BOOM, It hits you, 'the call' out of nowhere, like a punch in the stomach. Like looking in your mirror and seeing a police car. The lesson is learned as soon as the lights go on.
The stormy midnight call from dam owner Dick Dingleberry saying “We have a problem”. “Weeeee”, you think as he explains that his POS dam is leaking 100 GPM of muddy water from an area somewhere in middle of his dam exactly over the outlet. It’s that Holy Crap Moment when life, as you know it, changes forever. Time will be measured, from here on out as before before or after this moment. Up to this point, you have done all the dam engineering and owner mentoring you could. You have handled the politics, the public posturing and the personalities involved with this structure. You have handled all of the FEMA defined and dictated emergency preparedness and mitigation but now it is time for reaction, response and hopefully recovery.
As in any emergency, the first thing you do is treat yourself for shock. If you are a bumbling basket case at this point, then the cause is already lost. Clear your mind, relax your nerves, feel your senses. Take a chill pill, a deep breath and an accurate evaluation of your abilities. Get help if you need it, right away. This is no time to be winging it or to go it alone. Look at this as an opportunity, the kind that makes or breaks careers. Don’t blow it. Above all – Do no harm.
As in any human endeavor, the first step is critical since it sets the pace and direction for every subsequent step. Think of Michael Jordan,
Taylor, Wayne Gretzky Not only did they
have a quick first step, but they intuitively knew in which direction to take
it. Trust your instincts because they
are a subconscious amalgamation of everything you know. Trust your gut. Lawrence
I received a call like this one day, at noon on a clear Tuesday. I was pissed. I was supposed to play hoops at lunch time and this was a terrible inconvenience. ‘Maybe i'll check it out after lunch’, I thought. Wrong. Get the file and plans, get the phone and the flashlight and get in the truck and go.
Sure enough this 100 year old nightmare dam, located just above
in a fault line graben, was
full and leaking badly. The new HDPE
outlet liner and annulus grouting were almost a year old and this was the first
filling after repairs. This dam, that
never had seepage issues, now had them in a big way. How often has this happened? The amount of damage done to this world in
the name of improvements and good intentions is baffling. If it ain't broke don't fix it. Salt Lake City
Seepage was pervasive on the downstream face but worse over the outlet. Small slumps and sluffs were starting to form. The first thought to my racing mind was evacuation, of the reservoir and perhaps the downstream inhabitants. The problem was with the outlet or the intake well but opening the outlet would drop the head on the upstream gate and start to draw the reservoir down. The owner wanted to fill the outlet tower with bentonite pellets that we didn't have and couldn't find, a move that would have sealed the outlet and sealed our fate by preventing evacuation of the reservoir. Gut check time, Screw the owner, I’ve got a better idea and I’m going for it. We opened the outlet fully to start to drain the lake, reduce the hazard and head. We sent someone downstream to warn of the impending high releases and possibly some very high flows.
Experts and officials began to materialize out of nowhere, all with their own credentials and opinions. At the worst possible moment, Deenie Wimmer, a 20 something knockout anchor woman from the local TV station dressed in a spotless white pants suit, came traipsing across the dam crest with a cameraman in tow, thrusting a microphone towards me. “What’s wrong with the dam, is it going to fail, do we need to evacuate, are people going to die, …” she fired questions at me in rapid succession, never pausing to hear an answer. My mind was swimming as I looked at her white Geno GamaGucci shoes covered in mud and told her ‘I didn't have a clue’. As things went from bad to worse, my Division head and Department director miraculously showed up, and with merely a nod to me, ushered the extraneous officials to one abutment and the press to the other, addressing their concerns and leaving a small group of real dam engineers and owners to figure out the problem.
We considered all of the cause and effects of blankets and bentonite filters and fabrics, diaphragms and drains, pumps and Piezometers, evaluation times and inundation maps. While we fiddled with the facts, I spotted the contractor from last years retrofit, off to the side, smoking nervously. ‘
’, I asked after brief pleasantries ‘how
much grout did you pump into the annular space between the new HDPE outlet and
the totally deteriorated CMP’. True to
form, he said ‘the design amount dictated in the plans and indicated on the pay
request’, as he looked away. ‘ Gary , how much grout did
you really pump,’ I repeated impatiently.
He said ‘about enough to grout half of the pipe’ and he shuffled his
feat. ‘ Gary , tell me the truth’ I said almost
yelling but placing my hand on his shoulder, ‘this is critical.’ He looked me in the eyes and spoke softly and
quickly – ‘the grouting went badly, and if there was 10 feet inserted at the
bottom end of the pipe, that would be a lot’.
This was the ‘Ahh Haaa’ breakthrough moment we had been hoping for. Gary
We quickly mobilized a concrete driller and drilled into the annular space above the outlet. When we drilled in about 9 feet, water exploded around the drill stem and shot all over everyone. When we pulled the drill out, the 4 inch water stream shot out horizontally at least 10 feet before succumbing to the gravity of the plunge pool. Within one half hour the seepage began to abate and eventually stop. The old rotten CMP outlet had functioned as an embankment drain for years and when we fixed the outlet, we had sealed the drain. This dam was never filled again and eventually decommissioned.
We were done by sundown, tragedy narrowly averted. We went for a beer and discussed what had gone right and what had gone wrong. We had used our experience and good engineering, we trusted our gut, we kept our cool, we isolated the press and officials but kept them informed, and we counted on the people and personalities we trusted and new best. We got lucky too. This could have been at night, in a storm, with no one to help and no one to care. This could have been bad.
In years to come we would breach a downstream dam to prevent the imminent breach of an upstream dam from being compounded and killing someone. A homeless man, attempting to cross the flooded river fell from an overhanging cable to his death. On New Years Eve in 1989 when we sent the sheriff, with sirens, around to evacuate downstream residents below the impending Quail Creek breach flood, they were saluted and told ‘Happy New Year to you too”. So we chalk it all up to experience. What doesn't kill you makes you stronger. We hope to share our experiences here today, not to kill anyone, but to make us all a little stronger.