Most of us remember the spillway disaster a few years ago at the nation’s tallest dam in Oroville, California. In February of 2017 heavy rains caused the waters to pile up behind the dam. The main spillway was damaged and the emergency spillway nearly collapsed. Estimates say between 180,000 and 200,000 people were forced to evacuate — and evacuate quickly.
Since then the dam has been repaired.
A two-year study by the Associated Press (AP) has found the Oroville Dam is not alone. The study discovered that man dams are in very bad condition and a huge percentage are in equally bad and dangerous locations.
And — like the Oroville Dam — they hover over the homes and businesses of entire communities. This story outlines the frightening details.
The AP — no pun intended — poured through federal reports and data from a number of sources and found 1,688 dams in 44 states and Puerto Rico that are rated in poor or unsatisfactory condition. Some states refused to part with information and cited legal exemptions from pubic records requests. Others had no data at all because of no funding or staffing or the authority to do so.
So some dams haven’t been rated at all. That led the news source to think the 1,688 figure is likely higher; maybe much, much higher.
The AP report also cites information provided by Stanford University’s National Performance of Dams Program. It found most dams have been built for flood control, irrigation, to save water, for hydro power, recreation and even industrial waste storage. Sometimes they were built for all of those reasons.
The program’s stats say 1,000 dams have failed in the last 40-years and 34 people have died.
Stanford’s program also points out that many are — on average — 50-years old or older and are no longer able to handle the intense rainfall and flooding attributed to climate change. Yet — says Mark Ogden of the Association of State Dam Safety Officials — no one seems to notice or care.
“There are thousands of people in this country that are living downstream from dams that are probably considered deficient given current safety standards,” he said.
Ogden’s group thinks it will take over $70 billion to repair and modernize the 90,000 dams that dot this nation’s landscape. Many of those dams — by the way — are privately owned. And those owners and operators often refuse to pay the high cost associated with making them safer.
Craig Fugate — the former administrator for the Federal Emergency Management Agency (FEMA) — said what’s most scary is most people living downstream from these dams do not know they are dangerous.
“Most people have no clue about the vulnerabilities when they live downstream from these private dams,” Fugate said. “When they fail, they don’t fail with warning. They just fail, and suddenly you can find yourself in a situation where you have a wall of water and debris racing toward your house with very little time, if any, to get out.”
Here’s how dams are categorized by the National Inventory of Dams database:
• High hazard — loss of human life if the dam fails
• Significant hazard — no deaths but economic and environmental damage likely
• Low hazard
What the AP found to be the most astounding is that there are no national standards for dam inspection. Some states have regulations. Others have none. Worse. The low hazard dams are rarely inspected.
Then there are the condition definitions. They are unsatisfactory, poor, fair, or satisfactory. Sadly, they are subjective. How they are defined depends on the individual inspector or inspectors, and how they see things. And how they see them is often not disclosed.
At least publicly.
The most common problem for an aging dam is spillways. A high percentage are not capable of handling an extreme rainfall event. If water — as noted at Oroville — can’t quickly get down a spillway, it can flow over the top of the dam. That could lead to erosion and to a dangerous collapse.
The AP report notes the Army Corps of Engineers was worried about dams as far back as 1982. It found most dam owners at the time would not modify, repair or even maintain their structures. States — at the time — were equally scrooge-like.
Since then states have gotten better and all of them except for Alabama have a dam safety program. Budget cuts and the elimination of personnel from the Great Recession of 2009 and beyond decimated spending on dam safety. The low point was 2011.
Things are better now. In 2019 spending on safety hit $59 million. Staffing levels are up 20%.
California leads the nation in doling out dam safety dollars. Oroville is likely the reason. The budget ramped up to $20 million a year from $13 million, and employees went from 63 to 77. The state also spent $1.1 billion repairing the Oroville spillway and put an emergency plan into effect. California also put 93 other dams under its safety microscope.
Some states — however — continue to cut. Thirteen states spend less now than they did in 2011 and 11 of those states now have fewer dam safety employees. Ogden and the Association of State Dam Safety Officials say these states need to come to their collective senses and that almost every state needs to take a hard look in the mirror.
Additional money and manpower is critical and critical now, not later. “If you don’t have the staff to inspect a dam, or don’t have the authority to do that, you don’t know what the problems are,” Ogden said. “If you are able to do the inspection but you can’t follow up, and you have dam owners who don’t have the resources to fix their dam, then ultimately you know what the problem is but you can’t get it addressed.”
Source link: Insurance Journal