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<br />more recent maps and surveys, prior use of, data in publications and re-
<br />ports, new determinations sinee publication of last pamphlets, and
<br />similar items. Revised drainage areas ana other data are footnoted.
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<br />4. Procedures. The delineations of watershed boundaries, break-
<br />down and' determination of drainage, areas",iriel1'!dingc noncont'ributing areas, .
<br />and ,establishment of river miles, and other, eslfential items developed for
<br />this report' are considered, to be 'consistent 'With'the FIARBC bulletin dated
<br />November 1951. However, there may,beminor devi~tions in methods, .for- '
<br />mat of working tabulations and similar items since most of the original
<br />work was accOmplished in the late '1940' s before the FIARBC bulletin was
<br />promulgated. However, the accuracy of data'pr'esented here complies with
<br />standards prescribed in theFIARBC bulletin. '
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<br />5. Maps. The name and,type of maps and'aeri'al photos used to
<br />delineate' boundaries and frOm which areas were planimetered are listed in
<br />Appendix I, together with their publication scale and date., The DiStrict
<br />Offices, Corps of Engineers, are the custodian of these work maps except
<br />for those used in connection with'noncontributing areadetermihations in
<br />the Red River Basin which are in the USGS Office, Austin, 'rexas. Drainage
<br />boundaries delineated ,on work maps were transferred, to base maps (scale =
<br />1:500,000 by projection. A print ,of, these' maps, reduced in scale,' are
<br />inclosed in attached envelope.,' Becaus,e'of small scale reduction' and
<br />variable paper shrinkage,"the'inc16sed maps ShoUld be 'considered largely
<br />schematic and should not .be used for"determination of 'hew or revised areas.'
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<br />6. Stream miles. River mileages were determined ',from ,the ,latest
<br />available Corps of Engineers survey,maps of'ithe'streams, supplemented by
<br />surveys for reservoir areas. If stream or' reservoir.survey maps were not
<br />available, then mileages were compiled from'thelatest published maps,
<br />such as those prepared by the U. S.' Geological Survey" ~lississ:l,ppiRiver
<br />Commission, National Forest ,Service, Bureau of Soils, Soil Conservation
<br />Service, etc. ' As a matter of specific information the' source ,of certain'
<br />mileages is shown in Appendix II.
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<br />7. Special conditions~,'
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<br />a. Interconnected basins.,.'c, I,n the~R<;ld River Basinth19.Boeuf,
<br />Tensas Rivers, Bayou Macon, Bayou- Darrow, Bayou Rigolette, Red Chute
<br />Bayou,' Bayou Cocodrie,- Kelley Bayou near Hoaston, La. (ata. 23), Flat
<br />River; and Lower Ouachita Sasins have an interlocking system of bayoua and
<br />drainage ditches which produce 'an interchange of flow under varying,con-
<br />ditions; hence, the drainage limits were more or less arbitrarily determined.
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<br />b. Red-Brazos boundarY. The Red River boundary as delineated
<br />for this report varies slightly fl'om the boundaries of'the'Brazos River
<br />Basin as'determined by the Texas State Board of 'Water' Engineers. A spot
<br />check of contact aerial photographs flown il1'1936 indicates,the' need' for
<br />more data and maps to make a definite and precise determination of the
<br />Red-Brazos Watershed boundary. Funds for such surveys do not appear
<br />probable in the immediate future, and it has been decided to accept the
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