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<br />DAMS AND THE FEDERAL GOVERNMENT
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<br />. The u.s. Army Corps of Engineers has some responsibility for five categories of dams: dams planned, designed,
<br />constructed, and operated by the Corps; dams designed and constructed by the Corps but operated and maintained
<br />by others; dams owned by other agencies in which flood control storage has been provided at federal expense; dams
<br />for which the Corps issues permits under its regulatory authority; and dams that the Corps inventoried and inspected
<br />under the National Dam Inspection Act of 1972 and the Dam Safety Act of 1986.
<br />
<br />. Upon its creation in 1979, the Federal Emergency Management Agency was given responsibility for coordinating
<br />dam safety. The agency coordinates the national dam safety programs and repons progress to the President; chairs
<br />the Interagency Committee on Dam Safety; encourages the development and use of uniform guidelines and stan.
<br />dards; coordinates dam safety research; coordinates the development and funding of training materials; facilitates infor.
<br />mation exchange among federal and state officials; encourages the use of model state legislation and programs; and
<br />fosters preparedness, warning, and evacuation programs.
<br />
<br />. The Bureau of Reclamation is the coordinating agency for dam safety within the Department of the Interior. In
<br />addition to responsibility for the safety of its own dams, it provides standards and guidelines for the safety of dams
<br />owned or operated by seven other Interior agencies.
<br />
<br />. The Tennessee Valley Authority has complete responsibility for the planning, design, construction, operation, and
<br />maintenance of its dams. The TVA's situation is unique in that it constructs its dams with its (M'n resources, and all
<br />except one of its dams are located in a single river basin and operated and maintained for the unified development
<br />and regulation of the Tennessee River system.
<br />
<br />. The U.S. Department of Agriculture, in fulfilling assigned responsibilities [0 American agriculture, is a permitter,
<br />(M'ner, manager, planner, designer, constructor, financier, and grantor of dams. Most of the dams are small, but a
<br />few range up to 200 feet high.
<br />
<br />. The Soil Conservation Service has provided technical and/or financial assistance for the installation of ()'.,'er 25,000
<br />darns.
<br />
<br />. The U.S. Forest Service owns 1,316 dams and administers pennits for an additional 2,366. Most of the owned dams
<br />are designed and constructed by the Forest Service in conjunction with the management of national forests and
<br />grasslands.
<br />
<br />. The Farmers Home Administration, Rural Electrification Administration, and the Agricultural Research Service
<br />also serve on the u.s. Department of Agriculture's Dam Safety Committee and have some involvement with dams,
<br />but generally depend on the Soil Conservation Service for technical assistance.
<br />
<br />. The Federal Energy Regulatory Commission regulates and licenses nonfederal hydropower projects. The commis-
<br />sion is presently responsible for the safety of about 2,000 nonfederal hydropower dams and the Department of Energy
<br />(DOE) has asked FERC to be responsible for dam safety review on 20 DOE dams.
<br />
<br />THE DAMAGE PREVENTED
<br />BY FLOOD CONTROL DAMS
<br />
<br />No flccumtc numba II OI_'aifable (!/ thf' actual
<br />number oj pmpif protf'clrd I~y flood CIJ'Itru{
<br />dams. Be/loan 1960 and 1985, Cvr/JJ
<br />projects pm.mted an (I,timated $245 bill/OIl
<br />(1985 dollars) in potential flood r]a!llugn.
<br />Siner its inception, Ih( TtnJlI',I'see !--"nllt:J'
<br />Aut/writ)' muiti,tmrpo\'f' dam and re1{(Vu/r s)'s-
<br />tan has prtt'fnled J700d dama.1;t::J that lU,U{r!
<br />haDe amountf'd to neaT{}' $3.03 billion. Tht'J{
<br />ca!ni!ati07u' are based 071 tilt (Hsumption that
<br />flor;dplnins ii)(!I1ld have been just as intmji['(()'
<br />{IT .\panel;' deve!opl,J !f there Ik'fre no Jtw({uml
<br />prutation. Althou/!,h this is not nelfHoril;' the
<br />([Is-e, there iJ" no It}{l)' to (l({'()unl for the dt-
<br />velo/mumt that ma)' have IHen eruouragtd ~y
<br />the preset/a ~! thl' dam. Likewist. it II pon/-
<br />hie that iosses could be grmter without dam_I
<br />onause dn:efopment inmld !lm'e taken piace ill
<br />Ihe resenoiT aTm ~f Iht dam had not ban
<br />bl/iff.
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<br />Dams and Reservoirs
<br />
<br />Storing flood water in reservoirs can modify floods by reducing the speed
<br />at which the water flmvs, limiting the area flooded, and reducing and altering
<br />the timing of peak flows. However, misconceptions about or lack of understand-
<br />ing of dams can create an exaggerated sense of security. Reservoir sedimenta-
<br />tion can significantly reduce flood control capacity. Competing uses of the
<br />reservoir can impair flood control because those relying on the dam for recre-
<br />ation and \vater supply (irrigators, manufacturers and residential users) often
<br />press for continued high pool levels, resulting in less storage space in the
<br />reservoir for flood \....aters. In addition, most dams are designed for purposes
<br />other than flood control, although they do have the temporary effect of flood
<br />reduction through storage. The availability of water, pmver, or recreational
<br />opportunities associated with dams therefore often attracts ne"" development
<br />regardless of the flood risk or the ability of the dam to provide flood protec-
<br />tion. Over time, without adequate land use regulations, encroachment onto
<br />the floodplain downstream of dams can prevent proper operation of the
<br />structure and increase exposure to flooding. Once signs of dam failure
<br />become visible, breaching often occurs within minutes or a few hours, leaving
<br />little or no time for evacuation. The massive volume of v....ater and its high
<br />velocity will cause severe damage.
<br />I\1ore than 20 federal agencies and four independent offices and com-
<br />missions o\....n about 4,000 dams, have regulatory authority over 6,000 others,
<br />and have various other responsibilities for additional tens of thousands of non-
<br />federal dams. The number of dams of all types and sizes in the United States
<br />is unknown, but when small dams (such as for farm ponds) are included, the
<br />total could be as high as several million.
<br />State regulation of dams is generally considered to have started in
<br />California after the failure of the St. Francis Dam in 1928. The California la\v
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