City reviews last flood, prepares for future crises

November 3, 2009

By Warren Kagarise

David Bramwell (left) shovels sand into a bag held by Bruce Wendt in a sandbagging practice run for CERT volunteers last week. Courtesy of Brenda Bramwell

David Bramwell (left) shovels sand into a bag held by Bruce Wendt in a sandbagging practice run for CERT volunteers last week. Courtesy of Brenda Bramwell

Floodwaters caused about $1 million worth of damage and left behind piles of debris and muck when Issaquah and Tibbetts creeks overflowed in January, but the disaster also readied emergency planners for the next flood.

The next time flood waters rise, volunteers will fan out across flood-prone neighborhoods and city officials will unleash a deluge of information about water levels, road closures and recovery efforts. Many of the procedures were tested during what officials characterized as a successful response to the major flood in mid-January.

But the next flood could occur as early as the next several weeks, and officials said work remains to be done to prepare Issaquah for another natural disaster. On Oct. 27, City Council members received a briefing about the response to the January flood and preparation efforts for the upcoming flood season.

City Emergency Management Coordinator Steve Campbell said readings from a pair of flood gauges did not correlate with the damage caused by floodwaters. A U.S. Geological Survey gauge downstream on Issaquah Creek appeared inaccurate, Campbell said. The gauge indicated about 2,500 cubic feet per second, Campbell said, but flood damage was similar to the 3,500 cubic feet per second estimate from the last major flood to hit Issaquah, in 1996.A reading from a gauge upstream recorded levels less than the November 2006 flood — a much less severe event.

Municipal officials plan to install a new flood gauge on Issaquah Creek north of 15 Mile Creek, but the device will likely not be ready for the upcoming flood season. Public Works Operations Director Bret Heath requested $33,000 for the new gauge in the proposed 2010 city budget.

Councilman David Kappler called for real-time flood gauge data to be included on the city’s Channel 21. The data was included on the city Web site.

Kappler said how the January flood caught officials by surprise. He recalled that City Council members and Mayor Ava Frisinger were gathered at a breakfast with legislators on the morning when rain swelled Issaquah and Tibbetts creeks.

“We really didn’t know what was going on as well as we should have known,” Kappler said.

Breaking news

As Issaquah and Tibbetts creeks edged higher, city officials rolled out a widespread effort to alert residents to potential danger.

Flood information was broadcast through the city radio station, Web site, Channel 21 and a recorded phone line activated during the disaster. A section of the Web site dedicated to flood information received almost 6,000 views during the three-day span when flooding was the worst. Officials also made Google Maps to alert motorists to road closures caused by flooding, city spokeswoman Autumn Monahan said during a presentation to the Council.

“We had a huge amount of traffic on the Web site during those three days of flooding,” Monahan said.

Besides the phone, radio, TV and Web alerts, city officials splashed warnings on electronic message boards and activated flashing lights on signs to alert residents to tune into the city radio station, 1700-AM. Updates were also distributed through the Regional Public Information Network serving three counties.

“We have a really diverse selection of communication tools that I can use,” Monahan said. “We can pick those tools as needed, depending on what the incident is.”

Campbell said a key plan for future disasters has been prepared: Officials will step in to help Monahan, who logged more than 24 uninterrupted hours on the job during the crisis.

“Autumn’s not going to be here for 24 hours this time,” Campbell said.

Volunteers served as a crucial piece of the response to the January flood. Monahan said the city would rely on volunteers during future crises as well.

In late October, about 50 Community Emergency Response Team distributed almost 300 fliers to residents of flood-prone areas.

Through CERT training, volunteers are taught to identify neighbors with special skills — doctors, for example, or residents with equipment useful in disaster cleanup, such as chainsaws and ladders. Volunteers also determine whether neighbors have special needs and need additional assistance during a disaster.

“Volunteers can go into those neighborhoods and get familiar with the areas they could be deployed to, to help with sandbags and other things,” Monahan said.

In the aftermath

Floodwaters ruined houses in the hard-hit Sycamore neighborhood and damaged businesses at the Gilman Square retail complex, but Campbell said damage could have been much worse. The emergency management coordinator credited a years-long push to replace bridges and buy flood-prone land.

The city spent more than $10 million for crews to replace nine bridges on Issaquah Creek, the East Fork of Issaquah Creek and Tibbetts Creek in the decade before the January flood. Between 1994 and 2000, the city bought five flood-prone properties and removed structures and fill material to expand the floodplain. Officials also purchased vacant land along the creek to prevent development in areas likely to flood.

Moreover, the King County Flood Control Zone District kicks in about $60,000 per year to Issaquah for flood-mitigation projects. After the January flood, county crews brought debris bins to Issaquah where residents could dump flood detritus for free.

