DENIS LAW: Only a catastrophic event would flood downtown Renton

Last week there was a flurry of media reports about the possibility of flooding in the Green River Valley, including the news of the temporary relocation of King County offices in Renton. This, along with a lot of misinformation and rumors, created significant anxiety among our citizens –a lot of it uncalled for. We’ve also received several calls from concerned customers who received a mailing from King County alerting them to the situation. Unfortunately, this mailing was sent to many King County residents, whether or not they live in the floodplain. While there is a heightened risk of flooding within the Green River floodplain (and surrounding areas) due to reduced storage capacity at the Howard Hanson Dam, it would take a catastrophic event for the flood waters to reach downtown Renton. I want to assure you that the reason the cities and agencies are planning for this potential event is not to create panic but to be better prepared and help protect people and critical infrastructure in the event of flooding.

To provide a little background, the U.S. Army Corps of Engineers (USACE) manages the Howard Hanson Dam near the headwaters of the Green River. The dam helps maintain water storage and reduces the risk of flooding in the valley/floodplain. After this winter’s storms, USACE discovered accelerated leakage through the right abutment of the dam. As a result of this leakage, USACE determined the dam will hold less water during heavy rains than usual. This situation creates a higher possibility of flooding in areas of Renton that reside in the floodplain (Highway 167 west to the Green River and Renton’s southern boundary north to the Burlington Northern railway corridor). Unlike the residential areas along the Cedar River in Renton, the area affected by the Green River is occupied by businesses.

While it is impossible to predict exactly what will happen, based on the information we have received from the USACE, and assuming the Green River levees hold up, our engineers predict that chance of flooding in Renton is very small. There is an even greater chance for no flooding in the northern part of Renton for those facilities that were part of last week’s media stories. The possibility of 10 feet of water in Renton emphasized by the reports last week is only likely if this region experiences a catastrophic flood event.

I want to emphasize – we are taking this potential situation very seriously in Renton. In collaboration with our neighboring cities, we are developing a comprehensive strategy to deal with potential flooding in the valley with a goal to prevent injuries and minimize potential damage, especially to the business community. I recently proclaimed a pre-incident state of emergency as a proactive measure to face this elevated risk of flooding. City departments now have the required authorization to prepare for, stabilize and control any emergency or disaster situation. We have applied for federal funding which, if received, would help purchase flood barriers that could be installed prior to flood season. We are coordinating with King County to obtain large diesel-powered pumps that would be temporarily installed at the Black River Pump Station to keep water levels in Springbrook Creek below flood stage. We have recently launched CodeRED, a “reverse 9-1-1” automatic emergency notification system that gives us the ability to deliver urgent pre-recorded emergency telephone messages to targeted areas or the entire city at a rate of up to 60,000 calls per hour.

Taking steps to prepare now can make a significant difference in how we weather this storm. Get flood insurance if your property is in a floodplain, review plans for preparedness, establish strategies for continuity of operations, and sign up for the city’s new emergency notification system. All these steps help prepare us for the potential threats that we face in our region—whether potential flooding, winter storms or earthquakes. Renton businesses can contact the Office of Emergency Management at 425-430-7000 or by e-mail at dneedham@rentonwa.gov, for assistance with planning and preparedness.

Mayor Denis Law can be reached at dlaw@rentonwa.gov.