In his latest blog post, Mayor Friedberg’s discusses what the City has learned from Winter Storm Uri.

Tonight, City Council will present the 2021 February Winter Storms After Action Report that details the City’s response to the storm. The Mayor states that “the report includes a detailed chronology of emergency operations and departmental activities throughout the event, and identifies both strengths and areas for improvement.”

The Mayor says there is an “open acknowledgement that there could have been other causes for the initial loss of water pressure (before the systemwide drop), beyond what was included in our messaging at the time.  Retrospectively, it is very fair to assume that there [were] other causes” that “should have been considered in the messaging regarding this issue.”

The Mayor explains “the City had been fielding numerous calls reporting suspected water main breaks, which situation was only exacerbated by an erroneous message inadvertently publicized by Bellaire Police Department dispatchers about a break near the corner of Valerie and Englewood Streets (my understanding is they accidentally republished an old notice regarding a break that occurred a few years ago).”

“In response to these calls, as recounted previously Public Works opened fire hydrants at a number of locations and confirmed the mains were functioning and with satisfactory water pressure.  Having ruled that out, by deductive reasoning they concluded—and then I passed along in my communications—that the low (or no) pressure residents were experiencing was not the result of any problems with the mains, but must have been from their individual connections to the mains having frozen over.  For a great many residents that assessment proved entirely correct, although as a point of clarification what we’re hearing from plumbers is that the freezing of outdoor service lines occurred more at the riser leading into the home than underground or at the meter.  And again, it was in that context—responding to calls about broken mains—that the City sought to dispel such concerns.  (Note we did not have any water main breaks at all during the event.)”

“However, we then began hearing from other residents that their connections were not in fact frozen, and that what they were actually seeing was fluctuating water pressure rather than none at all.  To their minds, and justifiably so, this called into question the accuracy of Public Works’ determination as to the cause, and was in part the impetus for this aspect of the Report.  In hindsight, the Report acknowledges, “there is a large area where a variety of problems affecting pressure could have been present.”  As such, the City’s diagnosis in real time seems to have been somewhat of an overgeneralization based on observations at the hydrants that were tested, but that perhaps didn’t explain every issue at every location.  “Other options should have been considered even though area hydrants were tested, and system pressure deemed adequate.””

“That said, it doesn’t mean Public Works got it totally wrong.  Post-incident consultations with several civil engineering firms and plumbing companies, as well as with professional counterparts from other cities nearby, have all confirmed the widespread prevalence of frozen service connections across our region.  Not to mention, summarily dismissing their occurrence out of hand, in favor of simple speculation that it must have been because the water towers were empty and we had no incoming surface water from the City of Houston, leaves unexplained how it was that the fire hydrants were nevertheless flowing with good pressure.”

“But frozen connections aren’t the only likely scenario the experts have since come up with.  One thing we know now, but didn’t then, is that later on in the day systemwide pressures did indeed drop dramatically, enough to trigger a boil water notice.  Again with the benefit of hindsight, perhaps that was already happening to some degree earlier in the day, but unevenly throughout the City depending on location-specific circumstances.  Another possibility is that since the flow of surface water from the City of Houston stopped at different times at different delivery points, and our groundwater wells went down at different times, all of that could also have contributed to an uneven distribution of the resulting effects.  Point is, there’s probably a lot more to it than what we communicated at the time, based on the best available information we had at the height of the event.”

See the Mayor’s full blog post here.