Campbell noted how the preparation efforts earned Issaquah the highest rating from the Federal Emergency Management Agency. The flood management and response program saves residents 25 percent on flood insurance premiums, he said.

City Surface Water Manager Kerry Ritland said the city applied for a $1.5 million FEMA grant to help business- and homeowners elevate structures in low-lying areas. The project would involve elevating the first floors of houses in the Northwest Cherry Place and Sycamore neighborhoods. Gilman Square would be included in the project as well. Workers would also install specialized doors and windows designed to withstand floodwaters and seal utility lines to prevent water from seeping inside buildings.

Ritland said Issaquah has a good chance at the money because other communities’ applications were rejected. No city dollars would be used for the project; local property owners would shoulder a portion of the cost. Despite taking steps to prepare, damage costs rose alongside the floodwaters. Damage to public property totaled $153,980. The city received $135,554 in federal and state reimbursement; FEMA paid 75 percent, and the state picked up 12.5 percent. Issaquah will pay the difference.

Homeowners reported up to $500,000 worth of damage, and the flood left Gilman Square with about $500,000 in damage.

Efforts to ready the city for future flooding began soon after floodwaters receded last winter. City crews have restocked sandbags, calibrated flood gauges and installed reflective signs to direct residents to tune in to the city radio warning system when floodwaters rise. But Campbell said some work remains incomplete, such as the installation of another Issaquah Creek flood gauge.

“We still have some necessary improvements to do,” he said.

You should know

Crews delivered a desert’s worth of sand as Issaquah and Tibbetts creeks swelled in January. Workers delivered 15,000 sand bags and 450 yards of sand. Trucks made 68 deliveries to 60 locations around Issaquah.

Watch a flood preparedness video on a section of the city Web site dedicated to flooding, www.ci.issaquah.wa.us/flood. Follow the link for “Sandbags.”

Join Issaquah’s Community Emergency Response Team to help residents before, during and after floods. Register for CERT training at www.issaquahcitizencorps.com.

Green River flooding may cause trouble here

If the Green River swells from fall and winter rains, flooding could snarl traffic for Issaquah commuters, disrupt deliveries of food and fuel, and — a more remote possibility — cause local sewers to back up as floodwaters overwhelm the regional system.

Though the river winds through Auburn, Kent and Tukwila, the human and economic toll from flooding could reach Issaquah, emergency planners told City Council members Oct. 27. Employees who commute to Issaquah could be delayed by flooding or unable to reach the city. Issaquah might also open shelters to house flood evacuees.

If the Green River floods, closed roads — combined with the influx of evacuees — could clog Interstate 90, Issaquah-Hobart Road and state Route 900. Debris could destroy and damage bridges spanning the Green River, and interrupt utilities; gas, power and water lines are hung beneath bridge spans.

“We could have water eight miles wide and several feet deep” in the river valley, Tukwila Emergency Management Coordinator Hillman Mitchell told the City Council. “Within this corridor, we have an enormous amount of critical infrastructure.”

Authorities expect the Green River will flood because the U.S. Army Corps of Engineers will allow water to flow through the Howard Hanson Dam. The natural abutment adjacent to the dam was weakened by severe weather last winter, and engineers worry the earthen structure could fail if rain swelled the reservoir behind the dam.

“If that erosion is allowed to continue, the river will create a new channel and it will basically leave the engineered structure of the dam useless,” Mitchell said. “It will be an interesting sculpture up in the Cascades.”

Mitchell said there is a one-in-four chance that a heavy rainstorm could force dam operators to release water downstream.

Floodwaters could destroy up to 30,000 homes and displace thousands of South King County residents. Mitchell said the number of evacuees could be unprecedented: “5,000 people, we’ve never sheltered that in the Northwest. We don’t know what that looks like, so it’s a huge challenge.”

Councilman Fred Butler, a member of the Sound Transit board, said buses would be available to evacuate people from the Green River Valley if the river swells. Moreover, he said Metro Transit, Pierce Transit and Sound Transit officials plan to divert buses with routes affected by Green River flooding.

Flooding could cause problems with sewage systems, but authorities described the threat to Issaquah customers as minimal. Issaquah, like other Eastside and South King County cities, sends sewage to the South Treatment Plant in Renton.

Issaquah Public Works Operations Director Bret Heath said the possibility of sewer backups in Issaquah is unlikely. Heath also serves as the city’s emergency management director.

Authorities would likely release sewage into lakes to relieve pressure on the system and prevent backups.

“The question is where are you going to create the environmental disaster,” Heath said. “Are you just going to add to one that’s already existing or do you want to create additional ones in other communities?”

Heath said city crews have experience with maintaining the sewer system during floods.

“During a normal flood — you probably don’t know it — but the sewers even here in Issaquah are flowing full,” he said. “If you pop a manhole lid, they’re full.”

