Seattle Public Utilities (SPU) officials are taking steps to more closely monitor rainfall in the wake of a Dec. 14 flash flood that took the life of voice-over actor Kate Fleming and deluged dozens of homes and businesses farther down in Madison Valley.
"We have 17 rain gauges around town right now, and we are going to be replacing them immediately with higher-quality sets, and add another 10 to 17 gauges," said SPU media-relations coordinator Andy Ryan. "This is to increase the spatial density, for better short-term results."
Ryan said that's what the city has to do to try to keep pace with the kind of record-breaking weather that led to the tragedy. The intense rain storm dumped more than an inch of rain on the Madison Valley in one hour.
SPU director Chuck Clarke said this is an "urgent priority" with SPU, the agency responsible for stormwater and wastewater management. And its job is to investigate and to determine if changes to utility systems need to be made to prevent other incidents like this in the future.
SPU has already hired the engineering firm CH2M HILL to find out what specifically caused a surge of stormwater to run down the street and into Fleming's home, in the 500 block of 30th Avenue East, drowning Fleming in her basement.
Clarke said under the terms of a $216,000 contract, CH2M HILL will perform a variety of hydrologic, hydraulic and drainage engineering analyses and will perform other work such as assisting with conducting interviews with residents, business owners and other witnesses to the flood.
"We will look at the retaining wall and look at the connection to the county sewer line," Ryan said. "We're going to look at Kate Fleming's property and assess the drainage issues that were there. We're going to discuss all of the variety of factors, [as well as] the capacity of a line to handle that type of storm.
"What we know is that this is a really highly unusual rainstorm. It would have overwhelmed the capacity of the infrastructure in any part of the city," he added.
A RAINFALL BULL'S EYE
Ryan said in the wake of the tragedy, officials were amazed by the rain data they collected.
"It looks like someone painted a big red bull's eye over Madison Valley," he said.
According to the National Weather Service, the storm set new rainfall record of 2.17 inches at its forecast office. Ryan called it a "100-year-flood" - that's the kind of event officials expect once in 100 years.
Ironically, the city experienced another "100-year-flood" just a few years ago; the National Weather Service said its old record for Seattle was previously broken in 2002. So officials are looking to see if climate change could be part of the picture.
"That is the $1,000 question. We don't know. We do know that climate change is coming. Scientists have just released yet another climate change report, so it really is official," Ryan said. "One model, at least, shows frequent short-duration, high-intensity storms. We don't know if that's what we saw."
Just a few miles away, scientists at the Center for Science in the Earth System Climate Impacts Group at the University of Washington are closely studying this.
Team member Eric Salathé said simulations of climate change do show an increase in winter precipitation for the Pacific Northwest - in the future.
"It is not reasonable, however, to attribute recent extreme weather to climate change. There is a significant trend in temperature for the Northwest...[but] the same is not true of precipitation," Salathé said in an e-mail response to this writer's question.
He added that while scientists expect a steady shift to more precipitation in the future, there will always be considerable variability from year to year.< br>< br>"These events could be seen as a warning, however," Salathé said. "Given the impacts of such events, the likelihood of them becoming more frequent in the next 50 years should certainly affect how we think about adapting to the future."
DIFFERENT FLOODING PROBLEMS?
Ryan said that the surge of water that drowned Kate Fleming is a different problem from the flooding that has plagued Madison Valley for decades.
"It is not related; we are talking about two different things entirely," he said. "The issue down in the large part of Madison Valley 30 or 40 years ago is a chronic problem - that's what we are going to fix. The current investigation is specifically to investigate what happened to Kate and her house. It is not the same drainage."
Charles McDade, vice president of the Greater Madison Valley Community Council for 16 years, had to pump floodwater and sewage out of the basement of his home, after water from the storm overflowed a new retention pond at 30th Avenue and East John Street.
"I saw the pond filling up. I then saw the water going into the street and into all the basements that [were] nearby." McDade said. "I had about 3 feet [in my basement], but others had more. The contractor [for the retention pond] was out here, and he loaned me a pump."
McDade said his house has flooded about four times already. He noted that since the Dec. 14 flood, the contractor installed a valve to separate storm water from sewage. With this, McDade said he hopes that if there is another incident, he will only have to clear water from his basement.
He said the city paid to have his property cleaned, and he believes that Mayor Greg Nickels will keep his word to get something done about the flooding.
"He came out here and promised me he would do something about this," McDade said. "He is the first mayor who has decided to do something. [The city] need[s] to drill through the hill and take [the water] out to Lake Washington."
Ryan said a pipe to Lake Washington is one of four options SPU is studying as it seeks to provide better flood protection for Madison Valley.
Three of these options include different methods to carry the storm-water that causes surface flooding out of the basin using a new or expanded conveyance system, or store surface flood waters in temporary holding facilities and slowly convey through the existing system over time.
The Madison Valley flooding and the surge that took Kate Fleming's life do have one thing in common: "Both areas received a tremendous amount of rain," Ryan said.[[In-content Ad]]
