WSP00277 - Laserfiche WebLink

Home Browse Search

001355 GLOSSARY OF WATER MANAGEMENT TERMS BASE FLCM--That portion of runoff not resulting fran direct runoff of precipitation. It may cane fran ground water effluent or delayed runoff fran storage in lakes, ~s, glaciers, snow, etc. BASE FERIOD--l. A period of t:l.me chosen for the selection of data. The base period' shOuld be suf'ficientJ.y J.ong to contain data representative of the averages and deviations fran the averages that must be expected in other periods of similar and greater length. As an example, the U.S. Weather Bureau canputes values of average, heavy, and light monthly precipitation iran data observed during the base period 1931-1960. For ground water studies the base period shOUld begin and also end at the conclusion of either a dry or wet trend so that the difference between the amount of 'll8ter in transit at the ends of the base period is minimal. 2. That t:l.me when a stream exceeds the base flow as result of an isolated storm. BASm ACCOUNT--A development fund authorized by the Congress to be managed. and operated by the Secretary of Interior for the development, operation, and maintenance of water resources in a specified river basin region or project. BI!:D LOt\D--The sed:l.ment that moves by sliding, rolling, or bouncing on or very near the streambed; sed:l.ment moved mai~ by tractive or gravitational forces, or both, but at velocities less than the surrounding flow. BIllNEFICIAL USE OFWATER--The use of water for any purpose fran which benefits are derived, such as for danestic, irrigation, or industrial suppJs, power development, or recreation. BIllNEFIT-COST RATIO--The arithmetic proportion of estimated average annual benefits to average annual costs, insofar as the factors can be expressed in monetary termsj it is a measure of the degree of tangible econanic justification of a project. BENEFITS--Increase or gains, net of associated or induced costs, in the value of goods and services which result fran conditions with the project, as canpared with conditions without the project. Benefits include tangibles and intangibles and may be classed as primary or secondary. BIOCHEMICAL OXYGEN DEMAND (B.O.D.)--The quantity of oxygen utilized in the biochemical QXidation of organic matter in a specified t:l.me and at a specified temperature. . BRACKISH WATER--Water containing dissolved minerals in excess of that passing drinking water standards, but less than that in sea water. BREAKWATER--A structure protecting a shore area, harbor, anchorage, or basin :f'ran waves. l-B