People who live far from the floodplain could also face headaches related to everything from food to fuel to phones. Flooding could interrupt telecommunications, because cities in the river valley are the site of several switching facilities.

“If those systems are knocked out, they can have far-reaching, cascading effects,” Mitchell said. “Just so you know, the power grid and the substations are controlled via telecommunications lines. So, if we lose power, we could lose telecommunications, because they need power. If we lose telecommunications, we may not be able to control our power systems and shut those off appropriately.”

Despite the grim forecasts from emergency planners, officials said efforts were under way to prepare the Green River Valley and the region for floods.

“People are taking all of this very, very serious,” Butler said.

By Warren Kagarise
Issaquah Press reporter
If the Green River swells from fall and winter rains, flooding could snarl traffic for Issaquah commuters, disrupt deliveries of food and fuel, and — a more remote possibility — cause local sewers to back up as floodwaters overwhelm the regional system.
Though the river winds through Auburn, Kent and Tukwila, the human and economic toll from flooding could reach Issaquah, emergency planners told City Council members Oct. 27. Employees who commute to Issaquah could be delayed by flooding or unable to reach the city. Issaquah might also open shelters to house flood evacuees.
If the Green River floods, closed roads — combined with the influx of evacuees — could clog Interstate 90, Issaquah-Hobart Road and state Route 900. Debris could destroy and damage bridges spanning the Green River, and interrupt utilities; gas, power and water lines are hung beneath bridge spans.
“We could have water eight miles wide and several feet deep” in the river valley, Tukwila Emergency Management Coordinator Hillman Mitchell told the City Council. “Within this corridor, we have an enormous amount of critical infrastructure.”
Authorities expect the Green River will flood because the U.S. Army Corps of Engineers will allow water to flow through the Howard Hanson Dam. The natural abutment adjacent to the dam was weakened by severe weather last winter, and engineers worry the earthen structure could fail if rain swelled the reservoir behind the dam.
“If that erosion is allowed to continue, the river will create a new channel and it will basically leave the engineered structure of the dam useless,” Mitchell said. “It will be an interesting sculpture up in the Cascades.”
Mitchell said there is a one-in-four chance that a heavy rainstorm could force dam operators to release water downstream.
Floodwaters could destroy up to 30,000 homes and displace thousands of South King County residents. Mitchell said the number of evacuees could be unprecedented: “5,000 people, we’ve never sheltered that in the Northwest. We don’t know what that looks like, so it’s a huge challenge.”
Councilman Fred Butler, a member of the Sound Transit board, said buses would be available to evacuate people from the Green River Valley if the river swells. Moreover, he said Metro Transit, Pierce Transit and Sound Transit officials plan to divert buses with routes affected by Green River flooding.
Flooding could cause problems with sewage systems, but authorities described the threat to Issaquah customers as minimal. Issaquah, like other Eastside and South King County cities, sends sewage to the South Treatment Plant in Renton.
Issaquah Public Works Operations Director Bret Heath said the possibility of sewer backups in Issaquah is unlikely. Heath also serves as the city’s emergency management director.
Authorities would likely release sewage into lakes to relieve pressure on the system and prevent backups.
“The question is where are you going to create the environmental disaster,” Heath said. “Are you just going to add to one that’s already existing or do you want to create additional ones in other communities?”
Heath said city crews have experience with maintaining the sewer system during floods.
“During a normal flood — you probably don’t know it — but the sewers even here in Issaquah are flowing full,” he said. “If you pop a manhole lid, they’re full.”
People who live far from the floodplain could also face headaches related to everything from food to fuel to phones. Flooding could interrupt telecommunications, because cities in the river valley are the site of several switching facilities.
“If those systems are knocked out, they can have far-reaching, cascading effects,” Mitchell said. “Just so you know, the power grid and the substations are controlled via telecommunications lines. So, if we lose power, we could lose telecommunications, because they need power. If we lose telecommunications, we may not be able to control our power systems and shut those off appropriately.”
Despite the grim forecasts from emergency planners, officials said efforts were under way to prepare the Green River Valley and the region for floods.
“People are taking all of this very, very serious,” Butler said.
Warren Kagarise: 392-6434, ext. 234, or wkagarise@isspress.com. Comment at www.issaquahpress.com.

Warren Kagarise: 392-6434, ext. 234, or wkagarise@isspress.com. Comment at www.issaquahpress.com.

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One Response to “City reviews last flood, prepares for future crises”

  1. Plan ahead for flooding and severe winter weather : The Issaquah Press – News, Sports, Classifieds in Issaquah, WA on October 22nd, 2010 10:01 am

    […] city also faced flooding in January 2009, as rain- and snow-swollen Issaquah Creek inundated businesses and […]

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