Despite low funding, many state dams are inspected regularly
While Oklahoma is one of the lowest states in the nation in funding for dam safety, it does not mean all the dams are going without inspection. An article distributed by the Associated Press in January 2009 points out that Oklahoma is one of the lowest states in the nation for dam safety funding, with a budget of $395,336 for 2006. That is the budget for the dam safety activities of the Oklahoma Water Resources Board and not for the Oklahoma Conservation Commission or the state's 88 local conservation districts. All of the inspections carried out by local conservation districts and the assistance provided by the Conservation Commission, NRCS and county Emergency Management Agency staff take place without receiving any funding from that budget.
Of the 4,477 dams regulated by the Oklahoma Water Resources Board in the state, 2,105 are inspected annually by local conservation districts. These are small watershed upstream flood control dams that were constructed as floodwater retarding structures. And it is not just the high hazard structures that are inspected--conservation districts inspect all of their dams including those designated as low hazard.
Of these 2,105, 229 dams are classified as "high hazard" since they have the potential for loss of life if they should fail. For many of those the reclassification to high hazard has been a recent development--in recent years or even months. Case in point--42 low hazard dams were reclassified as high hazard dams by the USDA Natural Resources Conservation Service within the last six months due to downstream development since the dams were originally constructed.
The Oklahoma Conservation Commission, working with local conservation districts, the NRCS and local county Emergency Management Agency personnel, are approaching the end of a campaign to update and standardize emergency action plans statewide for the 229 high hazard dams under the care of local conservation districts. Two hundred and twenty-seven of the dams have EAPs that were updated in the last year, including Bellcow Lake in Lincoln County, and the remaining two have EAPs that are 90 percent complete.
An upstream flood control dam originally built as far back as the late 1940s in a rural location becomes high hazard if the situation changes to where loss of life could occur if the dam breached--that could be only one residence or business built below a dam. The Oklahoma Conservation Commission and NRCS in Oklahoma continually review watershed dam inspection reports for operation and maintenance needs and determine if reclassification is required.
Some high hazard dams are being upgraded extensively to meet dam safety mandates for increased public safety. The upgrade usually requires that raising the height of the dam, widening the secondary earthen spillway and possibly replacing the concrete principal spillway. The average cost of modifying one such dam in Oklahoma is currently about $1 million.
Currently there are no restrictions on development below classified dams. The Oklahoma Legislature may consider legislation this session that would limit development in the breach inundation areas below dams. By eliminating development in these areas, fewer dams will be reclassified as high hazard in the future. This restriction on development downstream from dams would significantly reduce the liability and expense to the state and private citizens for dam modification to meet high hazard standards.
Oklahoma's 2,105 upstream floodwater retarding structures--watershed dams--represent a $2.1 billion infrastructure that provides the state with an average of $75 million in benefits annually according to NRCS.