Dam or Levee Failure
Data Limitations
The tools below do not provide dam or levee failure information but rather information on the locations of and pertinent details about dams and levees in Arkansas. The dam inventory is limited to dams with a height of at least 25 feet and exceed 15 acre-feet in storage or at least 50 acre-feet of storage and exceed six feet in height. The state of Arkansas regulates all dams that have a height of 25 feet and storage of 50 acre-feet.
Definition and Description
Catastrophic type of failure characterized by the sudden, rapid, and uncontrolled release of impounded water or the likelihood of such an uncontrolled release. It is recognized that there are lesser degrees of failure and that any malfunction or abnormality outside the design assumptions and parameters that adversely affect a dam’s primary function of impounding water is properly considered a failure. These lesser degrees of failure can progressively lead to or heighten the risk of a catastrophic failure. They are, however, normally amenable to corrective action (USSD 2018).
Dams help address the complex challenge of controlling and distributing water. They have been recognized as a key water management practice dating back to early civilizations of the Americas, ancient Egypt, and China. As water is a part of the hydrologic cycle, dams work to conserve water through reservoirs to prohibit flow back to the ocean. With the advancement of civilization and a growing population, water withheld in such reservoirs are an integral part of society and is a necessary source for energy, drinking water, irrigation practices, etc. Dams also protect areas of development and civilization from floods through flood control measures. Dam safety and maintenance standards have increased over time.
Historical Data
National Inventory of Dams by State
(1900-present) U.S. Army Corps of EngineersThis tool provides you with an overview of the dams in Arkansas, including the number by hazard potential, height, owner type, primary type, primary purpose, and completion date.
1. On the drop-down menu to the left of the map, select Arkansas. For specific counties, you can then select a county within Arkansas from the same menu. 2. The map then zooms in to Arkansas and shows all dam locations. A summary of dams in the state are visible on the top of the results page. 3. To view dams by hazard potential, click the Layer Controls button on the top left of the map, then click Categorize by and choose Dams by Hazard Potential. The number of dams in each category are shown under the map. Other categories can be mapped as well. 4. Click Browse These Dams above the map to access a list of dams with more information.
National Inventory of Dams – Dam Details
(1900-present) U.S. Army Corps of EngineersThis tool allows you to view the details of individual dams within the state of Arkansas.
1. At the top of the page, click on the Advanced Search tab. 2. On the top left of the page in the Location box, select State for the Geography Type, then type Arkansas in the space below. Click UPDATE RESULTS above this area. 3. Click the DAM DETAILS tab near the top of the page to access a chart of all Arkansas dams and associated information. 4. Choose which columns to display by clicking Columns, then select/de-select the columns as needed. 5. To sort by column, click the arrow to the right of the column header. Note: You can narrow results by selecting additional options on the left of the page (such as Hazard Potential Classification to view high hazard dams). Click UPDATE RESULTS for any changes made to update the list.
National Levee Database
(Levee Inventory: 1882- present)U.S. Army Corps of EngineersThis tool allows you to to explore levees in your area, including location, year constructed, length, number of people and structures at risk should failure occur, property values in the risk area, and more.
1. In the search bar, type Arkansas or a city, county, address, or levee name. After you type the location or levee name, click the selection from the dropdown menu. 2. The next page shows a map of levees in your selected area and a list of levees on the lefthand side. Click the levee from the list or on the map. If you select the levee from the map, then click it again in the Select a Levee System popup box when it appears. 3. The results page includes information about the levee, including a summary, performance and condition, a map, and the flooding hazard. The Behind the Levee section on the right includes consequence information (e.g., infrastructure, population, property values). Mouse over the squares to see more information.
Climate Change Trends
Increases in extreme rainfall (Easterling et al. 2017) may increase the likelihood of dam failure, however, this is highly dependent upon the quality of the structures. Most dams are at or near their 50 year design life, so the probability of failures increases with time. Dams that are not well maintained have an increased likelihood of failure. Washed out spillways, deteriorated primary spillway conduits, collapsed riser structures, and slope instability can lead to a dam breach. However, dam failures across Arkansas are few since owners are required to perform routine inspections and maintenance (ANRC 2018).