The city of Lafayette is applying for an emergency federal permit as work crews carve out a channel for Lafayette Creek through the sinkhole-collapsed section of Mountain View Drive.
The U.S. Army Corps of Engineers agreed to expedite the city's permit in a development that held some drama, City Manager Steve Falk reported in his Friday summary. Falk's account also recounts some drama from Sunday, Dec. 2, when the water was flowing high but the drain was performing well until a cache of debris — including a chest of drawers — apparently was dislodged upstream and flowed down to the block the drain at Mountain View Drive.
The swirling eddy "chewed away at the soil above the drain and under the road and within hours the roadbed was completely undermined," Falk wrote.
Both dramas were described in this excerpt of Falk's Friday summary:
It started last Sunday when the third of three heavy storms came blowing through the Bay Area. For whatever reason, Lafayette seemed to receive a larger share of downfall than most anywhere else, and by 6AM on Sunday morning, the City’s drains were cranking pretty hard.
We had crews out early and, in fact, checked the drain at Mt. View Drive at 7:30A; the water was flowing high but the drain was otherwise performing well. Sometime between 8:30A and 9A, though, a large cache of logs, branches, debris, and trash (there was even a full chest of drawers) must have become unloosed upstream and proceeded to flow down and block the storm drain. The water, now with nowhere to go, pooled and with the heavy eastward flow still feeding it, the pool became a swirling eddy.
The eddy, in turn, chewed away at the soil above the drain and under the road and within hours the roadbed was completely undermined. Nobody, fortunately, was hurt and crews had the road blocked off and secured by 11AM. The storm had passed through by early afternoon, and with the sun now out and the creek running at a much lower level, the worst appeared to have passed. Crews wearing hardhats and orange shirts took a breather, had some lunch, and began to talk about next steps.
At 2:30P, however, the entire roadway began to sag and, within minutes, it collapsed into the scoured creek bed, damaging sewer mains, gas lines, and water pipes as it fell. It was like when you blow on ants – suddenly everybody was running around scrambling to fix things. The work of the utilities was impressive, with CentralSan, PG&E, and EBMUD crews all simultaneously getting into the hole for the next twenty four hours in efforts to pinch off their utility lines. Once the utilities were stabilized, City crews began aggressively clearing debris from the area and stream bed, so as to avoid further damage or flooding, carving out a channel that can convey water downstream.
We had just begun to explore options for a permanent fix yesterday when City Engineer Tony Coe received a call from the Army Corps of Engineers inquiring why the City was working in the creek without a permit. After indicating that, well, we’ve been really busy, Tony politely requested that the Corps grant an emergency permit for immediate creek work, and the Corps – in a remarkable accommodation recognizing Lafayette’s predicament – agreed that it could expedite our application, but only if Lafayette delivered hard copies of the construction plans to the Corps’ San Francisco Office by 6AM Friday morning.
Since, of course, the City wasn’t planning to rebuild this drain anytime soon and, therefore, there were no construction plans, civil engineers Farzaneh Sanders and Matt Luttropp jumped on it and spent most of Thursday and deep into the night hunched over the City’s CAD system developing engineered plans for the new drain. To ensure that the plans were delivered to the Army Corps office well before the 6AM Friday deadline, Tony and Farzaneh then drove the completed plans to San Francisco after 11PM last night, with the intent to slip the envelope under the door. The office building, however, was guarded by a night watchman who refused “for security reasons” to either hold the slim envelope until morning or himself slip them under the door. [Insert your favorite story of frustration here]
Tony then explored whether the guy running the all night café next door could be trusted to hold the plans for a few hours and convey them to the office the next morning but concluded, probably correctly, that that wasn’t a great idea, fearing that the plans would have instead wound up lining the bottom of that one birdcage where the café operator keeps his two zebra finches. Anyway, now it’s after midnight and, having tried unsuccessfully to locate a courier who would agree to make a time-certain delayed delivery, Tony and Farzaneh instead drove to the house of the City’s Construction Inspector, Aziz Aineb (Aziz lives in San Francisco), woke him up, and asked him to get up early the next morning and deliver the plans in time for the 6AM deadline. He did, the plans were accepted, and now we’re waiting for a go ahead to proceed to final construction from the Army Corps. What a great engineering staff!
On most days, Lafayette City Manager Steven Falk issues a Daily Briefing, an aggregation of links to news articles from local and regional newspapers, magazines, websites and blogs. Its purpose is to alert readers to current affairs that may impact Lafayette. Falk also prepares, most weeks, a Friday Summary with original content describing issues, events, inside looks, and other strange, ordinary, and interesting things about Lafayette. Falk says more than 50 people subscribe to the Briefing, and about 800 receive the weekly Summary. To receive, Falk says to send him a request at firstname.lastname@example.org.