. She said one contractor indicated a blanket drain would involve significant excavation and could require road closures.
The board asked staff to press the contractor and the engineers for a clear, prioritized set of options and cost ranges, and to return with a recommendation. Daley said she planned to meet with the primary contractor on Monday to get cost estimates and to align engineers on the questions that a seepage model would answer.
No formal decisions or contract awards were made at the study session. Board members said they want a solution they can defend over time and that they will consider the cost and community disruption of a full blanket drain compared with less-invasive options only if the seepage study supports them.