The nation has been riveted by the massive flooding in Texas triggered by the onslaught of Hurricane Harvey.
The storm surges and high winds ravaged the Texas coast. But, the torrential rains inland have flooded and overwhelmed Houston and a host of smaller communities. The havoc wreaked by Harvey is estimated to exceed $100 billion, more or less.
Like many parts of the United States, Idahoans have stepped up to alleviate the suffering. In Eastern Idaho, Melaleuca and Rounds Trucking both sent trucks filled with relief supplies, donated by local residents.
It’s worth asking: Is Idaho at risk of massive disasters with widespread loss of life and expensive property damage?
Nationally, the big source of disaster damage is the harmful twins of harsh weather and flooding. Floods hit Idaho in wet years. Last spring Boise was hard hit, as were other spots in southern Idaho. I saw earlier this year roads washed out in the Twin Falls and Mini-Cassia areas. Still, the damage didn’t cause large number of deaths and most of the damage has since been handled. It in no way compares to what has hit Houston or the floods that regularly ravage the Mississippi Basin.
Where Idaho is vulnerable to big destruction is a dam failure. We have over 400 scattered around the state. And, we’ve had a big one before in 1976 when Teton Dam failed, killing 11 and destroying a couple billion dollars worth of property in Sugar City, Rexburg and other parts of the Upper Snake River Valley.
Two Idaho dams are at relatively high risk of failure: Oakley Dam in Cassia County and Mackay Dam in Custer County. Both are fairly old and have had leaks. Small downstream population somewhat limit the potential for loss. The two Idaho dams that could cause massive loss of life are Palisades Dam and Ririe Dam above Idaho Falls, but both are considered in solid shape.
Idaho is a bit lucky on storm risk. We are too far inland to be hit by a typhoon or hurricane. And, tornadoes, though not unknown, tend to be of modest strength. High winds can be problematic and winter storms can be harsh. But, the damage from such is not usually overwhelming.
What we do have is high earthquake potential. The hotspots are Custer County, Fremont County near Yellowstone and down in the Bear Lake region (I am discounting eruption of the Yellowstone caldera only because such episodes have historically been separated by hundreds of thousands of years). A 6+ on the Richter scale quake in any of those regions would cause property damage and could cost lives. But, the rural nature of those areas caps the potential for either, unlike high risk areas in California, Washington and Utah where big cities are in the danger zone.
Wildfires in Idaho are a continual risk, especially in dry years. In 1910, an unbelievable fire in North Idaho and Montana roared through 3 million acres and killed 86. It may have been the biggest in U.S. history. Since then we’ve had a series of fires in our rugged mountains and rangelands.
The more dangerous fires in Idaho are those that get into urban areas. In 2012, the Charlotte Fire above Pocatello quickly and unexpectedly burned roughly 60 homes and forced 5,000 from their residences. Such fires are a risk in any area of Idaho where either brush or trees intermingle with manmade improvements. This has always been a risk in the Wood River Valley. It is also an issue in the Boise foothills and many places in North Idaho.
Overall, Idaho is somewhat lucky in that it is unlikely to have a disaster that does billions of dollars in damage or kills thousands. Still, our history shows that smaller events are likely and such will cause continued grief for those impacted.