I am shivering as I sit down to write this, wearing new and dry clothes just picked up from my friends next door at Free to Ride Surf Shop. Today is Saturday, March 26, 2011, two days after the great Capitola Village flood. I came in to work today to compile some thoughts on the Village flood from two days ago, but necessity changed my plans. Today was a day of frantic sandbagging and photo documenting, everybody involved was soaked to the bone as heavy rains persisted from the pre-dawn morning hours to about 11am. Even the girls at Yvonne's boutique, those cuties, dressed in cashmere and designer jeans and high heeled rain boots had to sigh and knock back a beer at 11am and watch the waters finally recede. Our pals at Stand Up Paddle Capitola brought out their boards and paddled through the village out to the beach to pick up sandbags and float them back to the businesses when the trucks could no longer deliver due to the water depth. Today was a flood like you see on TV along the Missouri or the Mississippi, today was the real Capitola Village Flood.
Before getting too deep into today's mess, I want to reflect a bit on Thursday's flood. Thursday, March 24, 2011, it had been raining fairly hard all day. I parked my wife's car the afternoon before in a metered spot and forgot to turn off the headlights and dammit if the thing wasn't dead when I returned, so I left if overnight with plans to jump it and move it first thing in the morning before we got a parking ticket. Well, the rain meant that the parking police were indoors for the day so I wasn't too worried. But damn if I didn't kill the battery with my little stunt. And this rain! Changing out a battery in the rain won't be any fun. So I decided to leave the office to get a new battery and check out a job site I've been doing an extensive hydrology and hydraulic study on. I figured it had been raining fairly hard all day, likely the biggest storm of this winter, even the biggest of the last couple winters, and to give this particular job site a quick check would be a good idea for our continued site monitoring. Over the bridge we noticed Soquel Creek chugging pretty good and 5 minutes later the Emergency Alert system came on the radio saying there was a flash flood warning and that Soquel Creek may approach flood stage within an hour. Exciting stuff for a hydrologic engineer so we figured it best to check our site and hurry back to watch the waters rise in Soquel Creek.
And this is what we came back to. Thursday, March 24, 2011:
Something didn't seem right. The job site we checked wasn't experiencing anything unusual, we've studied every significant storm over the last 20 years at this site, only a few miles away, and this storm appeared to be one that occurred about once every two years. So then, why was there so much flooding in Capitola? Something must have happened.
So on Friday, March 25, we did some quick investigating. This all occurred within steps of our office, so why not? It turns out the source of the water was a failed storm drain pipe at the top entrance to the Pacific Cove Mobile Home Park off of Bay Avenue. The corrugated metal pipe failed causing stormwater to surface and run down Noble Gulch and then down Capitola Avenue and flood the Village. Damage was extensive, especially at the source of the failure.
Why did the pipe fail? How did the pipe fail? Was the storm drain system overwhelmed by the rainfall? Has the storm drain system experienced flows of similar magnitude in the past? The science underlying these questions is the study of hydrology and hydraulics, and it is the expert in hydrology and hydraulics that will find the answers to these questions. This is the practice of forensic hydrology, where the professional reconstructs the flood event through evidence gathered. Simulating the flood through the storm drain network and over the landscape is a study in forensic hydraulics.
God may have sent the rain, but its behavior when it hits the ground is predictable. The flood waters leave behind the clues necessary to determine its cause. Evidence such as photographs showing water line elevations on the sides of buildings or other fixed features and data from local rain gages are enough for the hydrologist to reconstruct the storm event. By constructing a model of the existing storm drain network through a combination of surveys, compiling as-built information of the storm drain system, and verification of existing features against record, the professional has all the tools necessary to simulate the flood event through the network and seek out the source of the failure.
The photos taken below represent all the necessary evidence for CFS Engineering to determine conclusively why the pipe failed and to show how the pipe failed. The cause is apparent to us based on our observations of the March 24 and March 26 flood events, respectively. It is a professional courtesy to keep quiet about it however.
The subrogation professionals will soon be out and about assessing the damage. Will they consider this flood an act of God? Will they seek a tortfeasor?
I truly feel for the business owners down here in the Village. I know some of these people suffering the damages these floods brought. Times are slow already, many commercial spaces are vacant due to the economy, and the busy season is still months away. Spring break brings customers by the thousands and many of these businesses may not even be able to open. I saw dozens of homeowners looking down from their second story windows and decks in disbelief. And those residents of the Pacific Cove Mobile Home Park, well most of their patio furniture, decks, and other belongings are likely scattered somewhere along the beach right now. Hopefully these people can recover their losses.
Was this flood preventable? Perhaps yes, but that becomes a legal question because it implies blame, and blame may become the name of the game from here on out.
I realize Monday morning back at the office is going to be difficult. My heart goes out to everybody in the Village and up there in the Pacific Cove Mobile Home Park. I'll see you all next week.
Cheers.
Clark E. Stoner
CFS Engineering is a civil engineering and land surveying firm located in Santa Cruz County, California. The firm is headed up by Clark E. Stoner, principal civil engineer and land surveyor for CFS Engineering. CFS Engineering's central office is located in Capitola Village, in the heart of Santa Cruz County.
March 26, 2011.
The sequence of the photos start down in Capitola Village and lead up to the source of the flood waters at the top of the Pacific Cove Mobile Home Park and then back down again into the Village. The photos were taken at the peak of the storm event. Notice how the water is deeper upon returning back down the hill into the Village. Some photos are blurry because I could not keep my camera dry. And then suddenly the rain stopped.
Just above this mobile home is where the failure occurred.
This is the inlet where Noble Gulch stormwater flows go underground, about 200 feet above where the pipe failure occurred. On March 25 I visited this spot and noted the high water mark evidence in the area. It was higher than that shown here. A lot of evidence about the pipe failure can be gathered from this photo.
This is at the lower entrance to Pacific Cove Mobile Home Park, at the junction with Capitola Avenue. The remaining photos were taken walking back down into the Village. The flows were higher than when we walked up.
And finally we were on our way back to the beach to get some sandbags for our office. And boom, a landslide occurred on the bluff above the old theater. While checking out the slide, I looked out off shore and noticed the storm was about to break. And it did. And the sun came out before I left the office, mandatory evacuation due to a gas leak in the area.
The CFS Engineering office was fine, located directly behind the Free to Ride Surf Shop just above flood level. And for more photos check out Terry Way Photography.