The Flooding Probability of the Green River Valley
The Howard Hanson Dam is an earthen dam located near the headwaters of the Green River in Washington State. It was built by the Army Corps of Engineers in 1961 for flood control in the Green River Valley. The dam has performed well up until last year when we had an unusual amount of rain and structural weaknesses were discovered in it. The first reaction was preparation for and planning of an impending flood of the valley. So to protect the cities along the river, a 3 foot high wall of sand bags was constructed along the top of the levee.
The following link shows current flood gage data, a map, alert phases and recent high water flows which indicates that currently the flow is well below the initial alert level. The map shows the area that could experience flooding. The alert phases are determined by the amount of flow going through the Howard Hanson Dam and are regulated by the Army Corps of Engineers. The recent high-water flow tables show the historically high levels. Repairs made this year have lowered the flood threat considerably since the Army Corps of Engineers found the Dam to be leaking through the earthen bunker on January 9th 2009. We at ADS Logistics are also on a reverse 911 call list in the event of an alert we will be notified by cell phone.
In the event of a flood, the Washington State DOT has developed evacuation routes to get people out of the area quickly with the least amount of restriction and to keep trucking moving where possible within the valley. As a preventative measure, everyone in the Green River Valley community came together to sandbag and build a 6 foot high barrier. Fortunately this flood season is about over and we did not see a hint of flooding.
We here at ADS Logistics Co LLC have developed a failsafe plan to follow in the event of an impending flood, even though records indicate that our warehouse is 1 foot higher than the waters would rise because of a complete dam failure. The failsafe encompasses protecting our customers' inventory for high water by elevating it another 14 inches. Long product would be raised using 6x6 wooden blocks and palletized product would be raised by putting additional pallets underneath them. To stay sharp, we routinely practice executing the Failsafe as well as the evacuation plan established by the Washington State DOT.
The Army Corps of Engineers has said it will be another 4-5 years before repairs are completed and the dam capable of retaining the amount of water it was designed to hold. While we can't do anything to speed up government work, rest assured to know that your product is as well-protected as it can be when under the careful watch of ADS Logistics.
Posted by Dale Prior- Manager, ADS Logistics Co, LLC.BBSWPPCSFQGX